VAX2 Background Information VAX2 (Ventral anterior homeobox 2) is a 290 amino acid homeobox protein that is expressed in the ventral portion of the early developing retina. Localized to the nucleus, VAX2 plays a crucial role in development of the eye, particularly in the specification of the ventral optic vesicle and in establishment of a correct dorsoventral pattern. VAX2 acts as a transcription factor with VAX1 to cooperatively regulate retinal differentiation, neuroepithelial cell proliferation and axial polarization in the retina. Together, VAX1 and VAX2 repress transcription of Pax-6, a strong inducer of retinal development. Once Pax-6 is repressed, retinal differentiation slows, thus allowing for proper development of the optic nerve. VAX2 contains one homeobox DNA-bindng domain and belongs to the EMX homeobox family of proteins.
