RDGBα, a PtdIns-PtdOH transfer protein, regulates G-proteincoupled PtdIns(4,5)P2 signalling during Drosophila phototransduction

Panda, Aniruddha and Mathre, Swarna (2015) RDGBα, a PtdIns-PtdOH transfer protein, regulates G-proteincoupled PtdIns(4,5)P2 signalling during Drosophila phototransduction. Journal of Cell Science, 128 (17). pp. 3330-3344.

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Abstract

Many membrane receptors activate phospholipase C (PLC) during signalling, triggering changes in the levels of several plasma membrane lipids including phosphatidylinositol (PtdIns),phosphatidic acid (PtdOH) and phosphatidylinositol 4,5- bisphosphate [PtdIns(4,5)P2]. It is widely believed that exchange of lipids between the plasma membrane and endoplasmic reticulum (ER) is required to restore lipid homeostasis during PLC signalling,yet the mechanism remains unresolved. RDGBα (hereafter RDGB)is a multi-domain protein with a PtdIns transfer protein (PITP) domain (RDGB-PITPd). We find that, in vitro, the RDGB-PITPd binds and transfers both PtdOH and PtdIns. In Drosophila photoreceptors, which experience high rates of PLC activity, RDGB function is essential for phototransduction. We show that binding of PtdIns to RDGB-PITPd is essential for normal phototransduction; however, this property is insufficient to explain the in vivo function because another Drosophila PITP (encoded by vib) that also binds PtdIns cannot rescue the phenotypes of RDGB deletion. In RDGB mutants, PtdIns(4,5)P2 resynthesis at the plasma membrane following PLC activation is delayed and PtdOH levels elevate. Thus RDGB couples the turnover of both PtdIns and PtdOH, key lipid intermediates during G-proteincoupled PtdIns(4,5)P2 turnover.

Item Type: Article
Uncontrolled Keywords: RDGB; Lipid transfer; Phosphoinositide; PITP
Subjects: Research > Research Center - Health Sciences
Depositing User: KMC Library
Date Deposited: 12 Apr 2019 08:57
Last Modified: 12 Apr 2019 08:57
URI: http://eprints.manipal.edu/id/eprint/153655

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