Phosphatidylinositol 5-phosphate 4-kinase regulates early endosomal dynamics during clathrin-mediated endocytosis.
|Phosphatidylinositol 5-phosphate 4-kinase regulates early endosomal dynamics during clathrin-mediated endocytosis.
|Year of Publication
|Kamalesh K, Trivedi D, Toscano S, Sharma S, Kolay S, Raghu P
|J Cell Sci
|2017 May 15
Endocytic turnover is essential to regulate the protein composition and function of the plasma membrane thus regulating the plasma membrane levels of many receptors. In Drosophila photoreceptors, photon absorption by the GPCR rhodopsin 1 (Rh1) triggers its endocytosis by clathrin-mediated endocytosis (CME). We find that CME of Rh1 is regulated by phosphatidylinositol 5 phosphate 4-kinase (PIP4K). Flies lacking PIP4K show mislocalization of Rh1 on expanded endomembranes within the cell body. This mislocalization of Rh1 was dependent on the formation of an expanded Rab5 compartment. The Rh1 trafficking defect in dPIP4K-depleted cells could be suppressed by downregulating Rab5 function or by selectively reconstituting dPIP4K in the PI3P enriched early endosomal (EE) compartment of photoreceptors. We also found that loss of PIP4K was associated with increased CME and an enlarged Rab5 compartment in cultured Drosophila cells. Collectively our findings define PIP4K as a novel regulator of early endosomal homeostasis during CME.
|J. Cell. Sci.