Regulation of catalytic activity of S6 kinase 2 during cell cycle.
Ribosomal S6 kinase 2 (S6K2) is one of the kinases regulated by the mammalian target of rapamycin (mTOR) signaling pathway. Although it has been identified as a kinase homologous to S6K1, evidence suggests that the two kinases have non-overlapping functions, and the biological function of S6K2 still remains unknown. In order to identify the cell cycle stage(s) during which S6K2 plays a role, we assessed changes in the catalytic activity of S6K2 throughout the cell cycle. Our data show that S6K2 is active throughout the cell cycle with higher activity in G2 and M phases. We also show that S6K1 activity peaks sharply during M phase. Our data suggest that S6K1 and S6K2 likely play yet-unknown roles in G2 and M phases.
Boyer
Derek
D
Department of Biological Sciences, California State University at Long Beach, Long Beach, CA 90840, USA.
Quintanilla
Rene
R
Lee-Fruman
Kay K
KK
D000818:Animals; D002384:Catalysis; D002453:Cell Cycle / Q000502:physiology*; D004789:Enzyme Activation; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D010766:Phosphorylation; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000378:metabolism*; D013997:Time Factors