PSL300H1 Lecture Notes - Lecture 3: Adenylyl Cyclase, Beta Sheet, Insulin Receptor
Document Summary
Following is from a video shown in class. Activation protein exchanges gdp to gtp, causing change. G protein activated then diffuses across membrane to adenase cyclase. Gtp is changed to gdp, stopping camp production. Protein kinase is no longer activated, stopping phosphorylation. See slide 2; answer: thyroid and thyroxine (tsh elevated) Goitre = swelling at base of throat due to thyroid issues. Activity must have an off switch - for every receptor. Estrogen receptor x-ray crystallography is showing that on estrogen, 2 molecules of zinc present. Zinc positions estrogen into the beta pleated sheets. Receptor forms a u shape because estrogen is there. Shape is critical for function - going to bind somewhere on nuclear dna. No response if the shape is wrong - it"s critical and specific to the hormone. If in cytosol, once hormone is bound - it will translocate from cytosol to nucleus. Membrane receptors - for peptides, eg g protein-coupled receptors.
