Open AccessRegulation of PI4P levels by PI4KIIIα during G-protein coupled PLC signaling inDrosophilaphotoreceptors
Author(s) -
Sruthi Balakrishnan,
Urbashi Basu,
Dhananjay Shinde,
Rajan Thakur,
Manish Jaiswal,
Padinjat Raghu
Publication year - 2018
Publication title -
journal of cell science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.384
H-Index - 278
eISSN - 1477-9137
pISSN - 0021-9533
DOI - 10.1242/jcs.217257
Subject(s) - biology , phosphatidylinositol , microbiology and biotechnology , phospholipase c , signal transduction , phosphorylation , g protein , gq alpha subunit , context (archaeology) , biochemistry , paleontology
The activation of phospholipase C (PLC) is a conserved mechanism of receptor activated cell signaling at the plasma membrane. PLC hydrolyzes the minor membrane lipid phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] and continued signaling requires the resynthesis and availability of PI(4,5)P2 at the plasma membrane. PI(4,5)P2 is synthesized by the phosphorylation of phosphatidylinositol-4-phosphate (PI4P). Thus, a continuous supply of PI4P is essential to support ongoing PLC signaling. While the enzyme PI4KA has been identified to perform this function in cultured mammalian cells, its function in the context of an in vivo physiological model has not been established. In this study, we show that in Drosophila photoreceptors, PI4KIIIα activity is required to support signaling during G-protein coupled PLC activation. Depletion of PI4KIIIα results in impaired electrical responses to light and reduced plasma membrane levels of PI4P and PI(4,5)P2. Depletion of conserved proteins Efr3 and TTC7 that assemble PI4KIIIα at the plasma membrane also results in an impaired light response and reduced plasma membrane PI4P and PI(4,5)P2 levels. Thus PI4KIIIα activity at the plasma membrane generates PI4P and supports PI(4,5)P2 levels during receptor activated PLC signaling.