CKMT2 belongs to the creatine kinase isoenzyme family, and is responsible for the transfer of high energy phosphate from mitochondria to the cytosolic carrier, creatine. It exists as two isoenzymes, sarcomeric CKMT2 and ubiquitous CKMT2, which are encoded by separate genes. Mitochondrial creatine kinase occurs in two different oligomeric forms: dimers and octamers, in contrast to the exclusively dimeric cytosolic creatine kinase isoenzymes. Sarcomeric mitochondrial creatine kinase has 80% homology with the coding exons of ubiquitous mitochondrial creatine kinase. This gene contains sequences homologous to several motifs that are shared among some nuclear genes encoding mitochondrial proteins and thus may be essential for the coordinated activation of these genes during mitochondrial biogenesis. Three transcript variants encoding the same protein have been found for this gene.