| Modification Notes |
The homeobox DNA-binding domain is a 60 amino acid motif that is conserved among many species and functions to bind DNA via a helix-turn-helix structure, thereby playing a role in transcriptional regulation and the control of gene expression. VAX1 (ventral anterior homeobox 1) is a 334 amino acid protein that is required for major tract formation and axon guidance in the developing brain and may play a role in the differentiation of various structures including the optic stalk, the neuroretina and the pigmented epithelium. VAX2 (ventral anterior homeobox 2) is a 290 amino acid homeobox protein that 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. VAX1 and VAX2 localize to the nucleus and contain one homeobox DNA-binding domain each. |