The S6K proteins are mTOR pathway effectors and accumulative evidence suggest that mTOR/S6K signaling contributes to several pathological conditions, such as diabetes, cancer and obesity. mTOR (mammalian Target Of Rapamycin) is a protein kinase known to control cell growth in response to nutrients (amino acids), growth factors (insulin, IGF-1) and cellular energy (ATP), and acting as a sensor of nutrient availability in the cell.  mTOR is present in the cell in two complexes, named mTORC1 and mTORC2. Once activated, mTORC1 is able to regulate several proteins, including two families of proteins: 4E-BPs (eukaryotic translation initiation factor 4E-binding protein) and S6Ks (ribosomal protein S6 kinase). S6K1 and S6K2 belong to the AGC kinase family.S6K1 and S6K2 share about 83% of identity in their kinase domains, which could justify the lack of interest on featuring consistently the S6K2 protein. AGC kinases are serine–threonine kinases that share some structural features and are implicated to regulate several cellular processes, such as growth, survival and metabolism. Besides S6Ks, proteins PKA, PKG, PKC and Akt, amongst others, are members of the AGC kinase family. Evidence show that the mTOR/S6K signaling pathway contributes to several diseases, such as cancer, diabetes and obesity.

References

1.Tavares MR,et al. Life Sci. 2015;131:1–10.