Yeast mutator phenotype enforced by Arabidopsis PMS1 expression
Yeast mutator phenotype enforced by Arabidopsis PMS1 expression
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DOI：
10.1007/s11033-012-2269-5
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发表时间：
2013-03-01
影响因子：
2.8
通讯作者：
Spampinato, Claudia P.
中科院分区：
文献类型：
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作者：
Galles, Celina;Spampinato, Claudia P.
DNA错配修复（MMR）系统是一种主要的DNA修复途径，其功能对于纠正DNA生物合成错误至关重要。MMR是通过MutS蛋白与错配和未配对核苷酸的结合，然后募集MutL蛋白而启动的。真核生物中的主要MutL活性是由MutL α（酵母和植物中MLH 1-PMS 1的异源复合物和人类中MLH 1-PMS 2的异源复合物）执行的。我们在这里报告拟南芥PMS 1蛋白的表达对酿酒酵母基因组稳定性的影响。选择携带特定微卫星不稳定性报告系统的菌株进行研究。该植物蛋白不能补充pms 1缺陷型菌株的超变子表型，但与野生型菌株相比，MMR熟练型菌株的his 7 -2和lys 2：：InsE-A（14）位点的突变率分别增加了约14倍和2，000倍。在AtPMS 1过量生产菌株中过表达AtMLH 1产生的突变率增加与单独AtPMS 1表达的突变率增加相当。删除涉及蛋白质-蛋白质相互作用的C-末端残基，包括AtPMS 1的推定核酸内切酶序列，完全消除了突变表型。总之，这些结果表明，植物蛋白影响酵母基因组的稳定性，很可能改变蛋白质-蛋白质相互作用是必要的，以完成修复。
The DNA mismatch repair (MMR) system is a major DNA repair pathway whose function is critical for the correction of DNA biosynthetic errors. MMR is initiated by the binding of MutS proteins to mismatches and unpaired nucleotides followed by the recruitment of MutL proteins. The major MutL activity in eukaryotes is performed by MutL alpha, the heterocomplex of MLH1-PMS1 in yeast and plants and MLH1-PMS2 in humans. We here report the effect the expression of Arabidopsis PMS1 protein exerts on Saccharomyces cerevisiae genomic stability. A strain carrying specific microsatellite instability reporter systems was chosen for the study. The plant protein failed to complement the hypermutator phenotype of a pms1 deficient strain but increased approximately 14-fold and 2,000-fold the mutation rates of his7-2 and lys2::InsE-A (14) loci of MMR proficient strains when compared to wild-type strains, respectively. Overexpressing AtMLH1 in the AtPMS1-overproducing strain generated an increase in mutation rate comparable to that of AtPMS1 expression alone. Deletion of the C-terminal residues implicated in protein-protein interaction and including the putative endonuclease sequence of AtPMS1 completely eliminated the mutator phenotype. Taken together, these results indicate that the plant proteins affect yeast genomic stability, very possibly altering protein-protein interactions that are necessary to complete repair.