Functional characterization of BRCA1 sequence variants using a yeast small colony phenotype assay
Functional characterization of BRCA1 sequence variants using a yeast small colony phenotype assay
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DOI：
10.4161/cbt.3.5.809
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发表时间：
2004-05-01
影响因子：
3.6
通讯作者：
Brody, LC
中科院分区：
文献类型：
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作者：
Coyne, RS;McDonald, HB;Brody, LC
肿瘤抑制基因BRCA 1的生殖系突变与乳腺癌和其他组织癌症的风险增加有关，但在人群中发现的许多错义变体的功能后果尚不确定。已经提出了几种预测方法来区分癌症易感错义突变与无害多态性，包括在模式生物酵母（酿酒酵母）中进行的小菌落表型（SCP）测定。本研究的目的是进一步评价该菌落大小试验。我们构建了28个错义突变的BRCA 1的C-末端305个氨基酸残基。突变蛋白在酵母中表达，并使用SCP测定进行评价。我们的结论是，目前还没有证据表明该检测方法可以识别BRCT重复序列上游的失活突变。然而，在BRCT重复序列内和之间，测定结果与基于结构建模、其他体外和体内测定以及跨物种序列保守性的预测大体一致。因此，酵母试验似乎提供了确证性的体内证据，以帮助表征一些BRCA 1错义变体。
Germline mutations that inactivate the tumor suppressor gene BRCA1 are associated with an increased risk of cancers of the breast and other tissues, but the functional consequence of many missense variants found in the human population is uncertain. Several predictive methods have been proposed to distinguish cancer-predisposing missense mutations from harmless polymorphisms, including a small colony phenotype (SCP) assay performed in the model organism, yeast (Saccharomyces cerevisiae). The goal of this study was to further evaluate this colony size assay. We constructed 28 missense mutations throughout the C-terminal 305 amino acid residues of BRCA1. Mutated proteins were expressed in yeast and evaluated using the SCP assay. We conclude there is as yet no evidence the assay can identify inactivating mutations upstream of the BRCT repeats. However, within and between the BRCT repeats, results of the assay are in general agreement with predictions based on structural modeling, other in vitro and in vivo assays, and cross-species sequence conservation. Thus, the yeast assay appears to provide confirmatory in vivo evidence to aid in characterizing some BRCA1 missense variants.