Mages G J, Feldmann H M, Winnacker E L
Institut für Biochemie der Universität München, Würmtalstrasse 221, 81375 München, Federal Republic of Germany.
J Biol Chem. 1996 Apr 5;271(14):7910-5. doi: 10.1074/jbc.271.14.7910.
The HDF1 protein of Saccharomyces cerevisiae shares biochemical properties and structural homology with the 70-kDa subunit of the human autoantigen Ku. The Ku protein, a heterodimer composed of a 70-kDa subunit and an 80-kDa subunit, has been identified as the regulatory subunit of the DNA-dependent protein kinase. This enzyme has recently been shown to be involved in DNA repair and recombination processes in mammalian cells. Here we show that hdf1-disrupted S. cerevisiae strains are strongly sensitive toward the radiomimetic antibiotic bleomycin. In addition, mating-type switching and rates of spontaneous mitotic recombination are strongly reduced. This phenotype is similar to that of mammalian cells lacking components of the DNA-dependent protein kinase holoenzyme, suggesting that HDF1 participates in and exerts equivalent functions in S. cerevisiae.
酿酒酵母的HDF1蛋白与人自身抗原Ku的70 kDa亚基具有生化特性和结构同源性。Ku蛋白是一种由70 kDa亚基和80 kDa亚基组成的异二聚体，已被确定为DNA依赖性蛋白激酶的调节亚基。最近已表明该酶参与哺乳动物细胞的DNA修复和重组过程。在此我们表明，hdf1基因缺失的酿酒酵母菌株对拟放射性抗生素博来霉素高度敏感。此外，交配型转换和自发有丝分裂重组率大幅降低。这种表型与缺乏DNA依赖性蛋白激酶全酶组分的哺乳动物细胞相似，表明HDF1在酿酒酵母中参与并发挥同等功能。
