A combined zinc/cadmium sensor and zinc/cadmium export regulator in a heavy metal pump
Baekgaard, Lone, Mikkelsen, Maria D., Sorensen, Danny M., Hegelund, Josefine N., Persson, Daniel P., Mills, Rebecca F., Yang, Zhang, Husted, Søren, Andersen, Jens Peter, Buch-Pedersen, Morten J., Schjoerring, Jan K., Williams, Lorraine E. and Palmgren, Michael G. (2010) A combined zinc/cadmium sensor and zinc/cadmium export regulator in a heavy metal pump. Journal of Biological Chemistry, 285, (41), 31243-31252. (doi:10.1074/jbc.M110.111260). (PMID:20650903).
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Description/Abstract
Heavy metal pumps (P1B-ATPases) are important for cellular heavy metal homeostasis. AtHMA4, an Arabidopsis thaliana heavy metal pump of importance for plant Zn2+ nutrition, has an extended C-terminal domain containing 13 cysteine pairs and a terminal stretch of 11 histidines. Using a novel size-exclusion chromatography, inductively coupled plasma mass spectrometry approach we report that the C-terminal domain of AtHMA4 is a high affinity Zn2+ and Cd2+ chelator with capacity to bind 10 Zn2+ ions per C terminus. When AtHMA4 is expressed in a Zn2+-sensitive zrc1 cot1 yeast strain, sequential removal of the histidine stretch and the cysteine pairs confers a gradual increase in Zn2+ and Cd2+ tolerance and lowered Zn2+ and Cd2+ content of transformed yeast cells. We conclude that the C-terminal domain of AtHMA4 serves a dual role as Zn2+ and Cd2+ chelator (sensor) and as a regulator of the efficiency of Zn2+ and Cd2+ export. The identification of a post-translational handle on Zn2+ and Cd2+ transport efficiency opens new perspectives for regulation of Zn2+ nutrition and tolerance in eukaryotes.
| Item Type: | Article |
|---|---|
| ISSNs: | 0021-9258 (print) 1083-351X (electronic) |
| Keywords: | atpases, plant, plasma membrane, transport metals, zinc, cadmium, p-type pump, regulatory domain |
| Subjects: | Q Science > QH Natural history > QH301 Biology Q Science > QH Natural history > QH426 Genetics R Medicine > R Medicine (General) |
| Divisions: | University Structure - Pre August 2011 > School of Biological Sciences |
| Item ID: | 186097 |
| Date Deposited: | 12 May 2011 10:43 |
| Last Modified: | 01 Jun 2011 15:41 |
| Contributors: | Baekgaard, Lone (Author) Mikkelsen, Maria D. (Author) Sorensen, Danny M. (Author) Hegelund, Josefine N. (Author) Persson, Daniel P. (Author) Mills, Rebecca F. (Author) Yang, Zhang (Author) Husted, Søren (Author) Andersen, Jens Peter (Author) Buch-Pedersen, Morten J. (Author) Schjoerring, Jan K. (Author) Williams, Lorraine E. (Author) Palmgren, Michael G. (Author) |
| Date: | 8 October 2010 |
| Status: | Published |
| URI: | http://eprints.soton.ac.uk/id/eprint/186097 |
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