A human muscle adenine nucleotide translocator gene has four exons, is located on chromosome 4, and is differentially expressed

The human heart-skeletal muscle adenine nucleotide translocator (ANT1) gene was isolated and sequenced. It spans 5.8 kilobases and contains four exons. The 5'-nontranscribed region contains typical CCAAT and TATA sequences, a 22-nucleotide pair inverted repeat and 13-nucleotide pair sequence homologous to a similar region in the ATP synthase β subunit gene. The region surrounding the first exon and intron is G+C-rich, and the intron contains three Sp1 binding motifs. ANT1 was assigned to chromosome 4 using both flow-sorted chromosomes and segregating human-mouse hybrid cells. Additional ANT sequences were found on at least two other chromosomes. ANT1 transcripts were present at high levels in human heart and skeletal muscle but were almost undetectable in liver, kidney, and brain. By contrast, fibroblast ANT (ANT2) mRNAs were present in all five tissues. The unique nature and arrangement of the ANT1 transcriptional control elements may account for this differential expression.