Control of fibronectin synthesis by rat granulosa cells in culture.
The secreted and cellular [35S]methionine-radiolabeled proteins of cultured rat granulosa cells were separated by electrophoresis on sodium dodecylsulfate (SDS) polyacrylamide gradient slab gels. From 24 to 72 h of culture FSH increased the intensity of labeling of most of the secreted proteins. A 220,000-dalton protein, however, increased in intensity only in control cultures and became the major secreted protein after 72 h, comprising 20% of the total radiolabeled proteins. This protein was identified as fibronectin by immunoprecipitation. There was no increase in the secreted or cellular fibronectin in FSH- or testosterone- and insulin-treated cultures. These studies indicate that a component of extracellular matrix is a major secretory product of unstimulated immature granulosa cells. As hormones induce the differentiated functions of granulosa cells in culture, the secretion of fibronectin is inhibited.
D000818:Animals; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005353:Fibronectins / Q000096:biosynthesis* / Q000302:isolation & purification; D006107:Granulosa Cells / Q000378:metabolism*; D007700:Kinetics; D008715:Methionine / Q000378:metabolism; D008970:Molecular Weight; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D013462:Sulfur Radioisotopes
D005353:Fibronectins; D013462:Sulfur Radioisotopes; D008715:Methionine