Abstract
AIMP2 (aminoacyl-tRNA synthetase interacting multifunctional protein 2; also known as JTV-1) was first identified as p38 in a macromolecular protein complex that consisted of nine different aminoacyl-tRNA synthetases and two other auxiliary factors. AIMP2 also plays pivotal roles in the regulation of cell proliferation and death. Although AIMP2 was previously shown to augment TNFα-induced cell death, its working mechanism in this signal pathway was not understood. Here, we investigate the functional significance and mode of action of AIMP2 in TNFα signaling. TNFα-induced cell death was compromised in AIMP2-deficient or -suppressed cells and exogenous supplementation of AIMP2 augmented apoptotic sensitivity to TNFα signaling. This activity was confirmed by the AIMP2-dependent increase of IκB and suppression of NFκB. We found binding of AIMP2 to TRAF2, a key player in the TNFα signaling pathway. AIMP2 augmented the association of an E3 ubiquitin ligase, c-IAP1, with TRAF2, causing ubiquitin-dependent degradation of TRAF2. These findings suggest that AIMP2 can mediate the pro-apoptotic activity of TNFα via the downregulation of TRAF2 expression.
Original language | English |
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Pages (from-to) | 2710-2715 |
Number of pages | 6 |
Journal | Journal of cell science |
Volume | 122 |
Issue number | 15 |
DOIs | |
Publication status | Published - 2009 Aug 1 |
All Science Journal Classification (ASJC) codes
- Cell Biology