BIOL 2020 Lecture Notes - Lecture 36: Grb2, Ectodomain, Glioma
22 May 2020
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Grb2 is an adaptor that helps connect proteins together, it contains 1 sh2 and 2 sh3 domains: Recruited from the cytoplasm to the membrane when ligand binding to receptor activates intrinsic tyrosine kinases which transphosphorylate tyrosine residues . Modulates downstream signaling by: sh3 domain which mediate signaling complex assembly by binding proline rich target sequences on sos. Sos is a guanine exchange factor (gef) that exchanges gdp gtp. Recruited when: grb2 translocates to the membrane, which brings sos close enough to ras. Modulates downstream signaling by catalyzing ras gdp gtp exchange leading to map kinase cascade. A proto-oncogene can become an oncogene through various mechanisms during tumourigenesis. Give a specific example for two of them; in each case, name the gene, the mechanism of proto-oncogene activation and the cancer where it is found to be deregulated. Different defects in rtk signaling can lead to cancer: Egfr overexpression is found in selective human tumors (ex.
