Dorsoventral patterning in Xenopus: inhibition of ventral signals by direct binding of chordin to BMP-4

Article Abstract:

The Xenopus protein was expressed in the baculovirus system and a peptide antibody was raised against its NH2-terminus to study the biochemical function of chordin (Chd). A myc epitope was also introduced at the COOH-terminus. Radio-receptor binding assay results showed that Chd protein is capable of inhibiting the binding of BMP-4 protein to its cognate receptor at subnanomolar concentrations. The execution of noncell-autonomous effects of Spemann's organizer on dorsoventral patterning is partly caused by diffusible signals that directly bind to and neutralize ventral bone morphogenetic proteins during gastrulation. This creates pattern in the ectodermal and mesodermal germ layers.

User Contributions:

Comment about this article or add new information about this topic:

Comment:  (50-4000 characters)

Name:

E-mail:

Security Code:

Xenopus chordin and Drosophila short gastrulation genes encode homologous proteins functioning in dorsal-ventral axis formation

Article Abstract:

The short gastrulation (sog) gene from Drosophila and the chordin gene from Xenopus encode proteins that are homologous and function in the development of the dorsal-ventral axis. The sog gene in the lateral blastoderm cells opposes the decapentaplegic (dpp) activity, which is essential for the development of dorsal structures in Drosophila. sog functions as a genetic signaling antagonist through the dpp pathway. The complementary expression of the dpp and sog domains in Drosophila and that of BMP-4 and chordin in Xenopus indicate the dorsal expression of chordin in Xenopus embryos and the lateral expression of sog in Drosophila blastoderm embryo.

User Contributions:

Comment about this article or add new information about this topic:

Comment:  (50-4000 characters)

Name:

E-mail:

Security Code:

Cleavage of chordin by Xolloid metalloprotease suggests a role for proteolytic processing in the regulation of Spemann organizer activity

Article Abstract:

Biochemical experiments show that a tolloid-related protein, the Xolloid secreted metalloprotease, cleaves Chordin and Chordin/BMP-4 complexes at two specific sites. Secondary axes caused by chordin were blocked by Xolloid mRNA. Xolloid-treated Chrodin protein could not antagonize BMP activity. The in vivo function of Xolloid is thought to restrict the extent of Spemann's organizer field.

User Contributions:

Comment about this article or add new information about this topic:

Comment:  (50-4000 characters)

Name:

E-mail:

Security Code: