P53 Pathway Flashcards
Which aa does p53 have lots of
Proline
Name the 4 parts of p53
TAD
NLS
Text (tetramerisation domain)
DBD
What does tumour repressor p53 do to stabilise dna Eg if it’s damaged
Induces apoptosis
Or arrests cell cycle for dna repair
What attaches to p53 under normal conditions to constantly cause degradation via ubiquitination
Mdm2
What is mdm2
E3 ubiquitin ligase
What happens when a signal is seen Eg dna damage or over proliferation
Both p53 and mdm2 are phosphorylated which disrupts their interaction
What enzymes phosphorylate mdm2 and p53
ATM/ATR kinase
What nf system regulates p53 activity
Over stimulation of p53 causes it to upregulste mdm2 to inhibit it
Which tumour suppressor is upregulsred in presence of oncogenes/cell proliferation and why
P14 ARF
It disrupts the mdm2 and p53 interaction and therefore ubiquitination of p53
P53 can then act to stop tumour development via apoptosis or cell arrest
How can viral infections like papilloma increase cancer
E6 proteins mutate and inactivate p53 activity
Which 2 genes are mutated / don’t work in cancer cells which usually cause activation of p53
ATm kinase and P14 arf
What is amplified in cancer to cause inhibition of p53
Mdm2
Where does p53 mutation occur
In hotspots on its dbd
Which syndrome is a hereditary mutation in tp53 and therefore p53 which increases risk of cancer
LPS
What do all 3 pathways have in common
All rapidly activated bc already made in cytosol
All regulated by proteolysis
