The DNA-binding protease,CND41, and the degradation of ribulose-1,5-bisphosphate carboxylase/oxygenase in senescent leaves of tobacco |
| |
Authors: | Yusuke?Kato Shinya?Murakami Yumiko?Yamamoto Hiroshi?Chatani Yoshihiko?Kondo Takeshi?Nakano Akiho?Yokota Email author" target="_blank">Fumihiko?SatoEmail author |
| |
Institution: | (1) Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, 606-8502 Kyoto, Japan;(2) Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, 606-8502 Kyoto, Japan;(3) The Institute of Physical and Chemical Research (RIKEN), 351-0189 Wako, Japan;(4) Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, 630-0101 Nara, Japan |
| |
Abstract: | Plastids bear their own genome, organized into DNA–protein complexes (nucleoids). Recently, we identified a DNA-binding protease (CND41) in the chloroplast nucleoids of cultured tobacco (Nicotiana tabacum L.) cells. In this study, we examine the biochemical function of this novel DNA-binding protease, particularly in senescent leaves, because antisense tobacco with a reduced amount of CND41 showed retarded senescence. Nitrogen-depletion experiments clearly showed that CND41 antisense tobacco maintained green leaves and constant protein levels, especially ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), throughout the whole plant, whereas wild-type tobacco showed marked senescence and the reduction of protein levels in the lower leaves. In vitro analyses confirmed that CND41 showed proteolytic activity at physiological pH when denatured Rubisco was used as the substrate. These results suggest that CND41 is involved in Rubisco degradation and the translocation of nitrogen during senescence. The possible regulation of protease activity of CND41 through DNA-binding is discussed.Abbreviations CABP 2-Carboxyarabinitol-1,5-bisphosphate - CBB Coomassie Brilliant Blue - GS Glutamine synthetase - OEC33 The extrinsic 33-kDa protein in the oxygen-evolving complex - Rubisco Ribulose 1,5-bisphosphate carboxylase/oxygenase |
| |
Keywords: | Aspartic protease Chloroplast Nicotiana Nitrogen depletion Rubisco degradation Senescence |
本文献已被 PubMed SpringerLink 等数据库收录! |
|