Tyrosine Kinases Flashcards
1
Q
How was it shown RSV caused cancer through a gene?
A
- A temperature dependent form of the virus was used which could only cause cancer at low/medium temperatures
- Even after many cell generations daughter cells still temp dependent
2
Q
How was the section of RSV which caused cancer found?
A
- Make cDNA of WT virus
- Transform WT with genome of a deletion mutant which is non-transforming
- Use enzyme which digests ds nucleic acids
3
Q
How was it shown that it was the kinase activity of v-src which is important in cancer?
A
- Did a western blot and added ATP
- In WT RSV there was high kinase activity and cancer
4
Q
What does the SH2 domain of Src bind to?
A
Phosphorylated tyrosine residues
5
Q
What does the SH3 domain bind to?
A
Pro-x-x-pro type II poly-proline helix
6
Q
How is src regulated?
A
- 2 phosphorylation sites
- One in active loop the other on the end of the protein
7
Q
What is lost in viral Src form causing constitutively active kinase?
A
The regulatpry Y530 residue
8
Q
How does Y530 regulate Src?
A
- When phosphorylated Y530 forms a binding site for Src’s own SH2 domain
- Intramolecular interaction forms and creates a hairpin structure
- This sequesters the catalytic domain
9
Q
Why can v-src cause cancer?
A
- kinase constitutively active
- generates lots of signalling and puts cells into overdrive
