STRUCTURAL ORGANIZATION OF THE HUMAN CARDIAC ALPHA-MYOSIN HEAVY-CHAIN GENE (MYH6)

The human myocardium expresses two cardiac myosin heavy chain (MyHC) isoforms, α and β, that exist in tandem array on chromosome 14q12. We have previously sequenced the entire human cardiac β-MyHC gene and now report the complete nucleotide sequence of the human cardiac α-MyHC, encompassing 26, 159 bp as well as the entire 4484-bp 5’-flanking intergenic region. The gene (MYH6) consists of 39 exons, 37 of which contain coding information. The 5’- untranslated region is split into 3 exons, with the third exon containing the AUG translation initiation codon. With the exception of the 13th intron of the human cardiac β-MyHC, which is not present within the α-isogene, all exon/intron boundaries are conserved. Conspicuous sequence motifs contained within the α-MyHC gene include four Alu repeats, a single (GT)(n) element, and a homopurine-homopyrimidine tract containing 23 GAA repeating units followed by 10 GAG repeating units. Comparison of the encoded amino acid sequence with a previously reported human α-MyHC cDNA sequence reveals several potential polymorphisms. © 1994 Academic Press. All rights reserved.