| *300480 | ||||
| TAK1-BINDING PROTEIN 3 | ||||
| Alternative titles; symbols | ||||
| TAB3 | ||||
| HGNC Approved Gene Symbol: TAB3 | ||||
| TEXT | ||||
| Cloning | ||||
| By random activation of gene expression (RAGE), Jin et al. (2004) generated a limited protein expression library in a transgenic NF-kappa-B (see 164011) reporter cell line, and the library was selected for cells that constitutively activated NF-kappa-B. By RT-PCR and 3-prime RACE of one of these clones, they obtained full length TAB3 and a splice variant that excludes exon 10. They termed the full length variant TAB3a, and the splice variant TAB3b. TAB3a encodes a deduced 712-amino acid protein that contains an N-terminal CUE domain, a central coiled-coil region, and a C-terminal zinc finger domain. The CUE domain is expected to direct self-monoubiquitylation. TAB3b encodes a deduced 684-amino acid protein that lacks 28 amino acids between the coiled-coil domain and the zinc finger domain. Within their C-terminal zinc finger domains, TAB3 shares 82% identity with TAB2 (605101). Overall, TAB3 shares 67% identity with X. laevis Tab3. PCR analysis detected both transcripts in all tissues examined, which included kidney, brain, prostate, and peripheral blood leukocytes. TAB3b represented 13 to 20% of the total TAB3 transcripts. RNA dot blot analysis detected expression in matched normal and tumor cells of testis, skin, and small intestine, with higher expression in most tumor samples. | ||||
| Gene Function | ||||
| Jin et al. (2004) found that both TAB3a and TAB3b increased expression from an IL8 (146930) promoter. Overexpression of TAB3 activated both NF-kappa-B and AP1 (see 165160) transcription factors. The activation of NF-kappa-B was blocked by an NF-kappa-B inhibitor, and by expression of dominant negative forms of TNF-alpha (TNFA; 191160)-associated factor 6 (AF6; 159559) and TGF-beta (TGFB; 190180)-activated kinase (AK) indicating that TAB3 is a constituent of the NF-kappa-B pathway, functioning upstream of TNFA-AF6 and TGFB-AK. Overexpression of TAB3 resulted in cellular transformation of NIH 3T3 mouse fibroblasts. | ||||
| Gene Structure | ||||
| Jin et al. (2004) determined that the TAB3 gene contains at least 12 exons. The open reading frame (ORF) begins in exon 6 and ends in exon 12. They predict the possibility of an additional uncharacterized upstream exon that may contribute to the 5-prime UTR. | ||||
| Mapping | ||||
| Jin et al. (2004) stated that TAB3 maps to chromosome X. | ||||
| REFERENCES | ||||
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