Serine/threonine-protein kinase pim-1 (PIM1)

Proto-oncogene with serine/threonine kinase activity involved in cell survival and cell proliferation and so providing a selective advantage in tumorigenesis. Exerts its oncogenic activity through: the regulation of MYC transcriptional activity, the regulation of cell cycle progression and by phosphorylation and inhibition of proapoptotic proteins (BAD, MAP3K5, FOXO3).

Phosphorylation of MYC contributes to a rise of MYC protein stability and thereby an increase of transcriptional activity. The stabilization of MYC exerted by PIM1 might explain partly the strong synergism between these two oncogenes in tumorigenesis.