J Biol Chem. 2002 Oct 4;277(40):37414-21. Epub 2002 Jul 23.

Identification of threonine 66 as a functionally critical residue of the interleukin-1 receptor-associated kinase.External

Ross, K., Yang, L., Dower, S., Volpe, F., Guesdon, F.,
--- - Division of Genomic Medicine, University of Sheffield, M Floor, Royal Hallamshire Hospital, Glossop Road, Sheffield S10 2JF, United Kingdom.
We have mutated a conserved residue of the death domain of the interleukin-1 (IL-1) receptor-associated kinase (IRAK), threonine 66. The substitution of Thr-66 with alanine or glutamate prevented spontaneous activation of NF-kappaB by overexpressed IRAK but enhanced IL-1-induced activation of the factor. Like the kinase-inactivating mutation, K239S, the T66A and T66E mutations interfered with the ability of IRAK to autophosphorylate and facilitated the interactions of IRAK with TRAF6 and with the IL-1 receptor accessory protein, AcP. Wild-type IRAK constructs tagged with fluorescent proteins formed complexes that adopted a punctate distribution in the cytoplasm. The Thr-66 mutations prevented the formation of these complexes. Measurements of fluorescence resonance energy transfer among fluorescent constructs showed that the Thr-66 mutations abolished the capacity of IRAK to dimerize. In contrast, the K239S mutation did not inhibit dimerization of IRAK as evidenced by fluorescence resonance energy transfer measurements, even though microscopy showed that it prevented the formation of punctate complexes. Our results show that Thr-66 plays a crucial role in the ability of IRAK to form homodimers and that its kinase activity regulates its ability to form high molecular weight complexes. These properties in turn determine key aspects of the signaling function of IRAK.
PMID: 12138165External
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 IRAK2 Fluorescence resonance energy transfer NIH 3T3 Not specified Not specified Not specified Full length 12138165
DD IRAK1 Link IRAK3 Fluorescence resonance energy transfer NIH 3T3 Not specified Not specified Human Not specified 12138165
(Link: click this icon to show interactions only between the two corresponding DDs)