Lec 8 - Wilms tumour (WT1) supressor gene

Question 1

What is the loci of WT1?

Answer 1

Chromosome 11p13

Question 2

What is the function of WT1?

Answer 2

Tumour supressor

Question 3

What is WT1 (50kb)?

Answer 3

4 zinc fingers in carboxyl terminus for DNA binding

consist of 10 exons

Has a glutamine-proline rich amoni terminus that mediates transcription repression

Question 4

Significance of Exon 5

Answer 4

An alternative splicing site

encodes protein-protein interaction (17AA) including 5 serines and 1 threonine

Question 5

Significance of Exon 9

Answer 5

Lysine,threonine and serine that modulates DNA binding and RNA processing

expression is constant in all tissues

Question 6

What is the significance of KTS region of WT1 gene?

Answer 6

disrupts spacing between zinc finger 3 and 4

reduction in DNA binding

Association with splicing factors

Question 7

What post-translational modification does WT1 protein undergo?

Answer 7

Phosphorylation ser365 and ser393 of C-terminus by PKA (cAMP dependant)

Effect:
No DNA binding ability
Sequestration of WT1 protein
Decrease in WT1 transcriptional repression

Question 8

What does Wt1 target?

Answer 8

Genes critical for differentiation of specific cell types (Dax1,AMF,SRY)

Genes in cell cycle regulation and apoptosis (p21,p27,Bcl2,EGFR,cyclin E, E-cadherin)

Question 9

How are isoforms of WT1 analyzed?

Answer 9

PCR > Capillary electrophoresis