Chenyu (Sophie) Lou
“Mechanisms of actin filament disassembly”
Chenyu (Sophie) Lou, Shashank Shekhar, Lishibanya Mohapatra, Jane Kondev, Jeff Gelles, and Bruce Goode Brandeis / Biology
Hosted by Goode's Lab
Abstract
The actin cytoskeleton serves as a key determinant in many crucial cellular processes including cell motility, cell division, morphogenesis, immune response and wound healing. Cells tightly control the architecture, size, site and timing of actin network assembly and disassembly via various protein machineries. Recently, disassembly factors such as Cofilins, Coronin and Aip1 have been shown to facilitate actin disassembly. By monitoring the activity of Cofilin and Spire over pre-assembled filaments using TIRF microscopy and microfluidics-assisted single filament assay, we investigated and compared the mechanisms Cofilin and Spire use to sever actin filaments. While Cofilin can both sever and depolymerize filaments, Spire only severs filaments. We verified that Cofilin grows into islands before inducing severing events at the boundaries between bare and Cofilin-decorated filament segments. Spire, on the contrary, follows a ‘hit and run’ principle to induce severing. Our experiments further show that Cofilin synergizes with Srv2/CAP to enhance the rate of filament pointed-end depolymerization by over 100 times in a Srv2 concentration dependent manner.
Support
SMURF (Summer MRSEC Undergrad Research Fellowship)