The primary substrate of S6K1 is the ribosomal protein S6, which plays a critical role in the translation of mRNA into proteins. Other important substrates include eukaryotic translation initiation factor 4B (eIF4B), eukaryotic elongation factor 2 kinase (eEF2K), and BAD (Bcl-2-antagonist of cell death). Phosphorylation of these substrates by S6K1 facilitates various stages of protein synthesis and cell survival.
