Isolation of an ion channel gene from Arabidopsis thaliana using the H5 signature sequence from voltage-dependent K+ channels.
A degenerate oligonucleotide corresponding to the K+ channel signature sequence (TMTTVGYGD) was used to isolate the genomic and cDNA forms of a new channel gene, AKT3, from Arabidopsis thaliana. The deduced protein sequence has a predicted membrane topography similar to Shaker-like K+ channels. Three distinct modules comprise the carboxyl-terminal half: a nucleotide-binding motif, an ankyrin repeat domain, and a polyglutamate track. Xenopus oocytes injected with cRNA exhibited an inward-rectifying K+ current, demonstrating that the AKT3 polypeptide is a functional transport protein. Two other Arabidopsis K+ transporters (AKT1 and KAT1) share 60% homology with AKT3; together these proteins constitute a family of plant inward-rectifying K+ channels.
Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA.
K A
KA
Ketchum
C W
CW
Slayman
D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D015139:Blotting, Southern; D018076:DNA, Complementary / Q000737:chemistry / Q000302:isolation & purification; D018744:DNA, Plant / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D007438:Introns; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D015221:Potassium Channels / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D016415:Sequence Alignment; D014162:Transfection; D014982:Xenopus laevis
D018076:DNA, Complementary; D018744:DNA, Plant; D015221:Potassium Channels