Department of Anatomy and Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
Minerva Foundation Institute for Medical Research, Helsinki, Finland.
EMBO J. 2021 Jul 15;40(14):e106871. doi: 10.15252/embj.2020106871. Epub 2021 Jun 14.
Low-density lipoprotein (LDL)-cholesterol delivery from late endosomes to the plasma membrane regulates focal adhesion dynamics and cell migration, but the mechanisms controlling it are poorly characterized. Here, we employed auxin-inducible rapid degradation of oxysterol-binding protein-related protein 2 (ORP2/OSBPL2) to show that endogenous ORP2 mediates the transfer of LDL-derived cholesterol from late endosomes to focal adhesion kinase (FAK)-/integrin-positive recycling endosomes in human cells. In vitro, cholesterol enhances membrane association of FAK to PI(4,5)P -containing lipid bilayers. In cells, ORP2 stimulates FAK activation and PI(4,5)P generation in endomembranes, enhancing cell adhesion. Moreover, ORP2 increases PI(4,5)P in NPC1-containing late endosomes in a FAK-dependent manner, controlling their tubulovesicular trafficking. Together, these results provide evidence that ORP2 controls FAK activation and LDL-cholesterol plasma membrane delivery by promoting bidirectional cholesterol/PI(4,5)P exchange between late and recycling endosomes.
低密度脂蛋白(LDL)-胆固醇从晚期内体向质膜的输送调节粘着斑动力学和细胞迁移,但控制其的机制尚未得到很好的描述。在这里,我们利用吲哚乙酸诱导的氧化固醇结合蛋白相关蛋白 2(ORP2/OSBPL2)的快速降解来表明内源性 ORP2 介导 LDL 衍生的胆固醇从晚期内体向粘着斑激酶(FAK)/整合素阳性再循环内体的转移。在体外,胆固醇增强 FAK 与含有 PI(4,5)P 的脂质双层的膜结合。在细胞中,ORP2 刺激 FAK 在质膜内的激活和 PI(4,5)P 的产生,从而增强细胞黏附。此外,ORP2 以 FAK 依赖的方式增加 NPC1 含有的晚期内体中的 PI(4,5)P,控制其管状小泡运输。综上所述,这些结果表明 ORP2 通过促进晚期和再循环内体之间的胆固醇/PI(4,5)P 的双向交换来控制 FAK 的激活和 LDL-胆固醇质膜的输送。