This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Yamamoto, T.
Right arrow Articles by Yamamoto, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Yamamoto, T.
Right arrow Articles by Yamamoto, M.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, April 2008, p. 2758-2770, Vol. 28, No. 8
0270-7306/08/$08.00+0     doi:10.1128/MCB.01704-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Physiological Significance of Reactive Cysteine Residues of Keap1 in Determining Nrf2 Activity{triangledown}

Tae Yamamoto,1,{dagger} Takafumi Suzuki,1,2,{dagger} Akira Kobayashi,3 Junko Wakabayashi,1 Jon Maher,1 Hozumi Motohashi,2,3 and Masayuki Yamamoto1,2,3*

Center for Tsukuba Advanced Research Alliance, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8577, Japan,1 Environmental Response Project, Exploratory Research for Advanced Technology-Japan Science and Technology Corporation, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8577, Japan,2 Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan3

Received 15 September 2007/ Returned for modification 18 October 2007/ Accepted 4 February 2008

Keap1 and Cul3 constitute a unique ubiquitin E3 ligase that degrades Nrf2, a key activator of cytoprotective genes. Upon exposure to oxidants/electrophiles, the enzymatic activity of this ligase complex is inhibited and the complex fails to degrade Nrf2, resulting in the transcriptional activation of Nrf2 target genes. Keap1 possesses several reactive cysteine residues that covalently bond with electrophiles in vitro. To clarify the functional significance of each Keap1 cysteine residue under physiological conditions, we established a transgenic complementation rescue model. The transgenic expression of mutant Keap1(C273A) and/or Keap1(C288A) protein in Keap1 null mice failed to reverse constitutive Nrf2 activation, indicating that cysteine residues at positions 273 and 288 are essential for Keap1 to repress Nrf2 activity in vivo. In contrast, Keap1(C151S) retained repressor activity and mice expressing this molecule were viable. Mouse embryonic fibroblasts from Keap1(C151S) transgenic mice displayed decreased expression of Nrf2 target genes both before and after an electrophilic challenge, suggesting that Cys151 is important in facilitating Nrf2 activation. These results demonstrate critical roles of the cysteine residues in vivo in maintaining Keap1 function, such that Nrf2 is repressed under quiescent conditions and active in response to oxidants/electrophiles.

* Corresponding author. Mailing address: Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan. Phone: 022-717-8084. Fax: 022-717-8090. E-mail: masi{at}mail.tains.tohoku.ac.jp

{triangledown} Published ahead of print on 11 February 2008.

{dagger} T.Y. and T.S. contributed equally to this work.

Molecular and Cellular Biology, April 2008, p. 2758-2770, Vol. 28, No. 8
0270-7306/08/$08.00+0     doi:10.1128/MCB.01704-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Kelleher, M. O., McMahon, M., Eggleston, I. M., Dixon, M. J., Taguchi, K., Yamamoto, M., Hayes, J. D. (2009). 1-Cyano-2,3-epithiopropane is a novel plant-derived chemopreventive agent which induces cytoprotective genes that afford resistance against the genotoxic {alpha},{beta}-unsaturated aldehyde acrolein. Carcinogenesis 30: 1754-1762 [Abstract] [Full Text]  
  • Rudolph, T. K., Freeman, B. A. (2009). Transduction of Redox Signaling by Electrophile-Protein Reactions. Sci Signal 2: re7-re7 [Abstract] [Full Text]  
  • MacLeod, A.K., McMahon, M., Plummer, S. M., Higgins, L. G., Penning, T. M., Igarashi, K., Hayes, J. D. (2009). Characterization of the cancer chemopreventive NRF2-dependent gene battery in human keratinocytes: demonstration that the KEAP1-NRF2 pathway, and not the BACH1-NRF2 pathway, controls cytoprotection against electrophiles as well as redox-cycling compounds. Carcinogenesis 30: 1571-1580 [Abstract] [Full Text]  
  • Kobayashi, M., Li, L., Iwamoto, N., Nakajima-Takagi, Y., Kaneko, H., Nakayama, Y., Eguchi, M., Wada, Y., Kumagai, Y., Yamamoto, M. (2009). The Antioxidant Defense System Keap1-Nrf2 Comprises a Multiple Sensing Mechanism for Responding to a Wide Range of Chemical Compounds. Mol. Cell. Biol. 29: 493-502 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»