CDX4
Identifiers
Aliases	CDX4, caudal type homeobox 4
External IDs	OMIM: 300025 MGI: 88362 HomoloGene: 3806 GeneCards: CDX4
Gene location (Human) Chr. X chromosome (human)[1] Band Xq13.2 Start 73,447,053 bp[1] End 73,455,171 bp[1]
Gene location (Mouse) Chr. X chromosome (mouse)[2] Band X D|X 46.06 cM Start 102,365,004 bp[2] End 102,374,198 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in skin of abdomen embryo skin of limb nervous system reproductive system reproductive organ gonad tibial nerve Top expressed in urethra male urethra primitive streak allantois proximal tubule blastocyst islet of Langerhans exocrine gland liver ureter More reference expression data BioGPS n/a
Gene ontology Molecular function RNA polymerase II cis-regulatory region sequence-specific DNA binding DNA binding sequence-specific DNA binding DNA-binding transcription activator activity, RNA polymerase II-specific protein binding DNA-binding transcription factor activity, RNA polymerase II-specific RNA polymerase II transcription regulatory region sequence-specific DNA binding DNA-binding transcription factor activity Cellular component nucleus Biological process animal organ morphogenesis multicellular organism development labyrinthine layer development cell differentiation blood vessel development anterior/posterior axis specification regulation of transcription, DNA-templated negative regulation of transcription by RNA polymerase II transcription, DNA-templated positive regulation of transcription by RNA polymerase II anterior/posterior pattern specification placenta development transcription by RNA polymerase II regulation of transcription by RNA polymerase II Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 1046 12592 Ensembl ENSG00000131264 ENSMUSG00000031326 UniProt O14627 Q07424 RefSeq (mRNA) NM_005193 NM_007674 RefSeq (protein) NP_005184 NP_031700 Location (UCSC) Chr X: 73.45 – 73.46 Mb Chr X: 102.37 – 102.37 Mb PubMed search [3] [4]
Wikidata
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Homeobox protein CDX-4 is a protein that in humans is encoded by the CDX4 gene. This gene is a member of the caudal-related homeobox transcription factor family that also includes CDX1 and CDX2.^[5]

Function

The transcription factor encoded by the CDX4 gene participates in the formation of extra-embryonic tissues, anterior-posterior patterning and blood formation during embryogenesis. It does so through the regulation of Hox gene expression. ^{[6] [7][8]}

Before placentation takes place, CDX4 plays a role in its development. CDX4 mutants are born healthy and are fertile, however its importance is revealed in compound CDX mutants. Compound mutants carrying one CDX2 null allele and homozygous null for CDX4 fail to generate posterior tissue caudal to the hindlimbs and most of these embryos die around embryonic day 10.5 from lack of placental development. Around 10% of this phenotype may progress to full term, but then die shortly after birth. Upon inspection the morphogenesis of ano-rectal and urethral tissues was observed. ^{[9] [10]}

The most well described function of CDX genes are their role in caudal body formation. Transcription factors of the CDX gene family, in part control Hox gene expression by responding to signaling molecules Retinoic Acid, Wnt, and FGF. The redundant contribution of CDX4 in axial elongation is shown in that neither CDX4 null or CDX1/CDX4 compound mutants appear with impaired axial elongation. However, CDX4 does have a role in determining pancreatic B-cell number, specifying anterior-posterior location of the foregut organs including the pancreas and liver. Thus, an abnormal state is shown in embryos deficient in CDX4 by posteriorly shifted pancreas, liver and small intestines. ^{[11] [12]}

In blood formation, CDX4 regulation of Hox genes is necessary for the specification of hematopoietic cell fate during embryogenesis. This is demonstrated by the fact that blood deficiencies in CDX4 mutants can be rescued by the over expression of certain Hox genes. ^[13]

Knockout models have been generated in mice as described in CDX4’s role in caudal body formation.