MsrB1 (Methionine-R-sulfoxide Reductase 1) Knock-out Mice ROLES OF MsrB1 IN REDOX REGULATION AND IDENTIFICATION OF A NOVEL SELENOPROTEIN FORM
MsrB1 (Methionine-R-sulfoxide Reductase 1) Knock-out Mice ROLES OF MsrB1 IN REDOX REGULATION AND IDENTIFICATION OF A NOVEL SELENOPROTEIN FORM
复制标题
DOI：
10.1074/jbc.m805770200
复制
发表时间：
2009-02-27
影响因子：
4.8
通讯作者：
Gladyshev, Vadim N.
中科院分区：
文献类型：
--
作者：
Fomenko, Dmitri E.;Novoselov, Sergey V.;Gladyshev, Vadim N.
蛋白质氧化与加速衰老有关，是许多疾病的促成因素。甲硫氨酸残基对氧化特别敏感，但甲硫氨酸R-亚砜（Met-RO）和甲硫氨酸S-亚砜（Met-SO）的混合物可以分别通过硫氧还蛋白依赖性酶MsrB和MsrA修复。在这里，我们描述了一个基因敲除小鼠缺乏硒蛋白MsrB 1，主要的哺乳动物MsrB位于细胞质和细胞核。在这些小鼠中，除了14 kDa MsrB 1的缺失，5 kDa硒蛋白形式被特异性去除。进一步的研究表明，5-kDa的蛋白质发生在小鼠组织和人HEK 293细胞;下调MsrB 1小干扰RNA，硒缺乏，硒代半胱氨酸tRNA突变;并免疫沉淀和识别MsrB 1抗体。特异性标记与Se-75和质谱分析表明，5-kDa硒蛋白对应的C-末端序列的MsrB 1。MsrB 1基因敲除小鼠缺乏5-和14-kDa MsrB 1形式，并显示MsrB活性降低，在肝脏和肾脏中观察到最强的影响。此外，MsrB 1缺乏还降低了MsrA的活性。肝脏和肾脏的MsrB 1基因敲除小鼠也表现出增加的丙二醛，蛋白质羰基，蛋白质蛋氨酸亚砜，氧化型谷胱甘肽的水平，以及降低水平的游离和蛋白质硫醇，而这些参数在其他器官检查变化不大。总的来说，这项研究确定了MsrB 1对小鼠肝脏和肾脏氧化还原控制的重要贡献，并确定了这种蛋白质的一种新形式。
Protein oxidation has been linked to accelerated aging and is a contributing factor to many diseases. Methionine residues are particularly susceptible to oxidation, but the resulting mixture of methionine R-sulfoxide (Met-RO) and methionine S-sulfoxide (Met-SO) can be repaired by thioredoxin-dependent enzymes MsrB and MsrA, respectively. Here, we describe a knock-out mouse deficient in selenoprotein MsrB1, the main mammalian MsrB located in the cytosol and nucleus. In these mice, in addition to the deletion of 14-kDa MsrB1, a 5-kDa selenoprotein form was specifically removed. Further studies revealed that the 5-kDa protein occurred in both mouse tissues and human HEK 293 cells; was down-regulated by MsrB1 small interfering RNA, selenium deficiency, and selenocysteine tRNA mutations; and was immunoprecipitated and recognized by MsrB1 antibodies. Specific labeling with Se-75 and mass spectrometry analyses revealed that the 5-kDa selenoprotein corresponded to the C-terminal sequence of MsrB1. The MsrB1 knock-out mice lacked both 5-and 14-kDa MsrB1 forms and showed reduced MsrB activity, with the strongest effect seen in liver and kidney. In addition, MsrA activity was decreased by MsrB1 deficiency. Liver and kidney of the MsrB1 knock-out mice also showed increased levels of malondialdehyde, protein carbonyls, protein methionine sulfoxide, and oxidized glutathione as well as reduced levels of free and protein thiols, whereas these parameters were little changed in other organs examined. Overall, this study established an important contribution of MsrB1 to the redox control in mouse liver and kidney and identified a novel form of this protein.