On the cellular site of two-pore channel TPC1 action in the Poaceae
Article first published online: 12 JUL 2013
© 2013 The Authors. New Phytologist © 2013 New Phytologist Trust
Volume 200, Issue 3, pages 663–674, November 2013
How to Cite
Dadacz-Narloch, B., Kimura, S., Kurusu, T., Farmer, E. E., Becker, D., Kuchitsu, K. and Hedrich, R. (2013), On the cellular site of two-pore channel TPC1 action in the Poaceae. New Phytologist, 200: 663–674. doi: 10.1111/nph.12402
- Issue published online: 11 OCT 2013
- Article first published online: 12 JUL 2013
- Manuscript Accepted: 2 JUN 2013
- Manuscript Received: 25 MAR 2013
- DFG. Grant Number: FOR964
- Oryza sativa (rice);
- patch clamp;
- Poaceae ;
- two pore channel 1 (TPC1);
- 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.