Dynamic regulation of caveolin-1 trafficking in the germ line and embryo of Caenorhabditis elegans

Mol Biol Cell. 2006 Jul;17(7):3085-94. doi: 10.1091/mbc.e06-03-0211. Epub 2006 May 3.

Abstract

Caveolin is the major protein component required for the formation of caveolae on the plasma membrane. Here we show that trafficking of Caenorhabditis elegans caveolin-1 (CAV-1) is dynamically regulated during development of the germ line and embryo. In oocytes a CAV-1-green fluorescent protein (GFP) fusion protein is found on the plasma membrane and in large vesicles (CAV-1 bodies). After ovulation and fertilization the CAV-1 bodies fuse with the plasma membrane in a manner reminiscent of cortical granule exocytosis as described in other species. Fusion of CAV-1 bodies with the plasma membrane appears to be regulated by the advancing cell cycle, and not fertilization per se, because fusion can proceed in spe-9 fertilization mutants but is blocked by RNA interference-mediated knockdown of an anaphase-promoting complex component (EMB-27). After exocytosis, most CAV-1-GFP is rapidly endocytosed and degraded within one cell cycle. CAV-1 bodies in oocytes appear to be produced by the Golgi apparatus in an ARF-1-dependent, clathrin-independent, mechanism. Conversely endocytosis and degradation of CAV-1-GFP in embryos requires clathrin, dynamin, and RAB-5. Our results demonstrate that the distribution of CAV-1 is highly dynamic during development and provides new insights into the sorting mechanisms that regulate CAV-1 localization.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADP-Ribosylation Factor 1 / antagonists & inhibitors
  • ADP-Ribosylation Factor 1 / genetics
  • ADP-Ribosylation Factor 1 / metabolism
  • Animals
  • Caenorhabditis elegans / chemistry
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / analysis
  • Caenorhabditis elegans Proteins / metabolism*
  • Caveolin 1 / analysis
  • Caveolin 1 / metabolism*
  • Cell Cycle
  • Cell Membrane / metabolism
  • Embryo, Nonmammalian / metabolism
  • Endocytosis
  • Female
  • Golgi Apparatus / metabolism
  • Green Fluorescent Proteins / analysis
  • Membrane Fusion
  • Oocytes / chemistry
  • Oocytes / metabolism*
  • RNA Interference
  • rab5 GTP-Binding Proteins / metabolism

Substances

  • Caenorhabditis elegans Proteins
  • Caveolin 1
  • Green Fluorescent Proteins
  • ADP-Ribosylation Factor 1
  • rab5 GTP-Binding Proteins