AMPH-1/Amphiphysin/Bin1 functions with RME-1/Ehd1 in endocytic recycling.
RME-1/EHD1 (receptor mediated endocytosis/Eps15 homology-domain containing 1) family proteins are key residents of the recycling endosome, which are required for endosome-to-plasma membrane transport in Caenorhabditis elegans and mammals. Recent studies suggest similarities between the RME-1/EHD proteins and the Dynamin GTPase superfamily of mechanochemical pinchases, which promote membrane fission. Here we show that endogenous C. elegans AMPH-1, the only C. elegans member of the Amphiphysin/BIN1 family of BAR (Bin1-Amphiphysin-Rvs161p/167p)-domain-containing proteins, colocalizes with RME-1 on recycling endosomes in vivo, that amph-1-deletion mutants are defective in recycling endosome morphology and function, and that binding of AMPH-1 Asn-Pro-Phe(Asp/Glu) sequences to the RME-1 EH-domain promotes the recycling of transmembrane cargo. We also show a requirement for human BIN1 (also known as Amphiphysin 2) in EHD1-regulated endocytic recycling. In vitro, we find that purified recombinant AMPH-1-RME-1 complexes produce short, coated membrane tubules that are qualitatively distinct from those produced by either protein alone. Our results indicate that AMPH-1 and RME-1 cooperatively regulate endocytic recycling, probably through functions required for the production of cargo carriers that exit the recycling endosome for the cell surface.
Pant
Saumya
S
Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854, USA.
Sharma
Mahak
M
Patel
Kruti
K
Caplan
Steve
S
Carr
Chavela M
CM
Grant
Barth D
BD
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D004705:Endocytosis; D006367:HeLa Cells; D006801:Humans; D008854:Microscopy, Electron; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D034622:RNA Interference; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; C101410:BIN1 protein, human; D029742:Caenorhabditis elegans Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; C486205:RME-1 protein, C elegans; D025521:Tumor Suppressor Proteins; C075637:amphiphysin