发生在成视网膜细胞瘤蛋白大袋立体结构外的错义突变

目的:了解成视网膜细胞瘤(RB)患者RB1基因突变至RB发生中RB蛋白(pRB)的变化。方法: 提取RB患者的基因组DNA, PCR扩增后, SSCP/异源双链筛查RB1基因的启动子和全部27个外显子, 克隆测序鉴定突变, 并分析突变产物对pRB的影响。结果:RB患者RB1基因的外显子4存在着错义突变, 该突变发生在pRB的大袋立体结构外。RB患者RB1基因存在着不影响pRB大袋的生殖细胞性突变, 这是迄今为止第4例报道。结论:pRB氨基末端可能参与pRB对细胞的生长抑制。

A missense mutation outside the large pocket of the retinoblastoma protein

AIM: To understand the effect of the RB1 gene mutation on the function of pRB (the protein product of the RB1 gene) in the patients with retinoblastoma (RB). METHODS: The genomic DNA from retinoblastoma patients was extracted. After amplification, the promoter and all 27 exons were screened by SSCP-heteroduplex method. The mutation was cloned and identified by sequencing. The effect of the mutation product on the function of pRB was analyzed. RESULTS: One missense mutations of the exon 4 of the RB1 gene was identified in the genomic DNA from RB patients. This mutation was outside the large pocket of the pRB. No mutation of the RB1 gene was found in the genome DNA of the patient's parents. This is the fourth report that there was a genome mutation located outside the large pocket of pRB in the RB patients. CONCLUSION: The amino-terminus of the pRB may be essential for growth suppression.