title: Plasma membrane organization and dynamics is probe and cell line dependent.
abstract: The action and interaction of membrane receptor proteins take place within the plasma membrane. The plasma membrane, however, is not a passive matrix. It rather takes an active role and regulates receptor distribution and function by its composition and the interaction of its lipid components with embedded and surrounding proteins. Furthermore, it is not a homogenous fluid but contains lipid and protein domains of various sizes and characteristic lifetimes which are important in regulating receptor function and signaling. The precise lateral organization of the plasma membrane, the differences between the inner and outer leaflet, and the influence of the cytoskeleton are still debated. Furthermore, there is a lack of comparisons of the organization and dynamics of the plasma membrane of different cell types. Therefore, we used four different specific membrane markers to test the lateral organization, the differences between the inner and outer membrane leaflet, and the influence of the cytoskeleton of up to five different cell lines, including Chinese hamster ovary (CHO-K1), Human cervical carcinoma (HeLa), neuroblastoma (SH-SY5Y), fibroblast (WI-38) and rat basophilic leukemia (RBL-2H3) cells by Imaging Total Internal Reflection (ITIR)-Fluorescence Correlation Spectroscopy (FCS). We measure diffusion in the temperature range of 298-310K to measure the Arrhenius activation energy (EArr) of diffusion and apply the FCS diffusion law to obtain information on the spatial organization of the probe molecules on the various cell membranes. Our results show clear differences of the FCS diffusion law and EArrfor the different probes in dependence of their localization. These differences are similar in the outer and inner leaflet of the membrane. However, these values can differ significantly between different cell lines raising the question how molecular plasma membrane events measured in different cell lines can be compared. This article is part of a Special Issue entitled: Interactions between membrane receptors in cellular membranes edited by Kalina Hristova.
authors.affiliation: Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore.
authors.forename: Shuangru
authors.initials: S
authors.lastname: Huang
authors.affiliation: NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore; Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore.
authors.forename: Shi Ying
authors.initials: SY
authors.lastname: Lim
authors.affiliation: Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore.
authors.forename: Anjali
authors.initials: A
authors.lastname: Gupta
authors.affiliation: NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore; Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore.
authors.forename: Nirmalya
authors.initials: N
authors.lastname: Bag
authors.affiliation: Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore; Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore. Electronic address: twohland@nus.edu.sg.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Wohland
mesh_terms: D000818:Animals; D016466:CHO Cells; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism*; D006224:Cricetinae; D003412:Cricetulus; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism*; D021962:Membrane Microdomains / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D013050:Spectrometry, Fluorescence
chemical_list: D008051:Lipid Bilayers
keywords: Arrhenius activation energy; Domain diffusion; Fluorescence correlation spectroscopy; Hop-diffusion; Imaging FCS; Lipid rafts