title: Unique features of two potassium channels, OsKAT2 and OsKAT3, expressed in rice guard cells.
abstract: Potassium is the most abundant cation and a myriad of transporters regulate K(+) homeostasis in plant. Potassium plays a role as a major osmolyte to regulate stomatal movements that control water utility of land plants. Here we report the characterization of two inward rectifying shaker-like potassium channels, OsKAT2 and OsKAT3, expressed in guard cell of rice plants. While OsKAT2 showed typical potassium channel activity, like that of Arabidopsis KAT1, OsKAT3 did not despite high sequence similarity between the two channel proteins. Interestingly, the two potassium channels physically interacted with each other and such interaction negatively regulated the OsKAT2 channel activity in CHO cell system. Furthermore, deletion of the C-terminal domain recovered the channel activity of OsKAT3, suggesting that the C-terminal region was regulatory domain that inhibited channel activity. Two homologous channels with antagonistic interaction has not been previously reported and presents new information for potassium channel regulation in plants, especially in stomatal regulation.
authors: Department of Molecular Breeding, National Academy of Agricultural Science, Rural Development Administration, Suwon, Korea.
authors: Hyunsik
authors: H
authors: Hwang
authors: Jinyoung
authors: J
authors: Yoon
authors: Hyun Yeong
authors: HY
authors: Kim
authors: Myung Ki
authors: MK
authors: Min
authors: Jin-Ae
authors: JA
authors: Kim
authors: Eun-Hye
authors: EH
authors: Choi
authors: Wenzhi
authors: W
authors: Lan
authors: Young-Min
authors: YM
authors: Bae
authors: Sheng
authors: S
authors: Luan
authors: Hana
authors: H
authors: Cho
authors: Beom-Gi
authors: BG
authors: Kim
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D003412:Cricetulus; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009928:Organ Specificity; D012275:Oryza / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D059828:Plant Cells / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D024661:Potassium Channels, Inwardly Rectifying / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D016415:Sequence Alignment; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
chemical_list: D024661:Potassium Channels, Inwardly Rectifying; D011188:Potassium
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