MKK3/6

Mitogen-activated protein kinase kinase 3 (MKK3), also known as MEK3, and the closely related MKK6 are activated by proinflammatory cytokines and environmental stresses. Activation occurs through phosphorylation by several upstream MAPK kinase kinases, including ASK1 and TAK1. Both MKK3 and MKK6 are dual specificity protein kinases, phosphorylating and activating the p38 MAP kinases at Thr and Tyr positions within the phosphoacceptor sequence Thr-Gly-Tyr.