. "Authored: Nasi, S, Annibali, D, 2006-10-10 09:07:07"^^ . "Reviewed: Greene, LA, 2007-11-08 15:39:37"^^ . "MSK1 (Ribosomal protein S6 kinase alpha-5) is a serine/threonine kinase that is localised in the nucleus. It contains two protein kinase domains in a single polypeptide. It can be activated 5-fold by ERK1/2 through phosphorylation at four key residues."^^ . . . . . . "ERK1/2 phosphorylates MSK1"^^ . "2.7.11"^^ . . . . . . .