Exam Review - Chapter 12

Synthesis of glycogen from glucose is accelerated 5

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Unformatted text preview: in activates CaM kinase Receptor tyrosine kinases: large family of plasma membrane receptors with intrinsic protein kinase activity Ligand binding domain on the extracellular face of the plasma membrane Cytoplasmic domain is a protein kinase that phosphorylates Tyr residues in a specific target protein Insulin is an example of a hormone that operates through this mechanism Autophosphorylation: opens up the active site so that the enzyme can phosphorylate Tyr resiudes of other target proteins Stimulation of Insulin Receptor to Alter Gene Expression 1. Insulin receptor binds insulin and undergoes autophosphorylation of its carboxyl- terminal Tyr residues 2. Insulin receptor phosphorylates IRS- 1 on its Tyr residues 3. SH2 domain of Grb2 binds to P- Tyr of IRS- 1. Sos binds to Grb2, then to Ras, causing GDP release and GTP binding to Ras 4. Activated Ras binds Raf- 1 5. Raf- 1 phosphorylates MEK on two Ser residues, activating it. MEK phosphorylates ERK on a Thr and a Tyr residue, activating them 6. ERK moves into the nucleus and phosphorylates nuclear transcription factors such as Elk1, activating them 7. Phosphorylated Elk1 joins...
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This note was uploaded on 02/06/2014 for the course BCHB 501 taught by Professor Jessicajones,elliottcrooke,ericgalsgow,marybethmartin during the Fall '12 term at Georgetown.

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