complete solutions
Molecular Drug Targets - correct answer ✔✔Receptors-45%
Enzymes-28%
Hormones-11%
Unknown-7%
Ion Channels-5%
DNA-4%
Channel-Linked (Ionotropic) Receptors - correct answer ✔✔Produce cellular effects in milliseconds
Nicotinic ACh receptor
GPCRs - correct answer ✔✔Effects happen in seconds
Muscarinic ACh receptor
Kinase-linked receptors - correct answer ✔✔Effects happen in minutes
Insulin receptor
Receptors linked to gene transcription - correct answer ✔✔Effects happen in hours
Estrogen receptor
Heterotrimeric G proteins - correct answer ✔✔alpha, beta and gamma subunits
GPCR Components - correct answer ✔✔More than 800 receptors
7 transmembrane domains
N and C termini
,Conformationally flexible
Constitutively active
GPCR Ligands - correct answer ✔✔Hormones, neurotransmitters, chemokine, ions, amino acids,
peptides
G-proteins - correct answer ✔✔a-20
Gas- increases AC
Gai - decreases AC
Gaq - increases PLC
b(6)y(12)
Why use G proteins - correct answer ✔✔Means of amplifying the signal
G proteins can regulate more than one effector
PKA - correct answer ✔✔Phosphorylase Kinase (glycogen breakdown)
CREB (gene transcription)
L-type Ca channels (heart contraction)
Pyruvate Kinase (glycolysis)
Hormone Sensitive Lipase (triglyceride breakdown)
Kinase-linked receptor signaling - correct answer ✔✔No second messenger
Protein kinase-linked receptors - correct answer ✔✔Receptors associated with cytosolic kinases
Receptor tyrosine kinases
Receptor serine/threonine kinases
Receptors associated with cytosolic kinases - correct answer ✔✔Ligands:
Prolactin
, GH
Interferons
Cytokines
Receptor tyrosine kinases - correct answer ✔✔Receptor tyrosine kinases (RTKs) consist of an
extracellular ligand
binding and dimerization domain, a single hydrophobic
transmembrane a-helix and a cytosolic domain with intrinsic
tyrosine kinase activity
Two types of RTKs - correct answer ✔✔Single transmembrane spanning proteins that dimerize when
ligand binds (EGF receptor, PGDF receptor)
Covalently linked dimers (insulin receptor, IGF-1 receptor)
PKB/Akt - correct answer ✔✔phosphorylate multiple proteins which regulate a wide variety of
intracellular events
Nuclear Receptor Subfamily - correct answer ✔✔Six structural domains:
A/B- AF-1
C- DBD
D- Hinge
E- LBD
F- AF-2
Steroid class receptors - correct answer ✔✔GR, MR, PR, AR, ER
RXR partnered receptors - correct answer ✔✔TR, RAR, VDR, PPAR, a, b, y
Orphan receptors - correct answer ✔✔COUP-TF, HNF-4