An Organized Co-assembly of Clathrin Adaptors Is Essential for Endocytosis

• Published in: Developmental cell Vol. 33; no. 2; pp. 150 - 162
• Main Authors: Skruzny, Michal, Desfosses, Ambroise, Prinz, Simone, Dodonova, Svetlana O., Gieras, Anna, Uetrecht, Charlotte, Jakobi, Arjen J., Abella, Marc, Hagen, Wim J.H., Schulz, Joachim, Meijers, Rob, Rybin, Vladimir, Briggs, John A.G., Sachse, Carsten, Kaksonen, Marko
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 20-04-2015
• Subjects: Adaptor Proteins, Vesicular Transport - metabolism; Biological Transport; Cell Membrane - metabolism; Cytoskeletal Proteins; Dictyostelium - metabolism; Endocytosis - physiology; Equilibrative Nucleoside Transporter 1 - metabolism; Phosphorylation; Protein Structure, Tertiary; Transport Vesicles; Yeasts - metabolism
• ISSN: 1534-5807; 1878-1551
• DOI: 10.1016/j.devcel.2015.02.023

Clathrin-mediated endocytosis, the main trafficking route from the plasma membrane to the cytoplasm, is critical to many fundamental cellular processes. Clathrin, coupled to the membrane by adaptor proteins, is thought to play a major structural role in endocytosis by self-assembling into a cage-like lattice around the forming vesicle. Although clathrin adaptors are essential for endocytosis, little is known about their structural role in this process. Here we show that the membrane-binding domains of two conserved clathrin adaptors, Sla2 and Ent1, co-assemble in a PI(4,5)P2-dependent manner to form organized lattices on membranes. We determined the structure of the co-assembled lattice by electron cryo-microscopy and designed mutations that specifically impair the lattice formation in vitro. We show that these mutations block endocytosis in vivo. We suggest that clathrin adaptors not only link the polymerized clathrin to the membrane but also form an oligomeric structure, which is essential for membrane remodeling during endocytosis.
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•ANTH and ENTH domains of clathrin adaptors Sla2 and Ent1 form lattices on membranes•Membrane-binding ANTH and ENTH domains oligomerize in a PI(4,5)P2-dependent manner•Cryo-EM showed a staggered arrangement of the ANTH-ENTH lattice on the membrane•Regular co-assembly of clathrin adaptors Sla2 and Ent1 is essential for endocytosis
Clathrin-mediated endocytosis is the main plasma-membrane-to-cytoplasm vesicle trafficking route. Skruzny et al. shed light on the structural role of clathrin adaptors, showing that yeast clathrin adaptors Sla2 and Ent1 (homologs of mammalian Hip1r and epsin) form a regular, membrane-bound co-assembly essential for endocytic vesicle formation.