#46 Physics of cellular degradation - a paradigm shift triggered by MaxSynBio

Roland L. Knorr (Max Planck Institute of Colloids and Interfaces / University of Tokyo, Potsdam)

Tuesday, 01 Dec 21:15 - 22:00 CET

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Abstract

Title: Physics of cellular degradation - a paradigm shift triggered by MaxSynBio

Author(s): Roland L. Knorr^a,b,c

Affiliation(s): ^aMPI of Colloids and Interfaces, Potsdam, Germany; ^bUniversity of Tokyo, Tokyo, Japan; ^cMPI of Molecular Plant Physiology, Potsdam, Germany

Abstract: Compartmentalisation of cellular material in droplet-like structures is a hallmark of liquid-liquid phase separation, but the mechanisms of droplet removal are poorly understood. Evidence suggests that such proteinaceous droplets can be degraded by autophagy, a highly-conserved degradation system in which membrane sheets bend to isolate portions of the cytoplasm within double-membrane autophagosomes. Nurtured by a MaxSynBio project showing in vitro that droplet-membrane interactions are determined by wetting, recently we identified wetting droplets as novel key autophagy structure. We uncover a switching mechanism that allows droplets to act either as liquid assembly platforms for cytosol-degrading autophagosomes or as specific autophagy substrates. Further, we demonstrate that embryonic plant vacuole remodelling underlies similar physical principles, revealing the importance of wetting in cytosolic organization.

References

[1] Fujioka, Yuko, Jahangir Md Alam, Daisuke Noshiro, Kazunari Mouri, Toshio Ando, Yasushi Okada, Alexander I. May, u. a. „Phase Separation Organizes the Site of Autophagosome Formation“. Nature 578, Nr. 7794 (Februar 2020): 301–5. https://doi.org/10.1038/s41586-020-1977-6.

[2] Agudo-Canalejo, J.; Schultz, S.W.; Chino, H.; Migliano, S.; Saito, C.; Koyama-Honda, I.; Stenmark, H.; Brech, A.; May, A.I.; Mizushima, N.; Knorr, R. L. Wetting regulates autophagy of phase separated droplets and the cytosol. Nature, in press.

[3] Knorr, R. L.; Franzmann, T.; Feeney, M.; Kittelmann, M.; Frigerio, L.; Dimova, R.; Hyman, A. A.; Lipowsky, R.; Mutual Remodelling of Biomolecular Condensates and Membranes. in revision.