The interaction between thymine DNA glycosylase and nuclear receptor coactivator 3 is required for the transcriptional activation of nuclear hormone receptors.
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.
Chiang
Shirley
S
National Microbiology Laboratory, Health Canada, 1015 Arlington St, Winnipeg, MB, R3E 3R2, Canada.
Burch
Tanya
T
Van Domselaar
Gary
G
Dick
Kevin
K
Radziwon
Alina
A
Brusnyk
Craig
C
Edwards
Megan Rae
MR
Piper
Jessica
J
Cutts
Todd
T
Cao
Jingxin
J
Li
Xuguang
X
He
Runtao
R
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
D018160:Receptors, Cytoplasmic and Nuclear; D056921:Nuclear Receptor Coactivator 3; D044502:Thymine DNA Glycosylase