The PPR protein SLOW GROWTH 4 is involved in editing of nad4 and affects the splicing of nad2 intron 1
- 799 Downloads
SLO4 is a mitochondrial PPR protein that is involved in editing nad4, possibly required for the efficient splicing of nad2 intron1.
Pentatricopeptide repeat (PPR) proteins constitute a large protein family in flowering plants and are thought to be mostly involved in organellar RNA metabolism. The subgroup of PLS-type PPR proteins were found to be the main specificity factors of cytidine to uridine RNA editing. Identifying the targets of PLS-type PPR proteins can help in elucidating the molecular function of proteins encoded in the organellar genomes. In this study, plants lacking the SLOW GROWTH 4 PPR protein were characterized. Slo4 mutants were characterized as having restricted root growth, being late flowering and displaying an overall delayed growth phenotype. Protein levels and activity of mitochondrial complex I were decreased and putative complex I assembly intermediates accumulated in the mutant plants. An editing defect, leading to an amino acid change, in the mitochondrial nad4 transcript, encoding for a complex I subunit, was identified. Furthermore, the splicing efficiency of the first intron of nad2, encoding for another complex I subunit, was also decreased. The change in splicing efficiency could however not be linked to any editing defects in the nad2 transcript.
KeywordsMitochondria Complex I RNA editing Splicing Pentatricopeptide repeat
The authors would like to thank Prof. Ian Small from the University of Western Australia for assisting with prediction of PPR binding sites. This work was supported by the Deutsche Forschungsgemeinschaft.
SW and CC carried out all experimental work. SW, JS and CC were all involved in planning and designing experiments and all authors contributed to the writing of the manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare no conflicts of interest. None of the research presented here involved human participants or animals.
- Bosco CD, Lezhneva L, Biehl A, Leister D, Strotmann H, Wanner G, Meurer J (2004) Inactivation of the chloroplast ATP synthase γ subunit results in high non-photochemical fluorescence quenching and altered nuclear gene expression in Arabidopsis thaliana. J Biol Chem 279:1060–1069CrossRefGoogle Scholar
- des Francs-Small CC, Falcon de Longevialle A, Li Y, Lowe E, Tanz SK, Smith C, Bevan MW, Small I (2014) The Pentatricopeptide Repeat proteins TANG2 and ORGANELLE TRANSCRIPT PROCESSING439 are involved in the splicing of the multipartite nad5 transcript encoding a subunit of mitochondrial complex I1[W][OPEN]. Plant Physiol 165:1409–1416CrossRefGoogle Scholar
- He J, Duan Y, Hua D, Fan G, Wang L, Liu Y, Chen Z, Han L, Qu L-J, Gong Z (2012) DEXH Box RNA Helicase–mediated mitochondrial reactive oxygen species production in Arabidopsis mediates crosstalk between Abscisic acid and Auxin signaling [C][W][OA]. Plant Cell 24:1815–1833CrossRefPubMedPubMedCentralGoogle Scholar
- Keren I, Tal L, des Francs-Small CC, Araújo WL, Shevtsov S, Shaya F, Fernie AR, Small I, Ostersetzer-Biran O (2012) nMAT1, a nuclear-encoded maturase involved in the trans-splicing of nad1 intron 1, is essential for mitochondrial complex I assembly and function. Plant J Cell Mol Biol 71:413–426Google Scholar
- Koprivova A, Francs-Small des CC, Calder G, Mugford ST, Tanz S, Lee B-R, Zechmann B, Small I, Kopriva S (2010) Identification of a pentatricopeptide repeat protein implicated in splicing of Intron 1 of mitochondrial nad7 transcripts. J Biol Chem 285:32192–32199CrossRefPubMedPubMedCentralGoogle Scholar
- Nakagawa N, Sakurai N (2006) A mutation in At-nMat1a, which encodes a nuclear gene having high similarity to group II intron maturase, causes impaired splicing of mitochondrial NAD4 transcript and altered carbon metabolism in Arabidopsis thaliana. Plant Cell Physiol 47:772–783CrossRefPubMedGoogle Scholar
- Vidal G, Ribas-Carbo M, Garmier M, Dubertret G, Rasmusson AG, Mathieu C, Foyer CH, De Paepe R (2007) Lack of respiratory chain complex I impairs alternative oxidase engagement and modulates redox signaling during elicitor-induced cell death in tobacco. Plant Cell 19:640–655CrossRefPubMedPubMedCentralGoogle Scholar
- Zmudjak M, Colas des Francs-Small C, Keren I, Shaya F, Belausov E, Small I, Ostersetzer-Biran O (2013) mCSF1, a nucleus-encoded CRM protein required for the processing of many mitochondrial introns, is involved in the biogenesis of respiratory complexes I and IV in Arabidopsis. New Phytol 199:379–394CrossRefPubMedGoogle Scholar