DUSP9 Gene: Function, Expression, and Clinical Significance

DUSP9 (dual specificity phosphatase 9) encodes a member of the dual specificity protein phosphatase subfamily, which inactivates mitogen-activated protein (MAP) kinases by dephosphorylating both phosphothreonine and phosphotyrosine residues. This protein specifically inactivates ERK and JNK MAP kinases, and to a lesser extent p38, thereby negatively regulating MAPK signaling pathways. DUSP9 is predominantly expressed in the placenta, kidney, and liver, and plays critical roles in embryonic development, cell proliferation, and differentiation. Dysregulation of DUSP9 has been implicated in various cancers and developmental disorders.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• MAPK signaling pathway

• JNK signaling pathway

• ERK signaling pathway

• Insulin signaling pathway

DUSP9 (MKP-4) is a 384-amino acid dual specificity phosphatase that dephosphorylates phosphothreonine and phosphotyrosine residues on MAP kinases, primarily inactivating ERK and JNK. It contains a conserved dual specificity phosphatase catalytic domain and a MAP kinase binding domain. The protein is localized in the cytoplasm and nucleus, and its expression is tightly regulated during development. DUSP9 plays a crucial role in modulating cell growth, differentiation, and apoptosis by controlling the duration and magnitude of MAPK signaling.