Department of Biochemistry, University of Washington, Seattle, WA 98195, USA.
Mol Neurobiol. 2011 Dec;44(3):420-5. doi: 10.1007/s12035-011-8208-y. Epub 2011 Sep 18.
The importance of phosphoinositides (phosphorylated phosphatidyl inositol derivatives, PIs) for normal cellular function cannot be overstated. Although they represent a small fraction of the total phospholipid within the cell, they are essential regulators of many cellular functions. They direct membrane trafficking by functioning as recruitment factors for vesicular trafficking components, they can modulate ion channel activity through direct binding within cellular membranes, and their hydrolysis generates second messenger signaling molecules. Despite an explosion of information regarding the importance of these lipids in cellular biology, their precise roles in vertebrate retinal photoreceptors has not been established. This review summarizes the literature on potential roles for different phosphoinositides and their regulators in vertebrate rods and cones. A brief description of the importance of PI signaling in other photosensitive cells is also presented. The highly specialized functions of the vertebrate photoreceptor, combined with the established importance of phosphoinositides, promise significant future discoveries in this field.
不能过分强调磷脂酰肌醇（磷酸化磷脂酰肌醇衍生物，PI）对正常细胞功能的重要性。尽管它们在细胞内总磷脂中的比例很小，但它们是许多细胞功能的重要调节剂。它们通过作为囊泡运输成分的募集因子起作用来指导膜运输，通过在细胞膜内直接结合来调节离子通道活性，并且它们的水解生成第二信使信号分子。尽管有关这些脂质在细胞生物学中的重要性的信息大量涌现，但它们在脊椎动物视网膜光感受器中的确切作用尚未确定。本综述总结了有关不同磷脂酰肌醇及其调节剂在脊椎动物视杆和视锥细胞中的潜在作用的文献。还简要介绍了 PI 信号在其他感光细胞中的重要性。脊椎动物光感受器的高度专业化功能，加上磷脂酰肌醇的重要性，预示着该领域将有重大的未来发现。
