中文摘要：

BRD7被鉴定为一个鼻咽癌密切相关新基因和潜在的核转录调节因子.通过绿色荧光蛋白（GFP）介导的亚细胞定位方法,系统研究BRD7在非洲绿猴肾COS7细胞、人宫颈癌HeLa细胞以及人鼻咽癌HNE1细胞中的亚细胞定位,发现BRD7主要定位在细胞核,呈细点状或条梭状分布,3株细胞中没有明显的细胞类型差异.通过对BRD7编码蛋白氨基酸序列进行比对分析,发现了1个具有亮氨酸富集特征的假定核输出信号序列pNES,该区域具有类似核输出信号特征序列“L-x（2,3）-[LIVFM]-x（2,3）-L-x-[LI]”（X代表任意氨基酸）的结构;通过功能分析,发现它不具有介导异源蛋白GFP胞浆定位的功能,且其亚细胞定位或胞浆/胞核分布比例不受细霉素B（leptomycin B）干预的影响,说明这个pNES不具核输出信号结构域的功能,不是BRD7的核输出信号.

英文摘要：

BRD7 was identified as a novel gene tightly associated to nasopharyngeal carcinoma （NPC） and also a nuclear transcriptional regulatory factor. Cotransfection experiment with green fluorescence protein （GFP） was preformed to detect the subcellular localization of BRD7 in three different cell lines and it was found that BRD7 localized in nucleus in a thin dotted or diffused pattern, with no cell-specific difference in these kinds of cells. The nuclear export signal sequence （NES） with a characteristic of leucine-rich motif was screened by comparing to the NES database, and a putative NES （pNES） similar to NES consensus sequence of L-x（2,3）-[LIVFM]-x（2,3）-L-x-[LI] was found within BRD7. By functional analysis, it was found that the pNES couldn＇t mediate the cytoplasmic localization of GFP and leptomycin B had no effect on the distribution ratio of cytoplasm/nucleus of GFP-pNES. It was suggested that the pNES has no function of NES and is not a functional NES in BRD7.