Figure 1

GSK3β regulation of transcription factors activity is important for the modulation of inflammatory responses. Pattern ecognition receptors (PRRs) activation by pathogen-associated molecular patterns (PAMPs) or virulence factors recruits class IA of phosphoinositide 3-kinases [PI3K IA (p85–p110)] to the membrane by direct interaction of the p85 subunit with the activated receptors or by interaction with adaptor proteins associated with the receptors [3, 11]. The activated p110 catalytic subunit converts phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P₂ to phosphatidylinositol-3,4,5-trisphosphate [PtdIns(3,4,5)P₃, providing docking sites for the signaling proteins 3’-phosphoinositide-dependent kinase 1 (PDK1) and protein kinase B (PKB/Akt) that have pleckstrin homology domains [11]. Phosphatase and tensin homologue (PTEN) antagonizes the PI3K action by dephosphorylating [PtdIns(3,4,5)P₃[11]. Akt is phosphorylated and activated by PDK1 and the mammalian target of rapamycin complexes 2 (mTORC2) at Thr308 and Ser473, respectively, and then is able to phosphorylate and inactivates glycogen synthase kinase-3 beta [GSK3β (S9)] [11]. GSK3β can be also phosphorylated and inactivated by protein kinase A/C (PKA/C) and by the mammalian target of rapamycin complexes 1 (mTORC1) through ribosomal protein 6 kinase (S6K) [3, 10]. Inactivation of GSK3β results in the activation of transcription factors such as nuclear factor-κB (NF-κB), cAMP-response element binding protein (CREB), activator protein 1 (AP-1), signal transducers and activators of transcription 1-3 (STAT1-3) and β-catenin that are involved in the regulation of the inflammatory responses [3, 12, 13]. GSK3β regulation on NF-κB is complex due to cell-, stimulus-, and promoter-selective interactions that might be stimulatory or inhibitory [4].