CH250 Lecture Notes - Lecture 70: Insulin Receptor, Glycogen, T Cell
Document Summary
Figure 8. 35 growth factors bind to rtks encoding an intrinsic tyrosine kinase activity, which is activated by receptor dimerization. The intrinsic tyrosine kinase is required for both autophosphorylation of the rtk cytoplasmic tail and for phosphorylation of receptorassociated target proteins, which bind to rtk phosphotyrosine residues. Figure 8. 46 insulin receptor tyrosine phosphorylation of irs and shc proteins, which bind to the receptor cytoplasmic domain through ptb domains, leads to stimulation of two downstream signaling pathways. In one branch of the insulin signaling pathway, phosphorylated irs binds to sh2 domains on pi-3k and activates a downstream signaling pathway that leads to increased glucose uptake and stimulation of glycogen synthesis. The other branch involves binding of phosphorylated shc protein to sh2 domains on grb2, which activates the map kinase pathway, leading to altered gene expression and cell division. Same signal but no apoptosis = healthy cell.
