Transcriptional repression of hDaxx enhanced by adenovirus 12 E1B 55-kDa oncoprotein interacting with hDaxx

• Published in: Chinese medical journal Vol. 117; no. 5; pp. 753 - 757
• Main Author: 万艳平 吴移谋 朱翠明 尹卫国 蔡恒玲 余敏君
• Format: Journal Article
• Language: English
• Published: China Institute of Pathogenic Biology, Nanhua University, Hengyang 421001, China 01.05.2004
• Subjects: Adaptor Proteins, Signal Transducing; Adenovirus E1B Proteins - physiology; Carrier Proteins - analysis; Carrier Proteins - genetics; Cell Line, Tumor; E1B55-kDa; hDaxx; Humans; Intracellular Signaling Peptides and Proteins; Neoplasm Proteins - analysis; Nuclear Proteins - analysis; Nuclear Proteins - genetics; PML; Promyelocytic Leukemia Protein; Repressor Proteins - physiology; Transcription Factors - analysis; Transcription, Genetic; Tumor Suppressor Proteins; 早幼粒细胞白血病; 腺病毒型12; 致癌作用; 转录抑制; adenovirus type 12; transcriptional repression; hDaxx; oncoprotein
• ISSN: 0366-6999; 2542-5641

Background Daxx has been identified as a nuclear protein that involves in apoptosis and transcriptional repression. Daxx co-localizes with the promyelocytic leukemia (PML) protein and regulates transcription. Human Daxx (hDaxx) is a protein that functions as a transcriptional regulation through its interaction with some DNA-associated proteins. The aim of this study was to explore the transcriptional regulatory effect of hDaxx interacting with adenovirus (Ad) 12 E1 B (Ad12E1 B) 55-kDa oncoprotein.Methods The co-localization of hDaxx-Ad12E1B or hDaxx-PML protein in the nucleus was observed under a confocal microscope. Interaction of hDaxx and Ad12E1B was analyzed by yeast two-hybrid assay. Direct binding of hDaxx and Ad12E1 B was analyzed using coimmunoprecipitation and Westem blot in vivo and in vitro. The activity of a luciferase reporter gene, which was regulated by an hDaxx modulated thymidine kinase (TK) promoter, was detected in an automat luminometer.Results Ad12E1 B, which co-localized with hDaxx in the nuclei of G401 -CC3 cells, disrupted the colocalization of hDaxx and PML in the PML oncogenic domains (PODs). hDaxx bound directly to Ad12E1B in vivo and in vitro, hDaxx interacted with Ad12E1B along its full length. Ad12E1B enhanced transcriptional repression activity of hDaxx.Conclusion Ad12E1B disrupts the co-localization of hDaxx with PML in PODs and enhances transcriptional repression activity of hDaxx.