• Libraries
    • Log in to:
    View Item 
    •   MSpace Home
    • Faculty of Graduate Studies (Electronic Theses and Practica)
    • FGS - Electronic Theses and Practica
    • View Item
    •   MSpace Home
    • Faculty of Graduate Studies (Electronic Theses and Practica)
    • FGS - Electronic Theses and Practica
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Biochemistry and physiology of NhaP-type antiporters in Vibrio cholerae

    Thumbnail
    View/Open
    Resch_Craig.pdf (4.465Mb)
    Date
    2010
    2011
    2012
    2014
    Author
    Resch, Craig
    Metadata
    Show full item record
    Abstract
    Antiporters that exchange alkali cations (Na+ or K+) for protons play an important role in the physiology of all known bacterial species. They are involved in regulating intracellular pH and maintaining cellular volume as well as the formation of a chemical Na+ gradient across the membrane, which is important to many bacteria as an energy source for processes such as accumulation of substrates, ATP synthesis, and flagellar rotation. Another important role of cation/proton antiporters is homeostasis of intracellular cation content. The situation of a thermodynamic equilibrium of Na+ or K+ on the membrane would result in toxic intracellular levels of these cations, so bacteria have cation/proton antiporters, which expel excess of alkali cations at the expense of the proton motive force. Of many antiporters described to date, the NhaP-type family is one of the most interesting groups. Its members collectively demonstrate a great diversity of their features. There are three antiporters of NhaP type encoded in the genome of the dangerous human pathogen, Vibrio cholerae. Phenotype analysis of engineered chromosomal VcnhaP1, VcnhaP2 and VcnhaP3 deletion mutants has proven the three NhaP paralogues to be essential for V. cholerae growth at low pH in the presence of high or low concentrations of K+. Genes encoding Vc-NhaP1-3 were cloned and antiporters expressed in their functional form in an antiporter-less strains of Escherichia coli. Although initially annotated as Na+/H+ antiporters, when assayed in everted membrane vesicles, all three isoforms of Vc-NhaP were shown to be K+/H+ antiporters with only limited ability to Na+/H+ antiport. None of three proteins was able to mediate Li+/H+ exchange. Overall, the three antiporters differed in their biochemical profiles, predicted topology, and their phenotypic manifestations.
    URI
    http://hdl.handle.net/1993/31098
    Collections
    • FGS - Electronic Theses and Practica [25494]

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV
     

     

    Browse

    All of MSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    Login

    Statistics

    View Usage Statistics

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV