title: Different endocytic functions of AGEF-1 in C. elegans coelomocytes.
abstract: BACKGROUND
  ADP-ribosylation factors (ARFs) are a family of small GTP-binding proteins that play roles in membrane dynamics and vesicle trafficking. AGEF-1, which is thought to act as a guanine nucleotide exchange factor of class I ARFs, is required for caveolin-1 body formation and receptor-mediated endocytosis in oocytes of Caenorhabditis elegans. This study explores additional roles of AGEF-1 in endocytic transport.
  
  
  METHODS
  agef-1 expression was knocked down by using RNAi in C. elegans. Markers that allow analysis of endocytic transport in scavenger cells were investigated for studying the effect of AGEF-1 on different steps of membrane transport.
  
  
  RESULTS
  Knockdown of AGEF-1 levels results in two apparent trafficking defects in coelomocytes of C. elegans. First, there is a delay in the uptake of solutes from the extracellular medium. Second, there is a dramatic enlargement of the sizes of lysosomes, even though lysosomal acidification is normal and degradation still occurs.
  
  
  CONCLUSIONS
  Our results suggest that AGEF-1 regulates endosome/lysosome fusion or fission events, in addition to earlier steps in endocytic transport.
  
  
  CONCLUSIONS
  AGEF-1 is the first identified GTPase regulator that functions at the lysosome fusion or fission stage of the endocytic pathway. Our study provides insight into lysosome dynamics in C. elegans.
authors.affiliation: Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Department of Systems Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, PR China.
authors.forename: Lichun
authors.initials: L
authors.lastname: Tang
authors.forename: Hanna
authors.initials: H
authors.lastname: Fares
authors.forename: Xingfu
authors.initials: X
authors.lastname: Zhao
authors.forename: Wei
authors.initials: W
authors.lastname: Du
authors.forename: Bi-Feng
authors.initials: BF
authors.lastname: Liu
mesh_terms: D020727:ADP-Ribosylation Factors / Q000378:metabolism; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051242:Caveolin 1 / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology*; D011992:Endosomes / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008247:Lysosomes / Q000378:metabolism; D009835:Oligochaeta / Q000166:cytology / Q000378:metabolism*; D021381:Protein Transport; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: C000607009:AGEF-1 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D051242:Caveolin 1; D020662:Guanine Nucleotide Exchange Factors; D034741:RNA, Small Interfering; D020727:ADP-Ribosylation Factors