title: On the cellular site of two-pore channel TPC1 action in the Poaceae.
abstract: The slow vacuolar (SV) channel has been characterized in different dicots by patch-clamp recordings. This channel represents the major cation conductance of the largest organelle in most plant cells. Studies with the tpc1-2 mutant of the model dicot plant Arabidopsis thaliana identified the SV channel as the product of the TPC1 gene. By contrast, research on rice and wheat TPC1 suggested that the monocot gene encodes a plasma membrane calcium-permeable channel. To explore the site of action of grass TPC1 channels, we expressed OsTPC1 from rice (Oryza sativa) and TaTPC1 from wheat (Triticum aestivum) in the background of the Arabidopsis tpc1-2 mutant. Cross-species tpc1 complementation and patch-clamping of vacuoles using Arabidopsis and rice tpc1 null mutants documented that both monocot TPC1 genes were capable of rescuing the SV channel deficit. Vacuoles from wild-type rice but not the tpc1 loss-of-function mutant harbor SV channels exhibiting the hallmark properties of dicot TPC1/SV channels. When expressed in human embryonic kidney (HEK293) cells OsTPC1 was targeted to Lysotracker-Red-positive organelles. The finding that the rice TPC1, just like those from the model plant Arabidopsis and even animal cells, is localized and active in lyso-vacuolar membranes associates this cation channel species with endomembrane function.
authors.affiliation: Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, D-97082, Wuerzburg, Germany.
authors.forename: Beata
authors.initials: B
authors.lastname: Dadacz-Narloch
authors.affiliation: Department of Applied Biological Science, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan.
authors.forename: Sachie
authors.initials: S
authors.lastname: Kimura
authors.affiliation: Department of Applied Biological Science, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan.|School of Bioscience and Biotechnology, Tokyo University of Technology, Hachioji, Tokyo, 192-0982, Japan.
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Kurusu
authors.affiliation: Department of Plant Molecular Biology, University of Lausanne, Biophore, 1015, Lausanne, Switzerland.
authors.forename: Edward E
authors.initials: EE
authors.lastname: Farmer
authors.affiliation: Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, D-97082, Wuerzburg, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Becker
authors.affiliation: Department of Applied Biological Science, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Kuchitsu
authors.affiliation: Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, D-97082, Wuerzburg, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Hedrich
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D020013:Calcium Signaling; D002412:Cations / Q000378:metabolism; D017343:Genes, Plant; D057809:HEK293 Cells; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000235:genetics / Q000378:metabolism; D018408:Patch-Clamp Techniques; D006109:Poaceae / Q000235:genetics / Q000378:metabolism*; D014908:Triticum / Q000235:genetics / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism*; D000097903:Two-Pore Channels
chemical_list: D029681:Arabidopsis Proteins; D015220:Calcium Channels; D002412:Cations; C498240:TPC1 protein, Arabidopsis; D000097903:Two-Pore Channels
keywords: Oryza sativa (rice); Poaceae; lysosome; patch clamp; two pore channel 1 (TPC1); vacuole