interaction between thymine DNA glycosylase and nuclear receptor coactivator 3 is required for the transcriptional activation of nuclear hormone receptors

• Published in: Molecular and cellular biochemistry 2010-01, Vol.333 (1-2), p.221-232
• Main Authors: Chiang, Shirley, Burch, Tanya, Van Domselaar, Gary, Dick, Kevin, Radziwon, Alina, Brusnyk, Craig, Edwards, Megan Rae, Piper, Jessica, Cutts, Todd, Cao, Jingxin, Li, Xuguang, He, Runtao
• Format: Article
• Language: English
• Subjects: Amino Acid Motifs; Amino acids; Biochemistry; Biomedical and Life Sciences; Cardiology; Cell Line, Tumor; Deoxyribonucleic acid; DNA; DNA damage; Enzymes; Estrogen; Estrogens; Genetic aspects; Genetic research; Genetic transcription; Humans; Life Sciences; Medical Biochemistry; Molecular biology; Mutagenesis, Site-Directed; Mutation; Nuclear Receptor Coactivator 3 - metabolism; Nuclear Receptor Coactivator 3 - physiology; Oncology; Progesterone; Protein Interaction Mapping; Pyrimidines; Receptors, Cytoplasmic and Nuclear - genetics; Signal transduction; Steroids; Thymine DNA Glycosylase - metabolism; Thymine DNA Glycosylase - physiology; Transcriptional Activation; Two-Hybrid System Techniques
• ISSN: 0300-8177; 1573-4919
• DOI: 10.1007/s11010-009-0223-1

The T:G mismatch specific DNA glycosylase (TDG) is known as an important enzyme in repairing damaged DNA. Recent studies also showed that TDG interacts with a p160 protein, steroid receptor coactivator 1 or nuclear receptor coactivator 1 (SRC1), and is involved in transcriptional activation of the estrogen receptor. However, whether other members of the p160 family are also involved in TDG-interaction and signal transduction regulation remains to be seen. In this study, we employed the mammalian two-hybrid system to investigate the interaction between TDG and another member of the p160 family, nuclear receptor coactivator 3 (NCoA-3). We found that a DXXD motif from aa 294-297 within TDG was responsible for the TDG-NCoA-3 interaction, we also found that a LLXXXL motif (X means any amino acid) from aa 1029-1037 (LLRNSL) and a merged LLXXL motif (LLDQLHTLL) from aa 1053-1061 in NCoA-3 were important for the TDG-NCoA-3 interactions. Mutation of the two aspartic acids (aa 294 and 297) into two alanines in TDG significantly affected the interaction and subsequent transcriptional activation of several steroid hormone receptors including, estrogen-, androgen- and progesterone- receptors in Huh7 cells. We also identified that mutations of NCoA-3 at either leucines 1029-1030 or 1053-1054 (replaced by alanines) also reduced the interaction activity between TDG and NCoA1. These data indicated that the TDG-NCoA-3 interaction is important for broad range activation of steroid hormone nuclear receptors, and may also contribute significantly to further understanding of TDG-related nuclear receptor regulation.