Arabidopsis AtCNGC10 rescues potassium channel mutants of E. coli, yeast and Arabidopsis and is regulated by calcium/calmodulin and cyclic GMP in E. coli
- 1 January 2005
- journal article
- Published by CSIRO Publishing in Functional Plant Biology
- Vol. 32 (7), 643-653
- https://doi.org/10.1071/fp04233
Abstract
We have isolated and characterised AtCNGC10, one of the 20 members of the family of cyclic nucleotide (CN)-gated and calmodulin (CaM)-regulated channels (CNGCs) from Arabidopsis thaliana (L.) Heynh. AtCNGC10 bound CaM in a C-terminal subregion that contains a basic amphiphillic structure characteristic of CaM-binding proteins and that also overlaps with the predicted CN-binding domain. AtCNGC10 is insensitive to the broad-range K+ channel blocker, tetraethylammonium, and lacks a typical K+-signature motif. However, AtCNGC10 complemented K+ channel uptake mutants of Escherichia coli (LB650), yeast (Saccharomyces cerevisiae CY162) and Arabidopsis (akt1-1). Sense 35S-AtCNGC10 transformed into the Arabidopsis akt1-1 mutant, grew 1.7-fold better on K+-limited medium relative to the vector control. Coexpression of CaM and AtCNGC10 in E. coli showed that Ca2+ / CaM inhibited cell growth by 40%, while cGMP reversed the inhibition by Ca2+ / CaM, in a AtCNGC10-dependent manner. AtCNGC10 did not confer tolerance to Cs+ in E. coli, however, it confers tolerance to toxic levels of Na+ and Cs+ in the yeast K+ uptake mutant grown on low K+ medium. Antisense AtCNGC10 plants had 50% less potassium than wild type Columbia. Taken together, the studies from three evolutionarily diverse species demonstrated a role for the CaM-binding channel, AtCNGC10, in mediating the uptake of K+ in plants.Keywords
This publication has 48 references indexed in Scilit:
- A Cyclic Nucleotide-Gated Ion Channel, CNGC2, Is Crucial for Plant Development and Adaptation to Calcium StressPlant Physiology, 2003
- HLM1, an Essential Signaling Component in the Hypersensitive Response, Is a Member of the Cyclic Nucleotide–Gated Channel Ion Channel Family[W]Plant Cell, 2003
- TheArabidopsis dnd1“defense, no death” gene encodes a mutated cyclic nucleotide-gated ion channelProceedings of the National Academy of Sciences of the United States of America, 2000
- Characterisation of two distinct HKT1-like potassium transporters from Eucalyptus camaldulensisPlant Molecular Biology, 2000
- A tobacco plasma membrane calmodulin‐binding transporter confers Ni2+ tolerance and Pb2+ hypersensitivity in transgenic plantsThe Plant Journal, 1999
- The Structure of the Potassium Channel: Molecular Basis of K + Conduction and SelectivityScience, 1998
- Multiple Genes, Tissue Specificity, and Expression-Dependent Modulation Contribute to the Functional Diversity of Potassium Channels in Arabidopsis thalianaPlant Physiology, 1995
- Calcium Regulation in Plant Cells and its Role in SignalingAnnual Review of Plant Physiology and Plant Molecular Biology, 1995
- A single negative charge within the pore region of a cGMP-gated channel controls rectification, Ca2+ blockage, and ionic selectivity.Proceedings of the National Academy of Sciences of the United States of America, 1994
- Functional expression of a probable Arabidopsis thaliana potassium channel in Saccharomyces cerevisiae.Proceedings of the National Academy of Sciences of the United States of America, 1992