ES1 Protein Homolog, Mitochondrial (ES1)

The cDNA fragment GT335, corresponding to the C21ORF33 gene, spanned an estimated 13 kb of genomic DNA and was split into 7 exons. Five of the 6 introns conform to the GT...AG consensus for intronic splice junctions. The sixth contains nonconventional (AT...AC) intronic junctions. Several sequence variations, 2 of which caused conserved amino acid substitutions, were found.The full cDNA sequence corresponds to an mRNA of 1.7 kb with an open reading frame of 268 amino acids. The mRNA from this gene, termed HES1 by the authors, is ubiquitously expressed, but strongly so in heart and skeletal muscle. Potential mitochondrial targeting signals were found in both the human and the zebrafish proteins, consistent with the high expression level in muscle tissues.