Skip Navigation


Plant and Cell Physiology Advance Access originally published online on January 16, 2008
Plant and Cell Physiology 2008 49(2):273-283; doi:10.1093/pcp/pcn003
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
49/2/273    most recent
pcn003v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Kohinata, T.
Right arrow Articles by Fukuzawa, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kohinata, T.
Right arrow Articles by Fukuzawa, H.
Agricola
Right arrow Articles by Kohinata, T.
Right arrow Articles by Fukuzawa, H.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2008. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oxfordjournals.org

Significance of Zinc in a Regulatory Protein, CCM1, Which Regulates the Carbon-Concentrating Mechanism in Chlamydomonas reinhardtii

Tsutomu Kohinata, Haruku Nishino and Hideya Fukuzawa*

Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502 Japan

*Corresponding author: E-mail, fukuzawa{at}lif.kyoto-u.ac.jp; Fax, +81-75-753-6127.


  Abstract

In conditions with the poor availability of inorganic carbon (CO2 and HCO3 –: Ci) for photosynthesis, aquatic photosynthetic organisms induce active Ci uptake systems that allow accumulation of Ci within the cell, the so-called carbon-concentrating mechanism (CCM). In a unicellular green alga, Chlamydomonas reinhardtii, a regulatory factor CCM1 is indispensable for the regulation of the CCM by sensing CO2 availability. CCM1 has two putative zinc-binding domains with several conserved cysteine and histidine residues in its N-terminal region. To determine whether the domains actually bind zinc atoms, the N-terminal parts of CCM1 were expressed as glutathione S-transferase fusion proteins and subjected to atomic absorption spectrometry. It was found that 1 mol of zinc is bound to 1 mol of amino acid regions 1–71 and 72–101 of CCM1, respectively. In the case of the site-directed mutant proteins, H54Y, C77V and C80V, the zinc-binding ability was lost. Physiological analyses of the transgenic Chlamydomonas cells harboring a mutated Ccm1 gene revealed that amino acid residues such as C36, C41, H54, C77, C80, H90 and C93 were indispensable for induction of the CCM in response to Ci-limiting stress conditions. Size exclusion chromatography followed by immunoblot analyses indicated that CCM1 is present as a protein complex of approximately 290–580 kDa independent of Ci availability.

Keywords: Carbonic anhydrase — Carbon-concentrating mechanism — Carbon dioxide — Photosynthesis — Signal transduction — Zinc

Abbreviations: CA, carbonic anhydrase; CCM, carbon-concentrating mechanism; Ci, inorganic carbon; GST, glutathione S-transferase; high-CO2, 5% CO2-enriched air; HS, high salt; low-CO2, ordinary air containing 0.04% CO2; PBS, phosphate-buffered saline.

(Received November 22, 2007; Accepted December 27, 2007)
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.