BIOL 201 Lecture Notes - Lecture 33: Growth Factor, Cell Membrane, Tyrosine
27 Nov 2015
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Document Summary
Long-term signals lead to changes in gene expression. Nerve and epidermal growth factor trigger the growth of neurons and skin cells. Another experiment: discovered that snake venom is a source of ngf and dna digesting enzymes. Receptor tyrosine kinases receive signals from growth factors. When rtk binds to gf, it dimerizes and intracellular kinases are brought close to each other. Aberrant rtk signaling is found in nearly all human cancers. Her2 over-expressed in 25% of breast cancers. Egf binds to two egfrs, extracellular domain clamps down on gf. Collapsing causes loop on the backside to stick out so they stick to each other and dimerize. Dimerization brings the intracellular kinase domains into proximity. 2 domains that proteins can have that will allow them to get recruited to an activated receptor tyrosine kinase: ptb domain and sh2 domain - they recognize phosphorylated tyrosine residues.
