Fwd: [All.ncl] Talk Announcement: Prof. Dirk Schneider

[Chetan Gadgil]

============ Forwarded message ============
From: Durba Sengupta <d.sengu...@csir.res.in>
To: "allncl"<all...@lsmgr.nic.in>
Date: Fri, 26 Sep 2025 13:07:20 +0530
Subject: [All.ncl] Talk Announcement: Prof. Dirk Schneider
============ Forwarded message ============

Dear colleagues,

We would like to invite you for a talk by Prof. Dirk Schneider

Title: Membrane interaction of a prokaryotic ESCRT-III protein 

 

Affiliation: Johannes Gutenberg University Mainz, Germany

Time: 30th September, Tuesday 11:30 am

Venue: SSBLT, PAM Building, CSIR-NCL

Tea will be served before the talk.

About the speaker: 

Prof. Dirk Schneider is Professor of Biochemistry at the University of Mainz, Germany. Previously he has held the posts of Director of the Institute of Pharmacy and Biochemistry, University of Mainz and Dean of the Faculty of Chemistry, Geosciences and Pharmacy, University of Mainz. His doctoral studies were at the Ruhr-University Bochum, Germany, followed by Postdoctoral fellowship with Prof. Dr. D.M. Engelman at Yale University, USA. His main research interests are Membrane Biochemistry and Biophysics; Membrane Protein Folding and Assembly; Structure and Dynamics of Membrane Proteins; Protein-Lipid interactions and Thylakoid Membrane Biogenesis. More details can be found at: http://www.bio.chemie.uni-mainz.de

Abstract: 

Dynamic membrane remodeling is essential for eukaryotic cell viability and function. Once thought to be unique to eukaryotes, proteins involved in these processes are now recognized in bacteria, suggesting conserved mechanisms. In eukaryotes, the highly conserved endosomal sorting complex required for transport (ESCRT) mediates processes such as cytokinesis and vesicle formation. Recently, proteins of the ESCRT-III superfamily have been identified in bacteria, sharing structural similarities and membrane-remodeling activity with their eukaryotic counterparts. The inner membrane-associated protein of 30 kDa (IM30) is involved in the biogenesis, protection and/or remodeling of internal membranes in cyanobacteria. An IM30 monomer spontaneously forms various homooligomeric barrel structures in solution. The oligomeric structure of IM30 exhibits a remarkable plasticity, which has also been observed with eukaryotic ESCRT-III proteins. In addition to barrels, we have observed the formation of rod structures in solution as well as carpets and spirals on membranes. Upon binding to solid-supported membranes, IM30 barrels disassemble into smaller oligomers, which involves partial unfolding of the monomers. In fact, the oligomeric assembly induces/stabilizes α-helical regions, and in IM30*, an IM30 variant defective in oligomerization, only a helical hairpin, the core of all ESCRT-III proteins, retains its ordered structure while the remaining regions are disordered. Intrinsically disordered proteins often undergo liquid-liquid phase separation and IM30 has previously been observed to form puncta structures in vivo under membrane stress. In line with this, we have demonstrated in vitro that IM30 monomers have the ability to form biomolecular condensates. Upon membrane binding, IM30 monomers oligomerize and form spiral structures on membrane surfaces, as also observed previously with eukaryotic ESCRT-III´s, as well as barrel and rod structures. Membrane-attached IM30 barrels and rods can engulf membranes, and here membrane contacts appear to be mainly mediated by defined protein regions. Our findings support a conserved membrane-binding and remodeling mechanism across the ESCRT-III superfamily, shared between prokaryotic and eukaryotic proteins.

The talk is being held jointly as a part of the biomodeling talk series and as a part of the Divisional talks. 

Regards,

Durba

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