Receptor Classes, Structures, Signaling Mechanisms, and Drug Examples Flashcards
Ligand-gated ion channel receptors
- Nicotinic acetylcholine receptor
- plasma membrane
- 5 subunits
- 4 transmembrane domains each
Ligand-gated ion channel receptors
Agonist binding to extracellular domain opens transmembrane ion pore allowing Na+ ions to enter cell
G protein-coupled receptors
- B2-adrenergic receptor for epinephrine, norepinephrine
- in plasma membrane
- 7 transmembrane domains
G protein-coupled receptors
agonists binding inside the transmembrane domains activates associated GTP-binding proteins that in turn regulate effector enzymes that generate intracellular second messenger molecules
G protein-coupled receptors
Targets for OVER HALF OF ALL PRESCRIPTIONS
Receptors with intrinsic enzyme activity
- insulin receptor
- cell surface
2 single-transmembrane proteins
Receptors with intrinsic enzyme activity
agonist binding to extracellular domain activates enzymatic activity of intracellular domain
Receptors with intrinsic enzyme activity
- most commonly tyrosine kinase activity
- phosphorylated substrates then medicate effects
- “tyrosine kinase receptors”
Receptors with intrinsic enzyme activity
regulate gene expression, cell growth, cancer, differentiation
Nuclear transcription factor receptors
- estrogen receptor
- steroid hormone receptors
Nuclear transcription factor receptors
agonist binds to ligand binding domain, allows DNA binding domain to bind specific DNA sequences, activation domain then increases/decreases transcription of associated genes
Nuclear transcription factor receptors
regulate gene expression, cell growth, cancer, development