Identification of processing events in the synthesis of platelet-derived growth factor-like proteins by human osteosarcoma cells.
The human osteosarcoma-derived cell line U-2 OS expresses c-sis mRNA and synthesizes platelet-derived growth factor (PDGF)-like proteins. Pulse-chase experiments indicate that proteins of 23 kDa and 180 kDa are synthesized first. The 23-kDa protein undergoes dimerization and proteolysis, giving rise to the 30-kDa dimeric protein secreted by the cells. The 180-kDa protein is proteolytically cleaved in a complex series of steps that give rise to several intracellular species. It is also the likely precursor of high molecular mass PDGF-like or PDGF-associated proteins secreted by these cells. The processing and secretion of the 180-kDa protein is slower than that of the 23-kDa protein. Subcellular fractionation and studies with the antibiotic monensin indicate that the processing events occur in the Golgi-endoplasmic reticulum compartment of U-2 OS cells.
Graves
D T
DT
Owen
A J
AJ
Williams
S R
SR
Antoniades
H N
HN
D002460:Cell Line; D011232:Chemical Precipitation; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006056:Golgi Apparatus / Q000187:drug effects; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight; D008985:Monensin / Q000494:pharmacology; D012516:Osteosarcoma / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor / Q000096:biosynthesis* / Q000276:immunology; D011499:Protein Processing, Post-Translational
D010982:Platelet-Derived Growth Factor; D008985:Monensin