Séminaire Debasish Chaudhuri part. 2

Jeudi 25 mai, 16h00, amphi E4 (horaire exceptionnel)

Debasish Chaudhuri

Institute of Physics from Bhubaneswar, India

Collective properties of motor proteins: transport and drive (part 2)

Motor proteins participate in intracellular transport and can generate mechanical forces on cytoskeletal filaments. In the first part of the talk, we will describe the impact of ubiquitination and its absence on UNC-104, a Kinesin-3 motor in C. elegans that transports synaptic vesicles. The study uses RNAi and mutants, live animal imaging, and coarse-grained theory. We show that while the transport properties of the motors remain unaffected, the lack of ubiquitination increases cooperative cargo binding. In the second part, we will consider deformations of biofilaments and membranes under the active drive of motor proteins using analytic theory and numerical simulations. Semiflexible filaments undergo re-entrant morphological transitions from open chain to spiral conformations in a gliding assay. In a setup motivated by synthetic cells, we show that a spherical fluid membrane coupled to curvature-inducing activator proteins, polymerizing actins, and actomyosin pull undergo instabilities towards pattern formation and localized/running pulsations.