McDonald J P, Rapić-Otrin V, Epstein J A, Broughton B C, Wang X, Lehmann A R, Wolgemuth D J, Woodgate R
Section on DNA Replication, Repair and Mutagenesis, National Institute of Child Health and Human Development, Bethesda, Maryland, 20892-2725, USA.
Genomics. 1999 Aug 15;60(1):20-30. doi: 10.1006/geno.1999.5906.
The Saccharomyces cerevisiae RAD30 gene encodes a novel eukaryotic DNA polymerase, pol eta that is able to replicate across cis-syn cyclobutane pyrimidine dimers both accurately and efficiently. Very recently, a human homolog of RAD30 was identified, mutations in which result in the sunlight-sensitive, cancer-prone, Xeroderma pigmentosum variant group phenotype. We report here the cloning and localization of a second human homolog of RAD30. Interestingly, RAD30B is localized on chromosome 18q21.1 in a region that is often implicated in the etiology of many human cancers. The mouse homolog (Rad30b) is located on chromosome 18E2. The human RAD30B and mouse Rad30b mRNA transcripts, like many repair proteins, are highly expressed in the testis. In situ hybridization analysis indicates that expression of mouse Rad30b occurs predominantly in postmeiotic round spermatids. Database searches revealed genomic and EST sequences from other eukaryotes such as Aspergillus nidulans, Schizosaccharomyces pombe, Brugia malayi, Caenorhabditis elegans, Trypanosoma cruzi, Arabidopsis thaliana, and Drosophila melanogaster that also encode putative homologs of RAD30, thereby suggesting that Rad30-dependent translesion DNA synthesis is conserved within the eukaryotic kingdom.
酿酒酵母RAD30基因编码一种新型真核DNA聚合酶——聚合酶η，它能够准确且高效地跨越顺式-环丁烷嘧啶二聚体进行复制。最近，人们鉴定出了RAD30的一种人类同源物，其突变会导致对阳光敏感、易患癌症的着色性干皮病变异型组表型。我们在此报告RAD30的第二种人类同源物的克隆和定位。有趣的是，RAD30B定位于18号染色体q21.1区域，该区域常与许多人类癌症的病因有关。小鼠同源物（Rad30b）位于18E2号染色体上。与许多修复蛋白一样，人类RAD30B和小鼠Rad30b的mRNA转录本在睾丸中高度表达。原位杂交分析表明，小鼠Rad30b的表达主要发生在减数分裂后的圆形精子细胞中。数据库搜索显示，来自其他真核生物（如构巢曲霉、粟酒裂殖酵母、马来布鲁线虫、秀丽隐杆线虫、克氏锥虫、拟南芥和黑腹果蝇）的基因组和EST序列也编码RAD30的假定同源物，从而表明依赖Rad30的跨损伤DNA合成在真核生物界是保守的。
