The Cdx protein family is a group of the
transcription factor proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
which bind to DNA to regulate the expression of genes. In particular this family of proteins can regulate the
Hox genes. They are regulators of
embryonic development
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm ...
and
hematopoiesis in vertebrates, and are also involved in the development of some types of
gastrointestinal cancer
Gastrointestinal cancer refers to malignant conditions of the gastrointestinal tract (GI tract) and accessory organs of digestion, including the esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum and anus. The ...
s and
leukemias.
Cdx proteins
Humans have three genes (
CDX1,
CDX2, and
CDX4) that encode the caudal proteins:
*
Cdx1 protein
*
Cdx2 protein
*Cdx4 protein
The
human Cdx2 family protein has 94% identity with the
mouse
A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
Cdx2 and the
hamster Cdx3.
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.
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.
See also
*
Neural tube
*
Protein family
A protein family is a group of evolutionarily related proteins. In many cases, a protein family has a corresponding gene family, in which each gene encodes a corresponding protein with a 1:1 relationship. The term "protein family" should not be c ...
*
Transcription factor
References
{{reflist
Transcription factors
Protein families