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A dynamic ESCRT for the final step of cell division

Beata Mierzwa recently published her PhD findings in Nature Cell Biology. During her thesis Beata worked on the ESCRT-III machinery, which separates the emerging daughter cells in the final step of cell division. She discovered that ESCRT-III polymers are extremely dynamic and provides a new model for ESCRT-III function.

Illustration by Beata Mierzwa

During her PhD at IMBA, Beata Mierzwa set out to study cytokinetic abscission, the process by which two cells separate in the final step of cell division. At the start of Beata’s PhD, it was known that cytokinetic abscission is mediated by a protein machinery named ESCRT-III, which forms filaments and mediates membrane fission in many cellular pathways. However, the precise mechanism of how this molecular machine achieves constriction and fission of the membranes was not fully understood. Previous models proposed that ESCRT-III forms stable filaments that constrict membranes by changing their curvature.

Beata, her supervisor Daniel Gerlich, and their collaborators hypothesized that these filaments could be dynamic (such as other cellular filament structures, as for example actin or microtubules). By carefully studying the ESCRT-III complex and its components, they indeed showed that the protein machinery is extremely dynamic arising from a rapid exchange of subunits within the ESCRT-III polymers. This dynamic behavior enables the polymers to grow and adapt their shape to different membrane geometries. In the video below, Beata explains their findings to you (much better than I).

During her PhD Beata also advanced her artistic skills, she participated in different editions of our Opens internal link in current windowScience & Art Contest. In the past year, she contributed to multiple illustrations for scientific stories and started her own Science and Art project: beatascienceart.com

Beata is now doing a postdoc in San Diego. We are extremely proud of her achievements as a PhD Student at the Vienna Biocenter and we wish her all the best for her future career!

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Mierzwa BE, Chiaruttini N, Redondo-Morata L, Moser von Filseck J, König J, Larios J, Poser I, Müller-Reichert T, Scheuring S, Roux A and Gerlich DW (2017) Dynamic subunit turnover in ESCRT-III assemblies is regulated by Vps4 to mediate membrane remodelling during cytokinesis. Nat. Cell Biology Opens external link in new windowdoi:10.1038/ncb3569