The Arabidopsis UVH1 gene is a homolog of the yeast repair endonuclease RAD1
The Arabidopsis UVH1 gene is a homolog of the yeast repair endonuclease RAD1
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DOI：
10.1104/pp.124.2.579
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发表时间：
2000-10-01
期刊：
影响因子：
7.4
通讯作者：
Britt, AB
中科院分区：
文献类型：
--
作者：
Fidantsef, AL;Mitchell, DL;Britt, AB
紫外线辐射会诱导 DNA 损伤产物，主要以嘧啶二聚体的形式存在，具有毒性和致突变性。在大多数生物体中，包括拟南芥，这些损伤是通过二聚体特异性光再激活机制和效率较低的光独立机制来修复的。先前已经描述了这种“暗修复”途径中存在缺陷的几种突变体。这种修复的机制尚未阐明，但被认为与其他真核生物中发现的核苷酸切除修复机制同源。在这里，我们报告了拟南芥uvh1暗修复突变体与酵母核苷酸切除修复基因RAD1的拟南芥同源物的互补，RAD1编码5'-修复核酸内切酶的亚基之一。 uvh1-2 突变等位基因携带甘氨酸→天冬氨酸氨基酸变化，先前已鉴定该变化可在酵母中产生 RAD1 无效等位基因。尽管通过搜索基因组数据库很容易识别拟南芥中参与核苷酸切除修复的基因的同源物，但尚未确定这些同源物实际上是植物中暗修复所必需的。拟南芥 uvh1 突变与拟南芥 RAD1 同源物的互补清楚地表明，核苷酸切除修复机制在植物、动物和真菌界中是保守的。
Ultraviolet radiation induces DNA damage products, largely in the form of pyrimidine dimers, that are both toxic and mutagenic. In most organisms, including Arabidopsis, these lesions are repaired both through a dimer-specific photoreactivation mechanism and through a less efficient light-independent mechanism. Several mutants defective in this "dark repair" pathway have been previously described. The mechanism of this repair has not been elucidated, but is thought to be homologous to the nucleotide excision repair mechanisms found in other eukaryotes. Here we report the complementation of the Arabidopsis uvh1 dark repair mutant with the Arabidopsis homolog of the yeast nucleotide excision repair gene RAD1, which encodes one of the subunits of the 5'-repair endonuclease. The uvh1-2 mutant allele carries a glycine-->aspartate amino acid change that has been previously identified to produce a null allele of RAD1 in yeast. Although Arabidopsis homologs of genes involved in nucleotide excision repair are readily identified by searching the genomic database, it has not been established that these homologs are actually required for dark repair in plants. The complementation of the Arabidopsis uvh1 mutation with the Arabidopsis RAD1 homolog clearly demonstrates that the mechanism of nucleotide excision repair is conserved among the plant, animal, and fungal kingdoms.