Cdx protein family explained

The Cdx protein family is a group of the transcription factor proteins which bind to DNA to regulate the expression of genes.^[1] In particular this family of proteins can regulate the Hox genes. They are regulators of embryonic development and hematopoiesis in vertebrates, and are also involved in the development of some types of gastrointestinal cancers and leukemias.^[2]

Cdx proteins

Humans have three genes (CDX1, CDX2, and CDX4) that encode the caudal proteins:^[2]

• Cdx1 protein
• Cdx2 protein
• Cdx4 protein

The human Cdx2 family protein has 94% identity with the mouse Cdx2 and the hamster Cdx3.^[3]

Cdx proteins and regulation of Hox gene expression

Cdx proteins are key regulators of Hox genes. The vertebrate Cdx proteins act upstream of Hox genes. Cdx genes integrate the posteriorizing signals from retinoic acid and Wnt canonical pathways and relay this information to Hox promoters.^[4]

Expression in mouse embryo

Cdx2 expression begins at 3.5 days and is confined to the trophectoderm, being absent from the inner cell mass. From 8.5 days, Cdx2 begins to be expressed in embryonic tissues, principally in the posterior part of the gut from its earliest formation.^[5]

See also

• Neural tube
• Protein family
• Transcription factor

Notes and References

1. 3. Béland. M.. Pilon. N.. Houle. M.. Oh. K.. Sylvestre. J.R.. Prinos. P.. Lohnes. D.. Cdx1 Autoregulation is Governed by a Novel Cdx1-LEF1 Transcription Complex. Molecular and Cellular Biology. 2004. 24. 11. 5028–5038. 10.1128/MCB.24.11.5028-5038.2004. 15143193. 416402.
2. Lengerke C, Daley GQ . Caudal genes in blood development and leukemia . Annals of the New York Academy of Sciences . 1266 . 1. 47–54 . 2012 . 22901255 . 3431192 . 10.1111/j.1749-6632.2012.06625.x . 2012NYASA1266...47L .
3. 3. Mallo. G.V.. Rechreche. H.. Frigerio. J.M.. Rocha. D.. Zweibaum. A.. Lacasa. M.. Jordan. B.R.. Dusetti. N.J.. Dagorn. J.C.. Iovanna. J.L.. Molecular Cloning, Sequencing and Expression of the mRNA Encoding Human Cdx1 and Cdx2 Homeobox. Down-regulation of Cdx1 and Cdx2 mRNA Expression During Colorectal Carcinogenesis. International Journal of Cancer. 1997. 74. 1. 35–44. 9036867. 10.1002/(sici)1097-0215(19970220)74:1<35::aid-ijc7>3.0.co;2-1. 46416077 .
4. Lohnes. David. The Cdx1 Homeodomain Protein: An Integrator of Posterior Signaling in the Mouse. BioEssays. 2003. 25. 10. 971–980. 10.1002/bies.10340. 14505364.
5. 3. Beck. F.. Erler. T.. Russell. A.. James. R.. Expression of Cdx-2 in the Mouse Embryo and Placenta: Possible Role in Patterning of the Extra-embryonic Membranes. Developmental Dynamics. 1995. 204. 3. 219–227. 10.1002/aja.1002040302. 8573715. 19576530.