Cdx protein family

Caudal homeobox proteins ( Cdx ) are a family of proteins that control the spatial development of the caudal ( posterior ) region of the embryo in multicellular animals. You make this function through its capacity as transcription factors, ie by binding to DNA and control its transcription.

Humane Cdx proteins

In humans three Cdx proteins are known: Cdx -1, Cdx -2 and Cdx - fourth

  • Cdx -1 (gene name: CDX1 ) is 265 amino acids long and has two isoforms. UniProt P47902
  • Cdx -2 (gene name: CDX2 ) is 313 amino acids long. UniProt Q99626
  • Cdx -4 (gene name: CDX4 ) has 284 amino acids. UniProt O14627

Functions

The effect of the proteins Cdx as transcription factors was examined in mice and relates to genes in undifferentiated tissue types. Intervention time points are in the very early embryo, and - in the case of Cdx -2 - in the adult organism. More Hox genes have cis- elements with binding sites for the Cdk proteins that act as repressors there.

The expression of Cdx -1 and -2 in the small intestine takes up the colon steadily, causing the spatial pattern of differentiation of the intestinal tissues during embryonic development. The interaction of Cdx -1 and -2 with HoxC8 and HoxA9 defines the development of the neural tube and vertebrae. Cdx -4 acts as a repressor of HOXA5 expression and this is crucial for the posterior boundary of expression.

In the adult organism Cdx -2 only plays a role; its expression is stimulated by laminin -1 and provides a signal cascade for the differentiation and adhesion of intestinal epithelial cells.

171000
de