L3 - GPCR Flashcards
what do GPCR’s respond to? 6
hormones, neurotransmitters, paracrine and autocrine signals, odours and light
what part of a GPCR transduces the signal?
G-protein
what part of a GPCR is the effector?
alpha and beta-gamma subunits
what enzyme activates PKA
adenylate cyclase
what enzyme activates PKC
phospholipase C
what do protein kinases provide?
the major mechanism for changing the activity of an existing protein
what 4 actions can protein kinases perform?
- increase or reduce the activity of an enzyme
- turn a signalling protein on or off
- change the location of a protein
- alter the interaction of a protein with other molecules
what is the process of post-translational modification of a protein?
the regulated addition of a small molecule, most often the addition of a phosphate, adds a large negative charge, will cause the folded protein to adjust it’s shape
how is protein phosphorylation carried out?
- a phosphate is transferred from ATP to the target protein
- protein kinases add phosphates
- protein phosphatases remove them (regulate protein kinases)
what two categories are protein kinases put into (named after their amino acid targets)?
- serine/threonine kinases
- tyrosine kinases
what activates PKA?
cAMP
what activates PKC
Ca2+
what activates cyclin-dependent protein kinases (CDK)?
cyclins
what activates RTK’s (receptor tyrosine kinases)?
receptor-specific ligands, so only signals that work with tyrosine receptors
what is the process of PKA activation?
PKA exists as an inactive complex with it’s regulatory subunits, cAMP binds to the regulatory subunits, causes them to dissociate, which releases the active kinase
