144 - endocrine Flashcards
what are common features of ligands for nuclear receptors?
they are small and lipophillic. all are from dietary or metabolic precursors. Not directly encoded by the genome.
what are 5 groups of nuclear receptors?
classical, vitamins, metabolic intermediates, xenobiotics, and orphan
what are the key steps for nuclear receptor activation?
binding of ligand to receptor. transportation to nucleus. binding to promoter elements.
describe thyroid hormone resistance
goiter and tachycardia. elvated thyroid hormone with normal TSH. inactivating mutation of thyroid hormone beta receptor.
describe complete androgen insensitivity syndrome
genetically male but phenotypically female. androgen receptor mutated.
describe receptor tyrosine kinases
extracellular binding domain. single transmembrane domain. intracellular tyrosine kinase catalytic domain. Dimerization is needed most of the time. Insulin is an example.
What are MEN 2A and 2B?
2A is a mutation in the extracellular domain of receptor tyrosine kinase. 2B is an intracellular mutation.
describe receptor serine/threonine kinases
same as receptor tyrosine kinases except they phosphorylate serines and threonines
describe cytokine receptors
these are similar to other receptor tyrosine kinases except that signaling occurs via tyrosine kinase associated proteins (JAKS)
what are examples of cytokine receptors?
growth hormone, prolactin, leptin
describe GPCRs
7 transmembrane helices. needs the help of trimeric complex (alpha, beta, gamma)
describe diabetes insepidus
vasopressin 2 receptor mutation (GPCR). central is a deficiency of ADH while nephrogenic is insensitivity to ADH.
describe graves
Gain of function GPCR due to antibodies that act on the receptor
