Myotonin-protein kinase

Myotonin-protein kinase (also known as DMRK or DMPK) is a serine/threonine-protein kinase that is encoded by the DMPK gene in humans. This protein plays a crucial role in muscle function and has been linked to a type of muscular dystrophy known as Myotonic dystrophy.

Function

Myotonin-protein kinase is involved in myocyte differentiation and the regulation of myotonic dystrophy symptoms. It is a member of the protein kinase family, which are enzymes that modify other proteins by chemically adding phosphate groups to them. This process, known as phosphorylation, is a common method of regulating protein function.

Structure

The DMPK gene is located on the long (q) arm of chromosome 19 at position 13.3. The protein encoded by this gene is a serine/threonine kinase, meaning it phosphorylates proteins on serine or threonine residues. The protein is approximately 70 kDa in size and is primarily expressed in skeletal muscle.

Clinical significance

Mutations in the DMPK gene are associated with myotonic dystrophy type 1 (DM1), a multisystem disorder that affects skeletal and smooth muscle as well as the eye, heart, endocrine system, and central nervous system. The mutation involves an expansion of a CTG trinucleotide repeat in the non-coding region of the DMPK gene. This repeat expansion leads to a decrease in the expression of the DMPK protein, which in turn leads to the symptoms of myotonic dystrophy.

See also

• Protein kinase
• Myotonic dystrophy
• Serine/threonine-protein kinase