Dual specificity phosphatase 28 (Dusp28)

Has phosphatase activity with the synthetic substrate 6,8-difluoro-4-methylumbelliferyl phosphate (in vitro). Has almost no detectable activity with phosphotyrosine, even less action with phosphothreonine and shows complete lack of action with phosphoserine.

The bad activity with phosphotyrosine might be due to steric hindrance by bulky amino acid sidechains that block access to the active website. .