Functional expression of a probable Arabidopsis thaliana potassium channel in Saccharomyces cerevisiae.
We report the isolation of a cDNA (KAT1) from Arabidopsis thaliana that encodes a probable K+ channel. KAT1 was cloned by its ability to suppress a K+ transport-defective phenotype in mutant Saccharomyces cerevisiae cells. This suppression is sensitive to known K+ channel blockers, including tetraethylammonium and Ba2+ ions. The KAT1 cDNA contains an open reading frame capable of encoding a 78-kDa protein that shares structural features found in the Shaker superfamily of K+ channels. These include a cluster of six putative membrane-spanning helices (S1-S6) at the amino terminus of the protein, a presumed voltage-sensing region containing Arg/Lys-Xaa-Xaa-Arg/Lys repeats within S4, and the highly conserved pore-forming region (known as H5 or SS1-SS2). Our results suggest that the structural motif for K+ channels has been conserved between plants and animals.
Anderson
J A
JA
Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, IL 60208.
Huprikar
S S
SS
Kochian
L V
LV
Lucas
W J
WJ
Gaber
R F
RF
D000595:Amino Acid Sequence; D001464:Barium / Q000494:pharmacology; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D017343:Genes, Plant; D005816:Genetic Complementation Test; D008562:Membrane Glycoproteins / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D010944:Plants / Q000235:genetics*; D015221:Potassium Channels / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D016415:Sequence Alignment; D012995:Solubility; D013329:Structure-Activity Relationship; D013757:Tetraethylammonium Compounds / Q000494:pharmacology
D008562:Membrane Glycoproteins; D015221:Potassium Channels; D013757:Tetraethylammonium Compounds; D001464:Barium; D004247:DNA