Mitochondrial creatine kinase (mtCK) (mtCK)

Mitochondrial creatine kinase (mtCK) is a key enzyme located in the mitochondrial intermembrane space, where it catalyzes the conversion of mitochondrial ATP and creatine into phosphocreatine and ADP (UniProt P12235, P17540). This process is central to the phosphocreatine shuttle, which facilitates the transport of high-energy phosphates from mitochondria to cytosolic sites of ATP consumption, such as myofibrils and ion pumps (Schlattner et al., 2006). There are two main isoforms: ubiquitous (uMtCK/CKMT1) and sarcomeric (sMtCK/CKMT2), which often form octameric complexes that can bridge the inner and outer mitochondrial membranes (Wallimann et al., 1992). In disease states, mtCK dysfunction is linked to impaired energy metabolism in heart failure and neurodegeneration, while its overexpression in certain cancers supports the high metabolic demands of tumor growth (Lodi et al., 2001; Patra et al., 2008). Therapeutic strategies involve either supplementing the system with creatine to improve energy buffering or targeting the enzyme with inhibitors like cyclocreatine to disrupt the energy supply of malignant cells (Miller et al., 2001).

Other names

Creatine kinase mitochondrialCKMTCKMT1CKMT2uMtCKsMtCKCreatine phosphokinase mitochondrialMitochondrial creatine kinase complexes

Catalyzes the reversible transfer of high-energy phosphate groups between ATP and creatine, facilitating energy transport and buffering via the phosphocreatine shuttle.