Irisin/FNDC5 Proteins and Enzymes

Irisin, also known as FNDC5, is a peptide hormone that is upregulated in skeletal muscle and subcutaneous adipose tissue during exercise. It induces expression of the mitochondrial proteins PPAR-gamma coactivator 1 alpha (PGC1a) and uncoupling protein-1 (UCP1). It contributes to the regulation of diabetes and obesity by inducing the transition of white adipose tissue into more metabolically active beige adipose tissue. Irisin also regulates neuronal cell differentiation, neurite outgrowth, and osteoblast differentiation.