The Brachypodium distachyon methionine sulfoxide reductase gene family
The Brachypodium distachyon methionine sulfoxide reductase gene family
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二穗短柄草甲硫氨酸亚砜还原酶基因家族
DOI：
10.1007/s13258-017-0561-4
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发表时间：
2017-09-01
期刊：
影响因子：
2.1
通讯作者：
Xia, Guangmin
中科院分区：
文献类型：
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作者：
Gao, Yankun;Zhu, Jiantang;Xia, Guangmin
甲硫氨酸亚砜还原酶（MSRs）是一类巯基依赖性酶，能够催化甲硫氨酸亚砜转化为甲硫氨酸。尽管已知一些植物MSR作为保护剂对抗各种非生物胁迫，但它们在模式草种二穗短柄草中的活性尚未被表征。给你，6个B。二穗草MSR（BdMSR）基因已被分离;它们产生八个不同的cDNA，因为其中两个（BdMSRB 1和-B5）产生一对选择性剪接的信息。这些基因在根、茎、叶和颖果发育的各个时期都有转录。非生物胁迫（盐，干旱，低温，氯化镉，过氧化氢和脱落酸）诱导的那些在其启动子序列中含有已知的胁迫响应顺式元件。在酵母中异源表达的五个BdMSRs（-A2，-A4，-B1.1，-B3和-B5.1）表明，他们的产品提供了一个措施，防止盐，甘露醇和氧化应激。底物特异性分析表明，BdMSRB 1.1能将游离Met-R-SO还原为Met。转化酵母中BdMSRA 4、-B1.1和-B5.1的酶活性在盐胁迫下受到抑制并明显增强，使更多的Met-SO在盐胁迫下转化为Met，包括肽和游离形式。
The methionine sulfoxide reductases (MSRs) are a group of thiol-dependent enzymes able to catalyze the conversion of methionine sulfoxide to methionine. Although some plant MSRs are known to act as protectants against various abiotic stresses, their activity in the model grass species Brachypodium distachyon has not been characterized as yet. Here, six B. distachyon MSR (BdMSR) genes have been isolated; they generate eight distinct cDNAs, since two of them (BdMSRB1 and -B5) produce a pair of alternatively spliced messages. The genes were transcribed in the root, culm, leaf and during various stages of caryopsis development. Those induced by abiotic stress (salinity, drought, low temperature, CdCl2, H2O2 and abscisic acid) harbored known stress-responsive cis elements in their promoter sequences. The heterologous expression of five of the BdMSRs (-A2, -A4, -B1.1, -B3 and -B5.1) in yeast revealed that their products gave a measure of protection against salinity, mannitol and oxidative stress. Substrate specificity analysis revealed that BdMSRB1.1 could reduce free Met-R-SO to Met. The enzymatic activities of BdMSRA4, -B1.1 and -B5.1 in transformed yeast under salt treatment have checked and increased obviously resulting in reducing more Met-SO to Met including the peptide and the free types under salt stress than those in control.