<?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%">Morita, Yasu S</style></author><author><style face="normal" font="default" size="100%">Yamaryo-Botte, Yoshiki</style></author><author><style face="normal" font="default" size="100%">Miyanagi, Kana</style></author><author><style face="normal" font="default" size="100%">Callaghan, Judy M</style></author><author><style face="normal" font="default" size="100%">Patterson, John H</style></author><author><style face="normal" font="default" size="100%">Crellin, Paul K</style></author><author><style face="normal" font="default" size="100%">Coppel, Ross L</style></author><author><style face="normal" font="default" size="100%">Billman-Jacobe, Helen</style></author><author><style face="normal" font="default" size="100%">Kinoshita, Taroh</style></author><author><style face="normal" font="default" size="100%">McConville, Malcolm J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Stress-induced synthesis of phosphatidylinositol 3-phosphate in mycobacteria.</style></title><secondary-title><style face="normal" font="default" size="100%">J Biol Chem</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Biol. Chem.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cell-Free System</style></keyword><keyword><style  face="normal" font="default" size="100%">Chromatography, High Pressure Liquid</style></keyword><keyword><style  face="normal" font="default" size="100%">Leishmania</style></keyword><keyword><style  face="normal" font="default" size="100%">Lipids</style></keyword><keyword><style  face="normal" font="default" size="100%">Mass Spectrometry</style></keyword><keyword><style  face="normal" font="default" size="100%">Mycobacterium smegmatis</style></keyword><keyword><style  face="normal" font="default" size="100%">Nucleotides</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxalic Acid</style></keyword><keyword><style  face="normal" font="default" size="100%">Phosphatidylinositol Phosphates</style></keyword><keyword><style  face="normal" font="default" size="100%">Phosphatidylinositols</style></keyword><keyword><style  face="normal" font="default" size="100%">Phospholipids</style></keyword><keyword><style  face="normal" font="default" size="100%">Phosphorylation</style></keyword><keyword><style  face="normal" font="default" size="100%">Salts</style></keyword><keyword><style  face="normal" font="default" size="100%">Signal Transduction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010 May 28</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">285</style></volume><pages><style face="normal" font="default" size="100%">16643-50</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Phosphoinositides play key roles in regulating membrane dynamics and intracellular signaling in eukaryotic cells. However, comparable lipid-based signaling pathways have not been identified in bacteria. Here we show that Mycobacterium smegmatis and other Actinomycetes bacteria can synthesize the phosphoinositide, phosphatidylinositol 3-phosphate (PI3P). This lipid was transiently labeled with [(3)H]inositol. Sensitivity of the purified lipid to alkaline phosphatase, headgroup analysis by high-pressure liquid chromatography, and mass spectrometry demonstrated that it had the structure 1,2-[tuberculostearoyl, octadecenoyl]-sn-glycero 3-phosphoinositol 3-phosphate. Synthesis of PI3P was elevated by salt stress but not by exposure to high concentrations of non-ionic solutes. Synthesis of PI3P in a cell-free system was stimulated by the synthesis of CDP-diacylglycerol, a lipid substrate for phosphatidylinositol (PI) biosynthesis, suggesting that efficient cell-free PI3P synthesis is dependent on de novo PI synthesis. In vitro experiments further indicated that the rapid turnover of this lipid was mediated, at least in part, by a vanadate-sensitive phosphatase. This is the first example of de novo synthesis of PI3P in bacteria, and the transient synthesis in response to environmental stimuli suggests that some bacteria may have evolved similar lipid-mediated signaling pathways to those observed in eukaryotic cells.</style></abstract><issue><style face="normal" font="default" size="100%">22</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/20364020?dopt=Abstract</style></custom1></record><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%">Morita, Yasu S</style></author><author><style face="normal" font="default" size="100%">Sena, Chubert B C</style></author><author><style face="normal" font="default" size="100%">Waller, Ross F</style></author><author><style face="normal" font="default" size="100%">Kurokawa, Ken</style></author><author><style face="normal" font="default" size="100%">Sernee, M Fleur</style></author><author><style face="normal" font="default" size="100%">Nakatani, Fumiki</style></author><author><style face="normal" font="default" size="100%">Haites, Ruth E</style></author><author><style face="normal" font="default" size="100%">Billman-Jacobe, Helen</style></author><author><style face="normal" font="default" size="100%">McConville, Malcolm J</style></author><author><style face="normal" font="default" size="100%">Maeda, Yusuke</style></author><author><style face="normal" font="default" size="100%">Kinoshita, Taroh</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">PimE is a polyprenol-phosphate-mannose-dependent mannosyltransferase that transfers the fifth mannose of phosphatidylinositol mannoside in mycobacteria.</style></title><secondary-title><style face="normal" font="default" size="100%">J Biol Chem</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Biol. Chem.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Amino Acid Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Proliferation</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Wall</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell-Free System</style></keyword><keyword><style  face="normal" font="default" size="100%">Genome, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Humans</style></keyword><keyword><style  face="normal" font="default" size="100%">Mannose</style></keyword><keyword><style  face="normal" font="default" size="100%">Mannosides</style></keyword><keyword><style  face="normal" font="default" size="100%">Mannosyltransferases</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Sequence Data</style></keyword><keyword><style  face="normal" font="default" size="100%">Mycobacterium</style></keyword><keyword><style  face="normal" font="default" size="100%">Mycobacterium smegmatis</style></keyword><keyword><style  face="normal" font="default" size="100%">Phosphates</style></keyword><keyword><style  face="normal" font="default" size="100%">Phosphatidylinositols</style></keyword><keyword><style  face="normal" font="default" size="100%">Sequence Homology, Amino Acid</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2006 Sep 1</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">281</style></volume><pages><style face="normal" font="default" size="100%">25143-55</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Phosphatidylinositol mannosides (PIMs) are a major class of glycolipids in all mycobacteria. AcPIM2, a dimannosyl PIM, is both an end product and a precursor for polar PIMs, such as hexamannosyl PIM (AcPIM6) and the major cell wall lipoglycan, lipoarabinomannan (LAM). The mannosyltransferases that convert AcPIM2 to AcPIM6 or LAM are dependent on polyprenol-phosphate-mannose (PPM), but have not yet been characterized. Here, we identified a gene, termed pimE that is present in all mycobacteria, and is required for AcPIM6 biosynthesis. PimE was initially identified based on homology with eukaryotic PIG-M mannosyltransferases. PimE-deleted Mycobacterium smegmatis was defective in AcPIM6 synthesis, and accumulated the tetramannosyl PIM, AcPIM4. Loss of PimE had no affect on cell growth or viability, or the biosynthesis of other intracellular and cell wall glycans. However, changes in cell wall hydrophobicity and plasma membrane organization were detected, suggesting a role for AcPIM6 in the structural integrity of the cell wall and plasma membrane. These defects were corrected by ectopic expression of the pimE gene. Metabolic pulse-chase radiolabeling and cell-free PIM biosynthesis assays indicated that PimE catalyzes the alpha1,2-mannosyl transfer for the AcPIM5 synthesis. Mutation of an Asp residue in PimE that is conserved in and required for the activity of human PIG-M resulted in loss of PIM-biosynthetic activity, indicating that PimE is the catalytic component. Finally, PimE was localized to a distinct membrane fraction enriched in AcPIM4-6 biosynthesis. Taken together, PimE represents the first PPM-dependent mannosyl-transferase shown to be involved in PIM biosynthesis, where it mediates the fifth mannose transfer.</style></abstract><issue><style face="normal" font="default" size="100%">35</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/16803893?dopt=Abstract</style></custom1></record></records></xml>