Description
IL-2 (Interleukin-2) is a T-Cell-derived cytokine important in the regulation of growth and differentiation of T-Cells, B-Cells, natural killer cells, glioma cells, and cells of the monocyte lineage after specifically interacting with its receptors. Human IL-2 is a 133-amino acid polypeptide with a molecular mass of 15-18 kDa. IL-2 signaling is mediated by a multichain receptor complex consisting of an alpha (CD25), beta (CD122) and gamma (CD132) chain. The IL-2R (IL-2 Receptor) alpha subunit primarily increases the affinity of ligand binding and is not known to contain a signaling domain, whereas the beta and gamma subunits participate in both ligand binding and signal transduction. The IL-2R signaling system proceeds through at least three different pathways, which mediate the flow of mitogenic and survival-promoting signals. One of the pathways proceeds through protein tyrosine kinase activity, Ras and the MAPK (Mitogen-Activated Protein Kinase) cascade, leading to expression of the protooncogenes C-Fos, c-Jun, and ELK1.The SYK, that is responsible for c-Myc gene induction, initiates the second pathway. The final pathway results in BCL2 (B-Cell Leukemia-2) expression, and progression through a RHO, PI3K (Phosphoinositide-3 Kinase) and AKT/PKB (Protein Kinase-B) mediated signaling pathway. This last pathway is also involved in IL-2-promoted regulation of actin cytoskeleton organization (Ref.1,2 & 3). References:
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