title: I-proteins - a proposed switch in myotubularin function.
abstract: In this article, we consider the functions of the myotubularins - a large family of phosphoinositide 3-phosphatases. By analogy with the phosphatidylinositol 3-phosphatase PTEN (phosphatase and tensin homolog deleted in chromosome ten) and many protein phosphatases, it has been proposed that the primary function of this protein family is to regulate substrate levels, in this case phosphatidylinositol (3)-phosphate. We propose an alternate, or additional, function that is analogous to the G-protein family of phosphatases, which use nucleotide-dependent conformational changes to transduce signals or do mechanical work.
authors.affiliation: Physiological Laboratory, University of Liverpool, Crown Street, Liverpool L69 3BX, UK. clague@liv.ac.uk
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Clague
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Dove
authors.forename: Francis A
authors.initials: FA
authors.lastname: Barr
mesh_terms: D004705:Endocytosis; D004789:Enzyme Activation; D025461:Feedback, Physiological; D008954:Models, Biological; D009154:Mutation; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D054558:Protein Tyrosine Phosphatases, Non-Receptor; D015398:Signal Transduction; D013379:Substrate Specificity; D025521:Tumor Suppressor Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D018129:Phosphatidylinositol Phosphates; D025521:Tumor Suppressor Proteins; D010744:Phosphoric Monoester Hydrolases; D017027:Protein Tyrosine Phosphatases; D054558:Protein Tyrosine Phosphatases, Non-Receptor; C099588:myotubularin; C061816:phosphatidylinositol-3-phosphatase