Peter Hepler University of Massachusets.
PETER K. HEPLER is the Ray Ethan Torrey Professor, Emeritus in the Biology Department at the University of Massachuse s, Amherst, MA. He has been inves ga ng the cytoskeleton in plants for over 50 years. He also studies the role of calcium and protons during signal transduc on, and is par cularly interested in the interplay between these ions and the cytoskeleton. Earlier work focused on the mechanism and control of cell division, with par cular emphasis on cytokinesis. More recently a en on has been given to studies on the mechanism and regula on of pollen tube growth. In his work Dr. Hepler uses a variety of microscopical methods and approaches including both light and electron microscopy. In more recent years an emphasis has been given to the examina on of structures and dynamic processes as observed in living cells. He and co-workers have been involved in developing the methods and use of fluorescent analog cytochemistry, and as well as transient expression of fluorescent reporters to examine the cytoskeleton in living plant cells. He has also championed the use of ra ometric ion imaging for examining the loca on and dynamics of calcium and protons during plant growth and development.
Talk: Polarized growth of the pollen tube: a role for ions and ac n.
Peter K. Hepler Biology Department, University of Massachuse s, Amherst, MA 01003.
Pollen tubes are polarized, p-growing cells that deliver sperm cells to the egg apparatus in higher plants. Their growth is essen al for sexual reproduc on, and for the development of the fruits, nuts and seeds that we eat. Herein I report on the mechanism of lily pollen tube growth. Rapid, polarized growth depends on the synthesis and localized secre on of cell wall components, which are packaged in vesicles, and transported apically along ac n microfilaments. Controlling factors include ac n, which is organized as a cor cal fringe in the pollen tube p, plus apical gradients of calcium and pH. All these factors demonstrate an oscillatory behavior that correlates with the oscilla on in growth rate. Quan ta ve studies indicate that increases in secre on, the alkaline band, and ac n polymeriza on an cipate the increases in growth rate, whereas increases in the calcium gradient follow the increases in growth rate. To gain further insight we reversibly inhibited growth with KCN, and followed the effects on calcium, pH, secre on and the apical ac n fringe. During recovery the calcium gradient reappears ≈2.5 minutes before growth restarts. However the alkaline band precedes the increase in calcium. Secre on follows a pa ern similar to the alkaline band, re-emerging before KCN has been removed. KCN also degrades the ac n fringe. Secre on, which restarts in the absence of the fringe, ini ally lacks focus and causes ballooning of the apex. However, with the re-appearance of the fringe, growth becomes polarized. I suggest that the ac n fringe delivers vesicles to their secretory locus, thereby giving polarity to the growing pollen tube, while the proton ATPase establishes the membrane poten al and ion gradients that control the transport of nutrients necessary for growth. Luis Cárdenas Ins tuto de Biotecnología, UNAM. LUIS CÁRDENAS is a tenured professor at the Ins tute of Biotechnology (IBT) of the Na onal Autonomous University of México (UNAM) and a researcher at the Plant Molecular Biology Department. He earned his PhD from IBT-UNAM and then visited Peter K. Hepler´s lab in the USA for a postdoctoral training. He described that Nod factors (NFs) from Rhizobium induced an extensive fragmenta on of the ac n cytoskeleton in living root hair cells. This study, which was as a cover story in Plant Physiology, has been cited over 100 mes and is emerging as a benchmark for further work on the structure of ac n in response to NFs. These studies formed the basis for a review in Plant Physiology in 2000, which was highlighted as an Editors' Choice in Science. Perhaps his most insigh ul work was the discovery that reduced NAD, an important energy co-enzyme associated with mitochondria, oscillated during pollen tube growth, with oxidized NAD an cipa ng the increase in growth rate. These studies led to the hypothesis that oscilla ons in metabolism ini ate cell growth. This work was published in Plant Physiology and con nues to be an emerging interes ng aspect of plant cell growth. This contribu on was singled out by Faculty of 1000 as an important contribu on. He was awarded with the Alfonso Caso medal from UNAM as the best PhD student of his genera on, and his thesis awarded the Weisman prize from the Mexican Academy of Science. He was also awarded an American Society of Microbiology (ASM) fellowship to do summer training in Simon Gilroy's lab. At the moment he is interested in life cell imaging, polar growth, differen a on, and plant– microbe interac on. His work is fully supported by DGAPA UNAM and CONACyT, the two main sources for financial support.
Talk: Reac ve oxygen species in plant root hair cells as key regulators of the symbio c interac ons and in pollen tubes as growth rate modulators.
Cárdenas, L.1, Hernández-Barrera, A.1, Velarde-Buendía, A., Sánchez, R.1, Johnson E.2, Wu, H.M.2, Quinto, C.1, Cheung, A.2. 1Ins tuto de Biotecnología, Universidad Nacional Autónoma de México, Ap. Postal 510-3 Cuernavaca, Morelos, México. [email protected] 2Department of Biochemistry and Molecular Biology, University of Massachuse s, Amherst.
In plant cells ROS accumula on have been involved in several processes such as: development, hypersensi ve response, hormonal percep on, gravitropism and stress response. In guard cells from Vicia faba it has been shown to regulates the opening of stomata and in root hair cells from Arabidopsis ROS levels generate and maintain an apical calcium gradient and it has been proposed to play a key role in the cell wall remodeling during polar growth in pollen tubes and other p growing cells. NADPH oxidases have emerged as the main source of ROS to sustain the polar growth since muta ons in this genes impairs the ROS genera on and root hair development. Furthermore, ROS have emerged as a key regulator during the mutualis c interac ons and silencing or overexpression of ROS genera ng enzymes such as NADPH oxidases affect the onset of nodula on and mycorrhiza on. Pollen tubes and root hairs exhibit an oscillatory growth with phase of high and low growth rate. It has been shown that extracellular ROS produc on also oscillate with a similar frequency, but out of phase. However, a clear analysis of intracellular ROS dynamic has not been depicted. Herein we report a new molecular probe to depict the ROS dynamic during root hair cell and pollen tube apical growth. Hyper is a new generated GFP fused to the OxyR domain that result in a hydrogen peroxide specific probe. This molecular probe was expressed in root hair cells from Arabidopsis and tobacco pollen tubes . By using high resolu on microscopy we depicted an apical H₂O₂ gradient at the p dome where the polar growth occur, furthermore we were able to visualize dynamic ROS oscilla ons in root hair cells, which are couple to growth. In pollen tubes we also found a par cular ROS distribu on, with clear oscilla ons couple to growth fluctua ons. In both p growing cells, the apical regions are the site where the more dynamic ROS changes were observed, furthermore we describe the localiza on of the NADPH oxidase in membrane lipid ra , sugges ng a pivotal role in polar growth. Reinhard Fischer Karlsruhe Ins tute of Technology.
REINHARD FISCHER is a Full Professor at the Karlsruhe Ins tute of Technology (KIT) in Karlsruhe, Germany. He is leading an independent research group on fungal molecular biology since 1994 and is interna onally well-recognized. He and his research team analyzes different aspects of fungal biology. Main fields are the photoresponse of Aspergillus nidulans, where he discovered a role for phytochrome in fungi. Another focus is the cell- and molecular biological analysis of polarized growth. In an applied research field, he analyzes the secondary metabolism of Alternaria alternata to discover novel compounds and understand the gene c regula on of the involved genes. Recently, he started a new line of research with the analysis of the molecular biology of nematode-trapping fungi. Reinhard Fischer has served as editor or associate editor for several journals such as Fungal Gene cs and Biology (2000-2012), Molecular Microbiology (since 2005), FEMS Microbiol. Le ers (2005-2007), Molecular Genomics and Gene cs (since 2006), Eukaryo c Cell (2013-2015), mSphere (since 2016), and mBio (since 2016). He was the organizer of the annual mee ng of the German Microbiological Society (VAAM)(1500 par cipants) in 2011 and of the interna onal mee ng on Fungal Biology (FBC)(300 par cipants) in 2013. He is elected member of the grant review panel for Microbiology, Immunology and Virology at the German Science Founda on (DFG) since 2012, re-elected 2016. He is liaison professor of the Studiens ung des deutschen Volkes since 2009. He has educated 35 Ph.D. students and more than 40 Diploma- or Master students. Talk: Septal microtubule-organizing centers of Aspergillus nidulans share proteins with the outer plaque of spindle pole bodies and are anchored at septa through the disordered protein Spa10. Ying Zhang1, Xiaolei Gao1, Raphael Manck1, Marjorie Schmid1, Aysha H. Osmani2, Stephen A. Osmani2, Norio Takeshita1, 3 and Reinhard Fischer11* 1Karlsruhe Ins tute of Technology (KIT) - South Campus, Ins tute for Applied Biosciences, Dept. of Microbiology Hertzstrasse 16 D-76187 Karlsruhe Phone: +49-721-6084-4630 Fax: +49-721-6084-4509 E-mail: reinhard.fi[email protected] homepage: www.iab.kit.de
Microtubule-organizing centers (MTOCs), such as centrosomes or spindle-pole bodies (SPBs) of fungi, are large, mul -subunit protein complexes. In the model fungus Aspergillus nidulans septum-associated MTOCs (sMTOCs) nucleate microtubules in addi on to SPBs. The structure of sMTOCs is poorly understood and how they are targeted to septa is unknown. Here, we show that in A. nidulans several SPB outer plaque proteins are conserved at sMTOCs, while SfiA, a protein required for SPB duplica on in S. cerevisiae and PcpA, the anchor for γ-TuRC at the SPB inner plaque, were specific for SPBs. The disordered protein Spa18 and the centrosomin-domain (CM) containing protein ApsB were required for recrui ng the γ-TuRC component GcpC to sMTOCs and for MT forma on from septa. The disordered protein Spa10 localized to the constric ng ring during septa on and at mature septa formed a central disk where Spa18 and ApsB a ached to the rim. Collec vely, we present first evidence that a septum-specific, disordered protein serves as an anchor for MTOCs. Rosa Mouriño Pérez CICESE, Ensenada
ROSA R. MOURIÑO-PERÉZ is a Research Professor in the Department of Microbiology at the Center for Scien fic Research and Higher Educa on of Ensenada (CICESE) since 2003. She is a leader in the combined use of molecular biology and different fluorescence microscopy methods to study basic aspects of the fungal cytoskeleton and hyphal morphogenesis. She has made progress in understanding the structure and func on of microtubules and ac n and their associated proteins, as well as processes such as endocytosis during polarized growth of fungal cells. She also studies the diversity of Candida spp and risk factors in women and HIV/AIDS pa ents in Baja California and the resistance to an fungal drugs. She is associated editor of Mycologia. She has served in the Mycological Society of America (MSA) as member of the Gene cs and Cell Biology Commi ee (2015-2018), and as councilor for Cell Biology/Physiology (2013-2015). She has served as member of the Biology Commission of CONACYT-Ciencia Basica (2013-2014).
Talk: Membrane asymmetry markers and polarized growth in Neurospora crassa.
Rosa R. Mouriño Pérez1 , Ivan Murillo Corona1 , Zachary Schultzhaus2 and Brian D. Shaw2 , Olga A. Callejas- Negrete1 . 1Department of Microbiology. Centro de Inves gación Cien fica y Educación Superior de Ensenada, Ensenada, B. C. Mexico. Carretera Ensenada-Tijuana 3918, Zona Playitas, 22860. 646-1750590. [email protected]. 2Department of Plant Pathology and Microbiology, Program for the Biology of Filamentous Fungi, 2132 TAMU, Texas A&M University, College Sta on, TX 77843, USA.
In fungal cells, specialized proteins gather in specific places to break cell symmetry and produce hyphae. This organiza on includes the orchestra on of two dis nct vesicle processes, endocytosis and exocytosis that take place in tandem in different areas of the apical compartment in growing hyphae. Part of the signals for endocytosis and endocytosis include the asymmetry of the plasma membrane phospholipid bilayer. We studied the flippases, DNF-1 and DRS-2 that seem to be responsible for this membrane asymmetry. The muta on of dnf-1 and drs-2 genes produced altera on in the maintenance and stability of the Spitzenkörper and affected the ac n cytoskeleton organiza on in the apical compartment. Surprisingly, neither of the flippases DNF-1 and DRS-2 was present in the plasma membrane, both were localized in different layers of the Spitzenkörper, associated to different secretory vesicles. DRS-2 was associated to vesicles transpor ng chi n synthases. These results indicate that phospholipid flippases (P4 ATPases) may be important for polarity on secretory vesicles, Spitzenkörper integrity and thus for the localiza on of many p growing proteins. . Michael Freitag Oregon State University, Corvallis.
MICHAEL FREITAG was born and raised in Germany, wandering the world a er finishing his degree in Forestry, and ending up in Oregon to study biocontrol of wood decay fungi (MS), which lead to a PhD on transla onal control of gene regula on in Neurospora. As post-doc Michael spent a decade at the University of Oregon to learn the ins and outs of DNA methyla on in fungi, and since 2006 has been a professor at the nearby Oregon State University working on centromeres, kinetochores and chroma n-mediated gene silencing in Neurospora, Fusarium and Zymoseptoria. Michael has been co-author on a dozen genome papers, including the first high-quality dra genome assembled from short reads alone (Sordaria). Recently his lab published the first high-density chromosome conforma on capture maps of Neurospora. Most of his current work centers on chroma n-mediated silencing in Fusarium, where histone H3 lysine 27 methyla on controls about 33% of all genes, including genes involved in pathogenicity and secondary metabolism. Michael is associate editor of GENETICS, PLOS Gene cs and PLOS ONE, and was an elected member of the Neurospora Policy Commi ee (2008-2012) and FusiGroup (2012-2016). He received the 2014 Beadle and Tatum Award. Talk: Heterochroma n, kinetochores and polarized growth.
Pallavi Phatale, Jonathan Galazka, Steve Friedman, Kris na Smith and Michael Freitag. Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA, [email protected]
The largest stretches of heterochroma n, the transcrip onally silent regions of the genome, are usually found in the centromeric regions of filamentous fungi. Recently we found that heterochroma n is not required for the proper conforma on of chromosomes in Neurospora. While absence of important proteins involved in assembly or maintenance of heterochroma n shi s the balance of the centromere-specific histone H3, CenH3 (CENP-A), the addi onal growth defects and differences in vegeta ve growth are minor. In addi on, many of the proteins that make up the kinetochore, the machinery involved in chromosome segrega on, are not essen al and few dele on mutants show growth defects. In earlier studies we showed that many nuclei were transported on microtubules that were a ached to the heterochroma c centromere-kinetochore region, and dragging the remainder of the nucleus along, resul ng in pear-shaped nuclei. While some kinetochore muta ons are lethal, presumably because of defects in division, it now seems unlikely that defec ve tethering to microtubules influences overall polarized growth. . Gerhard Braus Georg August University, Gö ngen.
GERHARD BRAUS studied Biology at the University of Freiburg. He earned a PhD degree (1987) and the habilita on (1992) at the ETH Zürich. He was appointed as Assoc. Professor of Biochemistry at University of Erlangen in 1993 and Full Professor of Microbiology & Gene cs in Gö ngen in 1996. Addi onal periods included the Biocenter in Basel, the University of Georgia in Athens GA, and the BMS Ins tute of Func onal Genomics, Princeton NJ. He is an elected fellow of the American Academy of Microbiology and the Akademie der Wissenscha en Gö ngen. The Braus laboratory focuses on gene cs, biochemistry and cell biology of eukaryo c microorganisms (yeasts and filamentous fungi). The interplay between development (adhesion, filament forma on, ssue forma on) and secondary metabolism (ac ng as benign or toxic bioac ve molecules) is analysed. A second line of research examines the impact of fungal pathogens on human health and agriculture. Research topics include: (i) From single cells to filaments (yeast vs. pseudohyphae). (ii) Control of fungal development & secondary metabolism. (iii) The ubiqui n family, the COP9 signalosome, the proteasome & fungal development. (iv)Fungal pathogenicity and human health: the opportunis c pathogen Aspergillus fumigatus. (v) Fungal pathogenicity and agriculture: the vascular plant pathogen Ver cillium spp. (vi) Fungi as models for neurodegenera ve diseases (Morbus Parkinson). Talk: Pos ransla onal modifica ons in fungal development, virulence and secondary metabolism.
Gerhard H. Braus. Molekulare Mikrobiologie and Gene k, Georg-August-Universität Gö ngen, D-37077 Gö ngen, Germany; [email protected]
Differen a on, virulence and secondary metabolism are linked processes in fungi. The control network is complex and includes several layers of regula on. Transcrip onal control is linked to controlled protein degrada on and epigene c control, which includes different forms of pos ransla onal modifica ons as phosphoryla on, acetyla on, methyla on or ubiqui n-like modifiers. Current work in the lab about A. nidulans and A. fumigatus will be discussed. . Jesús Aguirre UNAM, Mexico City.
JESÚS AGUIRRE is a Biologist. He received his PhD in Biomedical Research from Universidad Nacional Autónoma de México (UNAM) in 1988. Then he became postdoctoral associate in the laboratory of Dr. William Timberlake, Department of Gene cs, University of Georgia (USA) from 1988 to 1991. Since 1991, he has been a researcher at Ins tuto de Fisiología Celular-UNAM. From 2000-2001 Dr. Aguirre spent a sabba cal year at the University of California-Davis. Currently, he is professor and Head of the Department of Cell Biology and Development. Dr. Aguirre works with the model fungi Aspergillus nidulans and Neurospora crassa, to approach ques ons related to stress signaling and cell differen a on. A er proposing cell differen a on as a response to an hyperoxidant state, his research has been focused on studying the mechanisms by which fungi produce, perceive, and detoxify reac ve oxygen species (ROS), and the roles that ROS have in gene expression and cell differen a on. He has published 38 scien fic ar cles in indexed interna onal journals, including Molecular Microbiology, Trends in Microbiology, and The Plant Cell. His papers have been cited more than 2100 mes. Dr. Aguirre has obtained several na onal and interna onal grants to fund his research and is a regular reviewer for interna onal funding agencies, and journals like Eukaryo c Cell, Molecular Microbiology, Gene cs, Fungal Gene cs and Biology, and was member of the Eukaryo c Cell Editorial Board. Talk: Self-self communica on and polar growth in Aspergillus nidulans.
Gabriela Soid-Raggi, Olivia Sánchez, Jose Luis Ramos-Balderas and Jesús Aguirre. Departamento de Biología Celular y del Desarrollo, Ins tuto de Fisiología Celular-UNAM. Apartado Postal 70-242, 04510, Cd. de México, México.
Aspergillus nidulans asexual sporula on (conidia on) is triggered by different environmental signals and involves the differen a on of specialized structures called conidiophores. The elimina on of genes flbA- E, fluG and tmpA results in a fluffy phenotype characterized by delayed conidiophore development, decreased expression of the conidia on essen al gene brlA and con nuous polarized growth of the conidiophore stalk. While flbA-E encode regulatory proteins, fluG and tmpA encode enzymes involved in the biosynthesis of independent signals needed for normal conidia on. Here we iden fy afeA and tmpB as new genes encoding members the adenylate-forming enzyme superfamily, whose inac va on cause different fluffy phenotypes and decreased conidia on and brlA expression. AfeA is most similar to unknown func on coumarate ligase-like (4CL-Lk) enzymes and consistent with this, a K544N ac ve site modifica on eliminates AfeA func on. TmpB, iden fied previously as a larger homolog of the oxidoreductase TmpA, contains a NRPS-type adenyla on domain. A high degree of synteny in the afeA- tmpA and tmpB regions in the Aspergilli suggests that these genes are part of conserved gene clusters. afeA, tmpA and tmpB double and triple mutant analysis as well as afeA overexpression experiments indicate that TmpA and AfeA act in the same conidia on pathway. Furthermore, AfeA overexpression requires TmpA for conidia on to take place, indica ng that TmpA func ons downstream of AfeA. In contrast, TmpB acts in a different pathway. Fluorescent protein tagging shows that func onal versions of AfeA are localized in organelle-type lipid bodies and the plasma membrane, while TmpA and TmpB are localized at the plasma membrane. We propose that AfeA par cipates in the biosynthesis of an acylated compound, either a p-cuomaryl type or a fa y acid compound, which might be oxidized by TmpA and/or TmpB, while TmpB adenyla on domain would be involved in the ac va on of a hydrophobic amino acid, which in turn would be oxidized by the TmpB oxidoreductase domain. Both, AfeA-TmpA and TmpB signals are involved in self-communica on and reproduc on in A. nidulans. Jörg Kämper Karlsruhe Ins tute of Technology.
JÖRG KÄMPER is a Research Professor in the Department of Gene cs at the Ins tute of Applied Biosciences at Karlsruhe Ins tute of Technology (KIT). His research focuses on the processes during the switch from the saprophy c to the pathogenic lifestyle of the corn smut fungus Us lago maydis. His group has iden fied several transcrip on factors required to establish of the biotrophic phase using a combina on of array analysis and reverse-gene c approaches. These factors are part of a regulatory network that integrates different signals to coordinate cell cycle (and morphogenesis) and the adapta on of the hyphae to the environment in the host plant. The group is also interested in carbon acquisi on of the fungus during biotrophic growth, and the reprogramming of the plant by the fungus to redirect carbon flows. Other interests are novel connec ons between the RNA splicing machinery to cellular transport processes.
Talk: Controlling the lifestyle of Us lago maydis: a ma er of hierarchy, synergy and coopera on.
Jonas Ulrich, Benjamin Faist, Julia Fortenbacher, Ma eo Jurca, Jörg Kämper. Department of Gene cs, Karlsruhe Ins tute of Technology, 76187 Karlsruhe, Germany.
In Us lago maydis, the switch from saprophy c growth to the establishment of the pathogenic stage is controlled via a closely interconnected and cross-controlled network of transcrip on factors. This network integrates both signaling via a pheromone/receptor system and the control ini ated by the bE/bW heterodimeric transcrip on factor, encoded by the a and b-ma ng type loci, respec vely. The a and b pathways merge at Rbf1, a key transcrip onal regulator for pathogenic development, cell cycle control and the ini a on of the pathogenic program. Although ectopic expression of Rbf1 is sufficient to ini ate pathogenic development, further stages require (1) addi onal factors as the b-dependently expressed Clp1 protein for cell cycle progression and (2) addi onal b-regulated genes to establish the biotrophic interface. Chip-Seq analysis revealed that the bE/bW-heterodimer binds to the promoters of only few genes (including rbf1) on its own, while Rbf1 binding is found for more than 600 genes. A complex expression pa ern is achieved by the coopera ve binding of Rbf1 and bE/bW. Promoter-binding can be found for the one or other protein alone, but more frequently Rbf1 and bE/bW are tethered in a common complex where either DNA-binding of bE/bW, DNA-binding of Rbf1, or DNA-binding of both proteins is required. As binding of Rbf1 alters the expression only of a subset of genes, and Rbf1 expression is deceasing a er plant penetra on, we assume that Rbf1 resembles a pla orm to prime the cells for the regula on of next development stage in combina on with addi onal transcrip on factors as Hdp2 and Biz1. Both proteins are essen al for the ini a on of pathogenic development as well as for later stages in the host plant when the rbf1 is turned off. Addi onal control within the network is achieved via Clp1. Interac on of Clp1 with Rbf1 and bE stalls b-dependent gene regula on. As the protein/protein interac on with Clp1 has no impact on bE or Rbf1 DNA-binding, we are currently inves ga ng an altera on of chroma n structure upon Clp1 binding. The combinatorial control by bE/bW and Rbf1 with other factors in a mul layered network facilitates the complex regulatory traits of the sexual and pathogenic development in response to the plant environment. Ulrich Kück Ruhr-University, Bochum.
ULRICH KÜCK is Full Professor for General and Molecular Botany at the Ruhr-University Bochum, Germany. His main research interest is the field of fungal and organelle gene cs. In par cular, he has discovered trans-splicing of chloroplast intron RNA in the green alga Chlamydomonas reinhard i, and a sexual life cycle in the penicillin producing fungus Penicillium chrysogenum. Currently, he is interested in the func on of the stria n-interac ng phosphatases and kinases (STRIPAK) complex, a highly conserved eukaryo c protein complex that was recently described for diverse animal and fungal species. In the ascomycete Sordaria macrospora, STRIPAK controls hyphal fusion and frui ng body forma on. He is member of several professional socie es, e.g. German Society for the Associa on for General and Applied Microbiology (VAAM); American Society for Microbiology (ASM), Gene cs Society of America (GSA). From 1995 to 1999, he served as dean of the Biological Faculty (Ruhr-University). From 2001 to 2009, he was chairman of the DFG funded Research Ini a ve “Molecular Biology of Complex Performances of Botanical Systems” (SFB 480), and since 2014, he is Fellow of the American Academy of Microbiology. Currently, he is member of the Grant Panel 201 (Gene cs) of the German Science Founda on (DFG). Talk: Transcrip on factor PRO1, a master regulator of fungal developmental signaling pathways.
Ulrich Kück. Ruhr-University, Bochum.
The filamentous fungus Sordaria macrospora is a model system to study mul cellular development during frui ng body forma on. Previously, we demonstrated that this major process in the sexual life cycle is controlled by the Zn(II)2Cys6 zinc cluster transcrip on factor PRO1. In this contribu on, I will provide an inves ga on of the genome-wide regulatory network controlled by PRO1. To iden fy target genes and the corresponding binding sites for PRO1, we employed chroma n immunoprecipita on combined with next-genera on sequencing (ChIP-seq). We iden fied several target regions that occur in the promoter regions of genes encoding components of diverse signaling pathways. Furthermore, we iden fied a conserved DNA-binding mo f that is bound specifically by PRO1 in vitro. In addi on, PRO1 controls in vivo the expression of a DsRed reporter gene under the control of the esdC target gene promoter. Our ChIP-seq data suggest that PRO1 also controls target genes previously shown to be involved in regula ng the pathways controlling cell wall integrity, NADPH oxidase (NOX), and pheromone signaling. Our data point to PRO1 ac ng as a master regulator of genes for signaling components that comprise a developmental cascade controlling frui ng body forma on. Natalia Requena Karlsruhe Ins tute of Technology.
NATALIA REQUENA received undergraduate and graduate training at the University of Granada, Spain. Her PhD thesis was on “Restora on of degraded Ecosystems by the use of microorganisms”, supervised by Jose Miguel Barea. From 1997 to 2000 she was a post-doctoral fellow with Philipp Franken at the Max Planck Ins tute for terrestrial Microbiology, Marburg, Germany. Her research then focused on molecular analyses of the arbuscular mycorrhiza symbiosis. Dr. Requena established her own research group in 2001 at the University of Tübingen where she obtained her Habilita on for Microbiology and Botany. She then was awarded with a DFG Heisenberg S pendium and moved to the University of Karlsruhe. She was appointed as associate professor at the Karlsruhe Ins tute of Technology (KIT) in 2012. Her research currently focuses on the molecular dissec on of plant-microbial interac ons, par cularly on the arbuscular mycorrhiza symbiosis.
Talk: Plant cell rewiring through arbuscular mycorrhizal fungal effectors.
Natalia Requena, Ruben Betz, Sven Heidt, Meike Hartmann and Stefanie Walter Molecular Phytopathology, Karlsruhe Ins tute of Technology, Fritz Haber-Weg 4, 76131 Karlsruhe. The arbuscular mycorrhiza (AM) symbiosis represents one of the most ancient and widespread symbiosis on the earth, characterized by an in mate life-long associa on between Glomeromycotan fungi and most plant roots. The establishment and maintenance of the symbiosis requires a complex communica on exchange between symbionts and secreted fungal effector proteins might be key to facilitate coloniza on and nutrient exchange. Compared to other biotrophic fungi, the effectome of the AM fungus Rhizophagus irregularis seems to be rather small, considering the small number of proteins iden fied containing a secre on signal. Interes ngly, R. irregularis is able to colonize the majority of land plants in contrast to most plant colonizing fungi that have a quite narrow host range. We thus hypothezise that the few effector candidates iden fied are conserved in other AM fungi and might play crucial roles in rewiring the plant physiology. We previously iden fied the effector SP7 (secreted protein 7) the first characterized AM effector, and a group of related proteins (SP7-like2, SP31 and SPrubi). All members of this family show the same basic protein structure with a central domain of tandem, hydrophilic and imperfect repeats and a nuclear localiza on signal. Although there is evidence of a posi ve effect on symbiosis for SP7, the molecular mechanisms underlying the symbio c func on of the SP family remain elusive. Detailed in planta co-localiza on experiments with defined cell markers together with interactomic studies revealed a direct associa on of the SP effectors with spliceosomal components, the nonsense mediated decay and plasmodesmata. Thereby Processing bodies (specific cytoplasmic RNA-Protein granules) could be iden fied as a novel plant target of fungal effectors. Our results point out towards a significant involvement of AM fungal SP effectors in the conserved plant mRNA processing machinery leading to transla onal control. Recent results will be presented. André Fleißner Technical University of Braunschweig.
ANDRÉ FLEISSNER studied Biology at the Freie Universität Berlin and the University of Münster, Germany, where he obtained his Diploma in Microbiology in 1999. In 2002 he graduated as Dr. rer. nat. at the University Münster, where he had studied plant-fungus interac ons. He then joined the group of Louise Glass at the University of California, Berkeley as a postdoctoral researcher. In Berkeley, he inves gated eukaryo c cell communica on and fusion, using Neurospora crassa as a model organism. In 2008, Andre joined the Braunschweig Ins tute of Technology, Germany, where he was promoted to an associate professor in 2014. In addi on to cell communica on and fusion, his group is studying fungal differen a on, pathogenic development and biotechnological applica ons.
Talk: Fungal dialogs: Cell communica on and fusion in Neurospora crassa.
André Fleißner Ins tut für Gene k, Technische Universität Braunschweig, Spielmannstraße 7, 38106 Braunschweig, Phone: +49- 531-3915795. E-mail: a.fl[email protected]
Germina ng conidia of many filamentous fungi sense each other and fuse. As a result, a germling network is formed, which further develops into the mycelial colony. Gene c analysis combined with live-cell imaging revealed an unusual mode of communica on during these spore interac ons in Neurospora crassa. The two fusion partners appear to switch between signal sending and receiving thereby establishing a kind of “cell- cell dialog”. This interac on involves the alterna ng recruitment of the MAK-2 MAP kinase module and the SO protein to the plasma membrane. Our further analysis revealed that the composi on of the plasma membrane is cri cal for a proper cell-cell interac on. Mutants accumula ng specific ergosterol precursors with a conjugated double bond in the side chain are deficient in germling fusion, par cularly in the processes a er cell-cell contact. While the membrane recruitment of MAK-2 is mostly unaffected in these strains, SO strongly mislocalizes. SO interacts with another MAP kinase module, the MAK-1 pathway. In wild type, MAK-1 is recruited to the fusion point a er cell-cell contact, but fails to accumulate in the sterol mutants. Inhibi on of MAK-1 in a chemical gene cs approach reproduces the phenotype of the sterol mutants. Together these data indicate that specific minor changes in the ergosterol molecule structure can exert major effects on specific signal transduc on pathways. In addi on, we recently iden fied a novel SO interac on partner, SIP-1. While SIP-1 exhibits similar subcellular dynamics as SO during the cell-cell interac on, it also localizes in an oscilla ng manner to individual, non-interac ng cell ps. This surprising finding indicates that germina ng spores con nuously alternate between two physiological stages. We currently extended our inves ga ons to the plant pathogenic grey mold Botry s cinerea. Germling fusion in this fungus also seems to involve the “cell-cell dialog” mechanism. Interes ngly, spores of both species can also interact with each other via this communica on mode, indica ng that it is highly conserved. Meritxell Riquelme CICESE, Ensenada.
MERITXELL RIQUELME is a Research Professor in the Department of Microbiology at the Center for Scien fic Research and Higher Educa on of Ensenada (CICESE). She is a leader in the combined use of molecular biology and confocal microscopy to study basic aspects of hyphal morphogenesis in fungi. She has made much progress in defining the biochemical role and secretory routes of vesicles involved in the polar growth of a fungal hypha. She also studies the ecological distribu on of the human pathogen Coccidioides spp., a fungus that causes Coccidiodomycosis or Valley Fever in the semi- arid regions of Baja California. More recently she has explored the fungal diversity of semiarid ecosystems of Baja California and of deep-sea sediments of the Gulf of México. She is editor of the journals Fungal Biology and Fungal Gene cs and Biology. She has served in the Mycological Society of America (MSA) as member of the Karling Lecture Commi ee (chair 2007-2008) and the Gene cs and Cell Biology Commi ee (chair 2009-2010), and as councilor for Cell Biology/Physiology (2014-2016). She has been elected member of the Neurospora Policy Commi ee (2008-2012), the Fungal Gene cs Policy Commi ee (since 2013), the Interna onal Fungal Biology Conference Steering Commi ee (since 2014), and the Execu ve Commi ee of the Interna onal Mycological Associa on (since 2014).
Talk: The making of Neurospora crassa hyphae: behind the scenes of a fungal mo on picture
Meritxell Riquelme, Leonora Mar nez-Núñez, Adriana Rico-Ramírez, Anayatzin Aguilar, and Alfredo Figueroa. Departamento de Microbiología, Centro de Inves gación Cien fica y de Educación Superior de Ensenada, CICESE.
Filamentous fungi have proven to be a be er-suited model system than unicellular yeasts when analyzing cellular processes such as polarized growth. Neurospora crassa has been at the vanguard of biochemistry and gene cs for over a century. We have used this fast- growing organism to iden fy and analyze by live fluorescence imaging key players of the secretory processes leading to a localized delivery of vesicles at sites of cell growth. Chi n synthases are contained in microvesicles (chitosomes), which concentrate at the core of the Spitzenkörper (Spk), while β-1,3-glucan synthases are contained in macrovesicles, which occupy the outer layer of the Spk. In contrast, glycoside hydrolases BGT-1 and BGT-2 are transported to the apical PM, without accumula ng at the Spk. This suggests different delivery routes of cell wall synthesizing and loosening enzymes to coordinately build a plas c wall at the apex. Small Rab GTPases mediate the vesicular journey along the hyphae towards the apex, where the octameric exocyst complex mediates vesicle tethering at the apical plasma membrane. Some of the most recent research in the lab has allowed us to iden fy early and late Golgi cisternae, an extensive ER network, early endosomes, vacuoles, and large globular organelles that seem to correspond to prevacuolar compartments or mul vesicular bodies. Our current efforts are oriented towards understanding the secretory pathway/s followed by the cell wall biosynthe c nanomachinery. Leonardo Peraza Reyes. UNAM, Mexico City.
LEONARDO PERAZA REYES is an Associate Research Professor in the Department of Biochemistry and Structural Biology at the Ins tute of Cell Physiology of the Na onal Autonomous University of Mexico (UNAM). His research is intended to understand organelle func on, dynamics and crosstalk during cellular development. His research has contributed to the understanding of peroxisome and mitochondrion func on and regula on during cell development, and in the elucida on of cellular processes governing sexual development in fungi. Current research from his laboratory aims to understand the basis, regula on and role of the interac ons between organelles –including peroxisomes, mitochondria, the endoplasmic re culum and endosomes– during fungal development. He is a Na onal Researcher from the Na onal System of Researchers of Mexico (SNI), and member of the Mexican Society of Biochemistry. He has been fellowship recipient from the European Leukodystrophy Associa on (ELA), and has served as reviewer for specialized journals like Molecular Microbiology and Fungal Gene cs and Biology.
Talk: Role of peroxisomes and the endoplasmic re culum in meio c development of Podospora anserina.
Antonio de Jesús López-Fuentes, Karime Naid Nachón-Garduño, Fernando Suaste-Olmos, Harumi Takano-Rojas, Claudia Zirión Mar nez, Leonardo Peraza-Reyes.
Fungal sexual reproduc on is a complex process that requires precise coordina on between the differen a on of mul ple cell types, the forma on of mul cellular frui ng bodies and nuclear progression through karyogamy and meiosis. Research on the filamentous ascomycete Podospora anserina has shown that peroxisomes play important roles at different steps of this process. We have shown that different stages of sexual development depend on specific peroxisome biogenesis factors. In addi on, we have demonstrated that the func onal state of the protein machinery that drives the import of proteins into peroxisomes changes along sexual development progression. Furthermore, we discovered a precise regula on of peroxisome dynamics throughout sexual development, in which peroxisome morphology, distribu on, size and number change between different cell types, and at different developmental stages. These data suggest that peroxisome cons tu on and func on during development depend on the concerted ac vity of the proteins driving peroxisome assembly and dynamics. Actually, our data are consistent with the existence of dis nct peroxisome protein import pathways implicated in different stages of sexual development: whereas progression through meio c development depends on the canonical peroxisome matrix protein import pathways, the ini a on of meio c development could rely on an alterna ve peroxisome protein import pathway. Importantly, it is known that peroxisome forma on and dynamics depend on the endoplasmic re culum (ER), and we have observed that progression through meio c development also requires the ac vity of proteins that shape the ER. Therefore, our research suggests that peroxisomes and the ER act together in the orchestra on of meio c development in P. anserina. Robert Roberson Arizona State University.
ROBBY ROBERSON is an Associate Professor of Cell Biology and Director of the Electron Microscopy Facility in the School of Life Sciences at Arizona State University in Tempe, Arizona, USA. His interests include polarized growth in eukaryo c cells; specifically, fungal hyphae where his research focuses on elucida ng aspects of cytoplasmic structure and mo lity. Contribu ons from Roberson's lab include the discovery of a Spitzenkörper and its role as a microtubule organizing center in hyphae of Allomyces, the use of high-resolu on electron tomography in describing the hyphal apex in Aspergillus, and studies of cytoskeletal dynamics and func on in Neurospora. Currently he is discovering novel subcellular characteris cs of the zygomycetes, a poorly known but important group of the Mycota, and is developing methods for imaging vitrified hyphae and spores use cryoEM. He has served as associate editor of Mycologia (2009-2012) and Mycological Research (2000- 2005). He has par cipated in the Mycological Society of America as member of the Gene cs and Cell Biology Commi ee (chair 2009-2010), was elected to the Interna onal Fungal Biology Conference Steering Commi ee (2003-2010), and has served as a reviewer of mul ply research ar cles, chapters, and books.
Talk: Hyphal Tip Organiza on and Behavior in the Zygomycetous Fungi.
Robert W. Roberson and Karen Fisher School of Life Sciences, Arizona State University, Tempe, Arizona 85287, USA.
The zygomycetous fungi (formerly Phylum Zygomycota) represent an extremely diverse group of fungi ranging from saprobes, to plant and insect pathogens, to the symbio c mycorrhiza, and are morphologically and ecologically dis nct from other fungi. Zygomycetes are filamentous, non-flagellated fungi and mark the major transi on away from the aqua c, zoosporic fungi (Chytridiomycota, Blastocladiomycota) to the non- flagellated, filamentous, mul cellular Dikarya (Basidiomycota, Ascomycota). As part of an NSF-funded collabora ve research effort to resolve evolu onary rela onships of the zygomycetes, we are inves ga ng subcellular hyphal characteris cs, including the organiza on of vesicles at hyphal ps of selected species using light and electron microscope techniques. While hyphal growth in the Dikarya is characterized by the presence of a Spitzenkörper, we found that in most zygomycetes a Spitzenkörper is not present; rather, there is a thin crescent-shaped band of vesicles (the apical vesicle crescent) at the hyphal p. Bio-imaging data from three phylogene cally dis nct zygomycetous fungi will be presented and discussed in terms of phylogeny and mechanisms of hyphal growth. Gregory Jedd Temasek Life Sciences Laboratory.
GREGORY JEDD earned his bachelors degree in biology at the Foothill Community College and Stanford University. He received his PhD from the University of Chicago and did his postdoctoral work at the Rockefeller University where he began to use the filamentous Neurospora crassa to inves gate fundamental ques ons in cell, developmental and evolu onary biology. In 2004 he moved to Singapore to establish an independent research group at the Temasek Life Sciences Laboratory (TLL) where he is currently a senior principal inves gator.
Talk: Innova on and constraint leading to complex mul cellularity in the Ascomycota
Gregory Jedd Temasek Life Sciences Laboratory.
Understanding the emergence of complex mul cellularity (CM) is a major challenge for evolu onary biology. In the fungi, CM is based on hyphal cells interconnected through septal pores. In the Ascomycota, it emerged in the Pezizomyco na. The genus Neolecta defines a fascina ng enigma: Phylogene cally placed with early diverging yeasts, Neolecta nevertheless possesses Pezizomyco na-like CM. In this work, we sequence the Neolecta irregularis genome and iden fy CM associated genes by searching for sequences conserved in Neolecta and the Pezizomyco na, which are absent or divergent in budding and fission yeasts. This group of over 1,000 genes is enriched for func ons related to endomembrane organiza on, and remarkably, most show evidence for divergence in both yeasts. Func onal genomics iden fies new genes playing important roles in hyphal complexifica on. Together, these data show that mul cellularity is deeply rooted in the Ascomycota. Extensive parallel gene divergence during simplifica on and constraint leading to CM suggest a determinis c evolu onary process where shared modes of cellular organiza on select for similarly configured organelle- and transport- related machineries. Salomón Bartnicki García CICESE, Ensenada.
SALOMÓN BARTNICKI-GARCIA (Ph.D. 1961) is Professor Emeritus of the Plant Pathology Department of the University of California, Riverside. Since 2000 he has been associated with the Center for Scien fic Research and Higher Educa on of Ensenada (CICESE). First, as Head of the Unit of de Experimental and Applied Biology, and later as founder and first director of the Division of Experimental and Applied Biology. He is currently a Research Professor in the Department of Microbiology of CICESE. In his long career, he has covered mul ple aspects of the physiology and biochemistry of fungi. Together with his students and associates he studied the chemistry of cell walls of a variety of fungi and developed a phylogene c scheme suppor ng the existence of two different evolu onary lines among the Fungi. Studies of cell wall biosynthesis yielded the first and so far the only evidence of microfibril synthesis in vitro, a preamble to the discovery of chitosomes, the microvesicular carriers of chi n synthase. A cyberne c excursion into fungal simula on led to the concept of the vesicle supply center, and an explana on of the func on of the Spitzenkörper in the polarized growth of fungal hyphae. He was the co-founder of the journal Experimental Mycology (currently Fungal Gene cs and Biology) and the author of 158 Research and review ar cles.
Talk: The VSC/hyphoid model and the interplay between exocytosis and endocytosis in apical growth of fungal hyphae.
Salomón Bartnicki-García. Departamento de Microbiología, Centro de Inves gación Cien fica y de Educación Superior de Ensenada. The vesicle-supply-center (VSC) concept and the underlying hyphoid equa on have given us a mathema cal framework to understand how polarized exocytosis can generate a tubular cell with the typical shape of a fungal hypha. Whereas exocytosis is directly responsible for the growth of the cell wall and plasma membrane, the exact role of endocytosis has yet to be clearly defined. By following ac n dynamics with Lifeact, exocytosis and endocytosis can be seen highly localized in the hyphal apex and the subapical collar of growing cells, respec vely. We have es mated that exocytosis can create an excess of plasma membrane and thus the need for its removal by endocytosis. Es mates of membrane flow from exocytosis and endocytosis are difficult to calculate given the absence of reliable values for some cri cal parameters. On an interac ng spreadsheet, we examined the interplay of parameters for which actual data exist such as growth rate, cell shape and size, wall thickness and vesicle size. But in the absence of factual data for other cri cal factors such as amount of wall generated by each exocy c discharge, rela ve contribu on of macro- vs. microvesicles, propor on of preformed cell wall vs. polymer synthesized in situ, and vesicle load des ned for extracellular secre on vs wall forma on, we have embodied them into a single factor: “vesicle packing efficiency”. Accordingly, using the best es mates for cri cal parameters, an excess of plasma membrane was always produced from exocytosis in a simulated hypha of Neurospora crassa. Actual measurements of endocytosis were made experimentally by photobleaching the subapical endocy c collar of hyphae of N. crassa tagged with the endocy c reporters fimbrin-GFP or coronin-GFP. The transient appearance of fluorescent patches, each an endocy c event, was monitored by confocal microscopy. Accordingly, 4.0 - 10.3 % of exocytosed membrane was endocytosed (depending on the value used for vesicle diameter). While the produc on of excess membrane is not an issue for the mathema cal model which generates an “open-end” tubular structure, it is for the closed system of a real hypha which solves it by recycling. But is the recycling provided by endocytosis indispensable? The proximity of the endocy c sites to the hyphal apex poses the ques on of interdependence. Dele on mutants of N. crassa lacking key components of the endocy c machinery, namely the ac n-binding proteins coronin, or myosin-1, grow very poorly. Confocal examina on of the living mutants showed intermi ent disorganiza on of the apical growth apparatus. Seemingly, the disorganiza on of the ac n cytoskeleton in the endocy c region affects the orderly deployment of the ac n cytoskeleton in the apical region (unstable Spitzenkörper). Hence, it seems likely that an interdependence between endo- and exocytosis resides largely in the factors that define the dynamics and integrity of their ac n cytoskeletons. Alfredo Herrera Langebio, Irapuato.
ALFREDO HERRERA-ESTRELLA grew up in Mexico City and graduated from Na onal School of Biological Sciences in 1985. He did his graduate research (1986-1990) with Prof. Marc Van Montagu at the State University of Ghent, Belgium, studying the T- DNA transfer process from Agrobacterium tumefaciens to plants. He described for the first me Agrobacterium virulence proteins capable of carrying the T-DNA into the plant cell nucleus, and began to study the mycoparasi c process of the biocontrol agent Trichoderma atroviride, and con nued those studies while at the Gene c Engineering Department of the Irapuato Unit of Cinvestav (1991-2004). Later he began studies towards the elucida on of the mechanisms involved in light responses in Trichoderma and con nues on that line of research. In 1998 he was awarded the “Carlos Casas Campillo” prize, and in 2000 the prize of the Mexican Academy of Sciences. By 2004, he became involved in the establishment of the Na onal Laboratory of Genomics for Biodiversity. Since then he and his group have been involved in Func onal Genomics Projects, including the elucida on of the complete maize and bean genomes, and the the study of changes in gene expression in response to environmental signals. In 2009 he was awarded the Agrobio prize for his contribu ons in the field of Biotechnology. Recently, his group discovered a mechanism of response to mechanical damage in fungi conserved across kingdoms. Dr. Herrera-Estrella has been member of the editorial board of 5 scien fic interna onal journals. He is the author and co-author of 13 book chapters and 85 original research papers, and 8 patents.
Talk: Non-coding RNAs shaping the life of Trichoderma
José Manuel Villalobos-Escobedo, Nohemí Carreras-Villaseñor, Cei Abreu-Goodger and Alfredo Herrera-Estrella LANGEBIO – CINVESTAV. Km 9.6 Libramiento Norte Carretera Irapuato-León. Irapuato, Guanajuato, C.P. 36821. Tel: 01 462 166 3070, email: [email protected]
Filamentous fungi perform highly specialized processes that allow them to survive in adverse condi ons. Understanding the mechanisms by which filamentous fungi perceive and respond to environmental s muli can provide knowledge for crop improvement and for new medical treatments. We have studied the biological control agent Trichoderma atroviride, an organism that establishes beneficial interac ons with plants, enhancing the development of aerial structures and modifying root architecture. In addi on, Trichoderma has the ability to regenerate and produce spores a er suffering a mechanical injury. We have previously reported on several lines of evidence that indicate that the central mechanisms of injury response are very similar between plants, animals and fungi. In animals and plants, cell prolifera on, systemic response, accumula on of reac ve oxygen species (ROS) and other essen al processes to respond to injury can be regulated by microRNAs. We found that RNAi machinery mutants of T. atroviride have defects in the forma on of conidia and regenera on. Sequencing small RNAs in both wild type and a Dicer mutant showed that there are poten al microRNAs involved in the response to injury. To further explore the pathways involved in this response, we also performed RNA-seq in wild type and the Dicer mutant during vegeta ve growth and a er receiving an injury. Our results show that nitrogen metabolism and phosphoryla on signalling pathways are no longer responding to injury in the Dicer mutant. Another interes ng phenomenon that has been observed when using mutants in the RNAi machinery is that they are altered in their capacity to interact with plants, perhaps due to altera ons in the profile of secondary metabolites they produce. Such altera ons appear to be linked to the capacity of the fungus to induce plant defence responses. Interes ngly, the mechanism by which sRNAs involved in this phenomenon are produced appears to be dicer independent. These results provide evidence for reconsidering the importance of this regulatory mechanism in fungi. Our findings in T. atroviride strongly suggest that microRNAs play a major role in the life of some filamentous fungi, although they had remained elusive when using models such as Aspergillus and Neurospora. Michael Feldbrügge Heinrich-Heine-University Düsseldorf .
MICHAEL FELDBRÜGGE is a Professor and head of the Ins tute of Microbiology at the Heinrich Heine University in Düsseldorf. He is interested in understanding the role of RNA biology in fungal cells. He discovered the process of endosomal mRNA transport along microtubules in Us lago maydis. Further research interests included plant/microbe interac ons and applied microbiology using fungi as host for heterologous proteins. Currently, he is a member of CEPLAS (Cluster of Excellence on Plant Sciences) department head of biology in Düsseldorf, member of the steering commi ee BioSC (Bio economy science center) in North Rhine Westphalia as well as the VAAM microbial society in Germany.
Talk: News from Mademoiselle domain proteins in Us lago maydis.
Michael Feldbrügge. Heinrich-Heine University Düsseldorf, Centre of Excellence on Plant Sciences, Ins tute for Microbiology, Universitätsstr. 1, 40225 Düsseldorf, Germany.
Ac ve transport and local transla on of mRNAs ensure the appropriate spa al organiza on of proteins within cells. Recent work has shown that this process is intricately connected to membrane trafficking. We discovered that in hyphae of Us lago maydis, microtubule- dependent co-transport of mRNAs and endosomes is essen al for efficient polar growth. Key players are RNA-binding proteins containing RNA recogni on mo fs for mRNA binding as well as Mademoiselle domains for protein/protein interac on. Here, new insights on protein interac on partners will be presented.