Abstract
Gemin5 is a 170-kDa WD-repeat-containing protein that was initially identified as a component of the survival of motor neurons (SMN) complex. We now show that Gemin5 facilitates the activation of apoptosis signal-regulating kinase 1 (ASK1) and downstream signaling. Gemin5 physically interacted with ASK1 as well as with the downstream kinases SEK1 and c-Jun NH2-terminal kinase (JNK1), and it potentiated the H2O2-induced activation of each of these kinases in intact cells. Moreover, Gemin5 promoted the binding of ASK1 to SEK1 and to JNK1, as well as the ASK1-induced activation of JNK1. In comparison, Gemin5 did not physically associate with MKK7, MKK3, MKK6, or p38. Furthermore, depletion of endogenous Gemin5 by RNA interference (RNAi) revealed that Gemin5 contributes to the activation of ASK1 and JNK1, and to apoptosis induced by H2O2 and tumor necrosis factor-α (TNFα) in HeLa cells. Together, our results suggest that Gemin5 functions as a scaffold protein for the ASK1-JNK1 signaling module and thereby potentiates ASK1-mediated signaling events.
Original language | English |
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Pages (from-to) | 1518-1528 |
Number of pages | 11 |
Journal | Cell Death and Differentiation |
Volume | 14 |
Issue number | 8 |
DOIs | |
Publication status | Published - 2007 Aug |
Bibliographical note
Funding Information:Acknowledgements. We thank Drs Ichijo H, Davis RJ, Woodgett J, Zon LI, Yoshioka K, Cobb MH, Ulevitch RJ, and Gutkind JS for providing ASK1, JNK1, SAPK, SEK1, Flag-SEK1, ERK2, p38, and MLK3 cDNA clones, respectively. EK Kim is a recipient of BK21 postdoctoral fellowship. This work was supported by the Molecular and Cellular BioDiscovery Research Program grant (M10601000136-06N0100-13610) from the Korean Ministry of Science and Technology, and by the Korea Research Foundation Grant (KRF-2006-341-C00023) funded by the Korean Government (MOEHRD) (E-JC).
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology