Reiss B, Klemm M, Kosak H, Schell J
Max-Planck-Institut für Züchtungsforschung, Cologne, Germany.
Proc Natl Acad Sci U S A. 1996 Apr 2;93(7):3094-8. doi: 10.1073/pnas.93.7.3094.
A number of RecA-like proteins have been found in eukaryotic organisms. We demonstrate that the prokaryotic recombination protein RecA itself is capable of interacting with genomic homologous DNA in somatic plant cells. Resistance to the DNA crosslinking agent mitomycin C requires homologous recombination as well as excision repair activity. Tobacco protoplasts expressing a nucleus-targeted RecA protein were at least three times as efficient as wild-type cells in repairing mitomycin C-induced damage. Moreover, homologous recombination at a defined locus carrying an endogenous nuclear marker gene was stimulated at least 10-fold in transgenic plant cells expressing nucleus-targeted RecA. The increase in resistance to mitomycin C and the stimulation of intrachromosomal recombination demonstrate that Escherichia coli RecA protein is functional in genomic homologous recombination in plants, especially when targeted to the plant nucleus.
在真核生物中已发现多种类RecA蛋白。我们证明原核重组蛋白RecA自身能够在植物体细胞中与基因组同源DNA相互作用。对DNA交联剂丝裂霉素C的抗性需要同源重组以及切除修复活性。表达定位于细胞核的RecA蛋白的烟草原生质体在修复丝裂霉素C诱导的损伤方面比野生型细胞效率至少高三倍。此外，在携带内源性核标记基因的特定位点的同源重组在表达定位于细胞核的RecA的转基因植物细胞中至少被刺激了10倍。对丝裂霉素C抗性的增加以及染色体内部重组的刺激表明大肠杆菌RecA蛋白在植物基因组同源重组中具有功能，特别是当定位于植物细胞核时。
