FOXE1

• OMIM: 602 617

• MGI: 1353500

Called the Forkhead box protein E1 ( FOXE1 ) also thyroidal transcription factor 2 (TTF -2) is a protein, as a transcription factor which controls, inter alia, the transcription of certain genes in the thyroid. The gene coding for the FOXE1 protein gene FOXE1 belongs to the family of forkhead box genes. FOXE1 has been proven not only in humans but also in a variety of animal species.

Structure and Function

The human 371 amino acid long, located in the cell nucleus protein contains in its amino acid sequence, a 95 amino acid long Forkheaddomäne, can bind on the FOXE1 to specific DNA sequence portions. These DNA binding is a prerequisite for the control of the transcription of other genes; controlled so FOXE1 inter alia in the thyroid gland, the gene expression of the gene encoding the thyroid peroxidase enzyme.

Knockout mice, which completely lack FOXE1, in addition to a cleft palate show a partially or completely missing thyroid; usually these mice die soon after birth. It was concluded that these mice could be a model for congenital hypothyroidism in humans. However, human geneticists were able to bring in rare cases, mutations in the gene FOXE1 with congenital hypothyroidism in conjunction.

Evolution

Within the large gene family Forkheadbox FOXE1 belongs to FOXE group, together with the paralogous genes FOXE2 and FOXE3. However, only FOXE1 in the thyroid active; other genes can be expressed inter alia in the eye and brain.

FOXE1 was originally identified in the rat, but soon demonstrated in many vertebrate species. Even in simpler chordates such as amphioxus or sea squirts related to FOXE1 Forkheadbox genes were found, which are expressed in these invertebrates in Endostyl; the Endostyl is considered homologous to the thyroid of vertebrates.