title: Split luciferase complementation assay to detect regulated protein-protein interactions in rice protoplasts in a large-scale format.
abstract: BACKGROUND
  The rice interactome, in which a network of protein-protein interactions has been elucidated in rice, is a useful resource to identify functional modules of rice signal transduction pathways. Protein-protein interactions occur in cells in two ways, constitutive and regulative. While a yeast-based high-throughput method has been widely used to identify the constitutive interactions, a method to detect the regulated interactions is rarely developed for a large-scale analysis.
  
  
  RESULTS
  A split luciferase complementation assay was applied to detect the regulated interactions in rice. A transformation method of rice protoplasts in a 96-well plate was first established for a large-scale analysis. In addition, an antibody that specifically recognizes a carboxyl-terminal fragment of Renilla luciferase was newly developed. A pair of antibodies that recognize amino- and carboxyl- terminal fragments of Renilla luciferase, respectively, was then used to monitor quality and quantity of interacting recombinant-proteins accumulated in the cells. For a proof-of-concept, the method was applied to detect the gibberellin-dependent interaction between GIBBERELLIN INSENSITIVE DWARF1 and SLENDER RICE 1.
  
  
  CONCLUSIONS
  A method to detect regulated protein-protein interactions was developed towards establishment of the rice interactome.
authors.affiliation: Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima 739-8528, Hiroshima, Japan.
authors.forename: Yukichi
authors.initials: Y
authors.lastname: Fujikawa
authors.affiliation: Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima 739-8528, Hiroshima, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nakanishi
authors.affiliation: Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima 739-8528, Hiroshima, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kawakami
authors.affiliation: Faculty of Human Environmental Sciences, Kyoto Prefectural University, Kyoto 606-8522, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Yamasaki
authors.affiliation: Faculty of Human Environmental Sciences, Kyoto Prefectural University, Kyoto 606-8522, Japan.
authors.forename: Masa H
authors.initials: MH
authors.lastname: Sato
authors.affiliation: Department of Plant Biology, Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma 630-0192, Nara, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsuji
authors.affiliation: Bioscience and Biotechnology Center, Nagoya University, Nagoya Aichi 464-8601, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Matsuoka
authors.affiliation: Department of Biological Sciences, Louisiana State University, 226 Life Sciences Building, Baton Rouge 70803, LA, USA.
authors.forename: Naohiro
authors.initials: N
authors.lastname: Kato
keywords: Interactome; Regulated protein-protein interactions; Split luciferase complementation