Regulators of yeast endocytosis identified by systematic quantitative analysis.
Endocytosis of receptors at the plasma membrane is controlled by a complex mechanism that includes clathrin, adaptors, and actin regulators. Many of these proteins are conserved in yeast yet lack observable mutant phenotypes, which suggests that yeast endocytosis may be subject to different regulatory mechanisms. Here, we have systematically defined genes required for internalization using a quantitative genome-wide screen that monitors localization of the yeast vesicle-associated membrane protein (VAMP)/synaptobrevin homologue Snc1. Genetic interaction mapping was used to place these genes into functional modules containing known and novel endocytic regulators, and cargo selectivity was evaluated by an array-based comparative analysis. We demonstrate that clathrin and the yeast AP180 clathrin adaptor proteins have a cargo-specific role in Snc1 internalization. We additionally identify low dye binding 17 (LDB17) as a novel conserved component of the endocytic machinery. Ldb17 is recruited to cortical actin patches before actin polymerization and regulates normal coat dynamics and actin assembly. Our findings highlight the conserved machinery and reveal novel mechanisms that underlie endocytic internalization.
Burston
Helen E
HE
Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver V5Z 4H4, British Columbia, Canada.
Maldonado-Báez
Lymarie
L
Davey
Michael
M
Montpetit
Benjamen
B
Schluter
Cayetana
C
Wendland
Beverly
B
Conibear
Elizabeth
E
D000199:Actins / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002966:Clathrin / Q000235:genetics / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology*; D020869:Gene Expression Profiling; D046228:Microarray Analysis; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism; D034041:Monomeric Clathrin Assembly Proteins / Q000235:genetics / Q000378:metabolism; D005810:Multigene Family; D050683:R-SNARE Proteins / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics* / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
C062612:ABP1 protein, S cerevisiae; D000199:Actins; D002966:Clathrin; C542161:Ldb17 protein, S cerevisiae; D008840:Microfilament Proteins; D034041:Monomeric Clathrin Assembly Proteins; D050683:R-SNARE Proteins; D011993:Recombinant Fusion Proteins; C083241:SNC1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C439023:clathrin assembly protein AP180