Hildebrandt M, Lacombe M L, Mesnildrey S, Véron M
Unité de Biochimie Cellulaire, CNRS-URA 1129, Institut Pasteur, Paris, France.
Nucleic Acids Res. 1995 Oct 11;23(19):3858-64. doi: 10.1093/nar/23.19.3858.
Recently, a DNA binding protein 'PUF' was purified that binds to a poly-pyrimidine rich element in the human c-myc promoter. Cloning of the corresponding gene surprisingly identified this putative transcription factor as isoform B of the enzyme nucleoside diphosphate kinase (NDPK-B) [Postel et al. (1993) Science, 261, 478-480], the product of the potential metastasis suppressor gene nm23-H2. Using different recombinant NDP kinases, we demonstrate by electrophoretic mobility shift analysis (EMSA) that the NDP kinase DNA binding properties are predominantly observed with human isoform B. Unlike typical DNA binding proteins that are involved in transcriptional regulation, binding occurs to single-stranded DNA rather than to a double-stranded oligonucleotide. As a consequence, complexes of single-stranded DNA and NDPK-B are generated from double-stranded oligonucleotide hybrids in an ATP independent manner. In addition to the c-myc element, NDPK-B is binding in vitro to a variety of poly-pyrimidine rich sequences including dC or dT homo-oligomers, (CT)n dinucleotide repeats, the initiator region of the Adenovirus major late promoter and even poly-pyrimidine rich RNAs. The possible consequences of these findings in understanding the multiple roles of NDP kinase are discussed.
最近，一种与人类c-myc启动子中富含多嘧啶元件结合的DNA结合蛋白“PUF”被纯化出来。相应基因的克隆令人惊讶地发现，这个假定的转录因子是核苷二磷酸激酶（NDPK-B）的同工型B[波斯泰尔等人（1993年），《科学》，第261卷，第478 - 480页]，即潜在转移抑制基因nm23-H2的产物。通过使用不同的重组NDP激酶，我们通过电泳迁移率变动分析（EMSA）证明，NDP激酶的DNA结合特性主要在人类同工型B中观察到。与参与转录调控的典型DNA结合蛋白不同，它与单链DNA而非双链寡核苷酸结合。因此，单链DNA和NDPK-B的复合物以不依赖ATP的方式从双链寡核苷酸杂交体中产生。除了c-myc元件外，NDPK-B在体外还能与多种富含多嘧啶的序列结合，包括dC或dT同聚物、（CT）n二核苷酸重复序列、腺病毒主要晚期启动子的起始区域，甚至富含多嘧啶的RNA。本文讨论了这些发现对于理解NDP激酶多种作用的可能影响。
