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| | Genomic organization (A) and transcript variants (B) of BRWD3. (A) Gene structure (drawn to scale): black boxes represent exons. (B) Transcripts (drawn to scale): boxes, exons; UTR, untranslated region; light shaded box, coding region; shaded and dark shaded boxes, nucleotide sequences coding for protein domains (WD40: WD40 tandem repeats; BROMO: bromodomain). For transcript variants BRWD3-C to BRWD3-P only the largest possible coding regions are indicated, though translation of different short proteins by using the start sites of BRWD3-A and BRWD3-B might also be possible. |
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| Description | 44 exons spanning 132.7 kb genomic DNA |
| Transcription | 5.6-6.2 kb mRNA, coding sequence: 4.2-5.4 kb
Alternative splicing results in the expression of at least 15 transcript variants (BRWD3-A to BRWD3-P): The two most abundant transcript variants A and B are the result of alternative splicing of the first four exons (BRWD3-A contains exons 1 to 4, whereas BRWD3-B starts with an extended version of exon 4). BRWD3-C to BRWD3-P represent alternatively spliced variants of A and B, which contain additional exons 6a, 6b, and/or 12a and lack exons 3, 5, 6, 7, 8, and/or 9. |
| Pseudogene | None. |
| Description | The amino-terminal region consists of eight tandem WD40 repeats, which had been identified as the structural determinant of the beta -subunit of the G-proteins that mediateting transmembrane signal transduction. The carboxy terminus is predicted to contain two bromodomains with the potential to mediate protein-protein interactions in DNA-binding proteins. BRWD3-C to BRWD3-P are amino-terminally truncated versions of BRWD3-A and BRWD3-B, which retain three or four of the eight WD40 repeats and both bromodomains. |
| Expression | Expressed in a variety of adult tissues (lymphocytes, brain, heart, kidney, placenta) and in fetal liver. |
| Function | By performing a systematic genomewide survey for genes required for JAK/STAT pathway activity (involved in cell proliferation and haematopoiesis), the Drosophila homologon of BRWD3 was isolated as a member of the JAK/STAT signalling cascade acting downstream of JAK. In vivo analysis demonstrated that disrupted Drosophila BRWD3 functions as a suppressor of leukemia-like blood cell tumors. |
| Homology | Drosophila melanogaster: BRWD3
Mouse: Brwd3
Pan troglodytes: BRWD3 |
| Translocation t(X;11)(q13;q23) in B-cell chronic lymphocytic leukemia disrupts two novel genes. |
| Kalla C, Nentwich H, Schlotter M, Mertens D, Wildenberger K, Dhner H, Stilgenbauer S, Lichter P |
| Genes, chromosomes & cancer. 2005 ; 42 (2) : 128-143. |
| PMID 15543602 |
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| Identification of JAK/STAT signalling components by genome-wide RNA interference. |
| Mšller P, Kuttenkeuler D, Gesellchen V, Zeidler MP, Boutros M |
| Nature. 2005 ; 436 (7052) : 871-875. |
| PMID 16094372 |
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