title: Functional analysis of the Arabidopsis thaliana CHLOROPLAST BIOGENESIS 19 pentatricopeptide repeat editing protein.
abstract: The Arabidopsis thaliana pentatricopeptide repeat (PPR) family of proteins contains several degenerate 35-aa motifs named PPR repeats. These proteins control diverse post-transcriptional regulatory mechanisms, including RNA editing. CLB19 belongs to the PLS subfamily of PPR proteins and is essential for the editing and functionality of the subunit A of plastid-encoded RNA polymerase (RpoA) and the catalytic subunit of the Clp protease (ClpP1). We demonstrate in vitro that CLB19 has a specific interaction with these two targets, in spite of their modest sequence similarity. Using site-directed mutagenesis of the rpoA target, we analyzed the essential nucleotides required for CLB19-rpoA interactions. We verified that, similar to other editing proteins, the C-terminal E domain of CLB19 is essential for editing but not for RNA binding. Using biomolecular fluorescence complementation, we demonstrated that the E domain of CLB19 interacts with the RNA-interacting protein MORF2/RIP2 but not with MORF9/RIP9. An interesting finding from this analysis was that overexpression of a truncated CLB19 protein lacking the E domain interferes with cell fate during megasporogenesis and the subsequent establishment of a female gametophyte, supporting an important role of plastids in female gametogenesis. Together these analyses provide important clues about the particularities of the CLB19 editing protein.
authors.affiliation: Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, 62210, México.
authors.forename: Maricela
authors.initials: M
authors.lastname: Ramos-Vega
authors.affiliation: Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, 62210, México.
authors.forename: Arturo
authors.initials: A
authors.lastname: Guevara-García
authors.affiliation: Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, 62210, México.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Llamas
authors.affiliation: Grupo de Desarrollo Reproductivo y Apomixis, Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV, Irapuato, 36821, México.
authors.forename: Nidia
authors.initials: N
authors.lastname: Sánchez-León
authors.affiliation: Grupo de Desarrollo Reproductivo y Apomixis, Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV, Irapuato, 36821, México.
authors.forename: Vianey
authors.initials: V
authors.lastname: Olmedo-Monfil
authors.affiliation: Grupo de Desarrollo Reproductivo y Apomixis, Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV, Irapuato, 36821, México.
authors.forename: Jean Philippe
authors.initials: JP
authors.lastname: Vielle-Calzada
authors.affiliation: Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, 62210, México.
authors.forename: Patricia
authors.initials: P
authors.lastname: León
mesh_terms: D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D056771:Ovule / Q000254:growth & development; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017393:RNA Editing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C000603135:CLB19 protein, Arabidopsis; D012333:RNA, Messenger; D016601:RNA-Binding Proteins
keywords: CLB19; ClpP protease; RNA editing; RNA-binding proteins; chloroplast; female gametogenesis; pentatricopeptide repeat (PPR) proteins; plastid-encoded RNA polymerase