Bockholt S M, Otey C A, Glenney J R, Burridge K
Department of Cell Biology and Anatomy, University of North Carolina, Chapel Hill 27599-7090.
Exp Cell Res. 1992 Nov;203(1):39-46. doi: 10.1016/0014-4827(92)90037-9.
Tyrosine phosphorylation of cytoskeletal proteins at adhesive junctions has been speculated to play a role in the regulation of cell signaling at these sites. Previously, monoclonal antibodies were generated against phosphotyrosine-containing proteins from Rous sarcoma virus-transformed chick embryo fibroblasts, resulting in two antibodies which recognized antigens of 76 and 215 kDa that localized to focal contacts. We have now localized the 215-kDa antigen to a number of adhesive junctions in vivo, including the zonula adherens, intercalated discs, and myotendinous and neuromuscular junctions. In sections of skeletal muscle and in isolated myofibrils, the 215-kDa protein was localized to the I-band. By immunoprecipitation and immunoblot analysis, we determined that the 215-kDa antigen cross-reacts with a polyclonal anti-tensin antibody.
据推测，黏附连接点处细胞骨架蛋白的酪氨酸磷酸化在这些位点的细胞信号调节中发挥作用。此前，针对劳氏肉瘤病毒转化的鸡胚成纤维细胞中含磷酸酪氨酸的蛋白制备了单克隆抗体，得到了两种识别定位于黏着斑的76 kDa和215 kDa抗原的抗体。我们现在已在体内将215 kDa抗原定位于多个黏附连接点，包括黏着小带、闰盘以及肌腱和神经肌肉连接点。在骨骼肌切片和分离的肌原纤维中，215 kDa蛋白定位于I带。通过免疫沉淀和免疫印迹分析，我们确定215 kDa抗原与多克隆抗张力蛋白抗体发生交叉反应。
