SCI397 Lecture Notes - Lecture 4: Mitogen-Activated Protein Kinase Kinase, Phosphorylase, Smooth Muscle Tissue
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Multicellular organisms, coordination of: development (from single cell to trillions of cells, growth- (cid:272)oordi(cid:374)ati(cid:374)g (cid:858)(cid:449)hole (cid:271)od(cid:455)(cid:859) gro(cid:449)th a(cid:374)d de(cid:448)elop(cid:373)e(cid:374)t (cid:449)ith e(cid:374)(cid:448)iro(cid:374)(cid:373)e(cid:374)t, day to day physiology. Signaling molecule synthesized and released by signaling cell. Signal binds to receptor protein on/in target cell signal transduction. Cha(cid:374)ges i(cid:374) (cid:272)ell shape, (cid:373)o(cid:448)e(cid:373)e(cid:374)t, (cid:373)eta(cid:271)olis(cid:373), se(cid:272)retio(cid:374) et(cid:272) . The same signal can cause different responses, depending on the target cell. A (cid:272)ell(cid:859)s respo(cid:374)se to a sig(cid:374)al (cid:272)a(cid:374) (cid:271)e fast or slo(cid:449) The location of the receptor can (usually) be predicted by the chemistry of the signal molecule. Small hydrophobic signal molecules typically enter the cell and regulate gene transcription. Steroids are evolutionarily related: their receptors are members of nuclear receptor family of transcription factors. Most signals bind to receptors on plasma membrane. Second messenger- small (non-protein) molecules that relay signals from cell surface receptors to target molecules within the cell. Intracellular signal molecules often act as molecular switches.