Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Sci Signal. 2012 Jan 31;5(209):ra10. doi: 10.1126/scisignal.2002446.
Class I myosins participate in various interactions between the cell membrane and the cytoskeleton. Several class I myosins preferentially bind to acidic phospholipids, such as phosphatidylserine and phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], through a tail homology 1 (TH1) domain. Here, we show that the second messenger lipid phosphatidylinositol 3,4,5-trisphosphate (PIP3) binds to the TH1 domain of a subset of Dictyostelium class I myosins (ID, IE, and IF) and recruits them to the plasma membrane. The PIP3-regulated membrane recruitment of myosin I promoted chemotaxis and induced chemoattractant-stimulated actin polymerization. Similarly, PIP3 recruited human myosin IF to the plasma membrane upon chemotactic stimulation in a neutrophil cell line. These data suggest a mechanism through which the PIP3 signal is transmitted through myosin I to the actin cytoskeleton.
I 类肌球蛋白参与细胞膜和细胞骨架之间的各种相互作用。几种 I 类肌球蛋白通过尾部同源 1（TH1）结构域优先与酸性磷脂，如磷脂酰丝氨酸和磷脂酰肌醇 4,5-二磷酸[PI（4,5）P2]结合。在这里，我们表明第二信使脂质磷脂酰肌醇 3,4,5-三磷酸（PIP3）与盘基网柄菌 I 类肌球蛋白（ID、IE 和 IF）的亚组的 TH1 结构域结合，并将其招募到质膜上。肌球蛋白 I 的 PIP3 调节的膜募集促进了趋化作用，并诱导了趋化刺激的肌动蛋白聚合。类似地，在中性粒细胞系中受到趋化刺激时，PIP3 将人肌球蛋白 IF 募集到质膜上。这些数据表明了一种通过肌球蛋白 I 将 PIP3 信号传递到肌动蛋白细胞骨架的机制。
