CKM (gene)

CKM, also known as Creatine Kinase, Muscle, is a gene that encodes the muscle isoform of the creatine kinase enzyme. Creatine kinase (CK) is a crucial enzyme involved in energy homeostasis, particularly in tissues with high and fluctuating energy demands, such as skeletal muscle, cardiac muscle, and brain.

Function:

The CKM gene product, CK-MM, catalyzes the reversible transfer of phosphate between creatine and ATP, facilitating the rapid regeneration of ATP from ADP. This process is vital for maintaining cellular energy levels during periods of increased metabolic activity. In muscle tissue, CK-MM plays a crucial role in buffering ATP concentrations, allowing for sustained muscle contraction.

Isoforms:

Creatine kinase exists as several isoenzymes, each composed of two subunits: M (muscle) and B (brain). The three major isoenzymes are CK-MM (primarily found in skeletal muscle and cardiac muscle), CK-MB (primarily found in cardiac muscle, but also present in skeletal muscle), and CK-BB (primarily found in brain and smooth muscle). The CKM gene specifically encodes the M subunit.

Clinical Significance:

Elevated levels of CK-MM in the blood can indicate muscle damage or injury. This can occur in conditions such as rhabdomyolysis, muscular dystrophy, myocardial infarction (although CK-MB is a more specific marker for cardiac damage), and intense exercise. Measuring CK-MM levels can therefore be a valuable diagnostic tool in assessing muscle health and identifying underlying medical conditions. Genetic variations in the CKM gene have also been investigated for their potential association with muscle performance and susceptibility to muscle-related disorders.

Genetics:

The CKM gene is located on chromosome 19q13.32 in humans. The gene consists of several exons and introns. Variations in the gene sequence can lead to differences in CK-MM enzyme activity and potentially influence individual susceptibility to muscle-related conditions. Further research is ongoing to fully understand the genetic factors influencing CKM expression and function.