title: Orthogonal lipid sensors identify transbilayer asymmetry of plasma membrane cholesterol.
abstract: Controlled distribution of lipids across various cell membranes is crucial for cell homeostasis and regulation. We developed an imaging method that allows simultaneous in situ quantification of cholesterol in two leaflets of the plasma membrane (PM) using tunable orthogonal cholesterol sensors. Our imaging revealed marked transbilayer asymmetry of PM cholesterol (TAPMC) in various mammalian cells, with the concentration in the inner leaflet (IPM) being ∼12-fold lower than that in the outer leaflet (OPM). The asymmetry was maintained by active transport of cholesterol from IPM to OPM and its chemical retention at OPM. Furthermore, the increase in the IPM cholesterol level was triggered in a stimulus-specific manner, allowing cholesterol to serve as a signaling lipid. We found excellent correlation between the IPM cholesterol level and cellular Wnt signaling activity, suggesting that TAPMC and stimulus-induced PM cholesterol redistribution are crucial for tight regulation of cellular processes under physiological conditions.
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Shu-Lin
authors.initials: SL
authors.lastname: Liu
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Ren
authors.initials: R
authors.lastname: Sheng
authors.affiliation: Department of Applied Chemistry, Kyung Hee University, Yongin, Korea.
authors.forename: Jae Hun
authors.initials: JH
authors.lastname: Jung
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Ewa
authors.initials: E
authors.lastname: Stec
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: O'Connor
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Seohyoen
authors.initials: S
authors.lastname: Song
authors.affiliation: Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Rama Kamesh
authors.initials: RK
authors.lastname: Bikkavilli
authors.affiliation: Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Winn
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Daesung
authors.initials: D
authors.lastname: Lee
authors.affiliation: Department of Genetic Engineering, Kyung Hee University, Yongin, Korea.
authors.forename: Kwanghee
authors.initials: K
authors.lastname: Baek
authors.affiliation: Institute for Integrated Cell-Material Sciences (WPI-iCeMS), and Division of Applied Life Sciences, Kyoto University, Kyoto, Japan.
authors.forename: Kazumitsu
authors.initials: K
authors.lastname: Ueda
authors.affiliation: Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Irena
authors.initials: I
authors.lastname: Levitan
authors.affiliation: Department of Applied Chemistry, Kyung Hee University, Yongin, Korea.
authors.forename: Kwang-Pyo
authors.initials: KP
authors.lastname: Kim
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois, USA.|Department of Genetic Engineering, Kyung Hee University, Yongin, Korea.
authors.forename: Wonhwa
authors.initials: W
authors.lastname: Cho
mesh_terms: D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry*; D002784:Cholesterol / Q000032:analysis*; D057809:HEK293 Cells; D006801:Humans; D008055:Lipids / Q000737:chemistry*
chemical_list: D008055:Lipids; D002784:Cholesterol