Functional analysis of the pathways for 2-Cys peroxiredoxin reduction in Arabidopsis thaliana chloroplasts.
Functional analysis of the pathways for 2-Cys peroxiredoxin reduction in Arabidopsis thaliana chloroplasts.
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DOI：
10.1093/jxb/erq218
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发表时间：
2010-09
影响因子：
6.9
通讯作者：
Cejudo FJ
中科院分区：
文献类型：
--
作者：
Pulido P;Spínola MC;Kirchsteiger K;Guinea M;Pascual MB;Sahrawy M;Sandalio LM;Dietz KJ;González M;Cejudo FJ
光合作用是一个不可避免地产生活性氧的过程，如过氧化氢，其通过叶绿体定位的解毒机制减少，其中之一涉及2-Cys过氧化物酶（2-Cys Prxs）。拟南芥叶绿体含有两个非常相似的2-Cys Prx（表示为A和B）。这些酶通过两种途径还原：NADPH硫氧还蛋白还原酶C（NTRC），其使用NADPH作为还原力的来源;和质体硫氧还蛋白（Trx），其与光合作用还原的铁氧还蛋白偶联，其中Trx x是体外最有效的还原剂。为了在体内建立NTRC、Trx x和2-Cys Prx之间的功能关系，已经鉴定了拟南芥Trx x敲除突变体，并且已经产生了2-Cys Prx含量<5%的双突变体（表示为Δ2cp）。在标准生长条件下以及对连续光照或长时间黑暗和氧化胁迫的响应中，比较了三种突变体ntrc、trxx和Δ2cp的表型。虽然所有的突变体显示改变氧化还原稳态，没有观察到差异，在响应氧化应激处理。此外，2-Cys Prx的氧化还原状态在ntrc突变体中是不平衡的，但在trxx突变体中不是。这些结果表明，NTRC是体内叶绿体2-Cys Prx还原最相关的途径，但该系统的抗氧化功能并不重要。通过生长、色素含量、CO2固定和Fv/Fm测定，NTRC的缺乏引起比Trx x或2-Cys Prxs的缺乏更严重的表型，表明NTRC的额外功能。
Photosynthesis is a process that inevitably produces reactive oxygen species, such as hydrogen peroxide, which is reduced by chloroplast-localized detoxification mechanisms one of which involves 2-Cys peroxiredoxins (2-Cys Prxs). Arabidopsis chloroplasts contain two very similar 2-Cys Prxs (denoted A and B). These enzymes are reduced by two pathways: NADPH thioredoxin reductase C (NTRC), which uses NADPH as source of reducing power; and plastidial thioredoxins (Trxs) coupled to photosynthetically reduced ferredoxin of which Trx x is the most efficient reductant in vitro. With the aim of establishing the functional relationship between NTRC, Trx x, and 2-Cys Prxs in vivo, an Arabidopsis Trx x knock-out mutant has been identified and a double mutant (denoted Δ2cp) with <5% of 2-Cys Prx content has been generated. The phenotypes of the three mutants, ntrc, trxx, and Δ2cp, were compared under standard growth conditions and in response to continuous light or prolonged darkness and oxidative stress. Though all mutants showed altered redox homeostasis, no difference was observed in response to oxidative stress treatment. Moreover, the redox status of the 2-Cys Prx was imbalanced in the ntrc mutant but not in the trxx mutant. These results show that NTRC is the most relevant pathway for chloroplast 2-Cys Prx reduction in vivo, but the antioxidant function of this system is not essential. The deficiency of NTRC caused a more severe phenotype than the deficiency of Trx x or 2-Cys Prxs as determined by growth, pigment content, CO2 fixation, and Fv/Fm, indicating additional functions of NTRC.
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DOI：
10.1111/j.1742-4658.2009.06985.x
发表时间：
2009-05
期刊：
The FEBS journal
影响因子：
--
作者：
Hall A;Karplus PA;Poole LB
通讯作者：
Poole LB
影响因子：
4.8
作者：
Collin, V;Issakidis-Bourguet, E;Miginiac-Maslow, M
通讯作者：
Miginiac-Maslow, M
影响因子：
4.3
作者：
Lee, Sang-Hoon;Ahsan, Nagib;Lee, Byung-Hyun
通讯作者：
Lee, Byung-Hyun
影响因子：
56.9
作者：
Alonso, JM;Stepanova, AN;Ecker, JR
通讯作者：
Ecker, JR
影响因子：
4.1
作者：
Kangasjarvi, Saijaliisa;Lepisto, Anna;Rintamaki, Eevi
通讯作者：
Rintamaki, Eevi