<p>The Eyes absent proteins are members of a conserved regulatory network implicated in the development of the eye, muscle, kidney and ear. Eyes absent is a nuclear transcription factor, acting through interaction withhomeodomain-containing Sine oculis (also known as Six) proteins. Eyes absent is also a protein tyrosine phosphatase [<cite idref="PUB00014199"/>, <cite idref="PUB00014200"/>], It does not resemble theclassical tyrosine phosphatases that use cysteine as a nucleophile and proceed by means of a thiol-phosphate intermediate. Rather, Eyes absent is the prototype fora class of protein tyrosine phosphatases that use a nucleophilic aspartic acid in a metal-dependent reaction. Furthermore, the phosphatase activity of Eyes absentcontributes to its ability to induce eye formation in drosophila. Thus, Eyes absent belongs to thephosphatase subgroup of the haloacid dehalogenase (HAD) superfamily and appears to act as a nuclear transcriptional coactivator with intrinsic phosphatase activity.</p> <p>The Eyes absent proteins contain a divergent 200-300-residue, amino-terminal region and a conserved carboxy-terminal domain of 271-274 residues (EYA domain), which iscritical for activity and believed to participate in protein-protein interactions </p> EYA