Institute of Sericulture and Apiculture, College of Animal Sciences, Zhejiang University, Hangzhou 310029, People's Republic of China.
Biosci Rep. 2009 Sep 17;30(1):19-26, 2 p following 26. doi: 10.1042/BSR20080169.
Rad23 is an NER (nucleotide excision repair) protein and it plays an important role in the UPP (ubiquitin-proteasome pathway). In the present study, BmRad23 (a homologous gene of Rad23 from Bombyx mori) was cloned and designated as BmRad23. The ORF (open reading frame) of the BmRad23 cDNA encoded deduced 324 amino acids with a calculated molecular mass of 36.13 kDa and an estimated pI of 4.50. The deduced amino acid sequence of the BmRad23 cDNA revealed several indispensable domains for the function of the Rad23 protein family, such as one UbL (ubiquitin-like) region domain and two UBA (ubiquitin-associated) domains. UV irradiation and treatment with chemical DNA-damaging reagent increased the expression of BmRad23. The BmRad23 gene was expressed in all the examined organs, and elevated expression was observed in testis and ovary. Northern blot and immunoblot analyses showed enhanced expression of BmRad23 after day 3 of the wandering stage in the silk gland. From the present results it is suggested that BmRad23 functions in the UPP during the silkworm metamorphosis as well as participating in the NER when the genetic material is damaged by UV irradiation and other genotoxic stresses.
Rad23 是一种 NER（核苷酸切除修复）蛋白，在 UPP（泛素-蛋白酶体途径）中发挥重要作用。本研究克隆了 BmRad23（来自家蚕的 Rad23 同源基因），并将其命名为 BmRad23。BmRad23 cDNA 的 ORF（开放阅读框）编码推测的 324 个氨基酸，分子量为 36.13 kDa，等电点为 4.50。BmRad23 cDNA 的推导氨基酸序列揭示了 Rad23 蛋白家族功能所必需的几个结构域，如一个 UbL（泛素样）区域结构域和两个 UBA（泛素相关）结构域。紫外线照射和化学 DNA 损伤试剂处理增加了 BmRad23 的表达。BmRad23 基因在所有检测到的器官中表达，在睾丸和卵巢中表达水平升高。Northern blot 和免疫印迹分析显示，丝腺中游走阶段第 3 天后 BmRad23 的表达增强。从目前的结果来看，BmRad23 在丝虫变态过程中 UPP 中发挥作用，并且在遗传物质受到紫外线照射和其他遗传毒性应激损伤时参与 NER。
