The generation of phosphoinositides (PIs) with spatial and temporal control is a key mechanism in cellular organization and signaling. The synthesis of PIs is mediated by PI kinases, proteins that are able to phosphorylate unique substrates at specific positions on the inositol headgroup to generate signaling molecules. Phosphatidylinositol 5 phosphate 4 kinase (PIP4K) is one such lipid kinase that is able to specifically phosphorylate phosphatidylinositol 5 phosphate, the most recently discovered PI to generate the well-known and abundant PI, phosphatidylinositol 4,5 bisphosphate [PI(4,5)P₂]. PIP4K appears to be encoded only in metazoan genomes, and several genetic studies indicate important physiological functions for these enzymes in metabolism, immune function, and growth control. PIP4K has recently been reported to localize to multiple cellular compartments, including the nucleus, plasma membrane, endosomal systems, and autophagosome. However, the biochemical activity of these enzymes that is relevant to these physiological functions remains elusive. We review recent developments in this area and highlight emerging roles for these enzymes in cellular organization.

具有空间和时间控制的磷酸肌醇 (PI) 的产生是细胞组织和信号传导的关键机制。PI 的合成由 PI 激酶介导，PI 激酶是能够磷酸化肌醇头基上特定位置的独特底物以产生信号分子的蛋白质。磷脂酰肌醇 5 磷酸 4 激酶 (PIP4K) 是一种能够特异性磷酸化磷脂酰肌醇 5 磷酸的脂质激酶，最近发现的 PI 可产生众所周知且丰富的 PI，磷脂酰肌醇 4,5 二磷酸 [PI(4,5)磷₂]。PIP4K 似乎只在后生动物基因组中编码，一些遗传研究表明这些酶在代谢、免疫功能和生长控制中具有重要的生理功能。最近有报道称 PIP4K 定位于多个细胞区室，包括细胞核、质膜、内体系统和自噬体。然而，与这些生理功能相关的这些酶的生化活性仍然难以捉摸。我们回顾了这一领域的最新发展，并强调了这些酶在细胞组织中的新兴作用。