HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 282, Issue 50, 36292-36302, December 14, 2007

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 282/50/36292    most recent M705217200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kim, H. S. Articles by Chung, W. S. Search for Related Content PubMed PubMed Citation Articles by Kim, H. S. Articles by Chung, W. S. Social Bookmarking                      What's this?

Identification of a Calmodulin-binding NAC Protein as a Transcriptional Repressor in Arabidopsis^*

Ho Soo Kim¹²³, Byung Ouk Park¹², Jae Hyuk Yoo, Mi Soon Jung², Sang Min Lee, Hay Ju Han, Kyung Eun Kim, Sun Ho Kim, Chae Oh Lim, Dae-Jin Yun, Sang Yeol Lee, and Woo Sik Chung⁴

From the Division of Applied Life Science (BK21 Program), Plant Molecular Biology and Biotechnology Research Center, and Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Korea

Calmodulin (CaM), a ubiquitous calcium-binding protein, regulates diverse cellular functions by modulating the activity of a variety of proteins. However, little is known about how CaM directly regulates transcription. Screening of an Arabidopsis cDNA expression library using horseradish peroxidase-conjugated calmodulin as a probe identified a calmodulin-binding NAC protein (CBNAC). Using gel overlay assays, a Ca²⁺-dependent CaM-binding domain was identified in the C terminus of this protein. Specific binding of CaM to CaM-binding domain was corroborated by site-directed mutagenesis and a split-ubiquitin assay. Using a PCR-mediated random binding site selection method, we identified a DNA-binding sequence (CBNACBS) for CBNAC, which consisted of a GCTT core sequence flanked on both sides by other frequently repeating sequences (TTGCTTANNNNNNAAG). CBNAC was able to bind to CBNACBS, which resulted in the repression of transcription in Arabidopsis protoplasts. Interestingly, the transcriptional repression mediated by CBNAC was enhanced by CaM. These results suggest that CBNAC may be a CaM-regulated transcriptional repressor in Arabidopsis.

Received for publication, June 26, 2007 , and in revised form, October 17, 2007.

^* This work was supported in part by a from the Plant Diversity Research Center of the 21st Century Frontier Research Program (Grant #PF06303-01) and by the Ministry of Science and Technology in Korea (Environmental Biotechnology National Core Research Center Grant #R15-2003-012-02003-0). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The on-line version of this article (available at http://www.jbc.org) contains supplemental Fig. S1.

¹ Both authors contributed equally to this work.

² Supported by scholarships from the BK21 program of the Ministry of Education and Human Resources.

³ Partially supported by the Seoul Science Fellowship Fund.

⁴ To whom correspondence should be addressed. Tel.: 82-55-751-6254; Fax: 82-55-759-9363; E-mail: chungws{at}gnu.ac.kr.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				M. C. Kim, W. S. Chung, D.-J. Yun, and M. J. Cho Calcium and Calmodulin-Mediated Regulation of Gene Expression in Plants Mol Plant, January 6, 2009; (2009) ssn091v1. [Abstract] [Full Text] [PDF]

				K. Lee, E. H. Song, H. S. Kim, J. H. Yoo, H. J. Han, M. S. Jung, S. M. Lee, K. E. Kim, M. C. Kim, M. J. Cho, et al. Regulation of MAPK Phosphatase 1 (AtMKP1) by Calmodulin in Arabidopsis J. Biol. Chem., August 29, 2008; 283(35): 23581 - 23588. [Abstract] [Full Text] [PDF]