Myotubularin Related Protein 1 (MTMR1)

Myotubularin-related protein 1 is a member of the myotubularin related family of proteins. Members of this family contain the consensus sequence for the active site of protein tyrosine phosphatases. Alternatively spliced variants have been described but their biological validity has not been determined.One of the transcripts is muscle specific, is induced during myogenesis, and represents the major isoform in adult skeletal muscle. The 2 main MTMR1 protein muscular isoforms, like myotubularin, efficiently dephosphorylate PI(3)P in vitro. The authors found a striking reduction in the level of the muscle-specific isoform and the appearance of an abnormal MTMR1 transcript in cultured differentiated muscle cells and in skeletal muscle from congenital myotonic dystrophy (DM1) patients.