BIOL 201 Lecture Notes - Lecture 33: Signal Transduction, Integrin, Serum Response Factor
Document Summary
Generally involved transcription factors, so long term changes in state. Long term signals lead to changes in gene expression. Long term signals can regulate step going from g1 to s, requires external signals to tell it to divide. What triggers the transition: signals consist primarily of peptides. Nerve growth factor causes neurons to send out axonal processes (rita uses chick embryos, induces growth of axons) Epidermal growth factor induces promotion of epithelial tissue (differentiation and proliferation) Receptor tyrosine kinase signal downstream to changes transcription: membrane resident proteins, transmembrane domain, extracellular domain, interior domain for signaling, you get binding of peptide to receptor and then dimerization of two receptor subunits. Number of phosphotyrosine binding domains (ptb) and they now have affinity and stick together. Sh2 domain (ptb domain) has residues that bind to phosphorylated tyrosines. G alpha subunit is similar to ras protein.