MAP2K4 phosphorylates MAP kinases in response to various environmental stresses or mitogenic stimuli.

Structurally, MAP2K4 contains a kinase domain that is phosphorylated and activated by MAP3K1(aka MEKK1).

[6] MAP2K4 contains multiple amino acid sites that are phosphorylated and ubiquitinated.

[7] Genetic studies using Map2k4 knockout mice revealed embryonic lethality, impaired hepatogenesis and defective liver formation.

[8][9] Analysis of chimeric mice identified a role for Map2k4 in T cell cytokine production and proliferation.