HLH106, a Drosophila transcription factor with similarity to the vertebrate sterol responsive element binding protein.
We cloned a Drosophila homolog to the sterol responsive element binding proteins (SREBPs). In vertebrates, the SREBPs are regulated by a mechanism that involves cleavage of the protein that normally residues in the cellular membranes and translocation of the released transcription factor into the nucleus. Regulation of the Drosophila factor HLH106 apparently follows the same mechanism, and we find the full-length gene product in the membrane fraction and a shorter cross-reacting form in the nuclear fraction. This nuclear form, which may correspond to proteolytically activated HLH106, is abundant in the blood cell line mbn-2. The general domain structure of HLH106 is very similar to that in SREBP. HLH106 is expressed throughout development, and it is present at high levels in Drosophila cell lines. In contrast to the rat homolog, HLH106 transcripts are not more abundant in adipose tissue than in other tissues.
Theopold
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Department of Molecular Biology, Stockholm University, Sweden.
Ekengren
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Hultmark
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D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D022762:CCAAT-Enhancer-Binding Proteins; D002458:Cell Fractionation; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000737:chemistry; D004330:Drosophila / Q000378:metabolism*; D029721:Drosophila Proteins; D015870:Gene Expression; D018257:Helix-Loop-Helix Motifs; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000737:chemistry; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017386:Sequence Homology, Amino Acid; D051780:Sterol Regulatory Element Binding Protein 1; D051779:Sterol Regulatory Element Binding Proteins; D014157:Transcription Factors / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D014158:Transcription, Genetic; D014714:Vertebrates
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; C098074:SREBP protein, Drosophila; C497389:Srebf1 protein, rat; D051780:Sterol Regulatory Element Binding Protein 1; D051779:Sterol Regulatory Element Binding Proteins; D014157:Transcription Factors