title: Transcriptional regulation of Xbr-1a/Xvent-2 homeobox gene: analysis of its promoter region.
abstract: Xvent homeobox proteins are induced by BMP-4 signaling and have been known to mediate many BMP-4 activities as key downstream transcriptional factors. In order to investigate the regulatory mode of Xvent transcription, we isolated genomic DNA of the Xbr-1a/Xvent-2 containing the promoter region responsive to BMP-4 signaling. The cis-acting elements located within the Xbr-1a/Xvent-2 promoter and the regulation modes by BMP-4 signaling were analyzed by serial deletion and site-directed mutagenesis experiments. The upstream -235bp of the promoter retained the full transcriptional activity and BMP-4-response when compared with the longest promoter construct. Further analysis indicated that two separated 15bp regions contained a strong positive element and BMP-4-response element. Site-directed mutagenesis of those regions suggests that those two regions cooperate for the promoter activity and BMP-4-response. Moreover, we found that the transcription factors, Oaz and PEBP2alphaA, were able to elicit additive effects with BMP-4 signaling on Xbr-1a/Xvent-2 reporter activities. These results indicate that transcriptional regulation of the Xbr-1a/Xvent-2 gene occurs in a complex mode through the cooperation of various transcription factors.
authors.affiliation: Department of Biochemistry, College of Medicine, Hallym University, ChunCheon, Kangwon-Do, Republic of Korea.
authors.forename: Hyun-Shik
authors.initials: HS
authors.lastname: Lee
authors.forename: Mae Ja
authors.initials: MJ
authors.lastname: Park
authors.forename: Sung-Young
authors.initials: SY
authors.lastname: Lee
authors.forename: Yoo-Seok
authors.initials: YS
authors.lastname: Hwang
authors.forename: Hyosang
authors.initials: H
authors.lastname: Lee
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Roh
authors.forename: Jong-Il
authors.initials: JI
authors.lastname: Kim
authors.forename: Jae-Bong
authors.initials: JB
authors.lastname: Park
authors.forename: Jae-Yong
authors.initials: JY
authors.lastname: Lee
authors.forename: Hsiang-fu
authors.initials: HF
authors.lastname: Kung
authors.forename: Jaebong
authors.initials: J
authors.lastname: Kim
mesh_terms: D000818:Animals; D001483:Base Sequence; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D005136:Eye Proteins / Q000235:genetics*; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction; D014157:Transcription Factors; D014158:Transcription, Genetic; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics* / Q000378:metabolism
chemical_list: D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D018076:DNA, Complementary; D005136:Eye Proteins; D018398:Homeodomain Proteins; D014157:Transcription Factors; C098679:Xbr-1 protein, Xenopus; D029867:Xenopus Proteins; C525812:bmp4 protein, Xenopus; C099992:ventx2.1 protein, Xenopus