Creatine kinase MT 1A: Proteins and Enzymes

Mitochondrial creatine (MtCK) kinase is responsible for the transfer of high energy phosphate from mitochondria to thecytosolic carrier, creatine. It belongs to the creatine kinase isoenzyme family. It exists as two isoenzymes,sarcomeric MtCK and ubiquitous MtCK, encoded by separate genes. Mitochondrial creatine kinase occurs in two differentoligomeric forms: dimers and octamers, in contrast to the exclusively dimeric cytosolic creatine kinase isoenzymes.Many malignant cancers with poor prognosis have shown overexpression of ubiquitous mitochondrial creatine kinase; thismay be related to high energy turnover and failure to eliminate cancer cells via apoptosis. Ubiquitous mitochondrialcreatine kinase has 80% homology with the coding exons of sarcomeric mitochondrial creatine kinase. Two genes locatednear each other on chromosome 15 have been identified which encode identical mitochondrial creatine kinase proteins.(provided by RefSeq)