The C-terminal cysteine-rich motif of NYE1/SGR1 is indispensable for its function in chlorophyll degradation in Arabidopsis
The C-terminal cysteine-rich motif of NYE1/SGR1 is indispensable for its function in chlorophyll degradation in Arabidopsis
复制标题
DOI：
10.1007/s11103-019-00902-1
复制
发表时间：
2019-07
影响因子：
5.1
通讯作者：
Zuokun Xie;Sheng-Cheng Wu;Junyi Chen;Xiaoyu Zhu;Xin Zhou;S. Hörtensteiner;Guodong Ren;B. Kuai
中科院分区：
文献类型：
--
作者：
Zuokun Xie;Sheng-Cheng Wu;Junyi Chen;Xiaoyu Zhu;Xin Zhou;S. Hörtensteiner;Guodong Ren;B. Kuai
NYE 1/SGR 1的C-末端富含半胱氨酸的基序可能通过介导其自身相互作用和构象变化，并以某种方式改变其Mg-脱螯合活性以响应氧化还原电位的变化来影响叶绿素的降解。NON-YELLOWING 1/STAY-GREEN 1（NYE 1/SGR 1）是近年来发现的一种能够将镁从Chlato中脱螯合并启动其降解的蛋白，但其功能的结构域/基序基础尚不清楚。在本研究中，我们进行了蛋白质截短分析，并在其C端鉴定了一个保守的富含半胱氨酸的基序（CRM，P-X3-C-X3-C-X-C2-F-P-X5-P），这是其功能所必需的。遗传分析表明，CRM中的所有四个半胱氨酸都是不可替代的，并且酶促测定表明，四个半胱氨酸中的每一个的突变都会影响其镁脱螯合活性。CRM通过形成分子间和分子内二硫键，在NYE 1的构象变化和自相互作用中起着关键作用。我们的研究结果可能会提供深入了解NYE 1如何响应快速氧化还原变化在叶片衰老和响应各种环境压力。
Key messageThe C-terminal cysteine-rich motif of NYE1/SGR1 affects chlorophyll degradation likely by mediating its self-interaction and conformational change, and somehow altering its Mg-dechelating activity in response to the changing redox potential.AbstractDuring green organ senescence in plants, the most prominent phenomenon is the degreening caused by net chlorophyll (Chl) loss. NON-YELLOWING1/STAY-GREEN1 (NYE1/SGR1) was recently reported to be able to dechelates magnesium (Mg) from Chlato initiate its degradation, but little is known about the domain/motif basis of its functionality. In this study, we carried out a protein truncation assay and identified a conserved cysteine-rich motif (CRM, P-X3-C-X3-C-X-C2-F-P-X5-P) at its C terminus, which is essential for its function. Genetic analysis showed that all four cysteines in the CRM were irreplaceable, and enzymatic assays demonstrated that the mutation of each of the four cysteines affected its Mg-dechelating activity. The CRM plays a critical role in the conformational change and self-interaction of NYE1 via the formation of inter- and intra-molecular disulfide bonds. Our results may provide insight into how NYE1 responds to rapid redox changes during leaf senescence and in response to various environmental stresses.