title: The interaction between thymine DNA glycosylase and nuclear receptor coactivator 3 is required for the transcriptional activation of nuclear hormone receptors.
abstract: 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.
authors: National Microbiology Laboratory, Health Canada, 1015 Arlington St, Winnipeg, MB, R3E 3R2, Canada.
authors: Shirley
authors: S
authors: Chiang
authors: Tanya
authors: T
authors: Burch
authors: Gary
authors: G
authors: Van Domselaar
authors: Kevin
authors: K
authors: Dick
authors: Alina
authors: A
authors: Radziwon
authors: Craig
authors: C
authors: Brusnyk
authors: Megan Rae
authors: MR
authors: Edwards
authors: Jessica
authors: J
authors: Piper
authors: Todd
authors: T
authors: Cutts
authors: Jingxin
authors: J
authors: Cao
authors: Xuguang
authors: X
authors: Li
authors: Runtao
authors: R
authors: He
mesh_terms: D020816:Amino Acid Motifs; D045744:Cell Line, Tumor; D006801:Humans; D016297:Mutagenesis, Site-Directed; D056921:Nuclear Receptor Coactivator 3 / Q000378:metabolism* / Q000502:physiology; D025941:Protein Interaction Mapping; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics*; D044502:Thymine DNA Glycosylase / Q000378:metabolism* / Q000502:physiology; D015533:Transcriptional Activation; D020798:Two-Hybrid System Techniques
chemical_list: D018160:Receptors, Cytoplasmic and Nuclear; D056921:Nuclear Receptor Coactivator 3; D044502:Thymine DNA Glycosylase