This Article Full Text Full Text (PDF) All Versions of this Article: 17/10/2805    most recent tpc.105.035287v1 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 ISI 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 ISI Web of Science (15) Citing Articles via Google Scholar Google Scholar Articles by Christensen, A. C. Articles by Mackenzie, S. A. Search for Related Content PubMed PubMed Citation Articles by Christensen, A. C. Articles by Mackenzie, S. A. Agricola Articles by Christensen, A. C. Articles by Mackenzie, S. A.

Dual-Domain, Dual-Targeting Organellar Protein Presequences in Arabidopsis Can Use Non-AUG Start Codons

^a School of Biological Sciences, Beadle Center for Genetics Research, University of Nebraska, Lincoln, Nebraska 68588-0660
^b Plant Science Initiative, Beadle Center for Genetics Research, University of Nebraska, Lincoln, Nebraska 68588-0660
^c Center for Biotechnology, Beadle Center for Genetics Research, University of Nebraska, Lincoln, Nebraska 68588-0660

¹ To whom correspondence should be addressed. E-mail smackenzie2{at}unl.edu; fax 402-472-3139.

The processes accompanying endosymbiosis have led to a complex network of interorganellar protein traffic that originates from nuclear genes encoding mitochondrial and plastid proteins. A significant proportion of nucleus-encoded organellar proteins are dual targeted, and the process by which a protein acquires the capacity for both mitochondrial and plastid targeting may involve intergenic DNA exchange coupled with the incorporation of sequences residing upstream of the gene. We evaluated targeting and sequence alignment features of two organellar DNA polymerase genes from Arabidopsis thaliana. Within one of these two loci, protein targeting appeared to be plastidic when the 5' untranslated leader region (UTR) was deleted and translation could only initiate at the annotated ATG start codon but dual targeted when the 5' UTR was included. Introduction of stop codons at various sites within the putative UTR demonstrated that this region is translated and influences protein targeting capacity. However, no ATG start codon was found within this upstream, translated region, suggesting that translation initiates at a non-ATG start. We identified a CTG codon that likely accounts for much of this initiation. Investigation of the 5' region of other nucleus-encoded organellar genes suggests that several genes may incorporate upstream sequences to influence targeting capacity. We postulate that a combination of intergenic recombination and some relaxation of constraints on translation initiation has acted in the evolution of protein targeting specificity for those proteins capable of functioning in both plastids and mitochondria.

This article has been cited by other articles:

				L. Chatre, L. A. Matheson, A. S. Jack, S. L. Hanton, and F. Brandizzi Efficient mitochondrial targeting relies on co-operation of multiple protein signals in plants J. Exp. Bot., December 26, 2008; (2008) ern319v1. [Abstract] [Full Text] [PDF]

				M. Ueda, T. Nishikawa, M. Fujimoto, H. Takanashi, S.-i. Arimura, N. Tsutsumi, and K.-i. Kadowaki Substitution of the Gene for Chloroplast RPS16 Was Assisted by Generation of a Dual Targeting Signal Mol. Biol. Evol., August 1, 2008; 25(8): 1566 - 1575. [Abstract] [Full Text] [PDF]

				E. A. Mudd, S. Sullivan, M. F. Gisby, A. Mironov, C. S. Kwon, W.-I. Chung, and A. Day A 125 kDa RNase E/G-like protein is present in plastids and is essential for chloroplast development and autotrophic growth in Arabidopsis J. Exp. Bot., July 1, 2008; 59(10): 2597 - 2610. [Abstract] [Full Text] [PDF]

				J. Puyaubert, L. Denis, and C. Alban Dual Targeting of Arabidopsis HOLOCARBOXYLASE SYNTHETASE1: A Small Upstream Open Reading Frame Regulates Translation Initiation and Protein Targeting Plant Physiology, February 1, 2008; 146(2): 478 - 491. [Abstract] [Full Text] [PDF]

				Y. Ono, A. Sakai, K. Takechi, S. Takio, M. Takusagawa, and H. Takano NtPolI-like1 and NtPolI-like2, Bacterial DNA Polymerase I Homologs Isolated from BY-2 Cultured Tobacco Cells, Encode DNA Polymerases Engaged in DNA Replication in Both Plastids and Mitochondria Plant Cell Physiol., December 1, 2007; 48(12): 1679 - 1692. [Abstract] [Full Text] [PDF]

				M. W. Murcha, D. Elhafez, R. Lister, J. Tonti-Filippini, M. Baumgartner, K. Philippar, C. Carrie, D. Mokranjac, J. Soll, and J. Whelan Characterization of the Preprotein and Amino Acid Transporter Gene Family in Arabidopsis Plant Physiology, January 1, 2007; 143(1): 199 - 212. [Abstract] [Full Text] [PDF]

				V. Zaegel, B. Guermann, M. Le Ret, C. Andres, D. Meyer, M. Erhardt, J. Canaday, J. M. Gualberto, and P. Imbault The Plant-Specific ssDNA Binding Protein OSB1 Is Involved in the Stoichiometric Transmission of Mitochondrial DNA in Arabidopsis PLANT CELL, December 1, 2006; 18(12): 3548 - 3563. [Abstract] [Full Text] [PDF]

				L. Palmieri, R. Arrigoni, E. Blanco, F. Carrari, M. I. Zanor, C. Studart-Guimaraes, A. R. Fernie, and F. Palmieri Molecular Identification of an Arabidopsis S-Adenosylmethionine Transporter. Analysis of Organ Distribution, Bacterial Expression, Reconstitution into Liposomes, and Functional Characterization Plant Physiology, November 1, 2006; 142(3): 855 - 865. [Abstract] [Full Text] [PDF]

				P. Pesaresi, S. Masiero, H. Eubel, H.-P. Braun, S. Bhushan, E. Glaser, F. Salamini, and D. Leister Nuclear Photosynthetic Gene Expression Is Synergistically Modulated by Rates of Protein Synthesis in Chloroplasts and Mitochondria PLANT CELL, April 1, 2006; 18(4): 970 - 991. [Abstract] [Full Text] [PDF]