title: Specific RNA binding to ordered phospholipid bilayers.
abstract: We have studied RNA binding to vesicles bounded by ordered and disordered phospholipid membranes. A positive correlation exists between bilayer order and RNA affinity. In particular, structure-dependent RNA binding appears for rafted (liquid-ordered) domains in sphingomyelin-cholesterol-1,2-dioleoyl-sn-glycero-3-phosphocholine vesicles. Binding to more highly ordered gel phase membranes is stronger, but much less RNA structure-dependent. All modes of RNA-membrane association seem to be electrostatic and headgroup directed. Fluorometry on 1,2-dimyristoyl-sn-glycero-3-phosphocholine liposomes indicates that bound RNA broadens the gel-fluid melting transition, and reduces lipid headgroup order, as detected via fluorometric measurement of intramembrane electric fields. RNA preference for rafted lipid was visualized and confirmed using multiple fluorophores that allow fluorescence and fluorescence resonance energy transfer microscopy on RNA molecules closely associated with ordered lipid patches within giant vesicles. Accordingly, both RNA structure and membrane order could modulate biological RNA-membrane interactions.
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309-0347, USA.
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Janas
authors.forename: Teresa
authors.initials: T
authors.lastname: Janas
authors.forename: Michael
authors.initials: M
authors.lastname: Yarus
mesh_terms: D001665:Binding Sites; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D021962:Membrane Microdomains / Q000737:chemistry / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry* / Q000378:metabolism; D012313:RNA / Q000737:chemistry / Q000378:metabolism*
chemical_list: D008051:Lipid Bilayers; D010743:Phospholipids; D012313:RNA