【摘要】 目的研究范可尼贫血(FA)患者 FANCA 蛋白的表达及其突变子的功能。方法用3例来源于 FA-A 型患者的外周血淋巴细胞建立的细胞系作为研究对象,分别提取其细胞总蛋白、细胞胞质蛋白和细胞核蛋白,用 Western blot 法分析 FANCA 蛋白的表达及其在细胞胞质和细胞核内的分布,对1例有 FANCA 截短型蛋白表达的 FA 患者,构建了质粒突变子并用哺乳动物细胞双杂交方法检测 FANCA 基因突变子(外显子5缺失)与 FANCG 蛋白的相互作用。结果用兔抗人抗体检测时,3例 FA-A 患者均无 FANCA 蛋白的表达,而用鼠抗人抗体检测时,有1例患者可检测到截短型 FANCA 蛋白表达,但此截短型 FANCA 蛋白不能从细胞胞质转运到细胞核,也不能在哺乳动物细胞双杂交系统中与 FANCG 蛋白相互作用。结论 3例 FA-A 患者中,2例无 FANCA 蛋白表达,1例可表达截短型FANCA 蛋白,但无正常 FANCA 蛋白功能,进一步证实其 FANCA 基因突变为致病性病理突变,FANCA基因外显子5参与了与 FANCG 的相互作用。更多还原

【Abstract】 Objective To study FANCA protein expression in Fanconi anemia patient’s(FA)cells and explore its function.Methods FANCA protein expression was analyzed in 3 lymphoblast cell lines de- rived from 3 cases of type A FA(FA-A)patients using Western blot.Nucleus and cytoplasm localization of FANCA protein was analyzed in one case of FA-A which contained a truncated FANCA(exon 5 deletion). The FANCA mutant was constructed from the same patient and its interaction with FANCG was evaluated by mammalian two-hybrid(M2H)assay.Results FANCA protein was not detected in the 3 FA-A patients by rabbit anti-hmnan MoAb,but a truncated FANCA protein was detected in 1 of them by mouse anti-human MoAb.The truncated FANCA could not transport from cytoplasm into nucleus.The disease-assoclated FANCA mutant was defective in binding to FANCG in M2H system.Conclusions FANCA proteins are defective in the 3 FA-A patients.Disfunetion of disease-associated FANCA mutant proved to be the pathogenic mutations in FANCA gene.Exon 5 of FANCA gene was involved in the interaction between FANCA and FANCG.更多还原