Two functional assays employed to detect an unusual mutation in the oligomerisation domain of p53 in a Li-Fraumeni like family-猫眼课题宝

DOI：

10.1038/sj.onc.1201133

发表时间：

1997-04-17

期刊：

ONCOGENE

影响因子：

8

通讯作者：

中科院分区：

医学1区

文献类型：

--

作者：

Lomax, ME;Barnes, DM;Camplejohn, RS

先前对Li-Fraumeni家族的研究（Barnes et al, 1992）表明，先证者及其母亲在肿瘤组织和远离肿瘤的正常组织中p53蛋白水平均升高，尽管p53基因未发现突变。在本研究中，两种最近描述的p53功能测定，凋亡测定和酵母等位基因分离的功能测定（FASAY）。凋亡实验结果表明该患者存在p53功能缺陷，FASAY结果表明该缺陷实际上是p53基因的种系突变，密码子337点突变导致半胱氨酸取代精氨酸，这一突变最初在cDNA中得到证实，并通过基因组DNA测序得到证实。这是一个不寻常的突变，因为它位于p53的寡聚化区域，与大多数p53突变在核心DNA结合区域相反，这种突变导致蛋白质在FASAY中仍然保留部分转激活活性，密码子337的突变只是第二个报道的发生在p53寡聚化区域的种系错义突变病例。

Previous investigations of a Li-Fraumeni like family (Barnes et al., 1992) demonstrated that both the proband and her mother had elevated p53 protein levels in both tumour tissue and normal tissue at sites distant from the tumour, although no mutation was found in the p53 gene, In the present study two recently described functional assays for p53, an apoptotic assay and the functional assay for the separation of alleles in yeast (FASAY), have been employed to study the functional activity of p53 from this patient, The results of the apoptotic assay demonstrated that this patient had a p53 functional defect and the FASAY result suggested that this defect was in fact a germline mutation of the p53 gene, A point mutation of codon 337, which results in an amino acid substitution of a cysteine for an arginine, was demonstrated initially in cDNA and was confirmed by sequencing of genomic DNA, This is an unusual mutation as it is in the oligomerisation domain of p53, in contrast to the majority of p53 mutations which are in the core DNA binding domain, This mutation results in a protein which still retains partial transactivational activity in the FASAY, The mutation of codon 337 is only the second reported case of a germline missense mutation occurring in the oligomerisation domain of p53.