A modular design for the clathrin- and actin-mediated endocytosis machinery.
Endocytosis depends on an extensive network of interacting proteins that execute a series of distinct subprocesses. Previously, we used live-cell imaging of six budding-yeast proteins to define a pathway for association of receptors, adaptors, and actin during endocytic internalization. Here, we analyzed the effects of 61 deletion mutants on the dynamics of this pathway, revealing functions for 15 proteins, and we analyzed the dynamics of 8 of these proteins. Our studies provide evidence for four protein modules that cooperate to drive coat formation, membrane invagination, actin-meshwork assembly, and vesicle scission during clathrin/actin-mediated endocytosis. We found that clathrin facilitates the initiation of endocytic-site assembly but is not needed for membrane invagination or vesicle formation. Finally, we present evidence that the actin-meshwork assembly that drives membrane invagination is nucleated proximally to the plasma membrane, opposite to the orientation observed for previously studied actin-assembly-driven motility processes.
Kaksonen
Marko
M
Department of Molecular and Cell Biology, University of California, Berkeley, 94720, USA.
Toret
Christopher P
CP
Drubin
David G
DG
D051344:Actin Capping Proteins; D000199:Actins / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002966:Clathrin / Q000235:genetics / Q000378:metabolism*; D022163:Clathrin-Coated Vesicles / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D004705:Endocytosis; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007700:Kinetics; D008164:Luminescent Proteins / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D000097573:Red Fluorescent Protein
D051344:Actin Capping Proteins; D000199:Actins; D015415:Biomarkers; D002352:Carrier Proteins; D002966:Clathrin; D003598:Cytoskeletal Proteins; D005656:Fungal Proteins; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D008562:Membrane Glycoproteins; D008840:Microfilament Proteins; D029701:Saccharomyces cerevisiae Proteins; D000097573:Red Fluorescent Protein; C062612:ABP1 protein, S cerevisiae; C464845:BBC1 protein, S cerevisiae; C489097:CAP1 protein, S cerevisiae; C090135:Cap2 protein, S cerevisiae; C111870:PAN1 protein, S cerevisiae; C089181:RVS161 protein, S cerevisiae; C082282:RVS167 protein, S cerevisiae; C082265:SLA1 protein, S cerevisiae; C026742:plastin