This gene encodes a transcription factor that contains four zinc finger motifs at the C-terminus and a proline / glutamine-rich DNA-binding domain at the N-terminus. It has an essential role in the normal development of the urogenital system, and it is mutated in a subset of patients with Wilms' tumor, the gene's namesake. Multiple transcript variants, resulting from alternative splicing at two coding exons, have been well characterized. There is also evidence for the use of non-AUG (CUG) translation initiation site upstream of, and in-frame with the first AUG, leading to additional isoforms.5
Wilm's tumour tumor suppressor gene1 (WT1) causes is an embryonic malignancy of the kidney, affecting around 1 in 10,000 infants. It occurs in both sporadic and hereditary forms. Inactivation of WT1 causes Wilm's tumour, and Denys-Drash syndrome (DDS), leading to nephropathy and genital abnormalities. The WT1 protein has been found to bind a host of cellular factors, e.g. p53, a known tumor suppressor.3789
The serine protease HtrA2 binds to WT1 and it cleaves WT1 at multiple sites following the treatment with cytotoxic drugs.1011
Editing is tissue specific and developmentally regulated. Editing shown to be restricted in testis and kidney in the rat.17 Editing of this gene product has been found to occur in mice and rats as well as humans.1719
The editing site is found at nucleotide position 839 found in exon 6 of the gene.It causes a codon change from a Proline codon (CCC) to a Leucine codon (CUC)17
The type of editing is a Uridine to Cytidine( U to C) base change .The editing reaction is thought to be an amidation of uridine which converts it to a Cytidine.The relevance of this editing is unknown as is the enzyme responsible for this editing.The region where editing occurs like that of other editing sites e.g. ApoB mRNA editing is conserved.Mice, rat and humans have conserved sequences flanking the editing site consiting of 10 nucleotides before the editing site and four after the site.17
Effects of editing
RNA editing results in an alternative amino acid being translated.17 The changes in amino acid occur in a region identified as a domain involved in transcription activation function.20
Editing has been shown to decrease repressive regulation of transcription of growth promoting genes in vitro compared to the non edited protein. Although the physiological role of editing has yet to be determined, suggestions have been made that editing may play a role in the pathogenesis of Wilms tumour.19
^Call KM, Glaser T, Ito CY, Buckler AJ, Pelletier J, Haber DA, Rose EA, Kral A, Yeger H, Lewis WH (February 1990). "Isolation and characterization of a zinc finger polypeptide gene at the human chromosome 11 Wilms' tumor locus". Cell60 (3): 509–20. doi:10.1016/0092-8674(90)90601-A. PMID2154335.
^ abGessler M, Poustka A, Cavenee W, Neve RL, Orkin SH, Bruns GA (February 1990). "Homozygous deletion in Wilms tumours of a zinc-finger gene identified by chromosome jumping". Nature343 (6260): 774–8. doi:10.1038/343774a0. PMID2154702.
^Huang A, Campbell CE, Bonetta L, McAndrews-Hill MS, Chilton-MacNeill S, Coppes MJ, Law DJ, Feinberg AP, Yeger H, Williams BR (November 1990). "Tissue, developmental, and tumor-specific expression of divergent transcripts in Wilms tumor". Science250 (4983): 991–4. doi:10.1126/science.2173145. PMID2173145.
^Han Y, San-Marina S, Yang L, Khoury H, Minden MD (2007). "The zinc finger domain of Wilms' tumor 1 suppressor gene (WT1) behaves as a dominant negative, leading to abrogation of WT1 oncogenic potential in breast cancer cells.". Breast Cancer Res9 (4): R43. doi:10.1186/bcr1743. PMC2206716. PMID17634147.
^Rauscher FJ (July 1993). "The WT1 Wilms tumor gene product: a developmentally regulated transcription factor in the kidney that functions as a tumor suppressor". FASEB J.7 (10): 896–903. PMID8393820.
^Buckler AJ, Pelletier J, Haber DA, Glaser T, Housman DE (March 1991). "Isolation, characterization, and expression of the murine Wilms' tumor gene (WT1) during kidney development". Mol. Cell. Biol.11 (3): 1707–12. PMC369476. PMID1671709.
^Little MH, Prosser J, Condie A, Smith PJ, Van Heyningen V, Hastie ND (June 1992). "Zinc finger point mutations within the WT1 gene in Wilms tumor patients". Proc. Natl. Acad. Sci. U.S.A.89 (11): 4791–5. PMC49173. PMID1317572.
^Leong AS-Y, Cooper K, Leong FJW-M (2003). Manual of Diagnostic Cytology (2 ed.). Greenwich Medical Media, Ltd. pp. 447–448. ISBN1-84110-100-1.
^Davies RC, Calvio C, Bratt E, Larsson SH, Lamond AI, Hastie ND (October 1998). "WT1 interacts with the splicing factor U2AF65 in an isoform-dependent manner and can be incorporated into spliceosomes". Genes Dev.12 (20): 3217–25. doi:10.1101/gad.12.20.3217. PMC317218. PMID9784496.
^Johnstone RW, See RH, Sells SF, Wang J, Muthukkumar S, Englert C, Haber DA, Licht JD, Sugrue SP, Roberts T, Rangnekar VM, Shi Y (December 1996). "A novel repressor, par-4, modulates transcription and growth suppression functions of the Wilms' tumor suppressor WT1". Mol. Cell. Biol.16 (12): 6945–56. PMC231698. PMID8943350.
^Wang ZY, Qiu QQ, Seufert W, Taguchi T, Testa JR, Whitmore SA, Callen DF, Welsh D, Shenk T, Deuel TF (October 1996). "Molecular cloning of the cDNA and chromosome localization of the gene for human ubiquitin-conjugating enzyme 9". J. Biol. Chem.271 (40): 24811–6. doi:10.1074/jbc.271.40.24811. PMID8798754.
Heathcott RW, Morison IM, Gubler MC, et al. (2002). "A review of the phenotypic variation due to the Denys-Drash syndrome-associated germline WT1 mutation R362X". Hum. Mutat.19 (4): 462. doi:10.1002/humu.9031. PMID11933209.