|
|
||||||||
1 Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
2
Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Ten-noudai, Tsukuba, Ibaraki 305-8577, Japan
3
Division of Yeast Genetics, National Institute for Medical Research, The Ridgeway, Mill Hill, London, UK
Yeast Sin1 binds to the Sty1 kinase, a member of the stress-activated kinases (SAPKs), and is required for stress-induced phosphorylation and activation of the transcription factor Atf1, a homolog of the vertebrate-activating transcription factor-2 (ATF-2). Here we report that mammalian Sin1 plays an important role in the SAPK signaling pathway by binding to both ATF-2 and p38. In response to stress, ATF-2, a member of the ATF/cAMP response element-binding protein family, is phosphorylated by p38/Jun NH2-terminal protein kinase and activates the transcription of apoptosis-related genes. In contrast, in response to serum stimulation, ATF-2 is phosphorylated via the Ras effector pathway and leads to the induction of growth-related genes. We found that Sin1 binds directly to both ATF-2 and p38. Sin1 over-expression enhanced osmotic stress-induced phosphorylation of ATF-2 and ATF-2-mediated transcription, whereas knockdown of Sin1 expression by siRNA suppressed these responses. Moreover, a reduction in Sin1 expression suppressed osmotic stress-induced apoptosis and the expression of Gadd45ß, one of the ATF-2 target genes that is correlated with apoptosis. Decreased Sin1 expression, however, did not affect the serum stimulation-induced phosphorylation of ATF-2. Sin1 may contribute to ATF-2 signaling specificity by acting as a nuclear scaffold.
* Correspondence: E-mail: sishii{at}rtc.riken.jp
This article has been cited by other articles:
![]() |
S.-Y. Park, J. H. Cho, D.-Y. Oh, J.-W. Park, M.-J. Ahn, J.-S. Han, and J.-W. Oh House Dust Mite Allergen Der f 2-induced Phospholipase D1 Activation Is Critical for the Production of Interleukin-13 through Activating Transcription Factor-2 Activation in Human Bronchial Epithelial Cells J. Biol. Chem., July 24, 2009; 284(30): 20099 - 20110. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Ghosh, G. P. Srivastava, D. Xu, L. C. Schulz, and R. M. Roberts A link between SIN1 (MAPKAP1) and poly(rC) binding protein 2 (PCBP2) in counteracting environmental stress PNAS, August 19, 2008; 105(33): 11673 - 11678. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. T. Jindra, Y.-P. Jin, E. Rozengurt, and E. F. Reed HLA Class I Antibody-Mediated Endothelial Cell Proliferation via the mTOR Pathway J. Immunol., February 15, 2008; 180(4): 2357 - 2366. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | ADVANCED SEARCH | TABLE OF CONTENTS |