Research Project
Grant-in-Aid for Scientific Research (C)
We have previously reported that COP9 signalosome (CSN) regulates signal transduction by mediating proteolysis in the nuclei. We have also identified novel CSN1 function that does not involve proteolysis in its regulation. Here, we focused on identifying proteins that directly bind to the functional portion of the CSN1 protein, using the Arabidopsis system to investigate the novel regulation of CSN1. The findings are summarized below.1. The putative CSN1-binding protein, SAP130 (spliceosome associated protein 130) was identified in a systematic pull-down using the functional domain of CSN1 as bait. In Arabidopsis, SAP130 was coded by two closely mapped genes, and its mRNA was detected in all of the tested organs. Plants harboring T-DNA insertions in the promoter or coding region of these genes did not display detectable changes. In attempt to analyze the loss-of-function and gain-of-function of these genes, we constructed transgenic plants that knock-down and over-express the two genes … More , by over-expression and by RNAi methods, together with an inducible system. Further analyses are in progress.2. SAP130 was shown to directly bind CSN1 in both mammalian and plant systems. This binding was mediated through the N-terminal half of CSN1. Plants expressing mutations in this binding-interface have been created to reveal the endogenous nature of this binding. Furthermore we revealed that, SAP130 is homologous to DDB1, directly binds cullin subunit of Cullin-RING ubiquitin E3 ligases, and possess polyubiquitinating activity.3. Since SAP130 has been identified in multiple complexes such as SF3b, STAGA, and TFTC, we tagged CSN1 and SAP130 with various fluorescence tags to investigate the localization patterns in detail, in combination with external stimuli. The proteins were dominantly detected in the nucleus and further analyses is in progress. These results have been reported through international and domestic conferences and through high-profiled international journal publications. Less
All 2008 2007 2006
All Journal Article (29 results) (of which Peer Reviewed: 11 results) Presentation (45 results) Book (4 results)
BMC Biochemistry 9
Pages: 1-1
The Plant Cell 20
Pages: 367-380
130006992735
The New Phytologist (印刷中)
The Plant Cell (印刷中)
Plant Cell Reports 27
Pages: 575-584
The New Phytologist (in press)
The Plant Cell (in press)
Molecular and Cellular Biology 27
Pages: 4708-4719
Plant & Cell Physiology 48
Pages: 263-277
10018519460
Pages: 332-344
10018519745
Plant and Cell Physiology 48
130006991437
130006991021
Molecular and Cellular Biology 27(in press)
"Tanpakushitu Kakusan Koso", Kyoritsu, Tokyo 51, 10 Suppl
Pages: 1352-1357
Pages: 1358-1358
Plantmimetics-learning from plants", NTS, Tokyo
Pages: 4-10
蛋白質 核酸 酵素 (8月号増刊ユビキチン-プロテアソーム系とオートファジー)(田中啓二・大隈良典 (編集))(共立出版 東京) 51
