MAP kinase-activated protein kinase 5 (MAPKAPK5)

Tumor suppressor serine/threonine-protein kinase involved with mTORC1 signaling and post-transcriptional regulation. Phosphorylates FOXO3, ERK3/MAPK6, ERK4/MAPK4, HSP27/HSPB1, p53/TP53 and RHEB.

Acts as a tumor suppressor by mediating Ras- induced senescence and phosphorylating p53/TP53. Involved in post- transcriptional regulation of MYC by mediating phosphorylation of FOXO3: phosphorylation of FOXO3 leads to promote nuclear localization of FOXO3, enabling expression of miR-34b and miR-34c, two post-transcriptional regulators of MYC that bind to the 3'UTR of MYC transcript and prevent MYC translation.