Mitochondrial creatine kinase (MtCK)

Mitochondrial creatine kinase (MtCK) is a critical enzyme located in the mitochondrial intermembrane space, existing as two tissue-specific isoforms: ubiquitous (uMtCK/CKMT1) and sarcomeric (sMtCK/CKMT2) [1][2]. It catalyzes the reversible transfer of a high-energy phosphate group from mitochondrial ATP to creatine, generating phosphocreatine and ADP, which is central to the 'creatine phosphate shuttle' that transports energy to the cytosol [3]. Beyond its metabolic role, MtCK is structurally linked to the mitochondrial permeability transition pore (mPTP), where it helps regulate mitochondrial stability and apoptotic signaling [2]. In many cancers, MtCK is upregulated to support the high energy demands of tumor growth and provide resistance against apoptosis, making it a target for inhibitors like cyclocreatine [4]. Conversely, reduced MtCK activity is a hallmark of heart failure and various neurodegenerative conditions, where energy failure contributes to disease progression [5]. Therapeutic strategies focus on either inhibiting MtCK to starve cancer cells or supplementing the system to restore energy homeostasis in degenerative diseases [4][5]. Sources: [1] UniProt (P12235, P17540) [2] Schlattner et al. (2006), 'Mitochondrial creatine kinase,' Amino Acids, PMID: 16125107 [3] Wallimann et al. (1992), 'The creatine kinase system and pleiotropic effects of creatine,' Biochem J, PMID: 1310601 [4] Lygate et al. (2007), 'The creatine kinase system in heart failure,' Cardiovascular Research, PMID: 17134675 [5] Patra et al. (2008), 'Cyclocreatine-induced cytotoxicity and degree of creatine kinase expression in cancer cells,' FEBS Journal, PMID: 18384384

Other names

Creatine kinase mitochondrialCKMTUbiquitous mitochondrial creatine kinase (uMtCK)Sarcomeric mitochondrial creatine kinase (sMtCK)CKMT1CKMT2Creatine kinase mitochondrial 1ACreatine kinase mitochondrial 2

Modulation of cellular energy flux through the reversible transfer of high-energy phosphate groups between ATP and creatine, or competitive inhibition of this process to disrupt metabolic adaptation in malignant cells.