title: Chloroplast ribosome release factor 1 (AtcpRF1) is essential for chloroplast development.
abstract: To study the functions of nuclear genes involved in chloroplast development, we systematically analyzed albino and pale green Arabidopsis thaliana mutants by use of the Activator/Dissociation (Ac/Ds) transposon tagging system. In this study, we focused on one of these albino mutants, designated apg3-1 (for a lbino or p ale g reen mutant 3). A gene encoding a ribosome release factor 1 (RF1) homologue was disrupted by the insertion of a Ds transposon into the APG3 gene; a T-DNA insertion into the same gene caused a similar phenotype (apg3-2). The APG3 gene (At3g62910) has 15 exons and encodes a protein (422-aa) with a transit peptide that functions in targeting the protein to chloroplasts. The amino acid sequence of APG3 showed 40.6% homology with an RF1 of Escherichia coli, and complementation analysis using the E. coli rf1 mutant revealed that APG3 functions as an RF1 in E. coli, although complementation was not successful in the RF2-deficient (rf2) mutants of E. coli. These results indicate that the APG3 protein is an orthologue of E. coli RF1, and is essential for chloroplast translation machinery; it was accordingly named AtcpRF1. Since the chloroplasts of apg3-1 plants contained few internal thylakoid membranes, and chloroplast proteins related to photosynthesis were not detected by immunoblot analysis, AtcpRF1 is thought to be essential for chloroplast development.
authors: Faculty of Agriculture, University of Shizuoka, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan. motohasi@agr.shizuoka.ac.jp
authors: Reiko
authors: R
authors: Motohashi
authors: Takanori
authors: T
authors: Yamazaki
authors: Fumiyoshi
authors: F
authors: Myouga
authors: Takuya
authors: T
authors: Ito
authors: Koichi
authors: K
authors: Ito
authors: Masakazu
authors: M
authors: Satou
authors: Masatomo
authors: M
authors: Kobayashi
authors: Noriko
authors: N
authors: Nagata
authors: Shigeo
authors: S
authors: Yoshida
authors: Akitomo
authors: A
authors: Nagashima
authors: Kan
authors: K
authors: Tanaka
authors: Seiji
authors: S
authors: Takahashi
authors: Kazuo
authors: K
authors: Shinozaki
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics*; D060365:Chloroplast Proteins; D002736:Chloroplasts / Q000502:physiology*; D018744:DNA, Plant / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010788:Photosynthesis; D014176:Protein Biosynthesis; D018749:RNA, Plant / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012270:Ribosomes / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D060365:Chloroplast Proteins; D018744:DNA, Plant; D018749:RNA, Plant; C521841:RRF protein, Arabidopsis