Biophysical Society Bulletin | May 2018

Communities

Exocytosis and Endocytosis

Intrinsically Disordered Proteins (IDP) The Intrinsically Disordered Proteins (IDP) Subgroup hosted an outstanding and highly attended subgroup symposium at the 2018 Annual Meeting. If you enjoyed the symposium and are not already a subgroup member, we hope you will consid- er joining. The opening keynote presentation was provided by Jane Clarke , who presented on the nature of cooperative folding and binding in the biofilm-promoting protein SasG. Immedi- ately following, Sarah Shammas discussed the thermodynamic and kinetic determinants of function in binding reactions involving a panel of IDPs. These talks led into a presentation on new methods to probe conformational dynamics with sin- gle molecule FRET, provided by Hoi Sung Chung . It is clear that quantitative studies of IDP structure, thermodynamics, and kinetics are now establishing molecular mechanisms for their diverse functional roles in the cell. Our symposium’s second session focused on disorder in multi-protein complexes and sub-cellular phase behavior. Frauke Gräter provided a computational perspective on tran- sient nucleoporin-receptor binding. The nuclear pore is one of many sub-cellular compartments that may feature liquid- liquid phase separation; Hue Sun Chan framed a general the- ory towards the sequence-determinants of phase separation involving IDPs. Our symposium closed with a keynote presen- tation by Peter Wright , who provided a remarkable overview of allosteric regulation between the CREB-binding protein and its extensive set of direct binding partners. Through the generosity of Ya-yue Van and Molecular Kinetics, the IDP subgroup recognized two distinguished postdocs in our field. Alessandro Borgia , from Benjamin Schuler’s laboratory, presented single-molecule fluorescence insights into coupled folding and binding of polyelectrolyte proteins in the absence of ordering. Jeong-Mo Choi , who is a member of Rohit Pap- pu’s laboratory, provided physical insights into the sequence determinants of liquid-liquid phase separation. The IDP subgroup is proud to continue promoting talented postdocs through our symposium and we hope you will consider nomi- nations (or being nominated) for next year’s meeting.

The Exo/Endo Subgroup had a great meeting this past Febru- ary, organized by Dixon Woodbury (BYU). All the speakers gave engaging presentations, and we especially thank Manfred Lindau , Cornell University and Max Planck Institute, who gave the Sir Bernard Katz Award Lecture. The meeting in San Francisco started with two student talks from Tina Han , University of California-San Francisco,and Huan Bao, University of Wisconsin-Madison. These were selected from the several dozen poster submissions from subgroup student members. This was followed by excellent presentations by Tom Kirchhausen , Harvard Medical School; Geert van den Bogaart , Radboud University; Patrik Rorsman , Oxford University; Michael Tamkun , Colorado State University; Katalin Toth , Centre de Recherche Universite Laval Robert-Gif- fard; and, finally, the Katz Award Lecture by Manfred Lindau . Lindau spoke on The Mystery of the Fusion Pore. Lindau was selected for the Katz award for his development of many new biophysical techniques for cell and neurobiolo- gy including the first perforated patch recordings, improved cell-attached patch capacitance measurements, development of patch amper¬ometry, and the first successful fabrication and application of surface-patterned amper¬ometric elec- tro¬chemical detector (ECD) arrays. By successfully combin- ing electrochemical ECD array recordings with total internal reflection fluorescence resonance transfer microscopy, he demonstrated a rapid conformational change in the SNARE protein SNAP25 preceding individual fusion events. The central goal of his current research is to elucidate the mech- anisms of exocytotic fusion and transmitter release using ex- perimental approaches and molecular dynamics simulations. The previous five Katz award winners were Robert Zucker (2017), Sandra Schmid (2016), Ronald Holz (2015), Axel Brunger (2014), and James Rothman (2013). We thank Dixon Woodbury for a great meeting and look for- ward to an exciting meeting next year in Baltimore, Maryland, on Saturday, March 2, 2019. Mark your calendars! — Amy Lee , Exo/Endo Subgroup Chair — Dixon J. Woodbury , Past-chair

Numbers By the

The Biophysical Society reached over 105,000 people through social media during the third Annual Biophysics Week, March 25-29.

May 2018

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