Glycogen synthase kinase 3 (GSK-3) is a multifunctional serine/threonine kinase consisting of two isoforms, alpha and beta. It is a highly conserved negative regulator of receptor tyrosine kinase, cytokine, and Wnt signaling pathways. Stimulation of these pathways inhibits GSK-3 to modulate diverse downstream effectors that include transcription factors, nutrient sensors, glycogen synthesis, mitochondrial function, circadian rhythm, and cell fate. GSK-3 also regulates alternative splicing in response to T-cell receptor activation, and recent phosphoproteomic studies have revealed that multiple splicing factors and regulators of RNA biosynthesis are phosphorylated in a GSK-3-dependent manner.
The malfunction or aberrant activity of GSK-3 leads to several of disorders, such as Alzheimer's disease (AD) and other neurodegenerative pathologies, and other type of diseases as diabetes, cardiovascular disorders and cancer. GSK-3 is also related to innate immune response against pathogens, which makes GSK-3 an excellent target for therapeutic intervention.