Genome-wide analysis identifies a general requirement for polarity proteins in endocytic traffic.
In a genome-wide RNA-mediated interference screen for genes required in membrane traffic - including endocytic uptake, recycling from endosomes to the plasma membrane, and secretion - we identified 168 candidate endocytosis regulators and 100 candidate secretion regulators. Many of these candidates are highly conserved among metazoans but have not been previously implicated in these processes. Among the positives from the screen, we identified PAR-3, PAR-6, PKC-3 and CDC-42, proteins that are well known for their importance in the generation of embryonic and epithelial-cell polarity. Further analysis showed that endocytic transport in Caenorhabditis elegans coelomocytes and human HeLa cells was also compromised after perturbation of CDC-42/Cdc42 or PAR-6/Par6 function, indicating a general requirement for these proteins in regulating endocytic traffic. Consistent with these results, we found that tagged CDC-42/Cdc42 is enriched on recycling endosomes in C. elegans and mammalian cells, suggesting a direct function in the regulation of transport.
Balklava
Zita
Z
Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854, USA.
Pant
Saumya
S
Fares
Hanna
H
Grant
Barth D
BD
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D016764:Cell Polarity; D004705:Endocytosis / Q000502:physiology*; D011992:Endosomes / Q000378:metabolism / Q000648:ultrastructure; D016678:Genome; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020764:cdc42 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; D008565:Membrane Proteins; C509689:PARD3 protein, human; C499657:PARD6A protein, human; D011993:Recombinant Fusion Proteins; C115015:PKC-3 protein; D011493:Protein Kinase C; D020764:cdc42 GTP-Binding Protein