Negative autoregulation of the organizer-specific homeobox gene goosecoid.
The homeobox gene goosecoid has been implicated to play a central role in the Spemann organizer tissue of the vertebrate embryo. Misexpression of goosecoid on the ventral side of a Xenopus laevis gastrula embryo was shown to result in a partial duplication of the primary body axis, reminiscent of the Spemann organizer graft. Normal embryonic development thus requires tight temporal and spatial control of genes instrumental for organizer function. In the present study we investigated the transcriptional control of goosecoid gene expression. Sequence analysis of the mouse and human promoter region revealed the presence of two palindromic binding elements for homeobox genes of the prd type to which goosecoid belongs. We show that Goosecoid protein can bind to these sites in vitro. By using reporter gene constructs of the human and mouse promoter, we demonstrate that Goosecoid can act as a repressor of its own promoter activity in transient co-transfection experiments in mouse P19 cells and in Xenopus embryos. Autorepression depends on the presence of the homeodomain and is mediated through the prd element more proximal to the transcriptional start site. Our results suggest a role for goosecoid in restricting organizer activity in the vertebrate gastrula embryo.
Danilov
V
V
Forschungszentrum Karlsruhe, Institute of Genetics, P.O. Box 3640, D-76021 Karlsruhe,Federal Republic of Germany.
Blum
M
M
Schweickert
A
A
Campione
M
M
Steinbeisser
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000378:metabolism; D005801:Genes, Homeobox; D051956:Goosecoid Protein; D018398:Homeodomain Proteins; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors; D014158:Transcription, Genetic; D014982:Xenopus laevis / Q000196:embryology
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C497992:GSC protein, human; D051956:Goosecoid Protein; C497993:Gsc protein, mouse; D018398:Homeodomain Proteins; D012097:Repressor Proteins; D014157:Transcription Factors