Mode of Action Flashcards
transduction event
initiated by receptor; activates amplifier
amplifier
(enzyme) makes 2nd messenger; activated by transduction event
second messenger
(CS) made by amplifier; activates internal effector
internal effector
(protein kinase) activated by 2nd messenger
protein kinase
internal effector; puts phosphate on specific substrate
G protein coupled receptor (GCPR)
receptor
G proteins
Gs, Gi, Gq; transducer
adenylyl cyclase (AC)
converts ATP to cAMP
phosphoproteins
de-phosphorylated proteins from PKA
phosphatase
enzyme that removes phosphate from a protein
positive allosteric event
actions of cAMP on PKA; cAMP activates PK; reversible and concentration dependent
transcription factor
CREB produced from cAMP activated PK
EPAC (cAMP regulated guanine nucleotide exchange protein)
cAMP binds to EPAC; Rap-1 causes GTP to GDP
phosphatidylinositol
phospholipid in PM; cleaved into IP3 and DAG by phospholipase C
inositol triphosphate (IP3)
ligand that binds to gated Ca++ channel; phospholipid; 2nd messenger
diacylglycerol (DAG)
allosterically activates PKC; 2nd messenger
calcium as 2nd messenger
IP3/DAG pathway; Ca++ released and activates PKC
protein kinase C
mediates biological response
Ca++/calmodulin (CAM kinase)
calcium binds to calmodulin
guanylate cyclase
converts GTP to cGMP
cGMP
GTP converted to cGMP; pathway w/no G protein
cGMP dependent protein kinase
allosterically activated by cGMP
tyrosine kinase type 1
ligand binds to receptor subunit; another receptor subunit; TK binds to activated complex; TK phosphorylates; bio response; internalized by ubiquitin
tyrosine kinase type 2
TK catalytic site in receptor; binding reversible; PO4 substrate protein mediates bio response; insulin receptor
auto-phosphorylate
phosphorylate itself; TK
ubiquitin
grabs phosphorylated homo-dimer and attracts proteins; internalizes receptor and stops signaling
heat shock protein (with steroid receptor)
binding to T receptor prior to stimulation
heterochromatin
cannot be transcribed; at ends of euchromatin
euchromatin
part being transcribed
hormone responsive element (HRE)
T/receptor complex binds to it; reversibly
nuclear pore
entrance into nucleus; highly selective
thyroid hormone
hydrophilic CS pathway; released from thyroid cell; needs transporter
thyroid hormone transporter
TH enters cell and binds to
thyroid hormone receptor
TH binds reversibly w/THR on HRE
hyposecretion
amount of hormones released is too low
hypersecretion
amount of hormones released is too high
autoimmune deficiency
body’s immune system attacks healthy cells
negative feedback
stops signaling; degrade TH; (+) TFs dissociate; (-) TFs bind to receptor
types of kinases in signal transduction pathways
PKC and CAM
