Phorbol ester, calcium ionophore, or serum added to quiescent rat embryo fibroblast cells all result in the elevated phosphorylation of two 28,000-dalton mammalian stress proteins.

摘要: Rat embryo fibroblast cells grown under stress (e.g. heat shock, arsenite, or amino acid analogue treatment) show elevated levels of a number proteins with apparent molecular masses between 28,000-110,000 daltons (i.e. proteins). It is shown that the smaller 28,000-dalton proteins, which do not contain methionine, are comprised at least four isoforms, all appear related as determined by one-dimensional peptide mapping. [32P]H3PO4 labeling normal and stressed demonstrates three 28-kDa isoforms phosphoproteins. In course other studies phosphorylation two was observed in quiescent rat fibroblasts following addition either phorbol diester, phorbol-12-myristate-13 acetate, calcium ionophore, A23187, simply fresh serum. here these fact 28 kDa mammalian proteins.