Competition between TRAF2 and TRAF6 regulates NF-kappaB activation in human B lymphocytes / 中国医学科学杂志(英文版)
Chinese Medical Sciences Journal
;
(4): 1-12, 2010.
Article
in English
| WPRIM
| ID: wpr-299467
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the role of TNF receptor-associated factor 2 (TRAF-2) and TRAF6 in CD40-induced nuclear factor-kappaB (NF-kappaB) signaling pathway and whether CD40 signaling requires TRAF2.</p><p><b>METHODS</b>Human B cell lines were transfected with plasmids expressing wild type TRAF2 or dominant negative TRAF2, TRAF2-shRNA, or TRAF6-shRNA. The activation of NF-kappaB was detected by Western blot, kinase assay, transfactor enzyme-linked immunosorbent assay (ELISA), and fluorescence resonance energy transfer (FRET). Analysis of the role of TRAF-2 and TRAF-6 in CD40-mediated NF-kappaB activity was examined following stimulation with recombinant CD154.</p><p><b>RESULTS</b>TRAF2 induced activity of IkappaB-kinases (IKKalpha, IKKi/epsilon), phosphorylation of IkappaBalpha, as well as nuclear translocation and phosphorylation of p65/RelA. In contrast, TRAF6 strongly induced NF-kappaB activation and nuclear translocation of p65 as well as p50 and c-Rel. Engagement of CD154-induced nuclear translocation of p65 was inhibited by a TRAF6-shRNA, but conversely was enhanced by a TRAF2-shRNA. Examination of direct interactions between CD40 and TRAFs by FRET documented that both TRAF2 and TRAF6 directly interacted with CD40. However, the two TRAFs competed for CD40 binding.</p><p><b>CONCLUSIONS</b>These results indicate that TRAF2 can signal in human B cells, but it is not essential for CD40-mediated NF-kappaB activation. Moreover, TRAF2 can compete with TRAF6 for CD40 binding, and thereby limit the capacity of CD40 engagement to induce NF-kappaB activation.</p>
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Physiology
/
B-Lymphocytes
/
Signal Transduction
/
Cell Line
/
NF-kappa B
/
Proto-Oncogene Proteins c-fos
/
CD40 Antigens
/
Cell Biology
/
Fluorescence Resonance Energy Transfer
/
Extracellular Signal-Regulated MAP Kinases
Limits:
Animals
/
Humans
Language:
English
Journal:
Chinese Medical Sciences Journal
Year:
2010
Type:
Article
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