|
|
|
|
|
|
|
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
First published online 29 June 2004
doi: 10.1242/jcs.01129
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Research Article |
B repressing factor NRF
Department of Gene Regulation and Differentiation, GBF – German Research Center for Biotechnology, Mascheroder Weg 1, 38124 Braunschweig, Germany
Author for correspondence (e-mail: hha{at}gbf.de)
Accepted 29 January 2004
NF-
B plays a central role in mediating pathogen and cytokine-stimulated gene transcription. NF-B repressing factor (NRF) has been shown to interact with specific negative regulatory DNA elements (NRE) to mediate transcriptional repression by inhibition of the NF-B activity at certain promoters. mRNA ablation experiments demonstrated that the trans-acting NRF protein is involved in constitutive but not post-stimulated silencing of IFN-ß, IL-8 and iNOS genes by binding to cis-acting NRE elements in their promoters.
We have examined the subcellular localization and mobility of the NRF protein. Since neither tagging nor overexpression perturbs NRF localization the GFP-tagged protein was used for detailed localization and mobility studies. Owing to an N-terminal nuclear localization sequence, all NRF fragments that contain this signal show a constitutive nuclear accumulation. C-terminal NRF fragments also localize to the nucleus although no canonical NLS motifs were detected. Full-length NRF is highly enriched in nucleoli and only a small fraction of NRF is found in the nucleoplasm and cytoplasm. This relationship was found to be independent of the protein expression rate. FRAP analysis proved to be a sensitive method to determine protein mobility and made it possible to differentiate between the NRF protein fragments. Nucleolar localization correlated inversely with mobility. The data demonstrate that a series of neighboring fragments in a large central domain of the protein contribute to the strong nucleolar affinity. These properties were not altered by viral infection or LPS treatment. Several sequence motifs for RNA binding were predicted by computer-mediated databank searches. We found that NRF binds to double stranded RNA (dsRNA). This property mapped to several NRF fragments which correlate with the nucleolar affinity domain. Since treatment with actinomycin D releases NRF from nucleoli the identified RNA binding motifs might act as nucleolar localization signals.
Key words: NF-B repressing factor, dsRNA binding, Nucleolus, FRAP, FLIP
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
 |
|
  S.-C. Ho, K.-Y. Lee, Y.-F. Chan, L.-W. Kuo, K. Ito, I. M. Adcock, B.-C. Chen, J.-R. Sheu, C.-H. Lin, and H.-P. Kuo Neutrophil Elastase Represses IL-8/CXCL8 Synthesis in Human Airway Smooth Muscle Cells through Induction of NF-{kappa}B Repressing Factor J. Immunol., July 1, 2009; 183(1): 411 - 420. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Neumann and M. Naumann Beyond I{kappa}Bs: alternative regulation of NF-{kappa}B activity FASEB J, September 1, 2007; 21(11): 2642 - 2654. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Xu, K. S. Wells, and R. B. Emeson Substrate-dependent Contribution of Double-stranded RNA-binding Motifs to ADAR2 Function Mol. Biol. Cell, July 1, 2006; 17(7): 3211 - 3220. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Froese, M. Schwarzer, I. Niedick, U. Frischmann, M. Koster, A. Kroger, P. P. Mueller, M. Nourbakhsh, B. Pasche, J. Reimann, et al. Innate Immune Responses in NF-{kappa}B-Repressing Factor-Deficient Mice Mol. Cell. Biol., January 1, 2006; 26(1): 293 - 302. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. A. Stark and M. G. Dunlop Nucleolar Sequestration of RelA (p65) Regulates NF-{kappa}B-Driven Transcription and Apoptosis Mol. Cell. Biol., July 15, 2005; 25(14): 5985 - 6004. [Abstract] [Full Text] [PDF]
|
|
