Myotubularin phosphatases: policing 3-phosphoinositides.
In eukaryotic cells, phosphatidylinositol is subject to differential phosphorylation, resulting in the production of seven distinct phosphatidylinositol phosphates, often referred to as phosphoinositides (PIs). PIs have numerous distinct roles in cellular regulation and membrane trafficking. Recently, myotubularin family PI 3-phosphatases have emerged as key regulators of phosphatidylinositol 3-phosphate and phosphatidylinositol 3,5-bisphosphate, two PIs that regulate traffic within the endosomal-lysosomal pathway. Mutations in several myotubularin genes lead to myotubular myopathy and Charcot-Marie-Tooth peripheral neuropathy. Strikingly, nearly half of the members of the human myotubularin family appear to be catalytically inactive. Several inactive myotubularins have essential functions in mammals. Recent work in mammalian cells and model organisms is shedding light on the roles of myotubularins in membrane traffic.
Robinson
Fred L
FL
Department of Pharmacology, School of Medicine, University of California San Diego, Leichtag Biomedical Research Building, Rm. 284, 9500 Gilman Drive, La Jolla, CA 92093-0721, USA.
Dixon
Jack E
JE
D000818:Animals; D002607:Charcot-Marie-Tooth Disease / Q000235:genetics; D005786:Gene Expression Regulation; D006801:Humans; D020914:Myopathies, Structural, Congenital / Q000235:genetics; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D010716:Phosphatidylinositols / Q000502:physiology*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D054558:Protein Tyrosine Phosphatases, Non-Receptor
D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; C106336:phosphatidylinositol 3,5-diphosphate; C055525:phosphatidylinositol 3-phosphate; D010744:Phosphoric Monoester Hydrolases; C116467:MTMR1 protein, human; C408986:MTMR2 protein, human; C444436:MTMR3 protein, human; C513490:MTMR6 protein, human; D017027:Protein Tyrosine Phosphatases; D054558:Protein Tyrosine Phosphatases, Non-Receptor; C099588:myotubularin