Protein sex-lethal

UniProtKB accession:  P19339

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Sex determination switch protein, which controls sexual development and dosage compensation in females (PubMed:10617208, PubMed:1547493, PubMed:1690860, PubMed:1710769, PubMed:19941818, PubMed:2503251, PubMed:25209665, PubMed:3144435, PubMed:7680770). Sxl protein is only active in females: it is inactive in males throughout development (PubMed:1547493, PubMed:1710769, PubMed:3144435). Acts as a mRNA-binding protein, which specifically binds to a subset of pre-mRNAs and mRNAs and regulates their processing and/or translation (PubMed:10217141, PubMed:10617208, PubMed:1690860, PubMed:19941818, PubMed:2503251, PubMed:7516476, PubMed:7680770). Promotes sexual development by controlling the female-specific alternative splicing of the transformer (tra) pre-mRNA: binds tightly to a characteristic uridine-rich polypyrimidine tract at the non-sex specific 3' splice site in one of the tra introns, preventing the general splicing factor U2AF from binding to this site and forcing it to bind to the female-specific 3' splice site (PubMed:10217141, PubMed:1690860, PubMed:2503251, PubMed:7680770). Acts as an inhibitor of dosage compensation in females by preventing production of msl-2 protein, an essential component of the MSL complex, the complex that mediates X-chromosome dosage compensation (PubMed:10545124, PubMed:10617208, PubMed:12769862, PubMed:16452508, PubMed:16452509, PubMed:19941818, PubMed:23788626, PubMed:25209665, PubMed:9144292, PubMed:9182767). Specifially binds to uridine stretches in both the 5'- and 3'-UTR of msl-2 transcripts (PubMed:10545124, PubMed:10617208, PubMed:12769862, PubMed:14532129, PubMed:16122421, PubMed:25209665, PubMed:9144292, PubMed:9182767). Sxl first acts at the splicing level by promoting retention of an intron in the 5' UTR of msl-2 pre-mRNA (PubMed:10617208). The retained intron contains Sxl-binding sites that are required for subsequent steps of repression: after msl-2 mRNA export into the cytoplasm, Sxl coordinates its translational repression by targeting early steps of translation initiation (PubMed:10545124, PubMed:12769862, PubMed:14532129, PubMed:16122421, PubMed:16452508, PubMed:16452509, PubMed:19941818, PubMed:9144292, PubMed:9182767). Together with how, Sxl also prevents production of msl-2 protein by preventing nuclear export of msl-2 transcripts (PubMed:23788626).