Showing papers by "Joan S. Brugge published in 1985"
TL;DR: Results indicate that a structurally distinct form of the cellular src protein that possesses an activated tyrosylkinase activity is expressed at very high levels in post-mitotic CNS neurones.
Abstract: Neural tissues contain high levels of the cellular homologue of the transforming protein of Rous sarcoma virus (RSV)1–4, but neither the specific cell types expressing high levels of c-src, nor the function of the cellular src (c-src) protein has been determined. Using primary culture methods, we have found that pure neurones and astrocytes derived from the rat central nervous system (CNS) contain 15- to 20-times higher levels of the c-src protein than fibroblasts. However, the specific activity of the c-src protein from the neuronal cultures is 6- to 12-times higher than that from the astrocyte cultures. In addition, the c-src protein expressed in neuronal cultures contains a structural alteration within the aminoterminal region of the molecule that causes a shift in the mobility of the c-src protein on the SDS-polyacrylamide gels. These results indicate that a structurally distinct form of the cellular src protein that possesses an activated tyrosylkinase activity is expressed at very high levels in post-mitotic CNS neurones.
341 citations
TL;DR: These present studies implicate a new role for this 90-kDa protein in the action of steroid hormones, which is indistinguishable from one of the major heat shock proteins which are induced under a variety of stress conditions in eukaryotic cells.
288 citations
TL;DR: In this paper, the authors examined the in vitro phosphorylation of cellular src protein (pp60c-src) molecules associated with the polyoma virus middle-sized tumor antigen (MSTA) and found that these molecules possessed an enhanced tyrosyl kinase activity, migrated aberrantly on NaDodSO4/polyacrylamide gels, and contained a novel site of tyrosine phosphoric activation within the amino-terminal region of the molecule.
Abstract: We have examined the in vitro phosphorylation of cellular src protein (pp60c-src) molecules associated with the polyoma virus middle-sized tumor antigen in polyoma virus-transformed cells. These pp60c-src molecules possessed an enhanced tyrosyl kinase activity, migrated aberrantly on NaDodSO4/polyacrylamide gels, and contained a novel site of tyrosine phosphorylation within the amino-terminal region of the molecule. The pp60c-src molecules not associated with the middle-sized tumor antigen were phosphorylated exclusively on a tyrosine residue within the carboxyl-terminal domain of pp60c-src. A similar modified form of the middle-sized tumor antigen-associated pp60c-src protein was detected in lysates from polyoma virus-transformed cells labeled in vivo with [32P]orthophosphate in the presence of sodium orthovanadate, an inhibitor of phosphotyrosyl phosphatases.
56 citations