Nguyen Nang, Zhang Xiaohong, Olashaw Nancy, Seto Edward
Department of Medical Microbiology and Immunology, College of Medicine, University of South Florida, Tampa, Florida 33612, USA.
J Biol Chem. 2004 Jun 11;279(24):25927-34. doi: 10.1074/jbc.M402525200. Epub 2004 Apr 15.
YY1 is a ubiquitous zinc finger transcription factor that binds to and regulates promoters and enhancers of many cellular and viral genes. Here we report the isolation of a human cDNA encoding a DNA sequence-specific binding protein with significant homology to the transcription factor YY1. A sequence analysis of this novel protein, YY2, revealed an overall 65% identity in the DNA sequence and a 56% identity in protein sequence compared with human YY1. The most pronounced similarity between YY1 and YY2 exists within the zinc finger regions of the two proteins, and consistent with this observation, YY2 can bind to and regulate some promoters known to be controlled by YY1. Similar to YY1, YY2 contains both transcriptional activation and repression functions. The finding of a protein with structure and function similar to YY1 provides a new opportunity to explore additional mechanisms by which YY1-responsive genes can be regulated and suggests that gene regulation by YY1 is far more complicated than previously assumed.
YY1是一种普遍存在的锌指转录因子，它能结合并调控许多细胞和病毒基因的启动子及增强子。在此，我们报告了一个人类cDNA的分离，该cDNA编码一种与转录因子YY1具有显著同源性的DNA序列特异性结合蛋白。对这种新蛋白YY2的序列分析显示，与人类YY1相比，其DNA序列整体一致性为65%，蛋白质序列一致性为56%。YY1和YY2之间最显著的相似性存在于这两种蛋白质的锌指区域，与此观察结果一致，YY2能结合并调控一些已知受YY1控制的启动子。与YY1相似，YY2同时具有转录激活和抑制功能。发现一种结构和功能与YY1相似的蛋白质，为探索YY1反应性基因的调控机制提供了新机会，并表明YY1对基因的调控远比之前设想的复杂。
