MKNK2/MNK2

MKNK2, MAPK-interacting kinase 2 or MNK2, partners with MNK1 in phosphorylating eukaryotic initiation factor 4E at serine 209. It differs fundamentally in regulation, showing substantially higher basal kinase activity than MNK1 and less dependence on ERK and p38 activation-loop phosphorylation. MNK2-mediated phosphorylation of the cap-binding factor promotes translation of messenger RNAs driving oncogenesis, and combined Mnk1 and Mnk2 deletion attenuates tumor formation in mouse cancer models, implicating the pathway in malignant progression. Dual MNK inhibitors such as tomivosertib have entered clinical trials in oncology, exploiting the dispensability of MNK signaling in normal adult tissues while targeting translation of pro-tumor transcripts.