The Cdx protein family is a group of the transcription factor

Transcription factor

In molecular biology and genetics, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the flow of genetic information from DNA to mRNA...

 proteins which bind to DNA to regulate the expression of genes. In particular this family of proteins can regulate the Hox genes.

Cdx proteins

• Cdx1 protein
  CDX1
  Homeobox protein CDX-1 is a protein that in humans is encoded by the CDX1 gene....
  
  
• Cdx2 protein
  CDX1
  Homeobox protein CDX-1 is a protein that in humans is encoded by the CDX1 gene....
  
  
• Cdx4 protein

The human

Human

Humans are the only living species in the Homo genus...

 Cdx2 family protein has 94% identity with the mouse

Mouse

A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...

 Cdx2 and the hamster

Hamster

Hamsters are rodents belonging to the subfamily Cricetinae. The subfamily contains about 25 species, classified in six or seven genera....

 Cdx3.

Cdx proteins and regulation of Hox gene expression

Cdx proteins are key regulatiors of Hox genes. The vertebrate Cdx proteins act upstream

Upstream and downstream (DNA)

In molecular biology and genetics, upstream and downstream both refer to a relative position in DNA or RNA. Each strand of DNA or RNA has a 5' end and a 3' end, so named for the carbons on the deoxyribose ring. Relative to the position on the strand, downstream is the region towards the 3' end of...

 of Hox genes. Cdx genes integrate the posteriorizing signals from retionic acic and Wnt canonical pathways and relay this information to Hox promoters.

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.