<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Al-Qusairi, L.</style></author><author><style face="normal" font="default" size="100%">Weiss, N.</style></author><author><style face="normal" font="default" size="100%">Toussaint, A.</style></author><author><style face="normal" font="default" size="100%">Berbey, C.</style></author><author><style face="normal" font="default" size="100%">Messaddeq, N.</style></author><author><style face="normal" font="default" size="100%">Kretz, C.</style></author><author><style face="normal" font="default" size="100%">Sanoudou, D.</style></author><author><style face="normal" font="default" size="100%">Beggs, A. H.</style></author><author><style face="normal" font="default" size="100%">Allard, B.</style></author><author><style face="normal" font="default" size="100%">Mandel, J. L.</style></author><author><style face="normal" font="default" size="100%">Laporte, J.</style></author><author><style face="normal" font="default" size="100%">Jacquemond, V.</style></author><author><style face="normal" font="default" size="100%">Buj-Bello, A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">T-tubule disorganization and defective excitation-contraction coupling in muscle fibers lacking myotubularin lipid phosphatase</style></title><secondary-title><style face="normal" font="default" size="100%">Proc Natl Acad Sci U S AProc Natl Acad Sci U S AProc Natl Acad Sci U S A</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Proceedings of the National Academy of Sciences of the United States of America</style></alt-title><short-title><style face="normal" font="default" size="100%">Proceedings of the National Academy of Sciences of the United States of AmericaProceedings of the National Academy of Sciences of the United States of America</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">*Lipid Metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">Calcium Channels/metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Calcium/metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation</style></keyword><keyword><style  face="normal" font="default" size="100%">Homeostasis/genetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Ion Channel Gating</style></keyword><keyword><style  face="normal" font="default" size="100%">Mice</style></keyword><keyword><style  face="normal" font="default" size="100%">Mice, Knockout</style></keyword><keyword><style  face="normal" font="default" size="100%">Muscle Contraction/*physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Muscle Fibers, Skeletal/*enzymology/*pathology/ultrastructure</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Tyrosine Phosphatases, Non-Receptor/*deficiency/metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Sarcoplasmic Reticulum/*enzymology/*pathology/ultrastructure</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Nov 3</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">44</style></number><volume><style face="normal" font="default" size="100%">106</style></volume><pages><style face="normal" font="default" size="100%">18763-8</style></pages><isbn><style face="normal" font="default" size="100%">1091-6490 (Electronic)0027-8424 (Linking)</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Skeletal muscle contraction is triggered by the excitation-contraction (E-C) coupling machinery residing at the triad, a membrane structure formed by the juxtaposition of T-tubules and sarcoplasmic reticulum (SR) cisternae. The formation and maintenance of this structure is key for muscle function but is not well characterized. We have investigated the mechanisms leading to X-linked myotubular myopathy (XLMTM), a severe congenital disorder due to loss of function mutations in the MTM1 gene, encoding myotubularin, a phosphoinositide phosphatase thought to have a role in plasma membrane homeostasis and endocytosis. Using a mouse model of the disease, we report that Mtm1-deficient muscle fibers have a decreased number of triads and abnormal longitudinally oriented T-tubules. In addition, SR Ca(2+) release elicited by voltage-clamp depolarizations is strongly depressed in myotubularin-deficient muscle fibers, with myoplasmic Ca(2+) removal and SR Ca(2+) content essentially unaffected. At the molecular level, Mtm1-deficient myofibers exhibit a 3-fold reduction in type 1 ryanodine receptor (RyR1) protein level. These data reveal a critical role of myotubularin in the proper organization and function of the E-C coupling machinery and strongly suggest that defective RyR1-mediated SR Ca(2+) release is responsible for the failure of muscle function in myotubular myopathy.</style></abstract><accession-num><style face="normal" font="default" size="100%">19846786</style></accession-num><notes><style face="normal" font="default" size="100%">Al-Qusairi, LamaWeiss, NorbertToussaint, AnneBerbey, CelineMessaddeq, NadiaKretz, ChristineSanoudou, DespinaBeggs, Alan HAllard, BrunoMandel, Jean-LouisLaporte, JocelynJacquemond, VincentBuj-Bello, AnnaengP50 NS040828/NS/NINDS NIH HHS/P50 NS040828-080003/NS/NINDS NIH HHS/Research Support, N.I.H., ExtramuralResearch Support, Non-U.S. Gov't2009/10/23 06:00Proc Natl Acad Sci U S A. 2009 Nov 3;106(44):18763-8. doi: 10.1073/pnas.0900705106. Epub 2009 Oct 21.</style></notes><custom2><style face="normal" font="default" size="100%">2773964</style></custom2><auth-address><style face="normal" font="default" size="100%">Department of Neurobiology and Genetics, and Imaging Center-Electron Microscopy, Institut de Genetique et de Biologie Moleculaire et Cellulaire, Institut National de la Sante et de la Recherche Medicale U964, Centre National de la Recherche Scientifique, Unite Mixte de Recherche 7104, Universite Louis Pasteur, College de France, 67404 Illkirch, France.</style></auth-address></record></records></xml>