Murine homeobox-containing gene, Msx-1: analysis of genomic organization, promoter structure, and potential autoregulatory cis-acting elements.
Detailed molecular organization of the coding and upstream regulatory regions of the murine homeodomain-containing gene, Msx-1, is reported. The protein-encoding portion of the gene is contained in two exons, 590 and 1214 bp in length, separated by a 2107-bp intron; the homeodomain is located in the second exon. The two-exon organization of the murine Msx-1 gene resembles a number of other homeodomain-containing genes. The 5'-(GTAAGT) and 3'-(CCCTAG) splicing junctions and the mRNA polyadenylation signal (UAUAA) of the murine Msx-1 gene are also characteristic of other vertebrate genes. By nuclease protection and primer extension assays, the start of transcription of the Msx-1 gene was located 256 bp upstream of the first AUG. Computer analysis of the promoter proximal 1280-bp sequence revealed a number of potentially important cis-regulatory sequences; these include the recognition elements for Ap-1, Ap-2, Ap-3, Sp-1, a possible binding site for RAR:RXR, and a number of TCF-1 consensus motifs. Importantly, a perfect reverse complement of (C/G)TTAATTG, which was recently shown to be an optimal binding sequence for the homeodomain of Msx-1 protein (K.M. Catron, N. Iler, and C. Abate (1993) Mol. Cell. Biol. 13:2354-2365), was also located in the murine Msx-1 promoter. Binding of bacterially expressed Msx-1 homeodomain polypeptide to Msx-1-specific oligonucleotide was experimentally demonstrated, raising a distinct possibility of autoregulation of this developmentally regulated gene.
Kuzuoka
M
M
Department of Medicine, University of Tennessee, Memphis.
Takahashi
T
T
Guron
C
C
Raghow
R
R
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D016384:Consensus Sequence; D005091:Exons; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D014158:Transcription, Genetic