High impact information on Cdx4

• In a subset of Cdx2/Cdx4 compound mutants, the fully grown allantois failed to fuse with the chorion [1].
• The Cdx4 mutation affects axial development and reveals an essential role of Cdx genes in the ontogenesis of the placental labyrinth in mice [1].
• Analysis of the transcriptional properties of Cdx-3 mutants in fibroblasts and islet cells revealed distinct amino-terminal subdomains that function in a cell-specific manner [2].
• The caudal-related protein Cdx-2/3 (the protein designated Cdx-2 in the mouse and Cdx-3 in the hamster) is expressed in the gastrointestinal epithelium and in islet and enteroendocrine cells, where it activates proglucagon gene transcription [2].
• We show here that Cdx-3 sequences amino-terminal to the homeodomain (amino acids 1-180) function as a heterologous transcriptional activation domain when fused to the LexA DNA binding domain [2].

Biological context of Cdx4

• We also found that the Cdx4 promoter responds to Wnt signaling in P19 embryocarcinoma cells and have identified several putative LEF/TCF response elements mediating this effect [3].
• These results suggest that the gene order of the region encompassing the Cdx4-Xist interval in the mouse is similar in human [4].
• Furthermore, internal deletions and selected point mutations within domain A, but not the B or C domains, resulted in accumulation of mutant Cdx-3 in the cytoplasm [2].

Anatomical context of Cdx4

• As development proceeds, Cdx-4 gene products continue to be restricted to the posterior of the embryo, including the remnants of the primitive streak [5].
• Cdx-4 is expressed transiently from 7.0 d.p.c. (days post coitum) until 10 d.p.c., starting at the beginning of gastrulation (7.0-7.5 d.p.c.) in the allantois and posterior tip of the primitive streak [5].
• Cdx-4 is expressed in neurectoderm, presomitic and lateral plate mesoderm, and hindgut endoderm, but the anterior boundary in the paraxial mesoderm is staggered with respect to the other germ layers [5].

Co-localisations of Cdx4

• Consistent with these data, chromatin immunoprecipitation assays from either embryocarcinoma cells or from the tail bud of embryos revealed that LEF1 and beta-catenin co-localize with the Cdx4 promoter [3].

Other interactions of Cdx4

• Taken together, these results suggest that Cdx4, like Cdx1, is a direct Wnt target [3].
• We found that Cdx4 responds to exogenous Wnt3a in mouse embryos ex vivo, and conversely, that its expression is down-regulated in Wnt3a(vt/vt) embryos and in embryos cultured in the presence of Wnt inhibitors [3].
• Data from a number of vertebrate model systems also suggest that Cdx1, Cdx2 and Cdx4 are targets of caudalizing signals such as RA, Wnt and FGF [3].

References