University at Buffalo - The State University of New York
Skip to Content
Conservation and dispersion of sequence and function in fungal TRK potassium transporters: focus on Candida albicans. - PubMed - NCBI
Format

Send to

Choose Destination
See comment in PubMed Commons below
FEMS Yeast Res. 2009 Mar;9(2):278-92. doi: 10.1111/j.1567-1364.2008.00471.x. Epub 2009 Jan 13.

Conservation and dispersion of sequence and function in fungal TRK potassium transporters: focus on Candida albicans.

Author information

1
Department of Genetics, Yale School of Medicine, New Haven, CT 06520, USA.

Abstract

TRK proteins - essential potassium (K(+)) transporters in fungi and bacteria, as well as in plants - are generally absent from animal cells, which makes them potential targets for selective drug action. Indeed, in the human pathogen Candida albicans, the single TRK isoform (CaTrk1p) has recently been demonstrated to be required for activity of histidine-rich salivary antimicrobial peptides (histatins). Background for a detailed molecular investigation of TRK-protein design and function is provided here in sequence analysis and quantitative functional comparison of CaTrk1p with its better-known homologues from Saccharomyces cerevisiae. Among C. albicans strains (ATCC 10261, SC5314, WO-1), the DNA sequence is essentially devoid of single nucleotide polymorphisms in regions coding for evolutionarily conserved segments of the protein, meaning the four intramembranal [membrane-pore-membrane (MPM)] segments thought to be involved directly with the conduction of K(+) ions. Among 48 fungal (ascomycete) TRK homologues now described by complete sequences, clades (but not the detailed order within clades) appear conserved for all four MPM segments, independently assessed. The primary function of TRK proteins, 'active' transport of K(+) ions, is quantitatively conserved between C. albicans and S. cerevisiae. However, the secondary function, chloride efflux channeling, is present but poorly conserved between the two species, being highly variant with respect to activation velocity, amplitude, flickering (channel-like) behavior, pH dependence, and inhibitor sensitivity.

[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Silverchair Information Systems Icon for Wiley
    Loading ...
    Support Center