CBIO 3400 Lecture Notes - Lecture 35: Dna-Binding Domain, Intracellular Receptor, Cholecalciferol
20 Apr 2016
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Document Summary
Too much/too little response can lead to cancer, allergies, or diabetes. Response between signal/response is varied based on pathways. Timing, sensitive, dynamic range, persistence, signal processing, integration, coordination. These both lead to altered cytoplasmic machinery and altered cell behavior. Threshold response: as much response and needed from the signal. Receptors with enzymatic activity - tyrosine kinase, serine/threonine kinase, protein phosphatases, guanylate cyclase receptors. Steroid receptors have 3 modular parts: hormone/ligand binding domain, dna binding domain, transcription activating domain. All family members are cys4 zn finger proteins. They bind as dimers and bind a zinc co-factor. Muscarinic - 7 tm spans and g protein. Nicotinic - ion channel, neuromuscular junction, subunits (alpha, beta, gamma, phi) **alpha subunit binds ligand both alpha subunits must bind to open. Channel closed -> ligand binding leads to open channel -> influx of na+ -> channel inactivates -> analogous to 3 stages of voltage gated na+ channel.
