
@article {108052,
	title = {Septins tune lipid kinase activity and PI(4,5)P turnover during G-protein-coupled PLC signalling in vivo.},
	journal = {Life Sci Alliance},
	volume = {5},
	year = {2022},
	month = {2022 Jun},
	abstract = {<p>Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P] hydrolysis by phospholipase C (PLC) is a conserved mechanism of signalling. Given the low abundance of PI(4,5)P, its hydrolysis needs to be coupled to resynthesis to ensure continued PLC activity; however, the mechanism by which depletion is coupled to resynthesis remains unknown. PI(4,5)P synthesis is catalyzed by the phosphorylation of phosphatidylinositol 4 phosphate (PI4P) by phosphatidylinositol 4 phosphate 5 kinase (PIP5K). In photoreceptors, photon absorption is transduced into PLC activity and during this process, PI(4,5)P is resynthesized by a PIP5K. However, the mechanism by which PIP5K activity is coupled to PI(4,5)P hydrolysis is unknown. In this study, we identify a unique isoform dPIP5K, that is both necessary and sufficient to mediate PI(4,5)P synthesis during phototransduction. Depletion of PNUT, a non-redundant subunit of the septin family, enhances dPIP5K activity in vitro and PI(4,5)P resynthesis in vivo; co-depletion of dPIP5K reverses the enhanced rate of PI(4,5)P resynthesis in vivo. Thus, our work defines a septin-mediated mechanism through which PIP5K activity is coupled to PLC-mediated PI(4,5)P hydrolysis.</p>
},
	issn = {2575-1077},
	doi = {10.26508/lsa.202101293},
	author = {Kumari, Aastha and Ghosh, Avishek and Kolay, Sourav and Raghu, Padinjat}
}
