The protein encoded by the transforming gene of avian sarcoma virus (pp60src) and a homologous protein in normal cells (pp60proto-src) are associated with the plasma membrane.
AUTOR(ES)
Courtneidge, S A
RESUMO
Oncogenesis by avian sarcoma virus is attributable to a single viral gene (src) which encodes a phosphoprotein (pp60src) with the enzymatic activity of a protein kinase. A closely related protein, pp60proto-src, occurs in uninfected cells from a wide variety of vertebrate species and is presumed to be the product of a cellular gene that served as progenitor for src. We explored the location of these proteins within the cell by using immunoprecipitation to analyze subcellular fractions prepared from avian sarcoma virus-transformed rat and chicken cells and from uninfected rat cells. We found that both pp60src and pp60proto-src were associated with the plasma membrane as active protein kinases and could be recovered efficiently only by disrupting the membranes with nonionic detergent. Our findings, in conjunction with those of other investigators, indicate that both proteins are embedded in the membrane by means of a hydrophobic domain(s); available evidence indicates that pp60src is not exposed on the surface of the cell but is accessible at the cytoplasmic aspect of the plasma membrane. These conclusions lend credence to two current speculations. First, pp60src and pp60proto-src may have similar or even identical functions. Second, neoplastic transformation may originate from derangements in the plasma membrane or its affiliated structures.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=349710Documentos Relacionados
- Association of pp60src and src protein kinase activity with the plasma membrane of nonpermissive and permissive avian sarcoma virus-infected cells.
- Association of the Transformation-Specific Protein pp60src with the Membrane of an Avian Sarcoma Virus
- Transit of pp60v-src to the plasma membrane.
- Tyrosine phosphorylation of a 50K cellular polypeptide associated with the Rous sarcoma virus transforming protein pp60src.
- Expression of Rous sarcoma virus transforming protein pp60v-src in Saccharomyces cerevisiae cells.