The secretion of proteins in vitro from Xenopus oocytes and their accessory cells: a biochemical and morphological study.
Protein secretion by Xenopus laevis oocytes and their surrounding follicular cells in vitro has been investigated using two-dimensional gel electrophoresis. Viable oocytes, devoid of follicle layers, were prepared by treatment with collagenase; they retain in full their capacity to synthesize, sequester and export secretory proteins following microinjection with heterologous messenger RNA. Both RNA-injected and normal cells export a large number of endogenous oocyte proteins and, as with heterologous secretory translation products, these proteins are found within the oocyte in a vesicle fraction. Electron microscopy indicates that secretion involves exocytotic release of cortical vesicle contents. The follicular cells themselves also seem to contribute a number of proteins to the incubation medium surrounding isolated oocytes, but the presence of follicle layers is not required for the export of endogenous oocyte proteins.
D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D008854:Microscopy, Electron; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D010063:Ovum / Q000378:metabolism*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000494:pharmacology; D014982:Xenopus laevis / Q000196:embryology*
D012333:RNA, Messenger