SNF2家族新成员Ercc61的cDNA克隆与表达分析

SNF2家族蛋白在基因组复制、修复与表达中具有重要作用.报道了SNF2家族新成员Ercc61(excisionrepair crosscomplementing rodent repair deficiency,complementation group 6-like)的cDNA克隆、特性与表达分析.通过表达序列标签(EST)搜索和组装,获得了cDNA全长4002bp的新基因Ercc6l(GenBank Acc.No AY172688),然后通过RT-PCR在小鼠胚胎心脏成功克隆了该基因.Ercc6l在小鼠基因组中由两个外显子和一个内含子组成,定位于X染色体,最大开放阅读框(ORF)编码一个含l240个氨基酸的假定蛋白质.该假定蛋白质含有SNF2蛋白的8个保守基序(SNF2结构域).通过与SNF2家族各亚家族的成员进行多重比对,初步确认Ercc6l属于ERCC6亚家族成员.将Ercc6l编码区克隆到pEGFP-C3然后转染HeLa,3T3和B16细胞,融合蛋白主要定位于胞浆.BLAST搜索检索出69条小鼠EST与Erccol同源,这些EST主要来自胚胎和肿瘤组织.对小鼠不同发育时期的多种组织进行RT-PCR,发现Ercc6l在胚胎期强表达,出生产后表达显著下调.这些结果提示Ercc6l在胚胎发育和肿瘤发生中可能具有重要作用.

cDNA Cloning and Expression Analysis of Mouse Gene Encoding The Protein Ercc61 Which Is a Novel Member of SNF2 Family

SNF2 family includes proteins essential to genome replication, repair, and expression. The cDNA cloning and initial characterization of a novel mouse member of this protein family was reported, and the new member was designated as Erccol ( excision repair cross-complementing rodent repair deficiency, complementation group 6-like) by MGNC. The cDNA of Erccol was 4 002 bp and firstly cloned in silico and then identified by RT-PCR in mouse embryo heart. This gene was composed of 2 extrons and mapped to mouse chromosome X. The longest ORF encoded a putative protein of 1240 amino acids. Eight highly conserved sequence regions of SNF2 protein were present in the deduced protein. Alignment against members of SNF2 family initially placed Ercc61 into ERCC6 subfamily of SNF2 family. EGFP-tagged Ercc61 protein was localized in cytoplasm of HeLa, NIH3T3 and B16 cells. BLAST search in EST database retrieved 69 homologous ESTs of Ercc6l, most of which were from mouse embryonic and tumorous tissues. RT-PCR performed on a panel of different mouse tissues demonstrated that Ercc6l strongly expressed in mouse embryo but significantly downregulated in neonate and adult normal tissue. These results suggest that Ercc61 is a novel member of SNF2 family and may be crucial for development of embryo and tumor.