Clone REA462 recognizes the human interleukin-1 receptor-associated kinase 4 (IRAK4) antigen, regardless of phosphorylation status. IRAK4 is a serine/threonine-protein kinase, which is also known as renal carcinoma antigen NY-REN-64. Interleukin-1 receptor-associated kinases (IRAKs) are key components in the signal transduction pathways utilized by interleukin-1 receptor (IL-1R), interleukin-18 receptor (IL-18R), and toll-like receptors (TLRs). Out of four members in the mammalian IRAK family, IRAK4 is considered to be the “master IRAK”, the only family member indispensable for IL-1R/TLR signaling. In MyD88-dependent TIR signaling, IRAK4 is the initial receptor-proximal protein kinase that is recruited and activated upon ligation of receptors, and it interacts with multiple, key downstream signaling molecules. Targeted deletion of IRAK4 in mice reveals severe defects in cytokine responses and downstream signaling pathways induced by IL-1R and TLRs. Cells derived from human patients, who are deficient in IRAK4 due to gene deletion/mutations, clearly exhibit impaired responses to IL-1, IL-18, or exogenous MyD88-dependent TLR ligands. Together with its broad impact on TLR and IL-1R signaling, IRAK4 may be a key target for therapeutic intervention in various inflammatory disorders.

Additional information: Clone REA462 displays negligible binding to Fc receptors.