Phospho-FoxO1 (Ser256) and Total FoxO1 assays to study the regulation of glucose/lipid metabolism in insulin-responsive tissues
These cell-based assays are designed to monitor the expression level and the phosphorylation of FoxO1 on Ser256, which is a hallmark of its inactivation.
FoxO1 (Forkhead box protein O1) is a member of the Forkhead transcription factor FOXO subfamily, which includes three other isoforms (FoxO3, FoxO4 and FoxO6).
FoxO1 is highly expressed in insulin-responsive tissues (liver, adipose tissue, skeletal muscle and pancreas) where it regulates glucose/lipid metabolism and stress resistance. It also functions as a tumor suppressor by inhibiting cell proliferation.
Its transcriptional activity is inhibited by the Insulin/IGF-1 signaling pathway, which leads to its phosphorylation on Ser256 by AKT and its cytoplasmic sequestration. Conversely, the AMPK/JNK/p38 pathways activates FoxO1 (dephosphorylated form) which then translocates to the nucleus.
FoxO1 deregulation plays a critical role in the development of metabolic disorders such as diabetes and NAFLD (Non-Alcoholic Fatty Liver Diseases). Its dysfunction is also linked to various types of cancer (cervical, gastric, breast & hellip;).