RRC ID 4290
Author Sato M, Grant BD, Harada A, Sato K.
Title Rab11 is required for synchronous secretion of chondroitin proteoglycans after fertilization in Caenorhabditis elegans.
Journal J. Cell. Sci.
Abstract We previously identified a novel type of caveolin-enriched secretory vesicle in Caenorhabditis elegans oocytes. These vesicles undergo synchronous fusion with the plasma membrane immediately after fertilization, suggesting that they could be cortical granules that have been described in diverse animal species. Here, we report that these vesicles are indeed cortical granules, delivering essential chondroitin proteoglycans and mucin-like glycoproteins to the early embryonic extracellular matrices (ECMs). Furthermore, we have found that the small GTPase RAB-11 and the target-SNARE SYN-4 are required for cortical granule excoytosis after fertilization. In oocytes, SYN-4 localizes mainly to the plasma membrane, whereas GFP::RAB-11 accumulates transiently on the cortical granules during ovulation, immediately prior to fertilization. Importantly, cytokinesis defects in early embryos are commonly observed after depletion of either rab-11 or syn-4, producing a phenotype very similar to that observed after blockade of chondroitin synthesis. Taken together, our results indicate that at least part of the essential role for RAB-11 and SYN-4 in early embryogenesis is in the targeting of cortical granules to the plasma membrane during the precisely regulated secretion of ECM components.
Volume 121(Pt 19)
Pages 3177-86
Published 2008-10-1
DOI 10.1242/jcs.034678
PII jcs.034678
PMID 18765566
MeSH Animals Caenorhabditis elegans / cytology Caenorhabditis elegans / embryology Caenorhabditis elegans / metabolism* Caenorhabditis elegans Proteins / metabolism Caveolin 1 / metabolism Chondroitin / metabolism* Cytokinesis Cytoplasmic Granules / metabolism Egg Shell / cytology Egg Shell / metabolism Embryo, Nonmammalian / cytology Embryo, Nonmammalian / metabolism Exocytosis Extracellular Space / metabolism Female Fertilization / physiology* Green Fluorescent Proteins / metabolism Oocytes / cytology Protein Transport Proteoglycans / metabolism* R-SNARE Proteins / metabolism Recombinant Fusion Proteins / metabolism Sequence Homology, Amino Acid Syndecan-4 / metabolism rab GTP-Binding Proteins / metabolism*
IF 4.517
Times Cited 41
C.elegans tm2341