IRAK4 Substrate Peptide, IRAK1 (360-380)

KKARFSRFAGSSPSQSSMVAR corresponds to the IRAK1 activation-loop region spanning residues 360-380 and is used as a peptide substrate for interleukin-1 receptor-associated kinase 4 (IRAK4). The sequence contains Ser376, a major IRAK1 phosphoacceptor site. Published biochemical studies have used this exact peptide for steady-state kinetic characterization of IRAK4 and for evaluating ATP-competitive kinase inhibitors.

• IRAK4 kinase activity assays
• IRAK1 activation-loop phosphorylation studies
• innate immune signaling research
• IRAK4 inhibitor screening

The peptide contains several serines in addition to the principal Ser376 site. Site-specific interpretation may require phosphopeptide mapping or orthogonal analytical methods.

1. Steady-State Kinetic Characterization of Kinase Activity and Requirements for Mg2+ of Interleukin-1 Receptor-Associated Kinase-4