Minogue Shane, Waugh Mark G
Centre for Molecular Cell Biology, Department of Inflammation, Division of Medicine, University College London, Rowland Hill Street, Hampstead, NW3 2PF, London, United Kingdom,
Subcell Biochem. 2012;58:1-24. doi: 10.1007/978-94-007-3012-0_1.
Phosphatidylinositol 4-phosphate (PtdIns4P) is a quantitatively minor membrane phospholipid which is the precursor of PtdIns(4,5)P (2) in the classical agonist-regulated phospholipase C signalling pathway. However, PtdIns4P also governs the recruitment and function of numerous trafficking molecules, principally in the Golgi complex. The majority of phosphoinositides (PIs) phosphorylated at the D4 position of the inositol headgroup are derived from PtdIns4P and play roles in a diverse array of fundamental cellular processes including secretion, cell migration, apoptosis and mitogenesis; therefore, PtdIns4P biosynthesis can be regarded as key point of regulation in many PI-dependent processes.Two structurally distinct sequence families, the type II and type III PtdIns 4-kinases, are responsible for PtdIns4P synthesis in eukaryotic organisms. These important proteins are differentially expressed, localised and regulated by distinct mechanisms, indicating that the enzymes perform non-redundant roles in trafficking and signalling. In recent years, major advances have been made in our understanding of PtdIns4K biology and here we summarise current knowledge of PtdIns4K structure, function and regulation.
磷脂酰肌醇4-磷酸（PtdIns4P）是一种含量较少的膜磷脂，在经典的激动剂调节的磷脂酶C信号通路中是PtdIns(4,5)P₂的前体。然而，PtdIns4P也主要在高尔基体中调控众多运输分子的募集和功能。大多数在肌醇头部基团的D4位置磷酸化的磷酸肌醇（PIs）都来源于PtdIns4P，并在包括分泌、细胞迁移、凋亡和有丝分裂等多种基本细胞过程中发挥作用；因此，PtdIns4P的生物合成可被视为许多PI依赖过程中的关键调控点。两个结构不同的序列家族，即II型和III型磷脂酰肌醇4-激酶，负责真核生物中PtdIns4P的合成。这些重要的蛋白质通过不同的机制进行差异表达、定位和调控，这表明这些酶在运输和信号传导中发挥着非冗余的作用。近年来，我们对磷脂酰肌醇4-激酶生物学的理解取得了重大进展，在此我们总结了目前关于磷脂酰肌醇4-激酶结构、功能和调控的知识。
