PLEKHM1 通过 HOPS 复合物和 LC3/GABARAP 蛋白调节自噬体-溶酶体融合。
PLEKHM1 regulates autophagosome-lysosome fusion through HOPS complex and LC3/GABARAP proteins.
机构信息
Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany.
Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université, UM2, 13288 Marseille, France; INSERM, U1104, 13288 Marseille, France; CNRS, UMR 7280, 13288 Marseille, France.
出版信息
Mol Cell. 2015 Jan 8;57(1):39-54. doi: 10.1016/j.molcel.2014.11.006. Epub 2014 Dec 11.
The lysosome is the final destination for degradation of endocytic cargo, plasma membrane constituents, and intracellular components sequestered by macroautophagy. Fusion of endosomes and autophagosomes with the lysosome depends on the GTPase Rab7 and the homotypic fusion and protein sorting (HOPS) complex, but adaptor proteins that link endocytic and autophagy pathways with lysosomes are poorly characterized. Herein, we show that Pleckstrin homology domain containing protein family member 1 (PLEKHM1) directly interacts with HOPS complex and contains a LC3-interacting region (LIR) that mediates its binding to autophagosomal membranes. Depletion of PLEKHM1 blocks lysosomal degradation of endocytic (EGFR) cargo and enhances presentation of MHC class I molecules. Moreover, genetic loss of PLEKHM1 impedes autophagy flux upon mTOR inhibition and PLEKHM1 regulates clearance of protein aggregates in an autophagy- and LIR-dependent manner. PLEKHM1 is thus a multivalent endocytic adaptor involved in the lysosome fusion events controlling selective and nonselective autophagy pathways.
溶酶体是内吞货物、质膜成分和通过巨自噬隔离的细胞内成分降解的最终目的地。内体和自噬体与溶酶体的融合取决于 GTPase Rab7 和同源融合和蛋白质分选 (HOPS) 复合物,但将内吞和自噬途径与溶酶体连接的衔接蛋白的特征描述很差。本文中,我们发现 Pleckstrin homology 结构域家族成员 1 (PLEKHM1) 可直接与 HOPS 复合物相互作用,且含有 LC3 相互作用区域 (LIR),可介导其与自噬体膜的结合。PLEKHM1 的耗竭会阻断内吞 (EGFR) 货物的溶酶体降解,并增强 MHC Ⅰ类分子的呈现。此外,在 mTOR 抑制时,PLEKHM1 的遗传缺失会阻碍自噬流,并且 PLEKHM1 以自噬和 LIR 依赖性的方式调节蛋白聚集体的清除。因此,PLEKHM1 是一种多价的内吞衔接蛋白,参与控制选择性和非选择性自噬途径的溶酶体融合事件。