biostudies-literatureMenon VKPurdue University Institute for Cancer ResearchGovernment of India Department of Atomic EnergyNIH110826https://www.ebi.ac.uk/biostudies/studies/S-EPMC12664033biostudies-literatureUnknown301(12)Organization and composition of the plasma membrane are important modulators of many cellular programs. Phosphatidylinositol phosphate (PIP) lipids are low-abundance membrane constituents with different arrangements of phosphate groups around an inositol head group, regulating many signaling pathways. Numerous strategies have been developed to detect and track PIP species to monitor their clustering, mobility, and interactions with binding partners. We implement a peptide-based, ratiometric sensor for the detection of PI(4,5)P₂ lipids in reconstituted membrane systems that permit absolute quantification of PI(4,5)P₂ densities down to physiological levels less than 4 mol per cent. The sensor is membrane-permeable and easily transferable to measurements in living cells.The Journal of biological chemistryDetection of PIP<sub>2</sub> distributions in biological membranes using a peptide-based sensor.PMC12664033RTI4003Scrudders KLKundu RLow-Nam STWu JMenon VKDatta AMondal SWalke APellicier-Caraballo JAlonzo AJSelvarajan SRogers KAfalseDetection of PIP<sub>2</sub> distributions in biological membranes using a peptide-based sensor.Organization and composition of the plasma membrane are important modulators of many cellular programs. Phosphatidylinositol phosphate (PIP) lipids are low-abundance membrane constituents with different arrangements of phosphate groups around an inositol head group, regulating many signaling pathways. Numerous strategies have been developed to detect and track PIP species to monitor their clustering, mobility, and interactions with binding partners. We implement a peptide-based, ratiometric sensor for the detection of PI(4,5)P₂ lipids in reconstituted membrane systems that permit absolute quantification of PI(4,5)P₂ densities down to physiological levels less than 4 mol per cent. The sensor is membrane-permeable and easily transferable to measurements in living cells.2025-01-01T00:00:00Z2025 Oct2026-06-05T21:32:40.694Z2026-05-22T03:11:08.385ZS-EPMC126640334110935010.1016/j.jbc.2025.110826