cell signaling pathways Flashcards
what activates adenyl cyclase in the cAMP pathway
by a GTP-bound G protein subunit alpha, forming cAMP from ATP
what does cAMP bind to release catalytic subunits
protein kinase A
what degrades cyclic AMP
cAMP dependent phosphodiesterase
what does the catalytic subunit from the cAMP pathway phosphorylate
transcription factor CRE binding protein (CREB) and cAMP response element CRE
what is the last step of the cAMP pathway
specific genes expression occurs
what activates the protein kinase domains of the dimerized receptor in the phospholipid calcium pathway
binding of a signal molecule
what mediates the association of phospholipase C (PLC) γ with activated receptor tyrosine kinase
SH domain
PLCγ catalysis of PIP2 leads to production of what
IP3 and DAG (diacylglycerol)
what does diacylglygerol activate
protein kinase C
what signals release of Ca from the intracellular storage sites
IP3
what interacts with the Raf protein kinase
GTP binding protein Ras (rat sarcoma virus)
- what does Raf phosphorylate and activate.
2. what does that then activate
- MEK (MAP kinase or ERK kinase)
2. ERK (extracellular signal regulated kinase)
what does ERK do
phosphorylates the transcription factor for Elk-1
what does Elk-1 binds SRE (serum response element) forming…..
SRF (serum response element) and then gene induction then occurs.
in the JAK-STAT pathway, the JAK protein tyrosine kinase binds to the inactive factor STAT via what
SH2 domains
what happens to STAT phosphorylation
it dimerizes
what happens to the phosphorylated STAT dimer
translocates to the nucleus where it activates transcription of target genes
in the NF-κβ transcription factor pathway, how is the inactive complex formed
NF-κβ association with inhibitory subunit I-κβ
what happens when protein kinase C is stimulated
I-κβ is phosphorylated and undergoes degradation after ubiquitinization by the 26S proteosome
what does I-κβ do
uncovers localization sites of NF-κβ, binds to DNA and regulates genes expression
