Regulation of interleukin receptor-associated kinase (IRAK) phosphorylation and signaling by iota protein kinase C.
We have previously shown that the activity of the interleukin-1 (IL-1) receptor-associated kinase (IRAK) is required for nerve growth factor (NGF)-induced activation of NF-kappaB and cell survival ((2002) J. Biol. Chem. 277, 28010-28018). Herein we demonstrate that NGF induces co-association of IRAK with atypical protein kinase C iota (PKC) and that the iota PKC.IRAK complex is recruited to the p75 neurotrophin receptor. Recruitment of IRAK to the receptor was dependent upon the activity of the iota PKC. Moreover, transfection of kinase-dead iota PKC blocked both NGF- and IL-1-induced IRAK activation and the activity of NF-kappaB. Hence, iota PKC lies upstream of IRAK in the kappaB pathway. Examining the primary structure of IRAK, we identified three putative PKC phosphorylation sites; iota PKC selectively phosphorylated peptide 1 (RTAS) within the death domain domain at Thr66, which is highly conserved among all IRAK family members. Mutation of Thr66 to Ala impaired the autokinase activity of IRAK and reduced its association with iota PKC but not TRAF6, resulting in impaired NGF- as well as IL-1-induced NF-kappaB activation. These findings provide insight into the underlying mechanism whereby IRAK regulates the kappaB pathway and reveal that IRAK is a substrate of iota PKC.
Mamidipudi
Vidya
V
Program in Cell and Molecular Biosciences, Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, USA.
Lin
Chunru
C
Seibenhener
M Lamar
ML
Wooten
Marie W
MW
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D053592:Interleukin-1 Receptor-Associated Kinases; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D020932:Nerve Growth Factor / Q000494:pharmacology; D016716:PC12 Cells; D010766:Phosphorylation; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D011494:Protein Kinases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D014162:Transfection; D000099293:Protein Kinase C-lambda
D018076:DNA, Complementary; D053592:Interleukin-1 Receptor-Associated Kinases; D007527:Isoenzymes; D020932:Nerve Growth Factor; D011493:Protein Kinase C; D011494:Protein Kinases; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor; D011994:Recombinant Proteins; D000099293:Protein Kinase C-lambda