Glycogen Synthase Kinase-3 Beta (GSK3β) is a serine/threonine protein kinase that plays a crucial role in various cellular processes. It was initially identified as the kinase responsible for phosphorylating and inhibiting glycogen synthase, an enzyme involved in glycogen synthesis . GSK3β is ubiquitously present in human tissues and is implicated in the regulation of several physiological processes, including glucose homeostasis, energy metabolism, and cell signaling .
GSK3β is a constitutively active kinase, meaning it is active under normal physiological conditions without the need for additional activation signals . It is involved in the hormonal control of glucose homeostasis, Wnt signaling, and the regulation of transcription factors and microtubules . GSK3β phosphorylates a wide range of substrates, including glycogen synthase, beta-catenin, and various transcription factors .
In skeletal muscle, GSK3β contributes to the regulation of glycogen synthesis by phosphorylating and inhibiting glycogen synthase activity . This regulation is crucial for maintaining proper glucose levels in the body. Additionally, GSK3β is involved in the development of insulin resistance by regulating the activation of transcription factors .
Recombinant GSK3β is often produced using the baculovirus expression system in sf9 insect cells. This system allows for the production of high-quality, biologically active proteins that are suitable for various research applications . The recombinant GSK3β expressed in sf9 cells is typically purified to high levels of purity and is used in studies related to enzyme activity, protein-protein interactions, and drug discovery .
GSK3β is a target of interest in various research fields, including neurodegenerative diseases, cancer, and diabetes. In Alzheimer’s disease, GSK3β is involved in the phosphorylation of tau protein, which leads to the formation of neurofibrillary tangles, a hallmark of the disease . In cancer research, GSK3β is studied for its role in cell proliferation and survival, making it a potential target for therapeutic interventions .