Regulation of the HMOX1 gene by the transcription factor AP-2δ with unique DNA binding site.
AP-2 transcription factors are important sequence-specific DNA-binding regulators that are expressed in the neural crest and other tissues during mammalian development. The human AP-2 family of transcription factors consists of five members, AP-2α, -β, -γ, -δ and -ε, which have an important role in the regulation of gene expression during development and in the differentiation of multiple organs and tissues. The present study aimed to investigate the mechanism by which AP-2δ mediates heme oxygenase-1 (HMOX1) gene expression. It was identified that the human AP-2δ protein exhibited weak binding to a suboptimal AP-2 sequence, 5'-GCCN3GGC-3', to which all other AP-2 proteins bind in vitro, providing the first example of DNA target specificity amongst the AP-2 family. AP-2δ protein bound to an optimized AP-2 consensus DNA sequence, 5'-GCCTGAGGC-3', in vitro and transactivated gene expression in eukaryotic cells. The transactivation domain of Ap-2δ differs notably from those in the other AP-2 proteins as it lacks the PY motif (XPPXY) and several other conserved residues that are important for the transcriptional activity of AP-2 proteins, yet it functions as an equally strong activator.
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China.
Liyun
L
Sun
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China.
Yuxia
Y
Zhao
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, P.R. China.
Shaohua
S
Gu
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, P.R. China.
Yumin
Y
Mao
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, P.R. China.
Chaoneng
C
Ji
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China.
Xiujuan
X
Xin
D020816:Amino Acid Motifs; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism*; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D050656:Transcription Factor AP-2 / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation
D020033:Protein Isoforms; D050656:Transcription Factor AP-2; D004247:DNA; C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1