Src is a non-receptor protein tyrosine kinase activated by a number of extracellular signal moleculars. It is recruited to peripheral sites through myristoylation and the SH3 domain. Src initiates intracellular signal...Src is a non-receptor protein tyrosine kinase activated by a number of extracellular signal moleculars. It is recruited to peripheral sites through myristoylation and the SH3 domain. Src initiates intracellular signal trandsduction pathways that influence cell adhesion, migration, growth, differentiation and survival though catalytic domain. Src is normally maintained in an inactive conformation because of carboxy terminal Src kinase, but can be activated transiently during cellular events such as mitosis or constitutively by abnormal events such as mutation and some cancers. In additions, c-Src protein is found to be highly activated and the Src gene is frequently over-expressed in many cancers. These findings suggest that the relationship between c-Src activation/over-expression and cancer progression appears to be significant.展开更多
Objective To investigate the role of cytoplasmic domain of integrin alphaⅡb in platelet signal transduction. Methods Binding capacity of integrin alphaⅡb R995A to antibody platelet activation complex-1 (PAC-1) and p...Objective To investigate the role of cytoplasmic domain of integrin alphaⅡb in platelet signal transduction. Methods Binding capacity of integrin alphaⅡb R995A to antibody platelet activation complex-1 (PAC-1) and pp125 focal adhesion kinase (FAK) phosphorylation of cells were detected by flow cytometry, immune precipitation, and Western blotting. Results Without activation, wild-type alphaⅡbbeta3 Chinese hamster ovary (CHO) cells failed to bind to PAC-1, but mutant chimera alphaⅡb R995A beta3 CHO cells were able to bind with PAC-1. Furthermore, phosphorylation of pp125 (FAK) in wild-type alphaⅡbbeta3 CHO cells occured only when cells were adhered to fibrinogen, but could not be detected in bovine serum albumin suspension. However in the mutant chimera group, it could be detected in both conditions. Conclusion The mutation in integrin alphaⅡb R995A alters its affinity state as a receptor, thus also mediating cytoplasmic signal transduction leading to the phosphorylation of pp125 (FAK) without ligand binding.展开更多
文摘Src is a non-receptor protein tyrosine kinase activated by a number of extracellular signal moleculars. It is recruited to peripheral sites through myristoylation and the SH3 domain. Src initiates intracellular signal trandsduction pathways that influence cell adhesion, migration, growth, differentiation and survival though catalytic domain. Src is normally maintained in an inactive conformation because of carboxy terminal Src kinase, but can be activated transiently during cellular events such as mitosis or constitutively by abnormal events such as mutation and some cancers. In additions, c-Src protein is found to be highly activated and the Src gene is frequently over-expressed in many cancers. These findings suggest that the relationship between c-Src activation/over-expression and cancer progression appears to be significant.
文摘Objective To investigate the role of cytoplasmic domain of integrin alphaⅡb in platelet signal transduction. Methods Binding capacity of integrin alphaⅡb R995A to antibody platelet activation complex-1 (PAC-1) and pp125 focal adhesion kinase (FAK) phosphorylation of cells were detected by flow cytometry, immune precipitation, and Western blotting. Results Without activation, wild-type alphaⅡbbeta3 Chinese hamster ovary (CHO) cells failed to bind to PAC-1, but mutant chimera alphaⅡb R995A beta3 CHO cells were able to bind with PAC-1. Furthermore, phosphorylation of pp125 (FAK) in wild-type alphaⅡbbeta3 CHO cells occured only when cells were adhered to fibrinogen, but could not be detected in bovine serum albumin suspension. However in the mutant chimera group, it could be detected in both conditions. Conclusion The mutation in integrin alphaⅡb R995A alters its affinity state as a receptor, thus also mediating cytoplasmic signal transduction leading to the phosphorylation of pp125 (FAK) without ligand binding.
