G-protein coupled receptirs Flashcards
what can activate a GPCR?
many different types of ligands, they are normally activated by hormones and neurotransmitters
why are they called effectors?
bc they produce intracellular messages
what happens at the signal transduction process?
the receptor proteins bind, Conformational changes in the structure of the receptor protein then convert the extra-cellular chemical signal into one or more intra-cellular signals
what physiological processes are GPCRs involved in?
visual sense, sense of smell, behavioural and mood regulation, Regulation of immune system activity and inflammation, Autonomic nervous system transmission, 30% of all drugs work by binding to GPCRs
give examples of a GPCR
muscarinic acetylcholine receptors (bind adrenaline), alpha and beta adrenergic receptor (bind adrenaline), also dopamine, serotonin and glutamate receptors
what is the beta adrenergic receptor turned on by?
adrenaline / noradrenaline, it works to relax smooth muscle
the receptor is activated by exchange of GTP to GDP in the G protein.
once the receptor is activated, the alpha subunit is going to migrate and bind to the adrenaline cyclase.
then, adenylate cyclase will convert ATP to cAMP
what is the main clinical use for adrenergic agonists?
the treatment of asthma (relaxing of the smooth muscles of the bronchi)
what is the main clinical use for adrenergic antagonists
the beta blockers (used in the treatment of angina, hypertension)
why are they called effectors?
because they produce intracellular messages
what is cAMP?
cyclic messenger, will go on to activate many other things, typically kinases, so lots of amplification
what is GTP hydrolysed to?
GDP
