Lack of myotubularin phosphatase activity is the main cause of X-linked myotubular myopathy.

ABSTRACT: The MTM1 gene encodes myotubularin (MTM1), a phosphatidylinositol 3-phosphate [PI(3)P] lipid phosphatase. Loss-of-function mutations in MTM1 cause X-linked myotubular myopathy (XLMTM), a severe congenital myopathy with no available cure and a poorly understood pathomechanism. The importance of MTM1 enzymatic activity and its PI(3)P substrate in physiology under normal conditions and in XLMTM is unclear. We generated the Mtm1-KI C375S mice in which the endogenous MTM1 was converted to a phosphatase-dead protein. Mutant mice survived a median of 12 weeks and demonstrated progressively impaired motor skills. Observed muscle hypotrophy and reduced force production compared with their WT littermates (~3.9-fold reduction in absolute maximal force) were responsible for these severe phenotypes. A

SUBMITTER: Moschovaki-Filippidou F 

PROVIDER: S-EPMC12643485 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature