GPCRs Flashcards
structure of the GPCRs
7TM alpha helices, TM3 is centrally located next to the binding pocket
different roles of the N terminus in GPCRS
A. help orientâte or guide ligands to the binding date e.g. enkephalins
B. block binding site e.g. adrenoreceptors
recognition of ligand at GPCR action
TM3 detects ligand and conformational change occurs. Causes the TM5+6 to move and reveal G protein binding pocket
difference in GEF in monomeric and trimeric GPCRs
monomeric you require additional GEF protein
trimeric the agonist bound to the receptor acts as the GEF
different types of 2nd messengers
hydrophobic ligands
small soluble - cAMP,cGMP, calcium ions
Gases - NO
different types of 2nd messengers and examples
hydrophobic ligands
small soluble - cAMP,cGMP, calcium ions
Gases - NO
what breaks down cAMP
Phosphodiesterase
rhodopsin receptor defects result in
activating mutation - night blindness
loss of function - retinal degeneration
thyroid hormone receptor defects result in
activating mutation -
hyperthyroidism, thyroid cancer
loss of function mutation - hypoparathyroidism
cone cell opsin defective results in
colour blindness
parathyroid calcium sensor defects results in
activating mutation -hypoparathyroidism
loss of function - hyperthyroidism
vasopressin receptor loss of function mutation results in
nephrogenic diabetes insipidus - kidneys fail to reabsorb water
