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Targeted Deletion of MKK4 Gene Potentiates TNF-Induced Apoptosis through the Down-Regulation of NF-κB Activation and NF-κB-Regulated Antiapoptotic Gene Products
| Content Provider | Scilit |
|---|---|
| Author | Sethi, Gautam Ahn, Kwang Seok Xia, Dianren Kurie, Jonathan M. |
| Copyright Year | 2007 |
| Description | MAPK kinase 4 (MKK4) is a dual-specificity kinase that activates both JNK and p38 MAPK. However, the mechanism by which MKK4 regulates TNF-induced apoptosis is not fully understood. Therefore, we used fibroblasts derived from MKK4 gene-deleted (MKK4-KO) mice to determine the role of this kinase in TNF signaling. We found that when compared with the wild-type cells, deletion of MKK4 gene enhanced TNF-induced apoptosis, and this correlated with down-regulation of TNF-induced cell-proliferative (COX-2 and cyclin D1) and antiapoptotic (survivin, IAP1, XIAP, Bcl-2, $Bcl-x_{L}$, and cFLIP) gene products, all regulated by NF-κB. Indeed we found that TNF-induced NF-κB activation was abrogated in MKK4 gene-deleted cells, as determined by DNA binding. Further investigation revealed that TNF-induced IκBα kinase activation, IκBα phosphorylation, IκBα degradation, and p65 nuclear translocation were all suppressed in MKK4-KO cells. NF-κB reporter assay revealed that NF-κB activation induced by TNF, TNFR1, TRADD, TRAF2, NIK, and IκBα kinase was modulated in gene-deleted cells. Overall, our results indicate that MKK4 plays a central role in TNF-induced apoptosis through the regulation of NF-κB-regulated gene products. |
| Ending Page | 1933 |
| Page Count | 8 |
| Starting Page | 1926 |
| ISSN | 00221767 |
| e-ISSN | 15506606 |
| DOI | 10.4049/jimmunol.179.3.1926 |
| Journal | The Journal of Immunology |
| Issue Number | 3 |
| Volume Number | 179 |
| Language | English |
| Publisher | The American Association of Immunologists |
| Publisher Date | 2007-08-01 |
| Access Restriction | Open |
| Subject Keyword | Cell Tissue Engineering Nf Κb Activation Tnf Induced |
| Content Type | Text |
| Resource Type | Article |
| Subject | Immunology and Allergy Immunology |