Rabbit polyclonal antibody to GSK3α (phospho~S21)

Glycogen synthase kinase~3 α and β (GSK~3α, β) are serine/threonine kinases that regulate metabolic enzymes and transcription factors, which are responsible for coordinating processes such as glycogen synthesis and cell adhesion. GSK~3β activity is also required for nuclear activity of Rel dimers, which mediate an anti~apoptotic response to TNFα in mice. GSK~3 catalytic kinase activity is controlled through differential phosphorylation of serine/threonine residues, which have an inhibitory effect, and tyrosine residues, which have an activating effect. Growth factor stimulation of mammalian cells expressing GSK~3α and GSK~3β induces phosphorylation of Ser 21 and Ser 9, respectively through a phosphatidylinositol 3~kinase (PI 3~kinase)~protein kinase B (PKB) dependent pathway, thereby enhancing proliferative signals. Additionally, GSK~3 physically associates with cAMP~dependent protein kinase A (PKA), which phosphorylates Ser 21 of GSK~3α or Ser 9 of GSK~3β and inactivates both forms