Tishkoff D X, Boerger A L, Bertrand P, Filosi N, Gaida G M, Kane M F, Kolodner R D
Division of Human Cancer Genetics, Dana-Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, USA.
Proc Natl Acad Sci U S A. 1997 Jul 8;94(14):7487-92. doi: 10.1073/pnas.94.14.7487.
A two-hybrid screen was used to identify Saccharomyces cerevisiae genes encoding proteins that interact with MSH2. One gene was found to encode a homologue of Schizosaccharomyces pombe EXO1, a double-stranded DNA-specific 5'-3' exonuclease. S. cerevisiae EXO1 interacted with both S. cerevisiae and human MSH2 in two-hybrid and coimmunoprecipitation experiments. exo1 mutants showed a mutator phenotype, and epistasis analysis was consistent with EXO1 functioning in the MSH2-dependent mismatch repair pathway. exo1 mutations were lethal in combination with rad27 mutations, and overexpression of EXO1 suppressed both the temperature sensitive and mutator phenotypes of rad27 mutants.
利用双杂交筛选来鉴定酿酒酵母中编码与MSH2相互作用蛋白的基因。发现一个基因编码粟酒裂殖酵母EXO1的同源物，EXO1是一种双链DNA特异性5'-3'核酸外切酶。在双杂交和免疫共沉淀实验中，酿酒酵母EXO1与酿酒酵母和人类MSH2都相互作用。exo1突变体表现出突变体表型，上位性分析表明EXO1在MSH2依赖的错配修复途径中发挥作用。exo1突变与rad27突变组合是致死的，EXO1的过表达抑制了rad27突变体的温度敏感性和突变体表型。
