Jouhet Juliette, Gros Valérie, Michaud Morgane
Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRAE, Universite Grenoble Alpes, IRIG, CEA Grenoble, Grenoble, France.
Institut des Biomolécules Max Mousseron (IBMM), Pôle Chimie Balard Recherche, UMR5247, CNRS, Université de Montpellier, ENSCM, Montpellier, France.
Methods Mol Biol. 2025;2888:167-191. doi: 10.1007/978-1-0716-4318-1_12.
Membrane biogenesis requires an extensive traffic of lipids between different cell compartments. Two main pathways, the vesicular and non-vesicular pathways, are involved in such a process. Whereas the mechanisms involved in vesicular trafficking are well understood, less is known about non-vesicular lipid trafficking, particularly in plants. This pathway involves the direct exchange of lipids at membrane contact sites (MCSs) between organelles. In plants, extensive traffic of the chloroplast-synthesized digalactosyldiacylglycerol (DGDG) to mitochondria is specifically promoted during phosphate starvation. This lipid exchange likely occurs by non-vesicular trafficking pathways at MCSs between mitochondria and plastids. By a biochemical approach, a mitochondrial lipoproteic super-complex called MTL (mitochondrial transmembrane lipoprotein complex) involved in mitochondrial lipid trafficking has been identified in Arabidopsis thaliana. This protocol describes the method used to separate the MTL complex and to study the implication of a component of this complex (AtMic60) in mitochondrial lipid transport.
膜生物合成需要脂质在不同细胞区室之间大量运输。该过程涉及两条主要途径，即囊泡运输途径和非囊泡运输途径。虽然囊泡运输所涉及的机制已得到充分了解，但对于非囊泡脂质运输，尤其是在植物中的情况，了解较少。这条途径涉及细胞器之间在膜接触位点（MCSs）直接进行脂质交换。在植物中，叶绿体合成的二半乳糖基二酰基甘油（DGDG）向线粒体的大量运输在磷饥饿期间会特别增强。这种脂质交换可能通过线粒体与质体之间MCSs处的非囊泡运输途径发生。通过生化方法，在拟南芥中鉴定出一种参与线粒体脂质运输的线粒体脂蛋白超复合物，称为MTL（线粒体跨膜脂蛋白复合物）。本实验方案描述了用于分离MTL复合物以及研究该复合物的一个组分（AtMic60）在线粒体脂质运输中的作用的方法。
