Tan Xiaojun, Thapa Narendra, Choi Suyong, Anderson Richard A
Program in Molecular and Cellular Pharmacology, University of Wisconsin-Madison School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA.
Program in Cellular and Molecular Biology, University of Wisconsin-Madison School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA.
J Cell Sci. 2015 Nov 15;128(22):4047-56. doi: 10.1242/jcs.175208.
Phosphoinositides are a collection of lipid messengers that regulate most subcellular processes. Amongst the seven phosphoinositide species, the roles for phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] at the plasma membrane, such as in endocytosis, exocytosis, actin polymerization and focal adhesion assembly, have been extensively studied. Recent studies have argued for the existence of PtdIns(4,5)P2 at multiple intracellular compartments, including the nucleus, endosomes, lysosomes, autolysosomes, autophagic precursor membranes, ER, mitochondria and the Golgi complex. Although the generation, regulation and functions of PtdIns(4,5)P2 are less well-defined in most other intracellular compartments, accumulating evidence demonstrates crucial roles for PtdIns(4,5)P2 in endolysosomal trafficking, endosomal recycling, as well as autophagosomal pathways, which are the focus of this Commentary. We summarize and discuss how phosphatidylinositol phosphate kinases, PtdIns(4,5)P2 and PtdIns(4,5)P2-effectors regulate these intracellular protein and membrane trafficking events.
磷酸肌醇是一类脂质信使,可调节大多数亚细胞过程。在七种磷酸肌醇物种中,质膜上磷脂酰肌醇4,5-二磷酸[PtdIns(4,5)P2]的作用,如在内吞作用、外排作用、肌动蛋白聚合和粘着斑组装中的作用,已得到广泛研究。最近的研究表明,PtdIns(4,5)P2存在于多个细胞内区室,包括细胞核、内体、溶酶体、自噬溶酶体、自噬前体膜、内质网、线粒体和高尔基体复合体。尽管在大多数其他细胞内区室中,PtdIns(4,5)P2的生成、调节和功能尚不清楚,但越来越多的证据表明,PtdIns(4,5)P2在内溶酶体运输、内体循环以及自噬体途径中起关键作用,这也是本评论的重点。我们总结并讨论了磷脂酰肌醇磷酸激酶、PtdIns(4,5)P2和PtdIns(4,5)P2效应器如何调节这些细胞内蛋白质和膜运输事件。