title: The Roles of mTOR Complexes in Lipid Metabolism.
abstract: The synthesis of lipids in response to food intake represents a key advantage that allows organisms to survive when energy availability is limited. In mammals, circulating levels of insulin and nutrients, which fluctuate between fasting and feeding, dictate whether lipids are synthesized or catabolized by tissues. The mechanistic target of rapamycin (mTOR), a kinase that is activated by anabolic signals, plays fundamental roles in regulating lipid biosynthesis and metabolism in response to nutrition. The mTOR kinase nucleates two large protein complexes named mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Following their activation, these complexes facilitate the accumulation of triglycerides by promoting adipogenesis and lipogenesis and by shutting down catabolic processes such as lipolysis and β-oxidation. Here, we review and discuss the roles of mTOR complexes in various aspects of lipid metabolism in mammals. We also use this opportunity to discuss the implication of these relations to the maintenance of systemic lipid homeostasis.
authors.affiliation: Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec (CRIUCPQ), Faculté de Médecine, Université Laval, Québec, Canada, G1V 4G5; email: mathieu.laplante@criucpq.ulaval.ca.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Caron
authors.forename: Denis
authors.initials: D
authors.lastname: Richard
authors.forename: Mathieu
authors.initials: M
authors.lastname: Laplante
mesh_terms: D050156:Adipogenesis / Q000502:physiology; D000818:Animals; D004032:Diet; D004435:Eating / Q000502:physiology; D006706:Homeostasis; D006801:Humans; D050356:Lipid Metabolism / Q000502:physiology*; D050155:Lipogenesis / Q000502:physiology; D008066:Lipolysis; D000076222:Mechanistic Target of Rapamycin Complex 1; D000076225:Mechanistic Target of Rapamycin Complex 2; D046912:Multiprotein Complexes / Q000502:physiology; D009747:Nutritional Physiological Phenomena; D010084:Oxidation-Reduction; D015398:Signal Transduction / Q000502:physiology; D051779:Sterol Regulatory Element Binding Proteins / Q000502:physiology; D058570:TOR Serine-Threonine Kinases / Q000502:physiology*; D014280:Triglycerides / Q000378:metabolism
chemical_list: D046912:Multiprotein Complexes; D051779:Sterol Regulatory Element Binding Proteins; D014280:Triglycerides; D000076222:Mechanistic Target of Rapamycin Complex 1; D000076225:Mechanistic Target of Rapamycin Complex 2; D058570:TOR Serine-Threonine Kinases
keywords: adipogenesis; lipid metabolism; lipogenesis; mTOR