description
Ribosomal S6 kinase has four isoforms in humans and each of the isoforms have sic conserved phosphorylation sites (S221, S363, S380,S749, T359,T573) out of which four are important for its activity (S221, S363, 380,T573).Phosphorylation and activation of ribosomal S6 Kinase (RSK) occurs at the plasma membrane, cytoplasm and in the nucleus. Phosphorylation of RSK first occurs at residue T573 followed by S363 an S380 by activated MAPK/ERK . This form is then phosphorylated by PDK1, which is active in the plasm membrane by an autophosphorylation event

external resources
NCBI:1268803
REACTOME:R-HSA-444257
PUBMED:18813292

genes
PDPK1 , MAPK1 , RPS6KA1 , RPS6KA2 , RPS6KA3 , RPS6KA6 ,