Lee Jae-Hoon, Kim Kyunghoon, Park Eun-Hee, Ahn Kisup, Lim Chang-Jin
Division of Life Sciences and Research Institute of Life Sciences, Kangwon National University, Chuncheon 200-701, Korea.
Mol Cells. 2007 Dec 31;24(3):316-22.
Glutaredoxins (Grxs), also known as thioltransferases (TTases), are thiol oxidoreductases that regulate cellular redox state in a variety of organisms. In the budding yeast Saccharomyces cerevisiae, Grx1 and 2 are cytosolic dithiol Grxs, while Grx3, 4 and 5 are monothiol Grxs. A gene encoding a new monothiol Grx, Grx6, was cloned from the genomic DNA of S. cerevisiae by PCR. Its DNA sequence contains 1,080 bp, and encodes a putative protein of 203 amino acid residues containing Cys-Phe-Tyr-Ser at the active site. Grx6 is similar to other monothiol Grxs in the same organism and to Grx3 in the fission yeast Schizosaccharomyces pombe. and its predicted three-dimensional structure resembles that of S. pombe Grx3. S. pombe cells harboring plasmid pFGRX6 containing the Grx6 gene had about 1.3-fold elevated Grx activity in the exponential phase, and grew better than the control cells under some stressful conditions. Synthesis of beta-galactosidase from a Grx6-lacZ fusion gene in S. pombe was enhanced by potassium chloride, aluminum chloride and heat (37 degrees C) treatment. S. pombe cells harboring plasmid pFGRX6 had elevated ROS levels whereas S. pombe cells harboring extra copies of Grx3 had reduced ROS levels.
谷氧还蛋白（Grxs），也被称为硫醇转移酶（TTases），是一类硫醇氧化还原酶，可调节多种生物体中的细胞氧化还原状态。在出芽酵母酿酒酵母中，Grx1和2是胞质二硫醇谷氧还蛋白，而Grx3、4和5是单硫醇谷氧还蛋白。通过PCR从酿酒酵母的基因组DNA中克隆了一个编码新的单硫醇谷氧还蛋白Grx6的基因。其DNA序列包含1080 bp，编码一个由203个氨基酸残基组成的推定蛋白，其活性位点含有半胱氨酸-苯丙氨酸-酪氨酸-丝氨酸。Grx6与同一生物体中的其他单硫醇谷氧还蛋白以及裂殖酵母粟酒裂殖酵母中的Grx3相似，其预测的三维结构与粟酒裂殖酵母Grx3的结构相似。携带含有Grx6基因的质粒pFGRX6的粟酒裂殖酵母细胞在指数生长期的谷氧还蛋白活性提高了约1.3倍，并且在某些应激条件下比对照细胞生长得更好。在粟酒裂殖酵母中，来自Grx6 - lacZ融合基因的β-半乳糖苷酶的合成通过氯化钾、氯化铝和热（37℃）处理得到增强。携带质粒pFGRX6的粟酒裂殖酵母细胞的活性氧水平升高，而携带Grx3额外拷贝的粟酒裂殖酵母细胞的活性氧水平降低。
