TAILIEUCHUNG - Báo cáo khoa học: Functional dissection of two Arabidopsis PsbO proteins PsbO1 and PsbO2

PsbO protein is an extrinsic subunit of photosystem II (PSII) and has been proposed to play a central role in stabilization of the catalytic manganese cluster. Arabidopsis thalianahas twopsbO genes that express two PsbO proteins; PsbO1 and PsbO2. We reported previously that a mutant plant that lacked PsbO1 (psbo1) showed considerable growth retardation despite the presence of PsbO2 [Murakami, R., Ifuku, K., Takabayashi, A., Shika-nai, T., Endo, T., and Sato, F. (2002)FEBS Lett523,138–142]. In the pre-sent study, we characterized the functional differences between PsbO1 and PsbO2 | ềFEBS Journal Functional dissection of two Arabidopsis PsbO proteins PsbO1 and PsbO2 Reiko Murakami1 Kentaro Ifuku1 Atsushi Takabayashi1 Toshiharu Shikanai2 Tsuyoshi Endo1 and Fumihiko Sato1 1 Division of Integrated Life Sciences Graduate Schoolof Biostudies Kyoto University Kyoto Japan 2 Graduate Schoolof Agriculture Kyushu University Higashiku Fukuoka Japan Keywords Arabidopsis thaliana isoform oxygen evolution psbO1 psbO2 Correspondence T. Endo Division of Integrated Life Sciences Graduate School of Biostudies Kyoto University Kyoto 606-8502 Japan Fax 81 75 7536398 Tel 81 75 7536381 E-mail tuendo@ Received 24 December 2004 revised 17 February 2005 accepted 1 March 2005 doi PsbO protein is an extrinsic subunit of photosystem II PSII and has been proposed to play a central role in stabilization of the catalytic manganese cluster. Arabidopsis thaliana has two psbO genes that express two PsbO proteins PsbO1 and PsbO2. We reported previously that a mutant plant that lacked PsbO1 psbol showed considerable growth retardation despite the presence of PsbO2 Murakami R. Ifuku K. Takabayashi A. Shika-nai T. Endo T. and Sato F. 2002 FEBS Lett 523 138-142 . In the present study we characterized the functional differences between PsbO1 and PsbO2. We found that PsbO1 is the major isoform in the wild-type and the amount of PsbO2 in psbol was significantly less than the total amount of PsbO in the wild-type. The amount of PsbO as well as the efficiency of PSII in psbol increased as the plants grew however it never reached the total PsbO level observed in the wild-type suggesting that the poor activity of PSII in psbol was caused by a shortage of PsbO. In addition an in vitro reconstitution experiment using recombinant PsbOs and urea-washed PSII particles showed that oxygen evolution was better recovered by PsbO1 than by PsbO2. Further analysis using chimeric and mutated PsbOs suggested that the amino acid changes Val186 fi Ser .

• Báo cáo khoa học
• Report medicine
• traditional medicine
• scientific reports
• intermediate cells
• cell proliferation
• medical analysis
• medical knowledge
• medical research
• analysis of cytoplasmic
• oxidation
• Crystal structure
• bacteria
• hemoglobin
• medicine
• breast cancer
• chemical reaction
• gastric cancer
• hormone medicine
• tumor cells
• biochemical studies
• environmental medicine