Dual-domain, dual-targeting organellar protein presequences in Arabidopsis can use non-AUG start codons

Alan C Christensen, Anna Lyznik, Saleem Mohammed, Christian G. Elowsky, Annakaisa Elo, Ryan Yule, Sally Mackenzie

Research output: Contribution to journalArticle

92 Citations (Scopus)

Abstract

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.

Original languageEnglish (US)
Pages (from-to)2805-2816
Number of pages12
JournalPlant Cell
Volume17
Issue number10
DOIs
StatePublished - Dec 1 2005

Fingerprint

start codon
Initiator Codon
Protein Transport
Arabidopsis
Plastids
Genes
5' Untranslated Regions
Proteins
proteins
translation (genetics)
plastids
Chloroplast Proteins
Untranslated Regions
genes
Intergenic DNA
Symbiosis
Terminator Codon
Sequence Alignment
Mitochondrial Proteins
DNA-Directed DNA Polymerase

ASJC Scopus subject areas

  • Plant Science
  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Cell Biology

Cite this

Dual-domain, dual-targeting organellar protein presequences in Arabidopsis can use non-AUG start codons. / Christensen, Alan C; Lyznik, Anna; Mohammed, Saleem; Elowsky, Christian G.; Elo, Annakaisa; Yule, Ryan; Mackenzie, Sally.

In: Plant Cell, Vol. 17, No. 10, 01.12.2005, p. 2805-2816.

Research output: Contribution to journalArticle

Christensen, AC, Lyznik, A, Mohammed, S, Elowsky, CG, Elo, A, Yule, R & Mackenzie, S 2005, 'Dual-domain, dual-targeting organellar protein presequences in Arabidopsis can use non-AUG start codons', Plant Cell, vol. 17, no. 10, pp. 2805-2816. https://doi.org/10.1105/tpc.105.035287
Christensen, Alan C ; Lyznik, Anna ; Mohammed, Saleem ; Elowsky, Christian G. ; Elo, Annakaisa ; Yule, Ryan ; Mackenzie, Sally. / Dual-domain, dual-targeting organellar protein presequences in Arabidopsis can use non-AUG start codons. In: Plant Cell. 2005 ; Vol. 17, No. 10. pp. 2805-2816.
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