Miranda M R, Canepa G E, Bouvier L A, Pereira C A
Laboratorio de Biología Molecular de Trypanosoma cruzi (LBMTC), Instituto de Investigaciones Médicas A. Lanari, Universidad de Buenos Aires and CONICET, Combatientes de Malvinas 3150, (1427) Buenos Aires, Argentina.
Parasitology. 2008 Dec;135(14):1661-6. doi: 10.1017/S0031182008005106. Epub 2008 Nov 4.
Here, we present the characterization of a trypanosomatid nucleoside diphosphate kinase (TcNDPK1) exhibiting nuclease activity. This is the first identification of a NDPK with this property in trypanosomatid organisms. The recombinant TcNDPK1 protein cleaves not only linear DNA, but also supercoiled plasmid DNA. Additionally, TcNDPK1 is capable of degrading Trypanosoma cruzi genomic DNA. ATP or ADP did not affect the nuclease activity, while the absence of Mg2+ completely inhibits this activity. NDPK and nuclease activities were inhibited at the same temperature, suggesting the presence of related catalytic sites. Furthermore, phenogram analysis showed that TcNDPK1 is close to Drosophila melanogaster and human NDPKs. The unspecific nuclease activity could suggest a participation in cellular processes such as programmed cell death.
在此，我们展示了一种具有核酸酶活性的锥虫核苷二磷酸激酶（TcNDPK1）的特性。这是首次在锥虫生物体中鉴定出具有此特性的核苷二磷酸激酶。重组TcNDPK1蛋白不仅能切割线性DNA，还能切割超螺旋质粒DNA。此外，TcNDPK1能够降解克氏锥虫基因组DNA。ATP或ADP不影响核酸酶活性，而Mg2+的缺失则完全抑制该活性。核苷二磷酸激酶和核酸酶活性在相同温度下受到抑制，表明存在相关催化位点。此外，系统发育树分析表明，TcNDPK1与黑腹果蝇和人类的核苷二磷酸激酶亲缘关系较近。这种非特异性核酸酶活性可能表明其参与了诸如程序性细胞死亡等细胞过程。
