Send to

Choose Destination
See comment in PubMed Commons below
Dev Biol. 2003 May 15;257(2):278-91.

Xenopus X-box binding protein 1, a leucine zipper transcription factor, is involved in the BMP signaling pathway.

Author information

Department of Zoophysiology, University of Essen, Universitätsstrasse 5, D-45117 Essen, Germany.


We describe a novel basic leucine zipper transcription factor, XXBP-1, which interacts with BMP-4 in a positive feedback loop. It is a maternal factor and is zygotically expressed in the dorsal blastopore lip and ventral ectoderm with the exception of the prospective neural plate during gastrulation. Overexpression of XXBP-1 leads to ventralization of early embryos as described for BMP-4, and inhibits neuralization of dissociated ectoderm. Consistent with mediating BMP signaling, we show that the ectopic expression of XXBP-1 recovers the expression of epidermal keratin and reverses the dorsalization imposed by truncated BMP receptor type I, indicating that it may act downstream of the BMP receptor. Its effects can be partially mimicked by a fusion construct containing the VP16 activator domain and the XXBP-1 DNA-binding domain. In contrast, fusing the DNA-binding domain to the even-skipped repressor domain leads to upregulation of the neural markers NCAM and nrp-1 in animal cap assay. Taken together, the results suggest a role for XXBP-1 in the control of neural differentiation, possibly as an activator.

[Indexed for MEDLINE]
Free full text

Publication type, MeSH terms, Substances, Secondary source ID

Publication type

MeSH terms


Secondary source ID

PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center