Involved in both the initiation and regulation of meiosis, mitosis, and postmitotic functions in differentiated cells by phosphorylating a number of transcription factors such as ELK1. Participates in a signaling cascade initiated by activated KIT and KITLG/SCF. Phosphorylates EIF4EBP1; required for initiation of translation. Phosphorylates microtubule-associated protein 2 (MAP2), heat shock factor protein 4 (HSF4) and ARHGEF2 (By similarity). Phosphorylates SPZ1.
Specificity
Natural and recombinant Mouse Mitogen-activated protein kinase 1
Interacts with ARHGEF2, HSF4 and NISCH (By similarity). Interacts with MORG1. Interacts (phosphorylated form) with CAV2 ('Tyr-19'-phosphorylated form); the interaction, promoted by insulin, leads to nuclear location and MAPK1 activation. Interacts with ARRB2 (By similarity). Interacts with ADAM15 (By similarity). Interacts with NEK2.