Phosphorylation of tyrosine residues of calmodulin in Rous sarcoma virus-transformed cells.
AUTOR(ES)
Fukami, Y
RESUMO
Calmodulin, a wide-spread eukaryotic Ca2+-binding protein, was phosphorylated at its tyrosine residues in Rous sarcoma virus (RSV)-transformed chicken and rat cells but not in normal chicken embryo fibroblasts. In contrast, serine and threonine phosphorylation of calmodulin was found to occur in both normal and virus-transformed cells. In an in vitro system containing purified src kinase from RSV-transformed cells, tyrosine phosphorylation of calmodulin by the src kinase was inhibited by Ca2+. Furthermore, the tyrosine-phosphorylated calmodulin showed slower mobility than that of nonphosphorylated calmodulin in NaDodSO4/polyacrylamide gel electrophoresis when Ca2+ was present. These results suggest that the structure of calmodulin Ca2+ complex may be altered by tyrosine phosphorylation. It is thus inferred that Ca2+ may regulate the level of tyrosine phosphorylation of calmodulin in RSV-transformed cells, and phosphorylation in turn may attenuate the function of this protein in vivo.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=323697Documentos Relacionados
- Phosphorylation of talin at tyrosine in Rous sarcoma virus-transformed cells.
- Changes in protein phosphorylation in Rous sarcoma virus-transformed chicken embryo cells.
- Glycoprotein tyrosine phosphorylation in Rous sarcoma virus-transformed chicken embryo fibroblasts.
- Phosphatidylinositol kinase activities in normal and Rous sarcoma virus-transformed cells.
- Cholera toxin treatment stimulates tumorigenicity of Rous sarcoma virus-transformed cells.