Disease relevance of DUSP9

• MKP-4 produced in Escherichia coli catalyzes vanadate-sensitive breakdown of p-nitrophenyl phosphate as well as in vitro inactivation of purified ERK2 [1].
• We used the Baculovirus expression system and purification with a combination of affinity and gel filtration chromatography to generate pure MKP-4 and MKP-4/p38 complex [2].

High impact information on DUSP9

• Northern analysis reveals a highly restricted tissue distribution with a single MKP-4 mRNA species of approximately 2.5 kilobases detected only in placenta, kidney, and embryonic liver [1].
• Immunocytochemical analysis showed MKP-4 to be present within cytosol although punctate nuclear staining co-localizing with promyelocytic protein was also observed in a subpopulation (10-20%) of cells [1].
• Chromosomal localization by analysis of DNAs from human/rodent somatic cell hybrids and a panel of radiation hybrids assign the human gene for MKP-4 to Xq28 [1].
• By searching the expressed sequence tag data base (dbEST) for homologues of known dual specificity phosphatases, we identified a novel partial human sequence for which we isolated a full-length cDNA (termed MKP-4) [1].
• MKP-4 and MKP-5 were uniformly absent [3].

Associations of DUSP9 with chemical compounds

• Both MKP-4 and the MKP-4/p38 complex exhibited moderate activity toward the surrogate substrates p-nitrophenyl phosphate, 6, 8-difluoro-4-methylumbelliferyl phosphate, and 3-O-methylfluorescein phosphate [2].

Other interactions of DUSP9

• Mitogen-activated protein kinase phosphatase-4 (MKP-4) is a dual specificity phosphatase, which acts as a negative regulator of insulin-stimulated pathways [2].

Analytical, diagnostic and therapeutic context of DUSP9

• Molecular cloning and functional characterization of a novel mitogen-activated protein kinase phosphatase, MKP-4 [1].

References