Wilms Tumour Protein

Question 1

What mutations occur in WAGR

Answer 1

Mainly nonsense mutation

Constituitional 11p13 deletions

Question 2

What is the phenotype and mutation in Denys-Drash Syndrome

Answer 2

Pseudohermaphrodism, nephropathy and predisposition to Wilms tumour

Mainly missense mutation in ZF domain and promoter truncations

Question 3

What mutations often occur in leukaemia regarding Wt1

Answer 3

Mutations small insertions on exons 1 & 7

Question 4

What mutations often occur in desmoplastic round cell tunmours and WT1

Answer 4

mainly EWS fusion proteins with Zinc Fingers 2 -4

Produces a phenotypically immature tumour tumour with a higher odds in young males

Question 5

when is wt1 involved in EMT

Answer 5

Heart vasculatore formation

Question 6

When is wt1 invovled in MET

Answer 6

IN kidney and gonad development

Question 7

How does WT1 regulate EMT

Answer 7

Activates SNAIL and directly represses E-Cadherin

Question 8

What does WT1 regulate to control adult tissue homeostasis

Answer 8

IGF2

Question 9

What occurs if you get WT1 knockout in adult mice

Answer 9

Die after 9 days
Often display loss of visceral fat and bone
Also get pancreatic atrophy and renal atrophy

Question 10

what lieage of cells is wt1 particularly important to maintain

Answer 10

Haematopoeitic cells

Question 11

If you lose wt1 what type of fat do you lose and what type do you keep

Answer 11

Lose visceral fat

However wt1 not detected in subcutaneous and BAT fat hence these arent affected

Question 12

Describe the structure of WT1

Answer 12

Very complex gene
10 exons, at least 36 isorforms
4 main isoforms are +/-KTS splice variant and +/- exon 5 par4 binding domain
Has 4 Zn fingers all in seperate exons

Question 13

What is the antisense of WT1 called

Answer 13

AWT1

Question 14

What is towards the N terminus of WT1

Answer 14

a dimerization domain
Transactivation domain
transrepression domain

Question 15

How do phosphorylation and sumolytion affect WT1

Answer 15

Phosphorylation of WT1 zinc fingers however doesnt affect nuclear localisation
Sumolyation DOES affect nuclear localisation and instead WT1 often found with splice factors

Question 16

What proteins interact with WT1

Answer 16

WTX –> wilms tumour associated protein
STAT3
BASP1
HtrA2

Question 17

What is the interaction of HtrA2 and WT1

Answer 17

Interacts with the suppression domain
Cleaves WT1 in several places
Makes more oncogenic forms of WT1

Question 18

What genes does normal WT1 repress

Answer 18

hTERT
Cyclin E
bcl-2

Question 19

What genes does normal WT1 induce

Answer 19

E-Cadherin

p21

Question 20

How does WT1 act in regards to Wnt4 in the kidney

Answer 20

Induces Wnt4

Recurits CBP/p300 coactivators

Question 21

How does WT1 act in regards to Wnt4 in the epicardium

Answer 21

Binds wnt4, recruits repressors e.g. BASP1

Question 22

What is the key regulator for kidney development

Answer 22

WNT4 that is at least partially transcriptionally regulated by Wt1

Question 23

What is the role of WT1 in RNA metabolism

Answer 23

+KTS Splice isoforms co localise in speckles, coiled bodies and nuclear bodies and are inovlved in RNA splicing

Question 24

What do Wt mutations often occur with

Answer 24

GOF of Beta catenin

Question 25

How many isoforms of Wt1 do non-mammals have

Answer 25

2 only have the +/- KTS isoforms

Question 26

Describe the mechanism of mutant Wt1 in Denys-Drash syndrome

Answer 26

Operates in a dominant-negative fashion –> where the mutant Wt can dimerise with the WT proteins

Question 27

What occurs in Meachan syndrome

Answer 27

CHD renal abnormalities

Question 28

What is necessary AND sufficient to undce MET in the metanephric mesenchyme

Answer 28

Wnt4

Question 29

What is wnt essential for in adult life

Answer 29

The maintenenance and differentiation of podocyte cells

Question 30

What is Wt fucntions in kidney development

Answer 30

Target genes for kidney development: PAX2, Sal< BMP7, Wnt4

Target genes for mesenchyme proliferation: Induces FGFs and represses BMP/SMAD signalling

Question 31

Why is Wt1 essential for diaphragm formation

Answer 31

Wt1 is needed to induce EMT in the post hepatic plate coleomic epithelium –> if defective then get congential diaphragmatic hernias

Question 32

How is Wt1 essential in sertoli cells

Answer 32

Cooperates with GATA4 to activate SRY which underlies Sertoli cell development

Question 33

What happens to Wt1 following cardiac ischaemia

Answer 33

Can be reactivated to produce new EPDCs whcih could give rise to new cardiac vasculature

Question 34

What happen sif you delete Wt1 in adults

Answer 34

Death due to loss of bone and visceral fat and severe glomeruosclerosis

Question 35

What can induce Wt1 in hypoxia

Answer 35

HIF-1 –> therefore there coudl be a potential role of exploiting Wt1 to respond to ischaemia

Question 36

How does Wt1 -KTS isoforms affect DNA

Answer 36

Bidns to DNA - first Zn finger just adds stability

can act as an activator or repressor depending on partner

Question 37

How can wt1 affect epigenetics

Answer 37

Can increases TET2 enzyme

Question 38

How does Wt1 bind to RNA

Answer 38

THe +KTS isoform –> idning does require the first Zn finger. Affets RNA stability and splicing
Also binds to Wilms Tumour Associated Protein

Question 39

What can WT1 also contol regarding RNa Pol II

Answer 39

Can control the differential occupancy of RNA PolIII relative to the Wnt4 transcritpional start site –> i.e. elongating PolII wnt TSS in kidney but stalling in the epicardium

Question 40

What does the chromatin flip flop refer to

Answer 40

Refers to the domain wide chromatin switch, rather than just the differential bidning of Wt1 to Wnt4 and this can determine the outcome of Wt1 action.