Forkhead Box Protein P2 (FOXP2)

The FOXP2 protein contains a forkhead-box DNA-binding domain, making it a member of the FOX group of transcription factors, involved in regulation of gene expression. In addition to this characteristic forkhead-box domain, the protein contains a polyglutamine tract, a zinc finger and a leucine zipper.

In humans, mutations of FOXP2 cause a severe speech and language disorder. Versions of FOXP2 exist in similar forms in distantly related vertebrates; functional studies of the gene in mice and in songbirds indicate that it is important for modulating plasticity of neural circuits. Outside the brain FOXP2 has also been implicated in development of other tissues such as the lung and gut. FOXP2 directly regulates a large number of downstream target genes.