Regulation of Gene Expression: HIF-1 Flashcards
hypoxia
decreased oxygen to tissues
2 tfs for hpoxia
hil1alpha and hil2 alpha
-cleavage
hif1
when active promotes increased blood flow, creation of blood, glycolysis, etc. through activation of large number of genes
what promotes degradation of hif1
prolyl hydroxlases and lysyl acetylases
-endables recognition by VHL (part of e3/ubi system)
cys-nitrosylation
promotes transcription of genes promoted by HIF1
VDU
deubiquiniates Hif1
PDH and VHL
targets HIF1 for proteasome
O2 dependent vs independent actication
dependent-occurs at transcriptional level (changes in metabolism)
independent-changes in protein synthesis
- trasnlation leel
- growth factors stimulate mTOR/Sbkinase
- mir210 inhibits transcription of mormoxic genes
- occurs under growth conditions
NfKb
p50/p56
reduce transcription of genes involves in inflammantory response
-inhibited by Ik-beta
Ik-beta kinase
kinase that phosphorylates IkB to make IkB degraded so NfKb can exhibit fucntion
Ik-beta
inhibits NfKb-meads ik-beta kinase to get rid of
what is point of being hypoxic
provides stimulus for embryogenesis/wound healing/maintains pluripotency of stem cells
ischemia
inadequate blood supply to part of body
tumors effects on oxygen conditions
make tissue hypoxic
how does high altitude lead to hypoxia
air pressure lessens as altitude increases
air holds less molecules and indivudal gas pressure is less
low number of oxygen per area/lower oxygen pressure
barometric pressure vs altitude
inverse relationship
symptoms of increased elevation
in order of increasing elevation
altered night vision, dizziness, learning/memory impaired, loss of consciousness, hallucinations,, etc.
-also depends how fast you change!
Acclimitization
adjustment to higher altitude
- depends on how high/how fast
- mediated by Hifi
what promotes hi1 protein synthesis
mtor/s6-kinase
what two enzymes control degredation (but both do not degrade)
VHL and VDU
what post translational mods promote degradation of Hif1
proloyl hydroxylation and lysyl acetylation