Department of Plant Biochemistry, Georg-August-University Göttingen, Göttingen, Germany.
Protoplasma. 2010 Apr;240(1-4):13-31. doi: 10.1007/s00709-009-0093-0. Epub 2009 Dec 20.
Phosphoinositides (PIs) are minor, but essential phospholipid constituents of eukaryotic membranes, and are involved in the regulation of various physiological processes. Recent genetic and cell biological advances indicate that PIs play important roles in the control of polar tip growth in plant cells. In root hairs and pollen tubes, PIs control directional membrane trafficking required for the delivery of cell wall material and membrane area to the growing tip. So far, the exact mechanisms by which PIs control polarity and tip growth are unresolved. However, data gained from the analysis of plant, fungal and animal systems implicate PIs in the control of cytoskeletal dynamics, ion channel activity as well as vesicle trafficking. The present review aims at giving an overview of PI roles in eukaryotic cells with a special focus on functions pertaining to the control of cell polarity. Comparative screening of plant and fungal genomes suggests diversification of the PI system with increasing organismic complexity. The evolutionary conservation of the PI system among eukaryotic cells suggests a role for PIs in tip growing cells in models where PIs so far have not been a focus of attention, such as fungal hyphae.
磷脂酰肌醇（PIs）是真核细胞膜中的少量但必需的磷脂成分，参与各种生理过程的调节。最近的遗传和细胞生物学进展表明，PIs 在植物细胞的极性顶端生长控制中发挥重要作用。在根毛和花粉管中，PIs 控制定向膜运输，这是向生长顶端输送细胞壁物质和膜面积所必需的。到目前为止，PIs 控制极性和顶端生长的确切机制尚不清楚。然而，从对植物、真菌和动物系统的分析中获得的数据表明，PIs 参与了细胞骨架动力学、离子通道活性以及囊泡运输的控制。本综述旨在概述 PIs 在真核细胞中的作用，特别关注与细胞极性控制相关的功能。植物和真菌基因组的比较筛选表明，随着生物体复杂性的增加，PI 系统的多样化。PI 系统在真核细胞中的进化保守性表明，PIs 在尖端生长细胞中发挥作用，而在真菌菌丝等 PIs 尚未成为关注焦点的模型中也是如此。
