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

J. Biol. Chem., Vol. 283, Issue 16, 10493-10499, April 18, 2008

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 283/16/10493    most recent M800735200v1 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 Merkouropoulos, G. Articles by Peck, S. C. Search for Related Content PubMed PubMed Citation Articles by Merkouropoulos, G. Articles by Peck, S. C. Social Bookmarking                      What's this?

An Arabidopsis Protein Phosphorylated in Response to Microbial Elicitation, AtPHOS32, Is a Substrate of MAP Kinases 3 and 6^*

Georgios Merkouropoulos¹², Erik Andreasson¹³, Daniel Hess, Thomas Boller^¶, and Scott C. Peck⁴

From the The Sainsbury Laboratory, John Innes Centre, Colney Lane, Norwich NR4 7UH, United Kingdom, the Friedrich Miescher Institute, Maulbeerstrasse 66, CH-4058, Basel, Switzerland, and the ^¶Institute of Botany, University of Basel, Hebelstrasse 1, CH-4056 Basel, Switzerland

Although mitogen-activated protein kinases (MAPKs) have been shown to be activated by a wide range of biotic and abiotic stimuli in diverse plant species, few in vivo substrates for these kinases have been identified. While studying proteins that are differentially phosphorylated upon treatment of Arabidopsis suspension cultures with the general bacterial elicitor peptide flagellin-22 (flg22), we identified two proteins with endogenous nickel binding properties that become phosphorylated after flg22 elicitation. These highly related proteins, AtPHOS32 and AtPHOS34, show similarity to bacterial universal stress protein A. We identified one of the phosphorylation sites on AtPHOS32 by nanoelectrospray ionization tandem mass spectrometry. Phosphorylation in a phosphoSer-Pro motif indicated that this protein may be a substrate of MAPKs. Using in vitro kinase assays, we confirmed that AtPHOS32 is a substrate of both AtMPK3 and AtMPK6. Specificity of phosphorylation was demonstrated by site-directed mutagenesis of the first phosphorylation site. In addition, immunosubtraction of both MAPKs from protein extracts removed detectable kinase activity toward AtPHOS32, indicating that the two MAPKs were the predominate kinases recognizing the motif in this protein. Finally, the target phosphorylation site in AtPHOS32 is conserved in AtPHOS34 and among apparent orthologues from many plant species, indicating that phosphorylation of these proteins by AtMPK3 and AtMPK6 orthologues has been conserved throughout evolution.

Received for publication, January 28, 2008

^* This work was supported by the Gatsby Charitable Foundation and by Biotechnology and Biological Sciences Research Grant P15616 [GenBank] (to SCP). 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 Table 1.

¹ Both authors contributed equally to this work.

² Present address: Institute of Agrobiotechnology, 6^th Km Charilou-Thermi Rd., P.O. Box 361, 570 01 Thermi, Thessaloniki, Greece.

³ Present address: Dept. of Cell and Organism Biology, Lund University, SE-223 62 Lund, Sweden.

⁴ To whom correspondence should be addressed: 271H Bond Life Sciences Center, University of Missouri-Columbia, Columbia, MO 65211. Tel.: 573-882-8102; Fax: 573-884-9676; E-mail: pecks{at}missouri.edu.

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

This article has been cited by other articles:

				G. J.M. Beckers, M. Jaskiewicz, Y. Liu, W. R. Underwood, S. Y. He, S. Zhang, and U. Conrath Mitogen-Activated Protein Kinases 3 and 6 Are Required for Full Priming of Stress Responses in Arabidopsis thaliana PLANT CELL, March 1, 2009; 21(3): 944 - 953. [Abstract] [Full Text] [PDF]