Characterization of the threonine–phosphatase of mouse eyes absent 3

Eyes absent (EYA) has tyrosine- and threonine–phosphatase activities in their C-terminal and N-terminal regions, respectively. Using various mutants of mouse EYA3, we showed that the 68-amino acid domain between positions 53 and 120 was necessary and sufficient for its threonine–phosphatase activity. Point mutations were then introduced, and residues Cys-56, Tyr-77, His-79, and Tyr-90 were essential for the EYA3s threonine–phosphatase. The 68-amino acid domain is not well conserved among the four mouse EYA members, but is evolutionally highly conserved in the orthologous EYA members of different species, suggesting that the threonine–phosphatase of EYA3 has a function distinct from that of the other EYAs.

► We determined the minimum domain for the threonine–phosphatase activity of mouse EYA3.
► The amino acid residues essential for the threonine–phosphatase activity of mouse EYA3 were assigned.
► The evolutional conservation of the EYA3 phosphatase domain is discussed.