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

J. Biol. Chem., Vol. 282, Issue 29, 21460-21466, July 20, 2007

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 282/29/21460    most recent M701985200v1 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 Gershater, M. C. Articles by Edwards, R. Search for Related Content PubMed PubMed Citation Articles by Gershater, M. C. Articles by Edwards, R. Social Bookmarking                      What's this?

Role of a Carboxylesterase in Herbicide Bioactivation in Arabidopsis thaliana^*

From the Centre for Bioactive Chemistry, Durham University, Durham DH1 3LE, United Kingdom

Arabidopsis thaliana contains multiple carboxyesterases (AtCXEs) with activities toward xenobiotics, including herbicide esters that are activated to their phytotoxic acids upon hydrolysis. On the basis of their susceptibility to inhibition by organophosphates, these AtCXEs are all serine hydrolases. Using a trifunctional probe bearing a fluorophosphonate together with biotin and rhodamine to facilitate detection and recovery, four dominant serine hydrolases were identified in the proteome of Arabidopsis. Using a combination of protein purification, capture with the trifunctional probe and proteomics, one of these hydrolases, AtCXE12, was shown to be the major carboxyesterase responsible for hydrolyzing the pro-herbicide methyl-2,4-dichlorophenoxyacetate (2,4-D-methyl) to the phytotoxic acid 2,4-dichlorophenoxyacetic acid. Recombinant expression of the other identified hydrolases showed that AtCXE12 was unique in hydrolyzing 2,4-D-methyl. To determine the importance of AtCXE12 in herbicide metabolism and efficacy, the respective tDNA knock-out (atcxe12) plants were characterized and shown to lack expression of AtCXE12 and have greatly reduced levels of 2,4-D-methyl-hydrolyzing activity. Young atcxe12 seedlings were less sensitive than wild type plants to 2,4-D-methyl, confirming a role for the enzyme in herbicide bioactivation in Arabidopsis.

Received for publication, March 7, 2007 , and in revised form, May 4, 2007.

^* The study with the chemical probes forms part of a Biotechnology and Biological Sciences and Research Council (BBSRC) research development fellowship (to R. E.). 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 Figs. S1-S4.

¹ Supported by a Cooperative Award in Science and Engineering from the BBSRC and Syngenta.

² To whom correspondence should be addressed: Tel.: 44-191-334-1318; Fax: 44-191-334-1201; E-mail: Robert.Edwards{at}durham.ac.uk.

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

This article has been cited by other articles:

				F. Kaschani, C. Gu, S. Niessen, H. Hoover, B. F. Cravatt, and R. A. L. van der Hoorn Diversity of Serine Hydrolase Activities of Unchallenged and Botrytis-infected Arabidopsis thaliana Mol. Cell. Proteomics, May 1, 2009; 8(5): 1082 - 1093. [Abstract] [Full Text] [PDF]