Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
|
What are the families included in the Ligand-Gated Ion Channel superfamily? (4)
|
1. nACh receptors
2. GABA_A receptors 3. Glycine receptors 4. 5HT_3 receptors |
|
|
what are the common features of ligand gated ion channels?
|
- 5 subunits around an ion pore
- N termianl extracellular domain with a CX_13_C motif - four TM domains - gating and desensitization are modified by phosphorylation of intracellular domains (betweeen TM3 and TM4) |
|
|
what are the common features of G-protein coupled receptors?
|
- 7 TM helicies
- extracellular N termianl domain - intracellular C-terminal domain |
|
|
What are the 5 classes of enzyme-linked cell surface receptors?
|
1. Receptor tyrosine kinases (RTKs)
2. Tyrosine kinase associated receptors (TKARs) 3. Receptor serine/threonine kinases (RSTKs) 4. Receptor guanylyl cyclases 5. Receptor tyrosine phosphates (RTPs) |
|
|
what are tyrosine kinase associated receptors?
|
like receptor tyrosine kinases, but don't have catalytic cytopasmic domains. They do dimerize however.
Once bound to ligand, these receptors activate membrers of the JAK family, which phosphorylate intracellular TKAR domains, signal transducers and activators of transcription (STATs) |
|
|
what are receptor serine/threonine kinases?
|
ligands: TFG-b, activin, and BMP
receptors: intrinsic serine/threonine kinase activity - can induce or inhibit celluluar proliferation and differentiation. |
|
|
What are receptor gyanylyl cyclases?
|
have intrinsic guanylyl cyclase activity that results in cGMP production
|
|
|
what are receptor tyrosine phosphatases
|
remove phosphate groups from tyrosines.
- essential in synaptic plasticity. |
|
|
how is drug dosage quantified?
|
milligrams per kilogram
|
|
|
What is the ED_50
|
the amount of drug that produces 50% of the maximal effect on a subject
|
|
|
what are the advantages and disadvantages of small hydrophilic ligands vs. large ligands?
|
small ligands are good for rapid cell-cell signaling
large ligands can form greater bonding affinity and specificity |
|
|
what is curare?
|
a nicotinic ACh receptor antagonist
|
|
|
what is atropine?
|
a muscarinic ACh receptor antagonist. Also called the bella donna, since it causes pupillary dilation
|
|
|
What structural similarity do nicotinic receptor ligands have?
|
all have tertiary or quaternary amine group --> positive charge
|
|
|
where are the orthosteric sites of the nACh receptor?
|
between the a-delta and a-gamma subunits
|
|
|
what types of superfamily does mAChR belong to?
|
G-protein couple receptors
|
|
|
describe the agonists and antagonists of mAChR
|
agonists: ACh and CCh (carbamylcholine)
antagonist: atropine |
|
|
Where is M1 found? what is it blocked by?
|
Brain/ANS ganglia.
Blocked by pirenzepine |
|
|
Where is M2 found? what is it blocked by?
|
Heart/Smooth muscle
Blocked by gallamine |
|
|
Where is M3 found? what is it blocked by?
|
exocrine glands/smooth muscle
|
|
|
Where is M4 found?
|
Lung/Brain
|
|
|
Where is M5 found?
|
brain
|
|
|
Describe mAChR signal transduction
|
a_q is released. It interacts with PLC (phospholipase C) which causes GTP to be displaced by GDP. PIP2 releases DAG and IP3. DAG goes to interact with PKC whie IP3 mediates intracellular Ca concentrations and protein kinases.
|
|
|
HOw do you measure GPCR responses?
|
measure 2nd messenger concentrations
|
