This entry represents Interleukin-1 receptor-associated kinase 4 (IRAK4) (). IRAK4 is required for the efficient recruitment of IRAK1 to the interleukin-1 (IL-1) receptor complex following IL-1 engagement, triggering intracellular signalling cascades leading to transcriptional up-regulation and mRNA stabilisation [, ]. IRAK4 phosphorylates IRAK1. Pellino-2 may be a substrate for both IRAK1 and IRAK4 []. Defects in IRAK4 are the cause of recurrent isolated invasive pneumococcal disease type 1 (IPD1) []. Recurrent invasive pneumococcal disease (IPD) is defined as two episodes of IPD occurring at least 1 month apart, whether caused by the same or different serotypes or strains. Defects in IRAK4 are also the cause of IRAK4 deficiency []. IRAK4 deficiency causes extracellular pyogenic bacterial and fungal infections in otherwise healthy children.
IRAK4 is a serine/threonine-protein kinase that plays a critical role in initiating innate immune response against foreign pathogens []. It is required for the efficient recruitment of IRAK1 to the interleukin-1 (IL-1) receptor complex following IL-1 engagement, triggering intracellular signalling cascades leading to transcriptional up-regulation and mRNA stabilisation [, ]. IRAK4 phosphorylates IRAK1. Pellino-2 may be a substrate for both IRAK1 and IRAK4 [].This entry represents the Death domain of IRAK4.DDs (Death domains) are protein-protein interaction domains found in a variety of domain architectures. Their common feature is that they form homodimers by self-association or heterodimers by associating with other members of the DD superfamily including CARD (Caspase activation and recruitment domain), DED (Death Effector Domain), and PYRIN. They serve as adaptors in signaling pathways and can recruit other proteins into signaling complexes [, ].
