title: Selective homo- and heteromer interactions between the multiple organellar RNA editing factor (MORF) proteins in Arabidopsis thaliana.
abstract: RNA editing in plastids and mitochondria of flowering plants requires pentatricopeptide repeat proteins (PPR proteins) for site recognition and proteins of the multiple organellar RNA editing factor (MORF) family as cofactors. Two MORF proteins, MORF5 and MORF8, are dual-targeted to plastids and mitochondria; two are targeted to plastids, and five are targeted to mitochondria. Pulldown assays from Arabidopsis thaliana tissue culture extracts with the mitochondrial MORF1 and the plastid MORF2 proteins, respectively, both identify the dual-targeted MORF8 protein, showing that these complexes can assemble in the organelles. We have now determined the scope of potential interactions between the various MORF proteins by yeast two-hybrid, in vitro pulldown, and bimolecular fluorescence complementation assays. The resulting MORF-MORF interactome identifies specific heteromeric MORF protein interactions in plastids and in mitochondria. Heteromers are observed for MORF protein combinations affecting a common site, suggesting their functional relevance. Most MORF proteins also undergo homomeric interactions. Submolecular analysis of the MORF1 protein reveals that the MORF-MORF protein connections require the C-terminal region of the central conserved MORF box. This domain has no similarity to known protein modules and may form a novel surface for protein-protein interactions.
authors.affiliation: From the Molekulare Botanik, Universität Ulm, 89069 Ulm and.
authors.forename: Anja
authors.initials: A
authors.lastname: Zehrmann
authors.affiliation: From the Molekulare Botanik, Universität Ulm, 89069 Ulm and.
authors.forename: Barbara
authors.initials: B
authors.lastname: Härtel
authors.affiliation: From the Molekulare Botanik, Universität Ulm, 89069 Ulm and.
authors.forename: Franziska
authors.initials: F
authors.lastname: Glass
authors.affiliation: From the Molekulare Botanik, Universität Ulm, 89069 Ulm and.
authors.forename: Eszter
authors.initials: E
authors.lastname: Bayer-Császár
authors.affiliation: the Max-Planck-Institut für Pflanzenphysiologie, 14476 Potsdam-Golm, Germany.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Obata
authors.affiliation: the Max-Planck-Institut für Pflanzenphysiologie, 14476 Potsdam-Golm, Germany.
authors.forename: Etienne
authors.initials: E
authors.lastname: Meyer
authors.affiliation: From the Molekulare Botanik, Universität Ulm, 89069 Ulm and.
authors.forename: Axel
authors.initials: A
authors.lastname: Brennicke
authors.affiliation: From the Molekulare Botanik, Universität Ulm, 89069 Ulm and mizuki.takenaka@uni-ulm.de.
authors.forename: Mizuki
authors.initials: M
authors.lastname: Takenaka
mesh_terms: D017360:Arabidopsis / Q000737:chemistry / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018087:Plastids / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D060066:Protein Interaction Maps; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D017393:RNA Editing / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C579840:MORF8 protein, Arabidopsis
keywords: Arabidopsis thaliana; Chloroplast; MORF Proteins; Mitochondria; Protein-Protein Interaction; RNA Editing