BMS 860 Lecture Notes - Lecture 5: Cyclin D1, Stat1, Catenin
26 Feb 2017
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Document Summary
Ras protein is permanently bound to the inner site of the plasma membrane. Activated receptors cannot move, but monomers can. Adaptor proteins are proteins that link other proteins together and facilitate creation of larger signaling complexes (bridge proteins): majority lack any intrinsic enzymatic activity, mediate very specific protein-protein interactions. Grb2 has 3 domains: sh2 and sh3 and sh3. Sh2 binds to phosphorylated tyrosine on receptor, and two sh3 binds to sos (gef)- tells gdp to leave and gtp binds onto ras, downstream signaling. Ras activation evokes a number of distinct changes in cells proliferation, survival, cytoskeletal changes. Src homology 2 (sh2) there are 2 binding sites: 1 is for phosphotyrosine on cytoplasmic tail of receptor, another is the flanking site for amino acids. Flanking amino acid residues determine the specificity of binding. Sh3 domain binds specifically to certain proline-rich sequence domains in partner proteins. Receptor phosphotyrosines are homing sites for various sh2 containing proteins.
