Reversible association of ribulose-1, 5-bisphosphate carboxylase/oxygenase activase with the thylakoid membrane depends upon the ATP level and pH in rice without heat stress.
Reversible association of ribulose-1, 5-bisphosphate carboxylase/oxygenase activase with the thylakoid membrane depends upon the ATP level and pH in rice without heat stress.
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DOI：
10.1093/jxb/erq122
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发表时间：
2010-06
影响因子：
6.9
通讯作者：
Xu DQ
中科院分区：
文献类型：
--
作者：
Chen J;Wang P;Mi HL;Chen GY;Xu DQ
类囊体膜 (TM) 中的 Ribulose-1, 5-二磷酸羧化酶/加氧酶 (Rubisco) 激活酶 (RCA) 已被证明在中等热应激下对光合作用的保护和调节发挥作用。然而，在没有热应激的情况下，RCA 与 TM (TM-RCA) 结合的生理意义仍然未知。在这项研究中，首次通过体内实验表明，TM-RCA在不同发育阶段、不同环境条件下的水稻叶片以及水稻突变体中存在差异。此外，研究表明，当 Rubisco 激活状态和 TM 上的 pH 梯度 (ΔpH) 降低时，TM-RCA 的量总是增加。然后在体外证明 RCA 与 TM 动态结合，并且 TM-RCA 的量在 Rubisco 激活过程中增加。高水平的 ATP 和高 pH 值促进 RCA 从 TM 解离。 RCA 与 TM 的结合和解离都显示出与 ATP 水平或 pH 相关的构象变化，如 1-苯胺萘-8-磺酸 (ANS) 与 RCA 结合的荧光强度的变化所示。这些结果表明 RCA 与 TM 的可逆关联依赖于 ATP 和 pH（或 ΔpH）；除了之前发现的在热应激下保护和调节光合作用的作用之外，它还可能参与 Rubisco 的 RCA 激活。
Ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) activase (RCA) in the thylakoid membrane (TM) has been shown to play a role in protection and regulation of photosynthesis under moderate heat stress. However, the physiological significance of RCA bound to the TM (TM–RCA) without heat stress remains unknown. In this study, it is first shown, using experiments in vivo, that the TM–RCA varies in rice leaves at different development stages, under different environmental conditions, and in a rice mutant. Furthermore, it is shown that the amount of TM–RCA always increased when the Rubisco activation state and the pH gradient across the TM (ΔpH) decreased. It was then demonstrated in vitro that the RCA bound dynamically to TM and the amount of TM–RCA increased during Rubisco activation. A high level of ATP and a high pH value promoted the dissociation of RCA from the TM. Both the RCA association with and dissociation from the TM showed conformational changes related to the ATP level or pH as indicated by the changes in fluorescence intensity of 1-anilinonaphthalene-8-sulphonic acid (ANS) binding to RCA. These results suggest that the reversible association of RCA with the TM is ATP and pH (or ΔpH) dependent; it might be involved in the RCA activation of Rubisco, in addition to the previously discovered role in the protection and regulation of photosynthesis under heat stress.
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影响因子：
6.2
作者：
Feng, Lingling;Wang, Kun;Zhu, Yingguo
通讯作者：
Zhu, Yingguo
影响因子：
7.4
作者：
BROOKS, A;PORTIS, AR;SHARKEY, TD
通讯作者：
SHARKEY, TD
影响因子：
3.7
作者：
Havaux, M
通讯作者：
Havaux, M
影响因子：
7.4
作者：
CAMPBELL, WJ;OGREN, WL
通讯作者：
OGREN, WL
DOI：
10.1071/pp99032
发表时间：
1999-01-01
期刊：
AUSTRALIAN JOURNAL OF PLANT PHYSIOLOGY
影响因子：
--
作者：
Cox, SD;Lilley, RM;Andrews, TJ
通讯作者：
Andrews, TJ