DOCSLIB.ORG

Cell Cycle-Dependent Transcription in Yeast: Promoters, Transcription Factors, and Transcriptomes

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Cell Cycle-Dependent Transcription in Yeast: Promoters, Transcription Factors, and Transcriptomes Oncogene (2005) 24, 2746–2755 & 2005 Nature Publishing Group All rights reserved 0950-9232/05 $30.00 www.nature.com/onc Cell cycle-dependent transcription in yeast: promoters, transcription factors, and transcriptomes Curt Wittenberg1 and Steven I Reed*,2 1Department of Molecular Biology, MB-3, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA; 2Department of Molecular Biology, MB-7, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA In the budding yeast, Saccharomyces cerevisiae,a 1983) allowed for the testing of a large number of genes significant fraction of genes (>10%) are transcribed with for cell cycle regulation of transcription. Not surpris- cell cycle periodicity. These genes encode critical cell cycle ingly, many genes involved in specific cell cycle processes regulators as well as proteins with no direct connection to were found to be expressed maximally during specific cell cycle functions. Cell cycle-regulated genes can be cell cycle intervals where synthesis of encoded products organized into ‘clusters’ exhibiting similar patterns of could be rationalized in terms of function (Wittenberg regulation. In most cases periodic transcription is achieved and Reed, 1991). Based on single-gene analyses, it could via both repressive and activating mechanisms. Fine- be predicted that a significant but limited set of genes tuning appears to have evolved by the juxtaposition of encoding proteins directly involved in periodic cell cycle regulatory motifs characteristic of more than one cluster functions would be subject to cell cycle regulation. within the same promoter. Recent reports have provided However, more recently, large-scale array analysis of the significant newinsight into the role of the cyclin-dependent yeast transcriptome has revealed that a much larger set kinase Cdk1 (Cdc28) in coordination of transcription with of genes (minimally 800 or >10% of protein-encoding cell cycle events. In early G1, the transcription factor genes) exhibit cell cycle regulation and that many of the complex known as SBF is maintained in a repressed state encoded proteins are not ostensibly linked to cell cycle by association of the Whi5 protein. Phosphorylation of functions (Cho et al., 1998; Spellman et al., 1998). This Whi5 by Cdk1 in late G1 leads to dissociation from SBF presumably reflects a more intricate and subtle relation- and transcriptional derepression. G2/M-specific transcrip- ship between cellular physiology and cell cycle progres- tion is achieved by converting the repressor Fkh2 into an sion than has been appreciated. Furthermore, high- activator. Fkh2 serves as a repressor during most of the resolution scrutiny has revealed that even within so- cell cycle. However, phosphorylation of a cofactor, Ndd1, called clusters of coordinately-regulated genes, there are by Cdk1 late in the cell cycle promotes binding to Fkh2 significant differences observable between individual and conversion into a transcriptional activator. Such members, suggesting individualized optimization of insights derived from analysis of specific genes when transcriptional programming according to function combined with genome-wide analysis provide a more (Cho et al., 1998; Spellman et al., 1998). In this article, detailed and integrated viewof cell cycle-dependent we will review advances based on detailed analysis of transcription. transcriptional control of individual genes, but also Oncogene (2005) 24, 2746–2755. doi:10.1038/sj.onc.1208606 discuss the implications of findings based on genome- wide analysis. Keywords: transcription; cell cycle; cyclin-dependent protein kinase The G1 gene cluster Cell cycle initiation during G1 phase is the consequence Introduction of transcriptional activation of greater than 200 genes, many of which participate in events specifically asso- With the advent of modern molecular biology, some 30 ciated with cell cycle progression (Cho et al., 1998; years ago, it became possible to efficiently analyse Spellman et al., 1998). The primary cis-acting regulators transcription patterns of individual genes. In yeast, the of the G1-specific gene cluster are targeted by two convergence of relatively straightforward cell cycle alternative heterodimeric transcription factors com- synchronization protocols (Amon, 2002) with rapid prised of unique DNA-binding components, Swi4 and efficient mutational cloning techniques (Struhl, (SBF) or Mbp1 (MBF), and a common component, Swi6, that participates in transactivation (Breeden, 1996). The optimal binding site for MBF is called the *Correspondence: SI Reed; E-mail: [email protected] Mlu Cell cycle Box (MCB), due to the presence of an Cell cycle-dependent transcription in yeast C Wittenberg and SI Reed 2747 MluI restriction site in the consensus sequence, and that of at least a portion of SBF and MBF target genes, for SBF is the Swi4 Cell cycle Box (SCB) (Breeden, 1996; including CLN1 and CLN2 (Epstein and Cross, 1994; Di Lee et al., 2002; Kato et al., 2004). Como et al., 1995; Wijnen and Futcher, 1999). The target genes for SBF and MBF have been The identification of a central role for Cln3/Cdk1 traditionally defined by the presence of redundant SCB in transcriptional activation (Cross and Tinklenberg, and MCB sequences in their promoters. Functionally, 1991; Dirick and Nasmyth, 1991), and the finding that SBF and MBF targets, respectively, fall roughly into Cdk1 is likely to act directly rather than via its effect on two classes. MBF targets include those involved in the the accumulation of other proteins (Marini and Reed, control or execution of DNA replication and repair 1992), has led to a protracted search for CDK targets (POL2, CDC2, RNR1, CLB5/6), whereas SBF targets involved in activation. Swi6 and Swi4 are established include those involved in cell morphogenesis, spindle targets in vitro and Swi6 is known to be phosphorylated pole body duplication and other growth-related func- in a Cdk1-dependent manner in vivo (Sidorova et al., tions (CLN1/2, PCL1/2, GIN4, FKS1/2). This apparent 1995; Ubersax et al., 2003; Geymonat et al., 2004). differentiation into distinct functional classes may have Elimination of Cdk sites by mutation leads to a defect in adaptive significance due to regulatory differences nuclear import of Swi6 (Sidorova et al., 1995; Geymonat between the two transcription factors. However, each et al., 2004). However, those mutations appear not to group also includes many members that do not fall have an effect on the timing, extent of transcriptional neatly into these categories. Consequently, it is possible activation or Cdk dependence of transcriptional activa- that this separation is merely a reflection of the tion, suggesting that phosphorylation of Swi6 is not rate evolutionary history of these transcriptional regulatory limiting for access to the nucleus. modules (see below). The lack of a functional link between phosphoryla- Whereas the optimal binding sites for SBF and MBF tion of the transcription factors and transcriptional are distinct, there is considerable overlap in their activation has led to the suggestion that Cdk1 acts specificity both in terms of the DNA sequence require- indirectly via phosphorylation of another factor (Wijnen ments for binding and the occurrence of such sites et al., 2002), perhaps a previously unrecognized tran- within promoters. Consequently, there is considerable scriptional activator or repressor. Although a number of ambiguity concerning the role of each factor in proteins have been shown to interact with Swi6 (e.g., regulating specific genes (Partridge et al., 1997). This is Hrr25 (Ho et al., 1997), Skn7 (Morgan et al., 1995), and apparent from the global analysis of the binding of the Stb1 (Costanzo et al., 2003)), none appears to play a specific transcription factors to promoters (Iyer et al., significant role in the Cln/Cdk-dependent activation of 2001; Simon et al., 2001; Lee et al., 2002) and may transcription. Recently, the search for additional factors explain the modest effect of inactivation of SBF or MBF regulating G1 transcription led to the discovery of Whi5 on the expression of G1-specific genes (Koch et al., as an SBF-associated transcriptional repressor (Costan- 1993; de Bruin and Wittenberg, unpublished). zo et al., 2004; de Bruin et al., 2004). Inactivation of Whi5, previously shown to cause cell cycle initiation at a Regulation of G1-specific transcription small cell size (Jorgensen et al., 2002; Zhang et al., 2002), suppresses the requirement for Cln3in the absence of G1-specific transcription is promoted, in large part, by Bck2 (Costanzo et al., 2004; de Bruin et al., 2004). G1 cyclin-associated CDK activity. In fact, deregulation Consistent with that phenotype, inactivation of WHI5 of that process was the basis for the discovery of the G1 leads to premature activation of G1-specific transcrip- cyclin Cln3(Cross, 1988; Nash et al., 1988). Mutations tion during the G1 phase. The Whi5 protein associates leading to stabilization of Cln3result in premature with G1-specific promoters in an SBF-dependent expression of G1-specific genes and, thereby, small cell manner and is released from DNA coincident with size and resistance to G1-phase arrest by mating transcriptional activation. It is phosphorylated at Cdk pheromone. Any of the three G1 cyclins (Cln1, Cln2, consensus sites in vivo and in vitro and can be or Cln3) in conjunction with Cdk1 (Cdc28) were later phosphorylated in vitro by both G1- and B-type shown to be sufficient to mobilize Cdk1-dependent cyclin-associated Cdk1. Consistent with a role for activation of G1-specific transcription (Cross and Cdk1 in activation of SBF-dependent transcription, Tinkelenberg, 1991; Dirick and Nasmyth, 1991; Marini phosphorylation of SBF/Whi5 complexes in vitro and Reed, 1992). However, whereas Cln1- and Cln2- promotes dissociation of the complex. The regulation containing CDK complexes are sufficient for transcrip- of SBF by Whi5 bears striking resemblance to the tional activation, Cln3/Cdk1 is the primary activator regulation of the metazoan G1/S transcription factor, under physiological conditions (Tyers et al., 1993; E2F, by the retinoblastoma tumor suppressor protein, Dirick et al., 1995; Stuart and Wittenberg, 1995).
Load more

Recommended publications
  • Regulation of Components of the Pseudomonas Aeruginosa Phosphate-Starvation-Inducible Regulon in Escherichia Coii
    Molecular Microbiology (1988) 2(3), 347-352 Regulation of components of the Pseudomonas aeruginosa phosphate-starvation-inducible regulon in Escherichia coii R. J. Siehnel, E. A. Worobec and R. E. W. Hancock* of the structural elements of the Pho regulon since, in such Department ot Microbioiogy, University ot British mutants, another regulatory gene product, PhoM, will tran- Columbia, Vancouver, British Columbia, Canada scriptionally activate PhoB. The PhoM activator is not con- V6T1W5. trolled by changes in phosphate levels and is repressed when PhoR is functional. Summary Conditions of low environmental phosphate stimulate the co-induction, in E. coli, of an outer membrane porin Plasmids pPBP and pRS-XP containing the cloned (PhoE), a periplasmic phosphate-binding protein (PhoS), genes for the Pseudomonas aeruginosa phosphate- and a periplasmic alkaline phosphatase (PhoA). JUephoB starvation-inducible periplasmic phosphate-binding gene product appears to activate the transcription of each protein and outer membrane porin P {oprP), respec- of these genes by interacting with specific regulation tively, were introduced into various Escherichia coti sequences located in analogous regions upstream from Pho-regulon regulatory mutants. Using Western the structural genes. These sequences are highly hom- immunoblots and specific antisera, the production of ologous and have been termed the 'Pho box' (Shinagawa both gene products was observed to be under the etai., 1987). control of regulatory elements of the E. coti Pho regu- Phosphate transport has been examined in several other lon. Sequencing of the region upstream of the trans- bacterial species and recent evidence suggests that a lationai start site of the oprP gene revealed a 'Pho phosphate-starvation-inducible regulon, similar to that box' with strong homology to the E.
    [Show full text]
  • Phosphate Uptake by the Phosphonate Transport System Phncde Raffaele Stasi†, Henrique Iglesias Neves† and Beny Spira*
    Stasi et al. BMC Microbiology (2019) 19:79 https://doi.org/10.1186/s12866-019-1445-3 RESEARCH ARTICLE Open Access Phosphate uptake by the phosphonate transport system PhnCDE Raffaele Stasi†, Henrique Iglesias Neves† and Beny Spira* Abstract Background: Phosphate is a fundamental nutrient for all creatures. It is thus not surprising that a single bacterium carries different transport systems for this molecule, each usually operating under different environmental conditions. The phosphonate transport system of E. coli K-12 is cryptic due to an 8 bp insertion in the phnE ORF. Results: Here we report that an E. coli K-12 strain carrying the triple knockout pitA pst ugp reverted the phnE mutation when plated on complex medium containing phosphate as the main phosphorus source. It is also shown that PhnCDE takes up orthophosphate with transport kinetics compatible with that of the canonical transport system PitA and that Pi-uptake via PhnCDE is sufficient to enable bacterial growth. Ugp, a glycerol phosphate transporter, is unable to take up phosphate. Conclusions: The phosphonate transport system, which is normally cryptic in E. coli laboratory strains is activated upon selection in rich medium and takes up orthophosphate in the absence of the two canonical phosphate-uptake systems. Based on these findings, the PhnCDE system can be considered a genuine phosphate transport system. Keywords: Phosphonates, Phosphate, Phn, PHO regulon Background phosphatase (AP). Genes belonging to the PHO regu- Phosphorus is a macronutrient of utmost importance to lon are synchronously induced by Pi-shortage [2]. For the all living beings. It is thus not surprising that bacte- sake of simplicity, the operons pstSCAB-phoU, ugpBAEC, ria developed several different mechanisms of phospho- phnCDEFGHIJKLMNOP will be respectively shortened to rus acquisition.
    [Show full text]
  • From Prokaryotic to Eukaryotic Cells
    This is a repository copy of Pi sensing and signaling: from prokaryotic to eukaryotic cells. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/95967/ Version: Accepted Version Article: Wanjun, QI, Baldwin, SA, Muench, SP orcid.org/0000-0001-6869-4414 et al. (1 more author) (2016) Pi sensing and signaling: from prokaryotic to eukaryotic cells. Biochemical Society Transactions, 44 (3). pp. 766-773. ISSN 0300-5127 https://doi.org/10.1042/BST20160026 © 2016, The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society. This is an author produced version of a paper published in Biochemical Society Transactions. Uploaded in accordance with the publisher's self-archiving policy. Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version - refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher’s website. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal
    [Show full text]
  • Signal Transduction in the Control of Phosphate-Regulated Genes of Escherichia Coli
    Kidney International, Vol. 49 (1996), pp. 964—967 Signal transduction in the control of phosphate-regulated genes of Escherichia coli BARRY L. WANNER Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA Bacteria such as Escherichia co/i regulate the synthesis of aunique proteins with signatures of a sensor kinase (transmitter) large number of proteins in response to extracellular inorganicdomain and 170 with signatures of a receiver domain have been phosphate (P) levels by activating transcription of co-regulatedidentified on the basis of sequence similarities at the protein level genes. More than 80 proteins are synthesized in increased(as determined from searching DNA databases for homologous amounts in response to P. limitation in the gram-negative bacte-proteins). Analogous signaling systems exist in eucaryotic cells rium E. co/i [1—3]. Many of these proteins are the products of a set including Saccharomyces cerevisiae [6—8], Arabidopsis thaliana [9], of co-regulated genes known as the phosphate (Pho) regulon.and Neurospora crassa [10]. In yeast, a two-component system Altogether 38 Pho regulon genes have now been characterized (by(SLN1 and SSK1) can provide signaling input to a MAP kinase cloning, sequencing, mutational analysis, and/or examination ofcascade that is responsive to small molecules [7, 11]. MAP kinase their gene products) in E. co/i, or the closely related bacteriacascades are extremely important in signaling; they are key Enterobacter aerogenes and Sa/monella typhimurium [4]. Thesecomponents of convergent signal transduction pathways in mam- genes are arranged in eight (or more) transcriptional units, andmalian cells [12, 13]. Although histidine phosphorylation has also their gene products probably all have a role in the assimilation ofbeen recently found in human cells [14], the phosphorylation alternative phosphorus (P) sources from the environment.
    [Show full text]
  • Molecular Mechanisms of Phosphate Sensing, Transport and Signalling in Streptomyces and Related Actinobacteria
    International Journal of Molecular Sciences Review Molecular Mechanisms of Phosphate Sensing, Transport and Signalling in Streptomyces and Related Actinobacteria Juan Francisco Martín * and Paloma Liras Department of Molecular Biology, Microbiology Section, University of León, 24071 León, Spain; [email protected] * Correspondence: [email protected] Abstract: Phosphorous, in the form of phosphate, is a key element in the nutrition of all living beings. In nature, it is present in the form of phosphate salts, organophosphates, and phosphonates. Bacteria transport inorganic phosphate by the high affinity phosphate transport system PstSCAB, and the low affinity PitH transporters. The PstSCAB system consists of four components. PstS is the phosphate binding protein and discriminates between arsenate and phosphate. In the Streptomyces species, the PstS protein, attached to the outer side of the cell membrane, is glycosylated and released as a soluble protein that lacks its phosphate binding ability. Transport of phosphate by the PstSCAB system is drastically regulated by the inorganic phosphate concentration and mediated by binding of phosphorylated PhoP to the promoter of the PstSCAB operon. In Mycobacterium smegmatis, an additional high affinity transport system, PhnCDE, is also under PhoP regulation. Additionally, Streptomyces have a duplicated low affinity phosphate transport system encoded by the pitH1–pitH2 genes. In this system phosphate is transported as a metal-phosphate complex in simport with protons. Expression of pitH2, but not that of pitH1 in Streptomyces coelicolor, is regulated by PhoP. Interestingly, in many Streptomyces species, three gene clusters pitH1–pstSCAB–ppk (for a polyphosphate kinase), are linked in a supercluster formed by nine genes related to phosphate metabolism.
    [Show full text]
  • Isolation and Characterization of Bacterial Phosphorous Metabolism Genes from Complex Microbial Communities
    Isolation and characterization of bacterial phosphorous metabolism genes from complex microbial communities by Adi Rolider A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Doctor of Philosophy in Biology Waterloo, Ontario, Canada, 2009 ©Adi Rolider 2009 Author’s declaration I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. Abstract Phosphorous (P) is an essential nutrient, playing a central role in the life of a bacterial cell. It is involved in cellular metabolic pathways, cell signaling and is a component of many of the cell’s macromolecules. Since a majority of the biosphere’s microorganisms have not yet been cultured, much more can be learned about the biochemical and genetic mechanisms that govern bacterial P metabolism. The function-driven approach to metagenomics was applied to study P metabolism in the bacterial communities present in pulp and municipal wastewater treatment plant activated sludge and soil, leading to the isolation and identification of three new phosphatases, genes involved in P transport, regulation of P related functions and additional genes which may be important for the bacterial cell’s adaptation to the above communities. The identification of two new nonspecific acid phosphatases (NSAPs) phoNACX6.13 and phoNBCX4.10 and an alkaline phosphatase, phoAACX6.71, belonging to the nucleotide pyrophosphatase phosphodiesterase (NPP) family is reported here. The genes for the three phosphatases were cloned, sequenced, and analysed for upstream regulatory sequences in addition to biochemical characterization of their protein products.
    [Show full text]
  • Studies of Phou in Escherichia Coli: Metal Binding, Dimerization,Protein/Protein Interactions, and a Signaling Complex Model
    Brigham Young University BYU ScholarsArchive Theses and Dissertations 2014-12-01 Studies of PhoU in Escherichia coli: Metal Binding, Dimerization,Protein/Protein Interactions, and a Signaling Complex Model Stewart G. Gardner Brigham Young University - Provo Follow this and additional works at: https://scholarsarchive.byu.edu/etd BYU ScholarsArchive Citation Gardner, Stewart G., "Studies of PhoU in Escherichia coli: Metal Binding, Dimerization,Protein/Protein Interactions, and a Signaling Complex Model" (2014). Theses and Dissertations. 5685. https://scholarsarchive.byu.edu/etd/5685 This Dissertation is brought to you for free and open access by BYU ScholarsArchive. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. Studies of PhoU in Escherichia coli: Metal Binding, Dimerization, Protein/Protein Interactions, and a Signaling Complex Model Stewart G. Gardner A dissertation submitted to the faculty of Brigham Young University in partial fulfillment of the requirements for the degree of Doctor of Philosophy William R. McCleary, Chair Joel Shelby Griffitts Brent Lynn Nielsen Julianne House Grose Zachary Thomas Aanderud Department of Microbiology and Molecular Biology Brigham Young University December 2014 Copyright ©2014 Stewart G. Gardner All Rights Reserved ABSTRACT Studies of PhoU in Escherichia coli: Metal Binding, Dimerization, Protein/Protein Interactions and a Signaling Complex Model Stewart G. Gardner Department of Microbiology and Molecular Biology, BYU Doctor of Philosophy Phosphate is an essential nutrient for all forms of life. Escherichia coli has a PhoR/PhoB two component regulatory system that controls the expression of various genes whose products allow the cell to thrive in low phosphate environments.
    [Show full text]
  • Budding Yeast Escape Commitment to the Phosphate Starvation Program Using Gene Expression Noise
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Current Biology 23, 2051–2057, October 21, 2013 ª2013 Elsevier Ltd All rights reserved http://dx.doi.org/10.1016/j.cub.2013.08.043 Report Budding Yeast Escape Commitment to the Phosphate Starvation Program Using Gene Expression Noise Noam Vardi,1 Sagi Levy,1 Michael Assaf,2 Miri Carmi,1 stage, the Pho regulon will be induced, resulting in the upregu- and Naama Barkai1,* lation of high-affinity transporters and downregulation of the 1Department of Molecular Genetics, Weizmann Institute of low-affinity ones. The phosphate influx will therefore become Science, Rehovot 7610001, Israel dependent on the high-affinity transporters alone, which at 2Racah Institute of Physics, Hebrew University of Jerusalem, this point work at maximal velocity, returning the phosphate Jerusalem 91904, Israel influx back to its maximum level. Maintaining the starvation program induced at intermediate phosphate therefore necessi- tates some positive feedback to maintain Pho4p active despite Summary the high phosphate influx. Further, replenishing phosphate at this stage will not be sensed by the cells, as it will not increase Cells must rapidly adapt to changes in nutrient availability. In phosphate uptake (Figure 1B). We therefore predicted that if budding yeast, limitation of phosphate rapidly induces the phosphate is replenished when cells are in intermediate phos- expression of the Pho regulon genes [1–4]. This starvation phate, the starvation program will remain active. Only when program depends on the transcription factor Pho4, which phosphate levels are reduced further, to a level that is compa- translocates to the nucleus within minutes when cells are rable to the dissociation constant of the high-affinity trans- transferred to a low-phosphate medium [5].
    [Show full text]
  • The Potential for Polyphosphate Metabolism in Archaea and Anaerobic Polyphosphate Formation in Methanosarcina Mazei Fabiana S
    www.nature.com/scientificreports OPEN The potential for polyphosphate metabolism in Archaea and anaerobic polyphosphate formation in Methanosarcina mazei Fabiana S. Paula1,2,6*, Jason P. Chin 3,6, Anna Schnürer2, Bettina Müller2, Panagiotis Manesiotis 4, Nicholas Waters 1,5, Katrina A. Macintosh 3, John P. Quinn3, Jasmine Connolly1, Florence Abram1, John W. McGrath3 & Vincent O’Flaherty 1* Inorganic polyphosphate (polyP) is ubiquitous across all forms of life, but the study of its metabolism has been mainly confned to bacteria and yeasts. Few reports detail the presence and accumulation of polyP in Archaea, and little information is available on its functions and regulation. Here, we report that homologs of bacterial polyP metabolism proteins are present across the major taxa in the Archaea, suggesting that archaeal populations may have a greater contribution to global phosphorus cycling than has previously been recognised. We also demonstrate that polyP accumulation can be induced under strictly anaerobic conditions, in response to changes in phosphate (Pi) availability, i.e. Pi starvation, followed by incubation in Pi replete media (overplus), in cells of the methanogenic archaeon Methanosarcina mazei. Pi-starved M. mazei cells increased transcript abundance of the alkaline phosphatase (phoA) gene and of the high-afnity phosphate transport (pstSCAB-phoU) operon: no increase in polyphosphate kinase 1 (ppk1) transcript abundance was observed. Subsequent incubation of Pi-starved M. mazei cells under Pi replete conditions, led to a 237% increase in intracellular polyphosphate content and a > 5.7-fold increase in ppk1 gene transcripts. Ppk1 expression in M. mazei thus appears not to be under classical phosphate starvation control.
    [Show full text]
  • Environmental Factors Influence Virulence of Pseudomonas
    Environmental factors influence virulence of Pseudomonas aeruginosa Von der Fakultät für Lebenswissenschaften der Technischen Universität Carolo-Wilhelmina zu Braunschweig zur Erlangung des Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.) genehmigte D i s s e r t a t i o n von Ahmed Mahmoud Haddad Abd Ellah aus Sohaj / Ägypten 1. Referent: Professor Dr. Jürgen Wehland 2. Referent: Professor Dr. Susanne Häußler eingereicht am: 14.06.2010 Mündliche Prüfung (Disputation) am: 24.08.2010 Druckjahr 2010 Vorveröffentlichungen der Dissertation Teilergebnisse aus dieser Arbeit wurden mit Genehmigung der Fakultät für Lebenswissenschaften, vertreten durch den Mentor der Arbeit, in folgenden Beiträgen vorab veröffentlicht: Publikationen Ahmed Haddad, Vanessa Jensen, Tanja Becker, Susanne Häussler (2009). The Pho regulon influences biofilm formation and type three secretion in Pseudomonas aeruginosa. Environmental Microbiology Reports 1(6), 488–494. Tagungsbeiträge Ahmed Haddad, Tanja Becker, Susanne Häußler. Biofilm formation and the expression of the type three secretion system are regulted by PhoB in Pseudomonas aeruginosa. Poster. Jahrestagung der Deutschen Gesellschaft für Hygiene und Mikrobiologie, Dresden, 2008. Ahmed Haddad, Vanessa Jensen, Tanja Becker, Susanne Häußler. Biofilm formation and the expression of the type three secretion system are regulated by PhoB in Pseudomonas aeruginosa. Poster. XII. International Conference on Pseudomonas, Hannover, 2009. [3] I. CONTENTS Contents 1 INTRODUCTION ..............................................................................................
    [Show full text]
  • Phosphorus Deprivation Responses and Phosphonate Utilization in a Thermophilic Synechococcus Sp
    JOURNAL OF BACTERIOLOGY, Dec. 2008, p. 8171–8184 Vol. 190, No. 24 0021-9193/08/$08.00ϩ0 doi:10.1128/JB.01011-08 Copyright © 2008, American Society for Microbiology. All Rights Reserved. Phosphorus Deprivation Responses and Phosphonate Utilization in a Thermophilic Synechococcus sp. from Microbial Matsᰔ† Melissa M. Adams,1,2 María R. Go´mez-García,1 Arthur R. Grossman,1 and Devaki Bhaya1* Carnegie Institution for Science, Department of Plant Biology, Stanford University, Stanford, California 94305,1 and Department of Biology, Stanford University, Stanford, California 943052 Received 22 July 2008/Accepted 3 October 2008 The genomes of two closely related thermophilic cyanobacterial isolates, designated Synechococcus isolate OS-A and Synechococcus isolate OS-B؅, from the microbial mats of Octopus Spring (Yellowstone National Park) have been sequenced. An extensive suite of genes that are controlled by phosphate levels constitute the Downloaded from putative Pho regulon in these cyanobacteria. We examined physiological responses of an axenic OS-B؅ isolate as well as transcript abundances of Pho regulon genes as the cells acclimated to phosphorus-limiting condi- tions. Upon imposition of phosphorus deprivation, OS-B؅ stopped dividing after three to four doublings, and absorbance spectra measurements indicated that the cells had lost most of their phycobiliproteins and chlorophyll a. Alkaline phosphatase activity peaked and remained high after 48 h of phosphorus starvation, and there was an accumulation of transcripts from putative Pho regulon genes. Interestingly, the genome of jb.asm.org Synechococcus isolate OS-B؅ harbors a cluster of phn genes that are not present in OS-A isolates. The proteins encoded by the phn genes function in the transport and metabolism of phosphonates, which could serve as an alternative phosphorus source when exogenous phosphate is low.
    [Show full text]
  • Phosphate in Virulence of Candida Albicans and Candida Glabrata
    Journal of Fungi Review Phosphate in Virulence of Candida albicans and Candida glabrata Julia R. Köhler *, Maikel Acosta-Zaldívar y and Wanjun Qi y Division of Infectious Diseases, Boston Children’s Hospital/Harvard Medical School, Boston, MA 02115, USA; [email protected] (M.A.-Z.); [email protected] (W.Q.) * Correspondence: [email protected] These authors contributed equally. y Received: 4 March 2020; Accepted: 22 March 2020; Published: 26 March 2020 Abstract: Candida species are the most commonly isolated invasive human fungal pathogens. A role for phosphate acquisition in their growth, resistance against host immune cells, and tolerance of important antifungal medications is becoming apparent. Phosphorus is an essential element in vital components of the cell, including chromosomes and ribosomes. Producing the energy currency of the cell, ATP, requires abundant inorganic phosphate. A comparison of the network of regulators and effectors that controls phosphate acquisition and intracellular distribution, the PHO regulon, between the model yeast Saccharomyces cerevisiae, a plant saprobe, its evolutionarily close relative C. glabrata, and the more distantly related C. albicans, highlights the need to coordinate phosphate homeostasis with adenylate biosynthesis for ATP production. It also suggests that fungi that cope with phosphate starvation as they invade host tissues, may link phosphate acquisition to stress responses as an efficient mechanism of anticipatory regulation. Recent work indicates that connections among the PHO regulon, Target of Rapamycin Complex 1 signaling, oxidative stress management, and cell wall construction are based both in direct signaling links, and in the provision of phosphate for sufficient metabolic intermediates that are substrates in these processes.
    [Show full text]