Biology 2382B Lecture Notes - Lecture 11: Cell Membrane, Lysosome, Gene Duplication
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Ras/map kinase pathway operation (raf, mek, mapk), egf. Downstream kinases: aberrant signaling is at root of many human cancers. Only single transmembrane as opposed to g coupled receptors which have 7. Only turned on when ligand binds to extracellular receptor > 2 receptors come together (dimerization) Ligand binds and causes 2 receptors to associate and dimerize. Lead to phosphorylation, and recruitment of a small g protein called ras. Which triggers phosphorylation of multiple kinases and ultimately phosphorylate a transcript factor (allowing them to enter nucleus and bind ti promoter region and activate gene expression) Figure 16-3 dimerization allows for trans-autophosphorylation of cytoplasmic domains phosphotyrosines serve as docking sites for downstream signal- transduction proteins containing sh2 domains (adapter proteins). Work by binding to an extracellular ligand e. g growth factor. When the growth factor is not present the ligand is integrated into the pm. Piece that sticks into cytosol that has v low or negligible rtk.