Spatiotemporal Control of Lipid Conversion, Actin-Based Mechanical Forces, and Curvature Sensors during Clathrin/AP-1-Coated Vesicle Biogenesis

Publication date: 29 August 2017
Source:Cell Reports, Volume 20, Issue 9
Author(s): Mihaela Anitei, Christoph Stange, Cornelia Czupalla, Christian Niehage, Kai Schuhmann, Pia Sala, Aleksander Czogalla, Theresia Pursche, Ünal Coskun, Andrej Shevchenko, Bernard Hoflack
Clathrin/adaptor protein-1-coated carriers connect the secretory and the endocytic pathways. Carrier biogenesis relies on distinct protein networks changing membrane shape at the trans-Golgi network, each regulating coat assembly, F-actin-based mechanical forces, or the biophysical properties of lipid bilayers. How these different hubs are spatiotemporally coordinated remains largely unknown. Using in vitro reconstitution systems, quantitative proteomics, and lipidomics, as well as in vivo cell-based assays, we characterize the protein networks controlling membrane lipid composition, membrane shape, and carrier scission. These include PIP5K1A and phospholipase C-beta 3 controlling the conversion of PI[4]P into diacylglycerol. PIP5K1A binding to RAC1 provides a link to F-actin-based mechanical forces needed to tubulate membranes. Tubular membranes then recruit the BAR-domain-containing arfaptin-1/2 guiding carrier scission. These findings provide a framework for synchronizing the chemical/biophysical properties of lipid bilayers, F-actin-based mechanical forces, and the activity of proteins sensing membrane shape during clathrin/adaptor protein-1-coated carrier biogenesis.

Graphical abstract

Teaser

Clathrin/adaptor protein-1 (AP-1) coats control the transport of specific cargoes between the biosynthetic and endocytic pathways. Anitei et al. illustrate the coordination of protein networks controlling the biophysical properties of lipid bilayers, actin-based mechanical forces, and membrane curvature during clathrin/AP-1-coated carrier biogenesis.


http://ift.tt/2wgWwk7