IL-6 (human) (rec.)

Interleukin-6 (IL-6) is a pleiotropic α-helical cytokine that plays important roles in a central player in the regulation of inflammation, haematopoiesis, immune response and host defense mechanisms. Human IL-6 molecular weight ranges between 21 and 28 kDa, depending on the state of glycosylation and phosphorylation. Mature human IL-6 is 183 amino acids and shares the homology between human and rat IL-6 is 41% at the amino acid level. IL-6 interacts with its receptor complex consisting of the membrane-bound IL-6 receptor (IL-6R) and the signal transducing protein gp130. IL-6R can exist as a soluble protein (sIL-6R), which binds the ligand IL-6. This soluble complex can bind to gp130 on cells that lack the membrane-bound IL-6R and initiate signaling. Two major signalling pathways are activated by IL-6: the JAK/STAT pathway and MAPK cascade.