Identification and embryonic expression of a new AP-2 transcription factor, AP-2 epsilon.
AP-2 proteins comprise a family of highly related transcription factors, which are expressed during mouse embryogenesis in a variety of ectodermal, neuroectodermal, and mesenchymal tissues. AP-2 transcription factors were shown to be involved in morphogenesis of craniofacial, urogenital, neural crest-derived, and placental tissues. By means of a partial cDNA fragment identified during an expressed sequence tag search for AP-2 genes, we identified a fifth, previously unknown AP-2-related gene, AP-2 epsilon. AP-2 epsilon encodes an open reading frame of 434 amino acids, which reveals the typical modular structure of AP-2 transcription factors with highly conserved C-terminal DNA binding and dimerization domains. Although the N-terminally localized activation domain is less homologous, position and identity of amino acids essential for transcriptional transactivation are conserved. Reverse transcriptase-polymerase chain reaction analyses of murine embryos revealed AP-2 epsilon expression from gestational stage embryonic day 7.5 throughout all later embryonic stages until birth. Whole-mount in situ hybridization using a specific AP-2 epsilon cDNA fragment demonstrated that during embryogenesis, expression of AP-2 epsilon is mainly restricted to neural tissue, especially the midbrain, hindbrain, and olfactory bulb. This expression pattern was confirmed by immunohistochemistry with an AP-2 epsilon-specific antiserum. By using this antiserum, we could further localize AP-2 epsilon expression in a hypothalamic nucleus and the neuroepithelium of the vomeronasal organ, suggesting an important function of AP-2 epsilon for the development of the olfactory system.
Max-Plank-Institute of Biochemistry, Martinsried, Germany.
Hao-Ven
HV
Wang
Kristina
K
Vaupel
Reinhard
R
Buettner
Anja-Katrin
AK
Bosserhoff
Markus
M
Moser
D000595:Amino Acid Sequence; D000818:Animals; D002490:Central Nervous System / Q000196:embryology / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000378:metabolism; D020224:Expressed Sequence Tags; D007031:Hypothalamus / Q000196:embryology / Q000378:metabolism*; D017403:In Situ Hybridization; D051379:Mice; D008969:Molecular Sequence Data; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C493672:Tfap2e protein, mouse; D050656:Transcription Factor AP-2; D014157:Transcription Factors