Figure 2.

Canonical IRS signaling. IRS proteins are recruited via their PH/PTB domains and are phosphorylated on tyrosine residues by upstream tyrosine kinase receptors. Tyrosine phosphorylation of IRS proteins triggers the activation of PI3K/AKT/mTOR and MAPK signaling, thus regulating many biological processes, including cell proliferation, protein synthesis, survival and gene expression, in specific human tissues. IRS proteins may also be activated by cytokine and hormone receptors (e.g., IL4, leptin, and angiotensin), which further induce JAK2 stimulation and IRS/JAK2 interaction, leading to the activation of STAT, PI3K/AKT/mTOR and MAPK signaling. Abbreviations: P, phosphorylation; PY, tyrosine phosphorylation. This figure was generated using Servier Medical Art (http://www.servier.com/Powerpoint-image-bank).