title: DNA-binding specificity, transcriptional activation potential, and the rin mutation effect for the tomato fruit-ripening regulator RIN.
abstract: The RIN gene encodes a putative MADS box transcription factor that controls tomato fruit ripening, and its ripening inhibitor (rin) mutation yields non-ripening fruit. In this study, the molecular properties of RIN and the rin mutant protein were clarified. The results revealed that the RIN protein accumulates in ripening fruit specifically and is localized in the nucleus of the cell. In vitro studies revealed that RIN forms a stable homodimer that binds to MADS domain-specific DNA sites. Analysis of binding site selection experiments revealed that the consensus binding sites of RIN highly resemble those of the SEPALLATA (SEP) proteins, which are Arabidopsis MADS box proteins that control the identity of floral organs. RIN exhibited a transcription-activating function similar to that exhibited by the SEP proteins. These results indicate that RIN exhibits similar molecular functions to SEP proteins although they play distinctly different biological roles. In vivo assays revealed that RIN binds to the cis-element of LeACS2. Our results also revealed that the rin mutant protein accumulates in the mutant fruit and exhibits a DNA-binding activity similar to that exhibited by the wild-type protein, but has lost its transcription-activating function, which in turn would inhibit ripening in mutant fruit.
authors: National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan. yasuito@affrc.go.jp
authors: Yasuhiro
authors: Y
authors: Ito
authors: Mamiko
authors: M
authors: Kitagawa
authors: Nao
authors: N
authors: Ihashi
authors: Kimiko
authors: K
authors: Yabe
authors: Junji
authors: J
authors: Kimbara
authors: Junichi
authors: J
authors: Yasuda
authors: Hirotaka
authors: H
authors: Ito
authors: Takahiro
authors: T
authors: Inakuma
authors: Seiji
authors: S
authors: Hiroi
authors: Takafumi
authors: T
authors: Kasumi
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000502:physiology; D000595:Amino Acid Sequence; D001483:Base Sequence; D018744:DNA, Plant / Q000378:metabolism*; D005638:Fruit / Q000166:cytology / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D018551:Solanum lycopersicum / Q000166:cytology / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000502:physiology*; D015533:Transcriptional Activation / Q000502:physiology
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins; D012333:RNA, Messenger