G-protein coupled receptors (lect 18-20) Flashcards
(108 cards)
what type of G proteins are Gi/o proteins?
inactivating g proteins that inactivate AC
what senses are dependent on GPCRs?
sight, taste, smell
give examples of signal molecules
proteins, small peptides, derivatives of aa, faaty acids, photons, molecules for smell and taste
give an example of a GPCR involved in asthma and the type of drug it can be used by?
b2-adrenergic receptor agonists for asthma
give an example of a GPCR involved in hypertension and the type of drug it can be used by?
b-adrenergic receptor antagonists for hypertension
give an possible experimental setup to solve the challenge ivolving GPCR structure?
(Challenge = it is TM) solubilize membrane with a detergent
what are GPCR’s most variable structures?
N and C terminus, and the extra/intracellular loops (basically the non TM domains)
where is the N and the C terminus located?
N-terminus is EXTRACELLULAR
C-terminus is INTRACELLULAR
what is a protein disulfide isomerase?
enzyme that helps generate the disulfide bond in GPCR (usually hardly found in the cell)
the disulfide bonds are created between what residues?
cysteines
GPCR cysteine must be activated by what?
palmitoylation
where on the GPCR does palmitoylation happen?
C terminal
is palmitoylation reversible?
yes
is disulfide bonding reversible?
no
what the inhibitory neurotransmitter of the CNS!!
GABA
name the GPCR families
rhodopsin, secretin receptor, glutamate receptor, adhesion, frizzled/TAS2
is there sequence similarity between families of GPCRs?
no
usually, ligand bind what part of GPCR? what is the exception?
N terminus (because its the extracellular one DUH)
exception is rhodopsin family GPCRs:
- alpha group bind ligans in the TM domains
- beta and y group bind ligans via extracellular loop
are ligands specific to GPCRs?
no (One ligand can bind to different GPCRs; One GPCR can bind to different ligands)
the same effectors can cause different consequences in different what?
tissue
what is the precursor for serotonin?
L-tryptophan
what modifications happen to L-tryptophan for it to become serotonin?
hydroxylation and decarboxylation
where is 5-HT (serotonin) produced?
gut and CNS
name some of its effect
gut movements, regulation of mood, appetite, sleep, muscle contraction