High impact information on Cer1

• Antagonistic signaling by Caronte, a novel Cerberus-related gene, establishes left-right asymmetric gene expression [1].
• Germ layer explant recombination assays demonstrated that Cerr1-expressing somitic-presomitic mesoderm, but not older Cerr1-nonexpressing somitic mesoderm, was able to mimic the anterior neuralizing ability of anterior mesendoderm and maintain Otx2 expression in competent ectoderm [2].
• In most Lim1-/- headless embryos, Cerr1 expression in the anterior endoderm was weak or absent [2].
• In somite stage embryos, Cerr1 expression is restricted to the most recently formed somites and in the anterior presomitic mesoderm [2].
• Analysis of a mouse interspecific backcross panel demonstrated that Cerr1 mapped to the central portion of mouse chromosome 4 [2].

Biological context of Cer1

• However, we present here genetic data that demonstrate that Cer1 is not necessary for anterior patterning, Otx2 expression, somite formation, or even normal mouse morphogenesis [3].
• Goosecoid and cerberus-like do not interact during mouse embryogenesis [4].
• We generated a mouse line in which the Cer1 gene was inactivated by replacing the first coding exon with a lacZ reporter gene [5].
• Murine cerberus homologue Cer1 maps to chromosome 4 [6].
• Preliminary analysis suggests that Cer1 is not essential for their morphogenesis, differentiation, or homeostasis [5].

Anatomical context of Cer1

• Cer1 marks the anterior visceral endoderm at E6 [7].
• The Cer1 protein is a member of the cysteine knot superfamily and is expressed in anterior regions of the mouse gastrula [3].
• However, in embryonic tissue layer recombination assays, Cerr1(-/-) presomitic/somitic mesoderm, unlike Cerr1-expressing wild-type presomitic/somitic mesoderm, was unable to maintain expression of the anterior neural marker gene Otx2 in ectoderm explants [8].
• To determine whether Cerr1 is required for head formation we generated a null mutation in Cerr1 by gene targeting in mouse embryonic stem cells [8].
• As other members of this family of proteins, Cer-l functions in the extracellular space, inhibiting signaling molecules [9].

Associations of Cer1 with chemical compounds

• Epitope-tagged versions of Cer1 show that, unlike in TGFbeta superfamily members, the cysteine knot motif is not processed away from a proprotein [7].

Physical interactions of Cer1

• Here we show that the neural-inducing and mesoderm-inhibiting activities of Cer-l result from specific binding to BMP and Nodal molecules, respectively [9].

Other interactions of Cer1

• In mouse, the cerberus-related gene, Cerr1, is expressed in the anterior mesendoderm that underlies the presumptive anterior neural plate and its expression is downregulated in Lim1 headless embryos [8].
• This defect is not rescued in chimeras containing wild-type embryonic, and Cerberus-like(-/-);Lefty1(-/-) extraembryonic, cells but is rescued in Cerberus-like(-/-); Lefty1(-/-) embryos after removal of one copy of the Nodal gene [10].
• The BMP antagonists cerberus-like and noggin do not interact during mouse forebrain development [11].

References