Shared Flashcard Set

Details

Membrane Receptor Tyrosine Kinase
EXAM 2
25
Medical
Professional
09/01/2010

Additional Medical Flashcards

 


 

Cards

Term
what are the 3 classes of receptor tyrosine kinases?
Definition
cytosol EGF, Insulin, and PDGF receptors
Term
Explain the concept of recetpor tyrosine kinase dimerization and cross phosphorylation
Definition
Growth factor binds bringing both strands togheter.
the binding causes cross phosphorylation in the cytoplasm
Term
what are the two roles of autophosphorylation?
Definition
P of Tyrosine in the catalytic domain increases protein kinase activity
Phosphorylation of tyrosine outside the catalytic domain creates binding sites for other proteins that transmit signals downstream of the activated receptors
Term
What binds to the phosphotryosines in the initial reaction?
Definition
SH2 domain
Term
Name 3 signaling molecules that contain the SH2 domain
Definition
PI 3-kinase
GTPase activating protein (GAP)
Phospholipase
Term
what type of receptor does the SH2 domains bind?
Definition
PDGF receptor
Term
what is the action of PI 3 Kinase?
Definition
phosphorylation of the third phosphate of PIP2-->PIP3
Term
which molecules activate Akt?
Definition
mTOR/rictor complex, PIP3, and PDK
Term
what is the function of S6 kinase?
Definition
controls translation by phosphorylating ribsomal protein
Term
what is eIF4E?
Definition
inhibition factor
Term
how mTOR regulate S6 kinase and eIF4E binding protein
Definition
it activates S6 and inhibits eIF4E leading to translation of proteins
Term
How does insulin bring the glut4 transporter to the membrane?
Definition
insulin binds to IRS-1-->PI3K-->PIP2 TO PIP3-->PDK-->PKB-->Stimulates factors to express membrane transportation
Term
once inside, can G6P diffuse out of the cell?
Definition
No. this helps keep the gradient of glucose flowing into the cell
Term
if growth factors are not present, what happens to FOXO?
Definition
Akt is inactive, and FOXO stimulates gene to get in there and f' shit up
Term
what is BcL-2 effect on cell?
Definition
when activated by the Akt pathway, it inhibits cell death
Term
there are two forms of PLC. what are they?
Definition
PLC-beta, which is stimulated by G proteins

PLC-gamma which has SH2 domains that bind with tyrosine kinase
Term
activation of MAPK (ERK)is mediated by two upstream protein kinases, which are coupled to growth factor receptors by the Ras GTP-binding protein.
Definition
Term
what is ras activated by?
Definition
guanine nucleotide exchange factor (SOS)
Term
what deactivates Ras?
Definition
GTPase activating protein (raf)
Term
what happens to mutations in Ras genes?
Definition
GTP hydrolysis is inhibited, leading to overproliferation even in the absence of growth factors
Term
what happens when ERK gets into the nucleus?
Definition
It phosphorylates Elk-1 and that along with SRF bind to the SRE and activate transcription.
Term
what is the specificity of MAPK signaling maintained by?
Definition
their physical association on scaffold proteins
Term
what is the purpose of the protein scaffold KSR?
Definition
holds signaling molecules in place
Term
what effect does Tel have on growth receptors?
Definition
they are constituitively on.
Term
what is gefitinib's therapeutic effect?
Definition
bind to the ErbB (EGF) receptor in inhibit oncogenic behavior
Supporting users have an ad free experience!