Proc Natl Acad Sci U S A. 2002 Apr 16;99(8):5567-72.

IRAK-4: a novel member of the IRAK family with the properties of an IRAK-kinase.External

Li, S., Strelow, A., Fontana, E. J., Wesche, H.,
--- - Tularik, Inc., 2 Corporate Drive, South San Francisco, CA 94080, USA.
Toll/IL-1 receptor family members are central components of host defense mechanisms in a variety of species. One well conserved element in their signal transduction is Ser/Thr kinases, which couple early signaling events in a receptor complex at the plasma membrane to larger signalosomes in the cytosol. The fruit fly Drosophila melanogaster has one member of this family of kinases, termed Pelle. The complexity of this pathway is vastly increased in vertebrates, and several Pelle homologs have been described and termed IL-1 receptor-associated kinase (IRAK). Here we report the identification of a novel and distinct member of the IRAK family, IRAK-4. IRAK-4 is the closest human homolog to Pelle. Endogenous IRAK-4 interacts with IRAK-1 and TRAF6 in an IL-1-dependent manner, and overexpression of IRAK-4 can activate NF-kappa B as well as mitogen-activated protein (MAP) kinase pathways. Most strikingly, and in contrast to the other IRAKs, IRAK-4 depends on its kinase activity to activate NF-kappa B. In addition, IRAK-4 is able to phosphorylate IRAK-1, and overexpression of dominant-negative IRAK-4 is blocking the IL-1-induced activation and modification of IRAK-1, suggesting a role of IRAK-4 as a central element in the early signal transduction of Toll/IL-1 receptors, upstream of IRAK-1.
PMID: 11960013External
Arrow2 In vitro interaction Arrow2 In vivo interaction Arrow2 Characterization Arrow2 Functional role Arrow2 top
In vivo interaction
  Endogenous
expression
Overexpression DD1 DD2 Reference
Family DD1 DD2 Method Species Region Species Region
DD IRAK1 Link Myd88 Co-immunoprecipitation HEK293 Human 1-215 Human Full length 11960013
DD IRAK4 Link Myd88 Co-immunoprecipitation HEK293 Human 1-215 Human Full length 11960013
(Link: click this icon to show interactions only between the two corresponding DDs)