Capping protein-controlled actin polymerization shapes lipid membranes.

Nature communications (2018-04-25)
Katharina Dürre, Felix C Keber, Philip Bleicher, Fridtjof Brauns, Christian J Cyron, Jan Faix, Andreas R Bausch

Arp2/3 complex-mediated actin assembly at cell membranes drives the formation of protrusions or endocytic vesicles. To identify the mechanism by which different membrane deformations can be achieved, we reconstitute the basic membrane deformation modes of inward and outward bending in a confined geometry by encapsulating a minimal set of cytoskeletal proteins into giant unilamellar vesicles. Formation of membrane protrusions is favoured at low capping protein (CP) concentrations, whereas the formation of negatively bent domains is promoted at high CP concentrations. Addition of non-muscle myosin II results in full fission events in the vesicle system. The different deformation modes are rationalized by simulations of the underlying transient nature of the reaction kinetics. The relevance of the regulatory mechanism is supported by CP overexpression in mouse melanoma B16-F1 cells and therefore demonstrates the importance of the quantitative understanding of microscopic kinetic balances to address the diverse functionality of the cytoskeleton.

Product Number
Product Description

L-α-Phosphatidylcholine, egg yolk, Type XVI-E, ≥99% (TLC), lyophilized powder
Mineral oil, suitable for preparation of Nujol mulls for infrared spectroscopy, light oil
L-(−)-Glucose, ≥99%
Maleimide, 99%
N-Acetyl-D-penicillamine, for HPLC derivatization, ≥99.0% (T)
Anti-CP antibody produced in rabbit, Prestige Antibodies® Powered by Atlas Antibodies, affinity isolated antibody, buffered aqueous glycerol solution