On the cellular site of two‐pore channel TPC1 action in the Poaceae. Issue 3 (12th July 2013)

• Record Type: Journal Article
• Authors: Dadacz‐Narloch, Beata; Kimura, Sachie; Kurusu, Takamitsu; Farmer, Edward E.; Becker, Dirk; Kuchitsu, Kazuyuki; Hedrich, Rainer
• Is Part Of: New phytologist. Volume 200:Issue 3(2013)
• Page Start: 663
• Page End: 674
• Publication Date: 2013-07-12
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.12402
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph12402-abs-0001"> <title>Summary</title> <p> <list id="nph12402-list-0001" list-type="bullet"> <list-item> <p>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 <italic>tpc1‐2</italic> mutant of the model dicot plant <italic>Arabidopsis thaliana</italic> identified the SV channel as the product of the <italic>TPC1</italic> gene. By contrast, research on rice and wheat TPC1 suggested that the monocot gene encodes a plasma membrane calcium‐permeable channel.</p> </list-item> <list-item> <p>To explore the site of action of grass TPC1 channels, we expressed <italic>OsTPC1</italic> from rice (<italic>Oryza sativa)</italic> and <italic>TaTPC1</italic> from wheat (<italic>Triticum aestivum)</italic> in the background of the <italic>Arabidopsis tpc1‐2</italic> mutant. Cross‐species <italic>tpc1</italic> complementation and patch‐clamping of vacuoles using <italic>Arabidopsis</italic> and rice <italic>tpc1</italic> null mutants documented that both monocot <italic>TPC1</italic> genes were capable of rescuing the SV channel deficit.</p> </list-item> <list-item> <p>Vacuoles from wild‐type rice but not the <italic>tpc1</italic> 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.</p> </list-item> <list-item> <p>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.</p> </list-item> </list> </p> </abstract>