OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 143/3/1119    most recent pp.106.093583v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science 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 CrossRef Citing Articles via Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Zeng, Q. Articles by Running, M. P. Search for Related Content PubMed PubMed Citation Articles by Zeng, Q. Articles by Running, M. P. Agricola Articles by Zeng, Q. Articles by Running, M. P.

CELL BIOLOGY AND SIGNAL TRANSDUCTION

Dual Lipid Modification of Arabidopsis G-Subunits Is Required for Efficient Plasma Membrane Targeting^{1,[C],[W],[OA]}

Donald Danforth Plant Science Center, St. Louis, Missouri 63132

Posttranslational lipid modifications are important for proper localization of many proteins in eukaryotic cells. However, the functional interrelationships between lipid modification processes in plants remain unclear. Here we demonstrate that the two heterotrimeric G-protein -subunits from Arabidopsis (Arabidopsis thaliana), AGG1 and AGG2, are prenylated, and AGG2 is S-acylated. In wild type, enhanced yellow fluorescent protein-fused AGG1 and AGG2 are associated with plasma membranes, with AGG1 associated with internal membranes as well. Both can be prenylated by either protein geranylgeranyltransferase I (PGGT-I) or protein farnesyltransferase (PFT). Their membrane localization is intact in mutants lacking PFT activity and largely intact in mutants lacking PGGT-I activity but is disrupted in mutants lacking both PFT and PGGT-I activity. Unlike in mammals, Arabidopsis Gs do not rely on functional G for membrane targeting. Mutation of the sixth to last cysteine, the putative S-acylation acceptor site, causes a dramatic change in AGG2 but not AGG1 localization pattern, suggesting S-acylation serves as an important additional signal for AGG2 to be targeted to the plasma membrane. Domain-swapping experiments suggest that a short charged sequence at the AGG2 C terminus contributes to AGG2's efficient membrane targeting compared to AGG1. Our data show the large degree to which PFT and PGGT-I can compensate for each other in plants and suggest that differential lipid modification plays an important regulatory role in plant protein localization.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Mark P. Running (mrunning{at}danforthcenter.org).

^[C] Some figures in this article are displayed in color online but in black and white in the print edition.

^[W] The online version of this article contains Web-only data.

^[OA] Open Access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.106.093583

^* Corresponding author; e-mail mrunning{at}danforthcenter.org; fax 314–587–1741.

Received November 22, 2006; accepted December 31, 2006; published January 12, 2007.

This article has been cited by other articles:

				D. H. Huizinga, R. Denton, K. G. Koehler, A. Tomasello, L. Wood, S. E. Sen, and D. N. Crowell Farnesylcysteine Lyase is Involved in Negative Regulation of Abscisic Acid Signaling in Arabidopsis Mol Plant, November 10, 2009; (2009) ssp091v1. [Abstract] [Full Text] [PDF]

				H. Zhu, G.-J. Li, L. Ding, X. Cui, H. Berg, S. M. Assmann, and Y. Xia Arabidopsis Extra Large G-Protein 2 (XLG2) Interacts with the G{beta} Subunit of Heterotrimeric G Protein and Functions in Disease Resistance Mol Plant, May 1, 2009; 2(3): 513 - 525. [Abstract] [Full Text] [PDF]

				Y. Trusov, W. Zhang, S. M. Assmann, and J. R. Botella G{gamma}1 + G{gamma}2 != G{beta}: Heterotrimeric G Protein G{gamma}-Deficient Mutants Do Not Recapitulate All Phenotypes of G{beta}-Deficient Mutants Plant Physiology, June 1, 2008; 147(2): 636 - 649. [Abstract] [Full Text] [PDF]

				S. Wang, S. M. Assmann, and N. V. Fedoroff Characterization of the Arabidopsis Heterotrimeric G Protein J. Biol. Chem., May 16, 2008; 283(20): 13913 - 13922. [Abstract] [Full Text] [PDF]