BIROn - Birkbeck Institutional Research Online

    Differential lipid dependence of function of bacterial sodium channel homologues

    d'Avanzo, N. and McCusker, Emily C. and Powl, Andrew M. and Miles, Andrew J. and Nichols, C.G. and Wallace, Bonnie A. (2013) Differential lipid dependence of function of bacterial sodium channel homologues. Biophysical Journal 104 (2), 14a. ISSN 0006-3495.

    [img]
    Preview
    Text
    12000.pdf - Published Version of Record
    Available under License Creative Commons Attribution Non-commercial.

    Download (35kB) | Preview

    Abstract

    The lipid bilayer is important for maintaining the integrity of cellular compartments and plays a vital role in maintaining the hydrophobic/charged interactions necessary for structure, conformational flexibility and function. Despite the intimate relationship between ion channels and the membranes in which they are embedded, challenges resulting from the dynamic and complex nature of cellular membranes have limited our ability to address the functional role of these interactions. To directly assess lipid dependence of activity, we examined channel function ofthree purified bacterial sodium channel orthologues (NaChBac, NavMs, and NavSp) by cumulative 22Na+ uptake into proteoliposomes containing a 3:1 ratio of POPE and another glycerophospholipid (POPC, POPG, POPS, Cardiolipin (CL), POPA, or PI). We observed a unique lipid dependence for each homologue tested. Common to each was a low level of activity above background (uptake into protein free liposomes) when the second lipid was a zwitterionic lipid such as POPE and POPC. Maximal activity for full-length NaChBac and NavMs proteins was observed in POPE + POPG liposomes. On the other hand, full-length NavSp channels possessed a different lipid dependence, with maximal activity in liposomes containing POPE + PI. No strong lipid dependence was observed for pore-only constructs of NavMs or NavSp, that lacked the S1-S4 segments, suggesting that the lipid dependence of sodium channels may arise from their abilities to affect the voltage-sensing domains. The effect may be maximized by specific lipid-protein interactions that are uniquely favourable in each homologue, giving rise to differing lipid dependences.

    Metadata

    Item Type: Article
    School: Birkbeck Faculties and Schools > Faculty of Science > School of Natural Sciences
    Research Centres and Institutes: Bioinformatics, Bloomsbury Centre for (Closed), Structural Molecular Biology, Institute of (ISMB)
    Depositing User: Administrator
    Date Deposited: 29 Apr 2015 12:18
    Last Modified: 02 Aug 2023 17:16
    URI: https://eprints.bbk.ac.uk/id/eprint/12000

    Statistics

    Activity Overview
    6 month trend
    0Downloads
    6 month trend
    0Hits

    Additional statistics are available via IRStats2.

    Archive Staff Only (login required)

    Edit/View Item Edit/View Item