A novel initiator regulates expression of the nontissue-specific helix-loop-helix gene ME1.
The mouse ME1 gene (HEB, REB and GE1, homologues in human, rat and chick, respectively) is a member of the nontissue-specific helix-loop-helix (HLH) gene family that includes E2A, E2-2 and Drosophila daughterless. We have examined the factors that control ME1 gene expression. ME1 is a single copy gene that spans > or = 150 kb of DNA and contains > 10 exons. Transcription was directed by an unusual initiator element that contained a 13 bp poly d(A) tract flanked by palindromic and inverted repeat sequences. Both RNase protection and primer extension analyses mapped the ME1 transcriptional start site to the center of the 13 bp poly d(A) tract. The ME1 initiator and its proximal sequences were required for promoter activity, supported basal levels of transcription, and contributed to cell type-specific gene expression. Other cis-elements utilized by the TATA-less ME1 promoter included a cluster of Sp1 response elements, E-boxes and a strong repressor. Collectively, our results suggest that the ME1 initiator and other cis-elements in the proximal promoter play an important role in regulating ME1 gene expression.
Shain
D H
DH
Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins 80523, USA.
Neuman
T
T
Zuber
M X
MX
D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D002460:Cell Line; D002645:Chickens; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D004330:Drosophila / Q000235:genetics; D005786:Gene Expression Regulation; D015698:Genomic Library; D018257:Helix-Loop-Helix Motifs / Q000235:genetics*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D005810:Multigene Family; D009838:Oligodeoxyribonucleotides; D051381:Rats; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D014162:Transfection
D051792:Basic Helix-Loop-Helix Proteins; D015500:Chloramphenicol O-Acetyltransferase; D004268:DNA-Binding Proteins; D009838:Oligodeoxyribonucleotides; D014157:Transcription Factors; C489532:Tcf12 protein, mouse; C073366:TCF12 protein, human