scholarly journals The Fn14 cytoplasmic tail binds tumour-necrosis-factor-receptor-associated factors 1, 2, 3 and 5 and mediates nuclear factor-kappaB activation

2003 ◽  
Vol 371 (2) ◽  
pp. 395-403 ◽  
Author(s):  
Sharron A.N. BROWN ◽  
Christine M. RICHARDS ◽  
Heather N. HANSCOM ◽  
Sheau-Line Y. FENG ◽  
Jeffrey A. WINKLES
Keyword(s):  
Amino Acid ◽  
Tumour Necrosis Factor ◽  
Tumour Necrosis ◽  
Cytoplasmic Tail ◽  
Luciferase Reporter ◽  
Nuclear Factor ◽  
3T3 Cells ◽  
Nih 3T3 ◽  
Necrosis Factor ◽  
Nih 3T3 Cells

Fn14 is a growth-factor-inducible immediate-early-response gene encoding a 102-amino-acid type I transmembrane protein. The human Fn14 protein was recently identified as a cell-surface receptor for the tumour necrosis factor (TNF) superfamily member named TWEAK (TNF-like weak inducer of apoptosis). In the present paper, we report that the human TWEAK extracellular domain can also bind the murine Fn14 protein. Furthermore, site-specific mutagenesis and directed yeast two-hybrid interaction assays revealed that the TNFR-associated factor (TRAF) 1, 2, 3 and 5 adaptor molecules bind the murine Fn14 cytoplasmic tail at an overlapping, but non-identical, amino acid sequence motif. We also found that TWEAK treatment of quiescent NIH 3T3 cells stimulates inhibitory κBα phosphorylation and transcriptional activation of a nuclear factor-κB (NF-κB) enhancer/luciferase reporter construct. Fn14 overexpression in transiently transfected NIH 3T3 cells also promotes NF-κB activation, and this cellular response requires an intact TRAF binding site. These results indicate that Fn14 is a functional TWEAK receptor that can associate with four distinct TRAF family members and stimulate the NF-κB transcription factor signalling pathway.

scholarly journals JFC1 is transcriptionally activated by nuclear factor-κB and up-regulated by tumour necrosis factor α in prostate carcinoma cells

2002 ◽  
Vol 367 (3) ◽  
pp. 791-799 ◽  
Author(s):  
Sergio D. CATZ ◽  
Bernard M. BABIOR ◽  
Jennifer L. JOHNSON
Keyword(s):  
Tumour Necrosis Factor ◽  
Cell Lines ◽  
Prostate Carcinoma ◽  
Tumour Necrosis ◽  
Nuclear Factor Κb ◽  
Luciferase Reporter ◽  
Nuclear Factor ◽  
Tumour Necrosis Factor Α ◽  
Factor Α ◽  
Necrosis Factor

The human promoter region of JFC1, a phosphatidylinositol 3,4,5-trisphosphate binding ATPase, was isolated by amplification of a 549bp region upstream of the jfc1 gene by the use of a double-PCR system. By primer extension analysis we mapped the transcription initiation site at nucleotide −321 relative to the translation start site. Putative regulatory elements were identified in the jfc1 TATA-less promoter, including three consensus sites for nuclear factor-κB (NF-κB). We analysed the three putative NF-κB binding sites by gel retardation and supershift assays. Each of the putative NF-κB sites interacted specifically with recombinant NF-κB p50, and the complexes co-migrated with those formed by the NF-κB consensus sequence and p50. An antibody to p50 generated a supershifted complex for these NF-κB sites. These sites formed specific complexes with nuclear proteins from tumour necrosis factor α (TNFα)-treated WEHI 231 cells, which were supershifted with antibodies against p50 and p65. The jfc1 promoter was transcriptionally active in various cell lines, as determined by luciferase reporter assays following transfection with a jfc1 promoter luciferase vector. Co-transfection with NF-κB expression vectors or stimulation with TNFα resulted in significant transactivation of the jfc1 promoter construct, although transactivation of a mutated jfc1 promoter was negligible. The expression of a dominant negative IκB (inhibitor κB) decreased basal jfc1 promoter activity. The cell lines PC-3, LNCaP and DU-145, but not Epstein—Barr virus-transformed lymphocytes, showed a dramatic increase in the expression of JFC1 after treatment with TNFα, suggesting that transcriptional activation of JFC1 by the TNFα/NF-κB pathway is significant in prostate carcinoma cell lines.

Thyrotropin modifies activation of nuclear factor κB by tumour necrosis factor α in rat thyroid cell line

2001 ◽  
Vol 354 (3) ◽  
pp. 573-579 ◽  
Author(s):  
Toyone KIKUMORI ◽  
Fukushi KAMBE ◽  
Takashi NAGAYA ◽  
Hiroomi FUNAHASHI ◽  
Hisao SEO
Keyword(s):  
Tumour Necrosis Factor ◽  
Tumour Necrosis ◽  
Nuclear Factor Κb ◽  
Luciferase Reporter ◽  
Nuclear Factor ◽  
Tumour Necrosis Factor Α ◽  
Tnf Α ◽  
Rat Thyroid ◽  
Factor Α ◽  
Necrosis Factor

We have recently demonstrated that nuclear factor κB (NF-κB) mediates the tumour necrosis factor α (TNF-α)-dependent expression of the gene encoding interleukin 6 (IL-6) in rat thyroid FRTL-5 cells cultured in the presence of thyrotropin (TSH). In the present study we investigated how TSH is involved in the activation of NF-κB by TNF-α in the cells. Electrophoretic mobility-shift assay revealed that, in the absence of TSH, TNF-α activated a single protein–DNA complex containing the p50 subunit but not other NF-κB subunits such as p65. In contrast, two distinct protein–DNA complexes were activated in the presence of TSH: the faster-migrating complex contained only p50 subunit; the slower-migrating complex consisted of p65–p50heterodimer. This TSH effect was mimicked by forskolin and thyroid-stimulating antibodies obtained from patients with Graves's disease, suggesting that an increase in intracellular cAMP is responsible for the induction of different NF-κBs by TNF-α. A transient transfection study with a luciferase reporter gene driven by multimerized NF-κB sites demonstrated that TNF-α increased the luciferase activities only in the presence of TSH, and that this increase was inhibited by the co-transfection of mutant p65, which prevented the function of wild-type p65 in a dominant-negative manner. Accordingly, TNF-α activated the expression of the IL-6 gene in the presence of TSH but not in its absence. Although the expression of the p105 gene, another known target for NF-κB, was increased by TNF-α in the absence of TSH, the presence of TSH further increased the mRNA level. Taken together, these observations indicate that the presence of TSH is crucial for the NF-κB-mediated actions of TNF-α on thyroid follicular cells.

scholarly journals The Oncogenic TLS-ERG Fusion Protein Exerts Different Effects in Hematopoietic Cells and Fibroblasts

2005 ◽  
Vol 25 (14) ◽  
pp. 6235-6246 ◽  
Author(s):  
Junhui Zou ◽  
Hitoshi Ichikawa ◽  
Michael L. Blackburn ◽  
Hsien-Ming Hu ◽  
Anna Zielinska-Kwiatkowska ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Rna Polymerase Ii ◽  
Hematopoietic Cells ◽  
Cellular Transformation ◽  
Luciferase Reporter ◽  
3T3 Cells ◽  
Pol Ii ◽  
G Cells ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

ABSTRACT The oncogenic TLS-ERG fusion protein is found in human myeloid leukemia and Ewing's sarcoma as a result of specific chromosomal translocation. To unveil the potential mechanism(s) underlying cellular transformation, we have investigated the effects of TLS-ERG on both gene transcription and RNA splicing. Here we show that the TLS protein forms complexes with RNA polymerase II (Pol II) and the serine-arginine family of splicing factors in vivo. Deletion analysis of TLS-ERG in both mouse L-G myeloid progenitor cells and NIH 3T3 fibroblasts revealed that the RNA Pol II-interacting domain of TLS-ERG resides within the first 173 amino acids. While TLS-ERG repressed expression of the luciferase reporter gene driven by glycoprotein IX promoter in L-G cells but not in NIH 3T3 cells, the fusion protein was able to affect splicing of the E1A reporter in NIH 3T3 cells but not in L-G cells. To identify potential target genes of TLS-ERG, the fusion protein and its mutants were stably expressed in both L-G and NIH 3T3 cells through retroviral transduction. Microarray analysis of RNA samples from these cells showed that TLS-ERG activates two different sets of genes sharing little similarity in the two cell lines. Taken together, these results suggest that the oncogenic TLS-ERG fusion protein transforms hematopoietic cells and fibroblasts via different pathways.

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