First Author | Laporte J | Year | 2002 |
Journal | J Cell Sci | Volume | 115 |
Issue | Pt 15 | Pages | 3105-17 |
PubMed ID | 12118066 | Mgi Jnum | J:175210 |
Mgi Id | MGI:5284818 | Doi | 10.1242/jcs.115.15.3105 |
Citation | Laporte J, et al. (2002) The PtdIns3P phosphatase myotubularin is a cytoplasmic protein that also localizes to Rac1-inducible plasma membrane ruffles. J Cell Sci 115(Pt 15):3105-17 |
abstractText | Myotubularin, the phosphatase mutated in X-linked myotubular myopathy, was shown to dephosphorylate phosphatidylinositol 3-monophosphate (PtdIns3P) and was also reported to interact with nuclear transcriptional regulators from the trithorax family. We have characterized a panel of specific antibodies and investigated the subcellular localization of myotubularin. Myotubularin is not detected in the nucleus, and localizes mostly as a dense cytoplasmic network. Overexpression of myotubularin does not detectably affect vesicle trafficking in the mammalian cells investigated, in contrast to previous observations in yeast models. Both mutation of a key aspartate residue of myotubularin and dominant activation of Rac1 GTPase lead to the recruitment of myotubularin to specific plasma membrane domains. Localization to Rac1-induced ruffles is dependent on the presence of a domain highly conserved in the myotubularin family (that we named RID). We thus propose that myotubularin may dephosphorylate a subpool of PtdIns3P (or another related substrate) at the plasma membrane. |