myotublarian phosphates genetic research from France

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Abstract from Human Molecular Genetics. 2003 Aug 12 (mentions CMT)

Myotubularins, a large disease-associated family of cooperating

catalytically active and inactive phosphoinositides phosphatases.

Laporte J, Bedez F, Bolino A, Mandel JL.

IGBMC, CNRS/INSERM/ULP, Illkirch, France.

The myotubularin family is a large eukaryotic group within the

tyrosine/dual-specificity phosphatase super-family (PTP/DSP). Among the

14 human members, three are mutated in genetic diseases:myotubular

myopathy and two forms of Charcot-Marie-Tooth neuropathy. We present an

analysis of the myotubularin family in sequenced genomes. The

myotubularin family encompasses catalytically active and inactive

phosphatases, and both classes are well conserved from nematode to man.

Catalytically active myotubularins dephosphorylate phosphatidylinositol

3-phosphate (PtdIns3P) and PtdIns3,5P2, leading to the production of

PtdIns and PtdIns5P. This activity may be modulated by direct

interaction with catalytically inactive myotubularins. These

phosphoinositides are signaling molecules that are notably involved in

vacuolar transport and membrane trafficking. Myotubularins are thus

proposed to be implicated in these cellular mechanisms, and recent

observations on myotubularins homologues in the nematode C. elegans

indicate a role in endocytosis.