RTKs Flashcards
What does dimerization cause in RTKs
allows for trans-autophsophorylation of cytoplasmic domains
What happens when the ligand binds to the ligand binding region of RTKS
causes a confrimational change
What gets phosphorylatesd on RTKS
Tyrosine
What does the phosphorylated tyrosine do
Act as a docking site for SH2 domains
What are adapter proteins
Contain unique domains that recognize specefic sequences
What Rous figure out about cancer
That is is a retrovirus which encodes a tyrosine kinase
What does the normal Src have vs v-src
The normal one has a carboxyl terminus the virus one doesn’t
What does the carboxyl terminus do
It is phosphorylated which acts as an inihibtory phoshphorylation because when it is phosphorylated it it stops the kinases
What is RAS
It is a GTPase switch protien it is waht binds to the GTP or GDP
Whats the difference between RAS and Ga
It is smaller
Lower GTPAse activtiy
Not linked directly to cell-surface receptors
How does RAS get activated
FGF binds to FGFR it dimerizes and phoshporylates then SH2 binds to phosphotyrosine and SH3 binds to Sos which binds to Ras
Sos is a GEF and it now active
What is the downstream kinase cascade
RAS-GTP
Activates RAF
MEK
MAPK
What does MAPK do
Gene controllng, cell cycle, cell growth
What is MAPK also called
ERK extracellular signal-regulated kinase
What does RAf bind to
S/T
What does MEK bind to
S/T/Y
What does MAPK bind too
S,T
What happens when there is a mutation in an activating protein NF1
It is a gap protien that swtiches from GTP Ras to GDP form and when it is inactive it is always in the GTP form and constantly turing Kinases on
What happens if there is a mutation in EGF receptor 2 (Her2)
It will causes dimerization and activation of receptor in absence of ligand
What happens when the exterior is cleaved
It is binding EGF receptors leads to constitutive activation of cytoplasmic kinase domain
Does HER2 bind to a ligand
NO
What does HER 2 bind with
EVERYTHING
What are the four ways that Herceptin can target HER2
- Makes sure that it doesn’t get cleaved
- Physically prevents them from hetero dimerizing
- Trigger a T-cell an immune response triggers a cytosolic signal and selective death
- Directed to lysosome physically removing it
