CKMT2 Gene - Mitochondrial Creatine Kinase 2
Key enzyme in cellular energy homeostasis, predominantly expressed in cardiac and skeletal muscle.
Gene Information Card
| Symbol | CKMT2 |
|---|---|
| Full Name | Creatine kinase, mitochondrial 2 (sarcomeric) |
| Gene Type | Protein coding |
| Chromosomal Location | 5q14.1 |
| NCBI Gene ID | 1160 ncbi.nlm.nih.gov/gene/1160 |
| Ensembl ID | ENSG00000113520 |
| UniProt ID | P17540 |
| OMIM ID | 602375 |
| HGNC ID | 1997 |
| Aliases | CKMT2, SMTCK, MTCK, MtCK, sarcomeric mitochondrial creatine kinase |
Description
CKMT2 encodes the sarcomeric isoform of mitochondrial creatine kinase, a key enzyme in the creatine/phosphocreatine energy shuttle. It is primarily expressed in cardiac and skeletal muscle, where it catalyzes the reversible transfer of a phosphate group from ATP to creatine, generating phosphocreatine. This high-energy phosphate reservoir is crucial for maintaining cellular ATP levels during periods of high energy demand. Mutations in CKMT2 have been associated with mitochondrial myopathy and cardiomyopathy.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cardiomyopathy, dilated, 1BB (CMD1BB) | Impaired energy buffering due to reduced phosphocreatine synthesis in cardiac muscle | OMIM #615235; ClinVar |
| Mitochondrial myopathy | Defective mitochondrial creatine kinase activity leads to energy deficiency in skeletal muscle | OMIM; PubMed studies |
| Creatine deficiency syndromes (secondary) | Altered CKMT2 expression may contribute to systemic creatine metabolism disorders | NCBI Gene; literature review |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 78.2 | High |
| Skeletal muscle | 65.4 | High |
| Brain | 1.3 | Low |
| Liver | 0.2 | Not detected |
| Kidney | 0.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Cardiomyocytes (AC16) | 82.1 | High expression; consistent with cardiac origin |
| Skeletal muscle myoblasts (LHCN-M2) | 70.5 | High expression; differentiation-dependent |
| HEK293 | 0.8 | Very low; non-muscle cell line |
| HeLa | 0.3 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.122G>A (p.Arg41Gln) | Missense | <0.01% | Reduced enzyme activity; associated with dilated cardiomyopathy |
| c.563C>T (p.Thr188Met) | Missense | <0.01% | Impaired substrate binding; reported in mitochondrial myopathy |
| c.784delC (p.Leu262Trpfs*12) | Frameshift | <0.001% | Loss of function; truncation of C-terminal domain |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations (e.g., c.784delC) lead to truncated, non-functional protein, reducing phosphocreatine production.
Gain of Function (GOF)
No gain-of-function mutations reported for CKMT2.
Dominant Negative (DN)
Missense mutations (e.g., p.Arg41Gln) may exert dominant-negative effects by interfering with dimerization or substrate binding.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Creatine metabolism (Reactome: R-HSA-71291)
• Muscle contraction (Reactome: R-HSA-397014)
• Energy metabolism (KEGG: hsa04932)
Protein Summary
CKMT2 is a 417-amino acid protein (UniProt P17540) localized to the mitochondrial intermembrane space. It forms homodimers or heterodimers with CKMT1A/B. The protein contains a mitochondrial transit peptide (residues 1-39) and a creatine kinase domain (residues 40-417). It is essential for the rapid regeneration of ATP in muscle tissues. Structural studies show a conserved active site with Arg41 and Thr188 critical for catalysis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CKMT2 Knockout HEK293 Cell Line | EDJ-KQ4281 | Human | 1160 | Details Get a Quote |
| CKMT2 Knockout HeLa Cell Line | EDJ-KQ52916 | Human | 1160 | Details Get a Quote |
| CKMT2 Knockout A-549 Cell Line | EDJ-KQ61383 | Human | 1160 | Details Get a Quote |
| CKMT2 Knockout HCT 116 Cell Line | EDJ-KQ69878 | Human | 1160 | Details Get a Quote |
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