The Endosomal Sorting Complex Required for Transport-III (ESCRT-III) is part of a conserved membrane remodeling machine. ESCRT-III employs polymer formation to catalyze inside-out membrane fission processes in a large variety of cellular processes, including budding of endosomal vesicles and enveloped viruses, cytokinesis, nuclear envelope reformation, plasma membrane repair, exosome formation, neuron pruning, dendritic spine maintenance, and preperoxisomal vesicle biogenesis.*
How membrane shape influences ESCRT-III polymerization and how ESCRT-III shapes membranes is yet unclear.*
In the article “Human ESCRT-III polymers assemble on positively curved membranes and induce helical membrane tube formation” Aurélie Bertin, Nicola de Franceschi, Eugenio de la Mora, Sourav Maity, Maryam Alqabandi, Nolwen Miguet, Aurélie di Cicco, Wouter H. Roos, Stéphanie Mangenot, Winfried Weissenhorn and Patricia Bassereau describe how human core ESCRT-III proteins, CHMP4B, CHMP2A, CHMP2B and CHMP3 are used to address this issue in vitro by combining membrane nanotube pulling experiments, cryo-electron tomography and Atomic Force Microscopy.*
The authors show that CHMP4B filaments preferentially bind to flat membranes or to tubes with positive mean curvature.*
The results presented in the article cited above underline the versatile membrane remodeling activity of ESCRT-III that may be a general feature required for cellular membrane remodeling processes.*
The authors provide novel insight on how mechanics and geometry of the membrane and of ESCRT-III assemblies can generate forces to shape a membrane neck.*
Please have a look at the NanoWorld blog for the full citation and a direct link to the full article.