RSK3, Active

RSK3 is a member of the RSK (ribosomal S6 kinase) family that encodes a 733-amino-acid protein with a unique N-terminal region containing a putative nuclear localization signal (1). RSK3 mRNA is widely expressed and is activated by growth factors, serum and phorbol ester. Upon stimulation, RSK3 translocates to the cell nucleus and phosphorylates nuclear proteins. RSK3 can bind to ERK1/2 and this association increases the duration of RSK3 activation (2).