Lecture 3--cell signaling

Beta and potassium channel activation interact with

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Unformatted text preview: brane Extracellular space cytosol rate limiting step is the GTP binding step to alpha, alpha hydrolyzed GTp to GDP and k channels close and inatcivates g protein Inactive G protein Closed K+ channel Activated ! subunit Channel opening Open K+ channel opens, causes potassium to leak out cell, hyperpolarizes cell. gets different Binding ofin heart and muscle. in response the neurotransmitter directly open muscle: the acetylcholine k c to its acetylcholinehannel G-protein- linked receptor on heart muscle Activated "# complex binds to and opens a K+ channel in the heart plasma membrane inactivation Closed K+ channel Inactivation of the a subunit by hydrolysis of bound GTP causes reassociation with the "# complex. Enzymes activated by G protein catalyze the synthesis of intracellular messenger molecules Activated enzyme Activated "# complex Activated ! subunit of G protein second messangers re not the second protein in the pathway, they can be generated anywhere in pathway, small molecules that get amplified...
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