Transcriptional Regulation of the Xbr-1a/Xvent-2 Gene by BMP-4 Signaling during Xenopus Embryonic Development.
- Author:
Jae Bong KIM
1
;
Hyo Sang LEE
;
Dong Hyun ROH
;
Yoo Seok HWANG
;
Ren He XU
;
Hsiang Fu KUNG
;
Yong Chul BAE
;
Mae Ja PARK
Author Information
1. Department of Biochemistry, College of Medicine, Hallym University, Chun-Cheon, 200-702, Korea.
- Publication Type:Original Article
- Keywords:
Xenopus laevis;
Xbr-1a/Xvent-2;
gene;
Transcriptional regulation;
Embryogenesis
- MeSH:
Clinical Coding;
Clone Cells;
Codon;
Embryonic Development*;
Embryonic Structures;
Exons;
Female;
Genes, Homeobox;
Genes, Reporter;
Luciferases;
Pregnancy;
RNA, Messenger;
Sequence Deletion;
Smad Proteins;
Transcription Initiation Site;
Xenopus laevis;
Xenopus*
- From:Korean Journal of Anatomy
2000;33(5):595-608
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BMP-4 signaling is mediated through Smad proteins which may translocate to the nucleus to activate transcription. Little is known about how BMP-4 signaling regulates the transcription of its target genes, e.g., Xvent genes. Therefore, we isolated the genomic clone of a BMP-4 responsive homeobox gene, Xbr-1a/Xvent-2. This clone contains a promoter and three exons for the entire coding region. Using the primer extension, we identified the transcription initiation site corresponding to position -64 bp upstream to the ATG codon of the Xvent-2 gene. The promoter was linked to the luciferase reporter gene, and promoter activity determined by luciferase assay. The temporal promoter activity peaked between embryonic stages 13~17, in agreement with its temporal mRNA expression in the whole embryo. Through the serial deletion mutation, the upstream -235 bp of the promoter retains the full transcriptional activity, and is regulated by BMP-4 signaling. The present results suggest that the BMP-4 responsive element is located on the upstream 235 bp of the promoter.
