Phosphatase Family Myotubularin

Phosphatase Classification: Superfamily Cys-based I: Myotubularin

Myotubularins are 3-phosphatases specific for PtdIns3P and PtdIns(3,5)P2, two PIs that function within the endosomal-lysomal pathway . In yeast, there is a single myotubularin Ymr1p, and its functions appear to be redundant with those of other 3-phosphatases. However, in C. elegans, which has six myotubularins, several of the myotublarins have non-redundant roles in regulating PtdIns3P during endocytosis. In human, there are 14 myotublarins, and mutations in several of them lead to myotubular myopathy and Charcot-Marie-Tooth peripheral neuropathy. Interestingly, around half of myotubularins are catalytically inactive. One of their possible function is regulating active myotubularins by protein interaction. For details, see the review [1].

Subfamilies

MTMR5 subfamily

Inactive myotubularin subfamily.

C2-MTMR1 subfamily

The feature of this subfamily is a C2 domain attached to the R1-like sequence.

Reference

1. Robinson FL and Dixon JE. Myotubularin phosphatases: policing 3-phosphoinositides. Trends Cell Biol. 2006 Aug;16(8):403-12. DOI:10.1016/j.tcb.2006.06.001 |