1 - Oncoproteins and tumour suppressors in cytokine and WNT signalling

Question 1

APC:

Answer 1

Adenomatous polyposis coli – Tumour suppressor scaffold protein which helps form the degradation complex. When lost, β catenin is not phosphorylated and increased signalling occurs.

Question 2

Degradation/Destruction Complex:

Answer 2

Complex of proteins: Axin, APC, GSK and β catenin which results in the phosphorylation of β catenin and its degradation.

Question 3

FAP:

Answer 3

Familial adenomatous polyposis – Syndrome associated with the inherited loss of APC which results in thousands of polyps in the colon with a vastly increased chance of getting colon cancer.

Question 4

JAK:

Answer 4

Janus Kinase- a tyrosine kinase which is bound to the cytokine receptor. It is activated and the two JAKs phosphorylate each other when ligand binds. It then phosphorylates the tail of the receptor on tyrosine amino acids.

Question 5

SOCS:

Answer 5

Suppressors of cytokine signalling- tumour suppressor protein that inhibits JAK.

Question 6

STAT:

Answer 6

Signal transducers and activators of transcription – transcription factors activated by phosphorylation, on tyrosine amino acids, by JAK to form active dimers.