کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1964013 1058522 2009 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Regulation of IRAK-1 activation by its C-terminal domain
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Regulation of IRAK-1 activation by its C-terminal domain
چکیده انگلیسی

Macrophages are important mediators of the immune response to infection by virtue of their ability to secrete cytokines that trigger inflammation. Toll-like receptors (TLRs) are largely responsible for meditating the activation of macrophages by pathogens. IRAK-1 is a proximal protein kinase in TLR signalling pathways and hence its activation must be tightly regulated. However, the mechanisms which control the activation of IRAK-1 are poorly understood. IRAK-1 contains a death domain at its N-terminus that mediates its interaction with other death domain containing proteins, a central Ser/Thr kinase domain, and a C-terminal domain that contains binding motifs for TRAF6. We show here that deletion of the death domain or the majority of the C-terminal domain markedly enhanced the capacity of IRAK-1 to activate NF-κB in a TLR-independent manner in RAW 264.7 macrophages. Furthermore, the C-terminal truncation mutant spontaneously oligomerised and formed complexes with the negative regulator IRAK-M in the absence of TLR activation. In contrast to the binding of IRAK-M to IRAK-1, the death domain of IRAK-1 was not required for the interaction of IRAK-4 with IRAK-1. On the basis of these results we propose a model in which IRAK-1 is held in a closed, inactive conformation via an intramolecular mechanism involving its C-terminal domain and possibly the death domain. Phosphorylation of IRAK-1 by IRAK-4 in response to TLR activation may then release IRAK-1 from the inhibitory constraint exerted by its C-terminal domain.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Cellular Signalling - Volume 21, Issue 5, May 2009, Pages 719–726
نویسندگان
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