W8OutlineLec20

W8OutlineLec20 - complexes by mediating interactions...

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Luis David Gomez 59866865 Bio 192 D103 Cell Biology Week 8 Lecture 20 Outline 2/25/08 Signaling Principles Review “Cross-Talking” between pathways can occur Sophistication and Responses Achieved by duplication of pathways and redundant pathways Signaling can coordinate regulation of opposing pathways Enzymes from one pathway will inhibit or up-regulate other enzymes in an opposing pathway Ex: PKA provides positive feedback on GPK to create more glucose (less glycogen synthesis) Scaffolds Regulate specificity of signaling Some pathways can use the same ligands, enzymes. Different scaffold proteins bring “sets” of kinases together to provide specificity of signaling Lipid Kinases o Create activation of signaling pathways by subcellular localization (bringing enzymes together in specific compartments) Domains What regulates binding of SH2 domain to specific tyrosine kinase? SH2 Domain (30-40 A.A. Acids) Conserved Sequences that are found in many proteins in the genome allows formation of signaling
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Unformatted text preview: complexes by mediating interactions between intracellular signaling proteins and associated molecules Ans: Amino acid sequence that surrounds SH2 domain. (Key and Lock anology) Cascades One ligand Interacts with Receptor Activates Effectors Many 2 nd messengers are made (amplification Transduction of Signal Effect Signaling Molecules Decreased synthesis of signal molecules=no significant change in signal molecules concentration If lifespan of signaling molecules is short then we can drastically change (inc/dec) concentration of signal molecule Allosteric Feedback Ligand binds enzyme is activated at low level substrate to product conversion after product is made it can bind back on the enzyme and up-regualte synthesis of product (reinforcement of signal)...
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This note was uploaded on 05/28/2008 for the course BIOL D103 taught by Professor Suetterlin/macgregor during the Winter '08 term at UC Irvine.

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