Activation of Src kinase in skeletal muscle cells by 1,25‐(OH)2‐vitamin D3 correlates with tyrosine phosphorylation of the vitamin D receptor (VDR) and VDR‐Src interaction

摘要: The rapid effect of 1 alpha,25(OH(2))-vitamin D(3) [1 alpha, 25(OH(2))D(3)] on tyrosine kinase Src and its relationship to the vitamin D receptor (VDR) was investigated further characterize hormone signaling mechanism in chick muscle cells. Exposure cultured myotubes alpha,25(OH(2))D(3) caused a time-dependent increase activity, which evident at min (one-fold) reached maximum 5 (15-fold). Immunoblotting with anti-phosphotyrosine antibody immunoprecipitated showed that decreased phosphorylation state maximal effects min. Using database for protein consensus motifs we found putative site (amino acids 164-170: KTFDTTY) within primary sequence VDR. When myotube VDR it appeared onto SDS-PAGE gels as single band 58 kDa recognized by an antibody. Prior treatment cells (1)alpha,25(OH(2))D(3) significantly increased (two- three-fold above basal levels). In agreement being SH2-domain containing involved recognition tyrosine-phosphorylated targets, immunoprecipitation anti-Src under native conditions followed blotting anti-VDR antibody, or using antibodies inverse order, co-precipitates Src, thus indicating existence VDR/Src complex. Stimulation cognate ligand formation complex respect conditions. These results altogether provide first evidence date activation involving association phosphorylated