Different ways to disassemble actin filaments

Image - Different ways to disassemble actin filaments
Event date :
Wednesday, July 19, 2017 - 16:00
Event Type :
Seminar
Categories
Location :
Lowy Cancer Research Centre, Level 4 seminar space
Contact for inquiries
Till Boecking till.boecking@unsw.edu.au

Guillaume Romet-Lemonne, Institut Jacques Monod
SoMS, BABS and GSBE Cross-Faculty Seminar Series
Abstract:The actin cytoskeleton comprises several networks of filaments that must be assembled and destroyed in a well-controlled manner, in space and time. A well-regulated filament disassembly is indeed vital, in order to remove aged filaments and to renew the pool of assembly-competent actin monomers. Proteins of the ADF/cofilin family are the central players in this process. Here, using microfluidics to monitor the action of ADF/cofilin on individual actin filaments, we characterize its ability to sever filaments and promote their disassembly from both ends. Strikingly, we show that the barbed ends of ADF/cofilin-decorated filaments can hardly stop depolymerizing.
Bio:Guillaume Romet-Lemonne was trained as a physicist, before turning to the biophysics and biochemistry of the cytoskeleton. He now leads the group “regulation of actin assembly dynamics”, together with Antoine Jégou at Institut Jacques Monod, in Paris. Their research focuses on the biochemical and mechanical regulation of the actin cytoskeleton, through in vitro experiments with purified proteins. In particular, they have developed an original microfluidics approach for the study of individual filaments, which provides new insight into a number of molecular mechanisms.
Key results include: demonstrating that ATP hydrolysis in actin filaments is a random mechanism (Jegou et al. PLoS Biol 2011); showing formins’ ability to sense mechanical tension applied to the actin filament and increase their elongation rate (Jegou et al. Nat Commun 2013); showing the coexistence and competition of capping proteins and formins at the barbed end (Shekhar et al. Nat Commun 2015); and revealing that ADF/cofilin promotes barbed end depolymerization (Wioland et al. Curr Bio 2017). Links: www.actindynamics.netwww.ijm.fr
Date & Time: Wednesday 19  July at 4.00 pm followed by Happy Hour.
Venue: Lowy Cancer Research Centre, Level 4 seminar space Map


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