XL Reunión Anual SBBMCH 26-29 de Septiembre 2017, Puerto Varas FALLING IN LOVE WITH SCIENCE ... A WAY OF LIFE The Chilean Society for Biochemistry and Molecular Biology promotes theoretical and experimental research, leading to the advancement and dissemination of Biochemistry and Molecular Biology in Chile. The Society also encourages and promotes initiatives aimed at maximizing the use of science for the benefit of the country and its citizens. This dream was founded in 1974, when Dr Hermann Niemeyer, Dr Marco Perreta, Dr Lylian Clark, Dr Enrique Beytia, Dr Arnaldo Foradori and Dr Arturo Yudelevich signed the document that gave legal status to the Chilean Society for Biochemistry and Molecular Biology. Subsequently, the first Annual Meeting was held in 1977. This year, our society celebrates the XL version of its Annual Meeting. Despite the passage of time, the quality, excellence and love for science remain the central axis of each and every one of our Meetings. Currently, the Society has more than 150 members, including researchers from Chilean and foreign universities. The enthusiasm and dedication to scientific activities of all our members constitute the body and soul of this Society. Our Annual Meeting aims to be an open door to the scientific community, at national and international levels, and a showcase for scientific excellence. We hope that the colleagues who entrusted us with the dissemination of their work at our meeting, can appreciate our firm commitment to high-quality research, with the solid aim of pursuing the advancement of biochemistry and molecular biology. As the Directive of the Society, we wish to transmit a strong signal that each member is important to us. The previous Directive began the process of legalizing the Society, a process that is culminating with the update of our statutes in the current Directive. It has been an honor for us to serve you and the Society in this exciting and historical process. We also believe in decentralization, for which we have been holding regional meetings in different cities throughout the country represented by a local Director, in addition to supporting several initiatives proposed by members. We wish to conclude this editorial letter by thanking all the people and institutions who, by placing their trust in this Directive, together with you, have made it possible to transform the dream of the founding colleagues of our beloved Society into a reality. To all our partners and friends of the Society, we say “WELCOME” and we hope you enjoy this excellent Annual Meeting that gathers prestigious national and international researchers. We also invite you to help us in the continuous growth of your Society, the Chilean Society for Biochemistry and Molecular Biology. Ilona I. Concha, President; Luis F. Larrondo, Vicepresident; Marcelo López-Lastra, Past-President; Christian A.M. Wilson, Secretary; Patricio Ramos, Treasurer; Claudia Stange, Director for Santiago; Lorena García, Director for Santiago; Luis Morales, Director for Talca; Maximiliano Figueroa, Director for Concepción; Claudia Quezada, Director for Valdivia. 2 XL Annual Meeting Sociedad de Bioquímica y Biología Molecular de Chile September , 2017 Puerto Varas DIRECTORY President : Ilona Concha Past President : Marcelo Lopez-Lastra Vice President : Luis F. Larrondo Secretary : Christian A.M. Wilson Theasurer : Patricio Ramos DIRECTORS Santiago : Claudia Stange : Lorena García Talca : Luis Morales Concepción : Maximiliano Fiqueroa Valdivia : Claudia Quezada 3 SPONSORS 4 LECTURES Opening Lecture Entry of enveloped viruses into cells and eukaryotic cell-cell fusion processes: a common origin dating back to LECA? Rey F1, 1Département de Virologie, UMR 3569 CNRS Institut Pasteur. Enveloped viruses infect cells by inducing the fusion of viral and cellular membranes for entry. Structural studies have identified three structural classes of viral fusion proteins (I, II and III), which undergo a fusogenic conformational change upon interactions with the cell to catalise the membrane fusion reaction. Although the structures are totally unrelated, the catalytic mechanism appears to be the same for the proteins of the three classes: insertion of a non-polar segment of the protein into the target membrane to make a trimeric, extended intermediate, followed by fold-back of the rod- like intermediate into a hairpin. This re-arrangement brings both membrane-interacting segments of the protein to the same end of a very stable, post-fusion trimer, thereby drawing the two membranes together. Our previous studies have identified that the viral fusion proteins belonging to class II, which are characterized by the presence of thee beta-sheet-rich domains, are homologous to proteins responsible for somatic cell fusion in eukaryotes. We have now identified that they are also homologous to the ancestral gamete fusion protein HAP2, present in the main eukaryotic branches except for fungi, and proposed to have been probably present in the last eukaryotic common ancestor (LECA). This discovery supports the notion that gene exchanges between viruses and cells have had a strong impact in evolution, and furthermore points to a possible role of viral envelope genes in the emergence of sexual life on earth. I will discuss the broad implications of these recent findings in my talk. Acknowledgements: ERC Advanced grant project (340371) CelCelFus; Grant ANR-2010-BLAN-1211 01; reccuring funding from CNRS and Institut Pasteur. Felix Rey is a structural biologist who obtained his PhD in 1988 at Paris XI, and then went for a 7-years post-doctoral period at Harvard University, until 1995, where he specialized in the structure of viruses. He became a Junior PI in 1995, working at CNRS in Gif-sur-Yvette (Paris area), where in 1999 he became Director of the CNRS Laboratory of Structural and Molecular Virology. In 2004, he joined Institut Pasteur as Head of the Virology Department (which he directed until 2012), and in parallel he launched the Structural Virology Unit, which he still directs today. His research focus has included the 3D structures of viral polymerases (like the hepatitis C virus RNA-dependent RNA polymerase) and the nucleoprotein template of replication for negative stranded RNA viruses such as the respiratory syncytial virus. But his main focus has been the study of viral envelope proteins, how they induce fusion, and how they are recognized by potently neutralizing antibodies. His studies in this area have very important implications in “reverse vaccinology”, open the way for epitope-focused vaccine design for viruses such as dengue and Zika. Felix Rey is an EMBO member since 2005 and a member of the French Academy of Sciences since 2010. Among the honors and awards he obtained are the CNRS “Médaille d’Argent” in 2004, the Beijerink Virology Prize of the Dutch Royal Academy in 2013 and the Pasteur-Weizmann-Servier award in 2015. 5 Osvaldo Cori Lecture Bacterial division depends on FtsZ GTPase activity as a motor of filaments treadmilling, a conserved evolutionary tubulin family mechanism. Monasterio O1, Araya G1, Montecinos F2, Diaz C3, Lagos R1, 1Departamento de Biologia, Facultad de Ciencias, Universidad De Chile.2Eunice Kennedy Shriver National Institute of Child Health and Human National Institute of Health.3Howard Hughes Medical Institute University of California. FtsZ and BtubAB are bacterial tubulin family proteins, important for cytokinesis and shape of bacteria respectively. FtsZ filaments showed treadmilling associated to GTPase activity. This work assessed experimentally the hypothesis that FtsZ self-assembles in the presence of GDP and GTP and that a conformational change occurs in FtsZ structure when these nucleotides exchange. The conformational changes induced by exchange between GDP and GTP nucleotides, was characterized using the intrinsic fluorescence of site directed tryptophan mutants located at the N- domain (F40W), the interdomain interface (Y222W) and the C-domain (F275W). Tryptophan lifetimes were measured using time-resolved fluorescence, knowing that the excited state is sensitive to changes in local environment, and changes at the interdomain interface were detected upon nucleotide exchange. These conformational changes were related to a hinge-like movement between FtsZ domains that might be responsible for the transition between straight and curved polymers. To understand the evolutionary importance of treadmilling as a key process for the dynamics of prokaryotic cellular cytoskeleton we determine the dynamics of Prosthecobacter BtubA/B. The results showed that BtubA/B assembly was consistent with a nucleation-elongation mechanism of polar bacterial microtubules that induced GTPase activity and, individual bacterial microtubules displayed treadmilling, which is characterized by the growth at one end and the shortening at the other end at the same rate. We conclude that treadmilling is a conserved mechanism of tubulin protein family that required GTP hydrolysis and a conformational change for its cellular function. FONDECYT Project 1130711 Dr. Octavio Monasterio obtained the professional title of Biochemist (1971) at the University of Chile after studying for five years at University of Concepción. His undergraduate thesis was on initiation of protein translation and was directed by Dr. Jorge E. Allende. He started his academic carrier at the Department of Biochemistry, University of Concepción (1972) and in 1977 he moved to the Faculty of Medicine, University of Chile, to finally move in 1980 to the