Abstract
The inhibition of male-specific lethal 2 (msl-2) mRNA translation by the RNA-binding protein sex-lethal (SXL) is an essential regulatory step for X-chromosome dosage compensation in Drosophila melanogaster. The mammalian upstream of N-ras (UNR) protein has been implicated in the regulation of mRNA stability and internal ribosome entry site (IRES)-dependent mRNA translation. Here we have identified the Drosophila homolog of mammalian UNR as a cofactor required for SXL-mediated repression of msl-2 translation. UNR interacts with SXL, a female-specific protein. Although UNR is present in both male and female flies, binding of SXL to uridine-rich sequences in the 3' untranslated region (UTR) of msl-2 mRNA recruits UNR to adjacent regulatory sequences, thereby conferring a sex-specific function to UNR. These data identify a novel regulator of dosage compensation in Drosophila that acts coordinately with SXL in translational control.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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3' Untranslated Regions / metabolism
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Animals
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism*
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DNA-Binding Proteins / physiology*
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Dosage Compensation, Genetic* / physiology
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Drosophila / genetics*
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Drosophila / metabolism
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Drosophila Proteins / genetics
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Drosophila Proteins / metabolism*
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Drosophila Proteins / physiology*
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Female
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Male
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Nuclear Proteins / physiology*
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Protein Biosynthesis / physiology*
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RNA-Binding Proteins / genetics
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RNA-Binding Proteins / metabolism
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Repressor Proteins / metabolism
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Transcription Factors / physiology*
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X Chromosome / metabolism*
Substances
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3' Untranslated Regions
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DNA-Binding Proteins
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Drosophila Proteins
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Nuclear Proteins
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RNA-Binding Proteins
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Recombinant Fusion Proteins
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Repressor Proteins
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Sxl protein, Drosophila
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Transcription Factors
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UNR protein, Drosophila
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msl-2 protein, Drosophila