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

J. Biol. Chem., Vol. 279, Issue 44, 45540-45545, October 29, 2004

This Article Full Text Full Text (PDF) All Versions of this Article: 279/44/45540    most recent M408686200v1 Alert me when this article is cited 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 Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Eastmond, P. J. Search for Related Content PubMed PubMed Citation Articles by Eastmond, P. J. Social Bookmarking                      What's this?

Cloning and Characterization of the Acid Lipase from Castor Beans^*

Peter J. Eastmond

From the Department of Biology, University of York, York YO10 5DD, United Kingdom

Castor bean endosperm contains a well known acid lipase activity that is associated with the oil body membrane. In order to identify this enzyme, proteomic analysis was performed on purified oil bodies. A 60-kDa protein was identified (RcOBL1), which shares homology with a lipase from the filamentous fungus Rhizomucor miehei. RcOBL1 contains features that are characteristic of an /-hydrolase, such as a putative catalytic triad (SDH) and a conserved pentapeptide (GXSXG) surrounding the nucleophilic serine residue. RcOBL1 was expressed heterologously in Escherichia coli and shown to hydrolyze triolein at an acid pH (optima 4.5). RcOBL1 can hydrolyze a range of triacylglycerols but is not active on phospholipids. The activity is sensitive to the serine reagent diethyl p-nitrophenyl phosphate, indicating that RcOBL1 is a serine esterase. Antibodies raised against RcOBL1 were used to show that the protein is restricted to the endosperm where it is associated with the surface of oil bodies. This is the first evidence for the molecular identity of an oil body-associated lipase from plants. Sequence comparisons reveal that families of OBL1-like proteins are present in many species, and it is likely that they play an important role in regulating lipolysis.

Received for publication, July 30, 2004 , and in revised form, August 17, 2004.

^* This work was supported by the Biotechnology and Biological Sciences Research Council through David Phillips Research Fellowship 87/JF/16985 (to P. J. 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 nucleotide sequence(s) reported in this paper has been submitted to the GenBank^TM/EBI Data Bank with accession number(s) AY360218, AY360219, AY360220, and AY360221.

To whom correspondence should be addressed. Tel.: 44-01904-328751; Fax: 44-01904-328762; E-mail: pje4{at}york.ac.uk.

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

This article has been cited by other articles:

				P. J. Eastmond MONODEHYROASCORBATE REDUCTASE4 Is Required for Seed Storage Oil Hydrolysis and Postgerminative Growth in Arabidopsis PLANT CELL, April 1, 2007; 19(4): 1376 - 1387. [Abstract] [Full Text] [PDF]

				P. J. Eastmond SUGAR-DEPENDENT1 Encodes a Patatin Domain Triacylglycerol Lipase That Initiates Storage Oil Breakdown in Germinating Arabidopsis Seeds PLANT CELL, March 1, 2006; 18(3): 665 - 675. [Abstract] [Full Text] [PDF]