The murine atrial myosin light chain-2 gene: a member of an evolutionarilyconserved family of contractile proteins

Recently the near complete cDNA of the regulatory atrial myosin light chain (MLC-2a) was cloned. The atrial specific isoform has been shown to be a us eful molecular marker for cardiac chamber specification. Therefore, the reg ulatory sequence of the gene will provide clues on cardiomyocyte differenti ation and atrial specific transcription regulation. Here we report the iden tification of the murine genomic sequence of the MLC-2a gene (Mylc2a). The entire 5' flanking region was identified and sequenced. In addition, the ex on-intron boundaries and 3' flanking region were determined. Sequence compa rison revealed the presence of the final exon (11) of the mouse glucokinase gene on chromosome 11, 2.0 kb upstream of the Mylc2a transcription start s ite. In addition, we compared the structure of the gene to other myosin lig ht chains to show evolutionary conservation. The intron-exon boundaries tur ned out to be highly conserved and an increasing intron size in more comple x mammalian species was found. At the amino acid level there is 95 % homolo gy between the human and mouse MLC-2a sequence. Copyright (C) 2000 S. Karge r AG, Basel.