851
|
Human T-cell leukemia virus type I Tax activation of NF-kappa B/Rel involves phosphorylation and degradation of I kappa B alpha and RelA (p65)-mediated induction of the c-rel gene. Mol Cell Biol 1994. [PMID: 7935451 DOI: 10.1128/mcb.14.11.7377] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The tax gene product of human T-cell leukemia virus type I (HTLV-I) is a potent transcriptional activator that both stimulates viral gene expression and activates an array of cellular genes involved in T-cell growth. Tax acts indirectly by inducing or modifying the action of various host transcription factors, including members of the NF-kappa B/Rel family of enhancer-binding proteins. In resting T cells, many of these NF-kappa B/Rel factors are sequestered in the cytoplasm by various ankyrin-rich inhibitory proteins, including I kappa B alpha. HTLV-I Tax expression leads to the constitutive nuclear expression of biologically active NF-kappa B and c-Rel complexes; however, the biochemical mechanism(s) underlying this response remains poorly understood. In this study, we demonstrate that Tax-stimulated nuclear expression of NF-kappa B in both HTLV-I-infected and Tax-transfected human T cells is associated with the phosphorylation and rapid proteolytic degradation of I kappa B alpha. In contrast to prior in vitro studies, at least a fraction of the phosphorylated form of I kappa B alpha remains physically associated with the NF-kappa B complex in vivo but is subject to rapid degradation, thereby promoting the nuclear translocation of the active NF-kappa B complex. We further demonstrate that Tax induction of nuclear c-Rel expression is activated by the RelA (p65) subunit of NF-kappa B, which activates transcription of the c-rel gene through an intrinsic kappa B enhancer element. In normal cells, the subsequent accumulation of nuclear c-Rel acts to inhibit its own continued production, indicating the presence of an autoregulatory loop. However, the pathologic action HTLV-I Tax leads to the deregulated and sustained nuclear expression of both NF-kappa B and c-Rel, a response that may contribute to HTLV-I-induced T-cell transformation.
Collapse
|
852
|
Traenckner EB, Wilk S, Baeuerle PA. A proteasome inhibitor prevents activation of NF-kappa B and stabilizes a newly phosphorylated form of I kappa B-alpha that is still bound to NF-kappa B. EMBO J 1994; 13:5433-41. [PMID: 7957109 PMCID: PMC395500 DOI: 10.1002/j.1460-2075.1994.tb06878.x] [Citation(s) in RCA: 530] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Activation of the inducible transcription factor NF-kappa B involves removal of the inhibitory subunit I kappa B-alpha from a latent cytoplasmic complex. It has been reported that I kappa B-alpha is subject to both phosphorylation and proteolysis in the process of NF-kappa B activation. In this study, we present evidence that the multicatalytic cytosolic protease (proteasome) is involved in the degradation of I kappa B-alpha. Micromolar amounts of the peptide Cbz-Ile-Glu(O-t-Bu)-Ala-leucinal (PSI), a specific inhibitor of the chymotrypsin-like activity of the proteasome, prevented activation of NF-kappa B in response to tumor necrosis factor-alpha (TNF) and okadaic acid (OA) through inhibition of I kappa B-alpha degradation. The m-calpain inhibitor Cbz-Leu-leucinal was ineffective. In the presence of PSI, a newly phosphorylated form of I kappa B-alpha accumulated in TNF- and OA-stimulated cells. However, the covalent modification of I kappa B-alpha was not sufficient for activation of NF-kappa B: no substantial NF-kappa B DNA binding activity appeared in cells because the newly phosphorylated form of I kappa B-alpha was still tightly bound to p65 NF-kappa B. Pyrrolidinedithiocarbamate, an antioxidant inhibitor of NF-kappa B activation which did not interfere with proteasome activities, prevented de novo phosphorylation of I kappa B-alpha as well as its subsequent degradation. This suggests that phosphorylation of I kappa B-alpha is equally necessary for the activation of NF-kappa B.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- E B Traenckner
- Institute of Biochemistry, Albert-Ludwigs-University, Freiburg, Germany
| | | | | |
Collapse
|
853
|
Lawrence R, Chang LJ, Siebenlist U, Bressler P, Sonenshein GE. Vascular smooth muscle cells express a constitutive NF-kappa B-like activity. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)61994-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
854
|
Sappey C, Legrand-Poels S, Best-Belpomme M, Favier A, Rentier B, Piette J. Stimulation of glutathione peroxidase activity decreases HIV type 1 activation after oxidative stress. AIDS Res Hum Retroviruses 1994; 10:1451-61. [PMID: 7888200 DOI: 10.1089/aid.1994.10.1451] [Citation(s) in RCA: 126] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Am important aspect of human immunodeficiency virus (HIV-1) infection is the regulation of its expression by nuclear factor kappa B (NF-kappa B) by redox-controlled signal transduction pathways. In this study, we demonstrate that selenium supplementation can effectively increase glutathione peroxidase (GPx) activity in latently infected T lymphocytes. The Se-supplemented cells exhibited an important protection against the cytotoxic and reactivating effects of hydrogen peroxide (H2O2). Concomitantly, NF-kappa B activation by H2O2 was also decreased in Se-supplemented cells. Selenium stimulation of GPx activity also induces a protective effect against cell activation by tumor necrosis factor alpha (TNF-alpha) but less significantly by phorbol esters such as PMA. These Se-mediated effects were specific because they were not found when AP-1 DNA-binding activity was studied after H2O2-induced stress. Hyperthermia was also studied because it could promote intracellular electron leakage in electron transport chains. Elevating the temperature to 42 degrees C did not induce NF-kappa B directly. Rather, it sensitized infected cells to subsequent oxidative stress by H2O2, demonstrating the importance of hyperthermia, often associated with opportunistic infections in the development of immunodeficiency. In this case, Se induced partial protection against the sensitizing effect of hyperthermia.
Collapse
Affiliation(s)
- C Sappey
- Laboratory of Virology, University of Liège, Belgium
| | | | | | | | | | | |
Collapse
|
855
|
Sun SC, Elwood J, Béraud C, Greene WC. Human T-cell leukemia virus type I Tax activation of NF-kappa B/Rel involves phosphorylation and degradation of I kappa B alpha and RelA (p65)-mediated induction of the c-rel gene. Mol Cell Biol 1994; 14:7377-84. [PMID: 7935451 PMCID: PMC359272 DOI: 10.1128/mcb.14.11.7377-7384.1994] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The tax gene product of human T-cell leukemia virus type I (HTLV-I) is a potent transcriptional activator that both stimulates viral gene expression and activates an array of cellular genes involved in T-cell growth. Tax acts indirectly by inducing or modifying the action of various host transcription factors, including members of the NF-kappa B/Rel family of enhancer-binding proteins. In resting T cells, many of these NF-kappa B/Rel factors are sequestered in the cytoplasm by various ankyrin-rich inhibitory proteins, including I kappa B alpha. HTLV-I Tax expression leads to the constitutive nuclear expression of biologically active NF-kappa B and c-Rel complexes; however, the biochemical mechanism(s) underlying this response remains poorly understood. In this study, we demonstrate that Tax-stimulated nuclear expression of NF-kappa B in both HTLV-I-infected and Tax-transfected human T cells is associated with the phosphorylation and rapid proteolytic degradation of I kappa B alpha. In contrast to prior in vitro studies, at least a fraction of the phosphorylated form of I kappa B alpha remains physically associated with the NF-kappa B complex in vivo but is subject to rapid degradation, thereby promoting the nuclear translocation of the active NF-kappa B complex. We further demonstrate that Tax induction of nuclear c-Rel expression is activated by the RelA (p65) subunit of NF-kappa B, which activates transcription of the c-rel gene through an intrinsic kappa B enhancer element. In normal cells, the subsequent accumulation of nuclear c-Rel acts to inhibit its own continued production, indicating the presence of an autoregulatory loop. However, the pathologic action HTLV-I Tax leads to the deregulated and sustained nuclear expression of both NF-kappa B and c-Rel, a response that may contribute to HTLV-I-induced T-cell transformation.
Collapse
Affiliation(s)
- S C Sun
- Gladstone Institute of Virology and Immunology, University of California, San Francisco 94141-9100, USA
| | | | | | | |
Collapse
|
856
|
Kinetic analysis of human T-cell leukemia virus type I Tax-mediated activation of NF-kappa B. Mol Cell Biol 1994. [PMID: 7935369 DOI: 10.1128/mcb.14.10.6443] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human T-cell leukemia virus type I (HTLV-I) Tax protein induces the expression of cellular genes, at least in part, by activating the endogenous NF-kappa B transcription factors. Induced expression of cellular genes is thought to be important for transformation of T cells to continued growth, a prelude to the establishment of adult T-cell leukemia. However, neither underlying mechanisms nor kinetics of the Tax-mediated activation of NF-kappa B are understood. We have analyzed a permanently transfected Jurkat T-cell line in which the expression of Tax is entirely dependent on addition of heavy metals. The initial NF-kappa B binding activity seen after induction of Tax is due almost exclusively to p50/p65 heterodimers. At later times, NF-kappa B complexes containing c-Rel and/or p52 accumulate. The early activation of p50/p65 complexes is a posttranslational event, since neither mRNA nor protein levels of NF-kappa B subunits had increased at that time. We demonstrate for the first time a Tax-induced proteolytic degradation of the NF-kappa B inhibitor, I kappa B-alpha, which may trigger the initial nuclear translocation of NF-kappa B. As nuclear NF-kappa B rapidly and potently stimulates resynthesis of I kappa B-alpha, the steady-state level of I kappa B-alpha does not significantly change. Thus, the dramatic Tax-induced increase in the I kappa B-alpha turnover may continually weaken inhibition and activate NF-kappa B. Additional, distinct actions of Tax may contribute further to the high levels of NF-kappa B activity seen.
Collapse
|
857
|
Abstract
The activation of nuclear factor kappa B (NF-kappa B) in intact cells is mechanistically not well understood. Therefore we investigated the modifications imposed on NF-kappa B/I kappa B components following stimulation and show that the final step of NF-kappa B induction in vivo involves phosphorylation of several members of the NF-kappa B/I kappa B protein families. In HeLa cells as well as in B cells, TNF-alpha rapidly induced nuclear translocation primarily of p50-p65, but not of c-rel. Both NF-kappa B precursors and I kappa B alpha became strongly phosphorylated with the same kinetics. In addition to the inducible phosphorylation after stimulation, B lymphocytes containing constitutive nuclear NF-kappa B revealed constitutively phosphorylated p65 and I kappa B alpha. Phosphorylation was accompanied by induced processing of the precursors p100 and p105 and by degradation of I kappa B alpha. As an in vitro model we show that phosphorylation of p105 impedes its ability to interact with NF-kappa B, as has been shown before for I kappa B alpha. Surprisingly, even p65, but not c-rel, was phosphorylated after induction in vivo, suggesting that TNF-alpha selectively activates only specific NF-kappa B heteromers and that modifications regulate not only I kappa B molecules but also NF-kappa B molecules. In fact, cellular NF-kappa B activity was phosphorylation-dependent and the DNA binding activity of p65-containing NF-kappa B was enhanced by phosphorylation in vitro. Furthermore, we found that the induction by hydrogen peroxide of NF-kappa B translocation to the nucleus, which is assumed to be triggered by reactive oxygen intermediates, also coincided with incorporation of phosphate into the same subunits that were modified after stimulation by TNF-alpha. Thus, phosphorylation appears to be a general mechanism for activation of NF-kappa B in vivo.
Collapse
Affiliation(s)
- M Naumann
- Max-Planck-Institut für Molekulare Genetik, Otto-Warburg-Laboratorium, Berlin Dahlem, Germany
| | | |
Collapse
|
858
|
Weber C, Erl W, Pietsch A, Ströbel M, Ziegler-Heitbrock HW, Weber PC. Antioxidants inhibit monocyte adhesion by suppressing nuclear factor-kappa B mobilization and induction of vascular cell adhesion molecule-1 in endothelial cells stimulated to generate radicals. ARTERIOSCLEROSIS AND THROMBOSIS : A JOURNAL OF VASCULAR BIOLOGY 1994; 14:1665-73. [PMID: 7522548 DOI: 10.1161/01.atv.14.10.1665] [Citation(s) in RCA: 241] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cell adhesion to endothelial cells stimulated by tumor necrosis factor-alpha (TNF) is due to induction of surface receptors, such as vascular cell adhesion molecule-1 (VCAM-1). The antioxidant pyrrolidine dithiocarbamate (PDTC) specifically inhibits activation of nuclear factor-kappa B (NF-kappa B). Since kappa B motifs are present in VCAM-1 and intercellular adhesion molecule-1 (ICAM-1) promoters, we used PDTC to study the regulatory mechanisms of VCAM-1 and ICAM-1 induction and subsequent monocyte adhesion in TNF-treated human umbilical vein endothelial cells (HUVECs). PDTC or N-acetylcysteine dose dependently reduced TNF-induced VCAM-1 but not ICAM-1 surface protein (also in human umbilical arterial endothelial cells) and mRNA expression (by 70% at 100 mumol/L PDTC) in HUVECs as assessed by flow cytometry and polymerase chain reaction. Gel-shift analysis in HUVECs demonstrated that PDTC prevented NF-kappa B mobilization by TNF, suggesting that only VCAM-1 induction was controlled by NF-kappa B. Since HUVECs released superoxide anions in response to TNF, and H2O2 induces VCAM-1, PDTC may act as a radical scavenger. Although ICAM-1 induction was unaffected, inhibitors of NADPH oxidase (apocynin) or cytochrome P-450 (SKF525a) suppressed VCAM-1 induction by TNF, revealing that several radical-generating systems are involved in its regulation. PDTC, apocynin, or SKF525a decreased adhesion of monocytic U937 cells to TNF-treated HUVECs (by 75% at 100 mumol/L PDTC). Inhibition by anti-VCAM-1 monoclonal antibody 1G11 indicated that U937 adhesion was VCAM-1 dependent and suppression by antioxidants was due to reduced VCAM-1 induction.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- C Weber
- Institut für Prophylaxe der Kreislaufkrankheiten, München, Germany
| | | | | | | | | | | |
Collapse
|
859
|
Westwick JK, Weitzel C, Minden A, Karin M, Brenner DA. Tumor necrosis factor alpha stimulates AP-1 activity through prolonged activation of the c-Jun kinase. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)47207-9] [Citation(s) in RCA: 213] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
860
|
Schmitz ML, dos Santos Silva MA, Altmann H, Czisch M, Holak TA, Baeuerle PA. Structural and functional analysis of the NF-kappa B p65 C terminus. An acidic and modular transactivation domain with the potential to adopt an alpha-helical conformation. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)47294-8] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
861
|
Kanno T, Brown K, Franzoso G, Siebenlist U. Kinetic analysis of human T-cell leukemia virus type I Tax-mediated activation of NF-kappa B. Mol Cell Biol 1994; 14:6443-51. [PMID: 7935369 PMCID: PMC359174 DOI: 10.1128/mcb.14.10.6443-6451.1994] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The human T-cell leukemia virus type I (HTLV-I) Tax protein induces the expression of cellular genes, at least in part, by activating the endogenous NF-kappa B transcription factors. Induced expression of cellular genes is thought to be important for transformation of T cells to continued growth, a prelude to the establishment of adult T-cell leukemia. However, neither underlying mechanisms nor kinetics of the Tax-mediated activation of NF-kappa B are understood. We have analyzed a permanently transfected Jurkat T-cell line in which the expression of Tax is entirely dependent on addition of heavy metals. The initial NF-kappa B binding activity seen after induction of Tax is due almost exclusively to p50/p65 heterodimers. At later times, NF-kappa B complexes containing c-Rel and/or p52 accumulate. The early activation of p50/p65 complexes is a posttranslational event, since neither mRNA nor protein levels of NF-kappa B subunits had increased at that time. We demonstrate for the first time a Tax-induced proteolytic degradation of the NF-kappa B inhibitor, I kappa B-alpha, which may trigger the initial nuclear translocation of NF-kappa B. As nuclear NF-kappa B rapidly and potently stimulates resynthesis of I kappa B-alpha, the steady-state level of I kappa B-alpha does not significantly change. Thus, the dramatic Tax-induced increase in the I kappa B-alpha turnover may continually weaken inhibition and activate NF-kappa B. Additional, distinct actions of Tax may contribute further to the high levels of NF-kappa B activity seen.
Collapse
Affiliation(s)
- T Kanno
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892
| | | | | | | |
Collapse
|
862
|
|
863
|
Reddy SA, Chaturvedi MM, Darnay BG, Chan H, Higuchi M, Aggarwal BB. Reconstitution of nuclear factor kappa B activation induced by tumor necrosis factor requires membrane-associated components. Comparison with pathway activated by ceramide. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)47258-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
864
|
Bach FH, Robson SC, Ferran C, Winkler H, Millan MT, Stuhlmeier KM, Vanhove B, Blakely ML, van der Werf WJ, Hofer E, de Martin R, Hancock WW. Endothelial cell activation and thromboregulation during xenograft rejection. Immunol Rev 1994; 141:5-30. [PMID: 7868157 DOI: 10.1111/j.1600-065x.1994.tb00870.x] [Citation(s) in RCA: 177] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- F H Bach
- Sandoz Center for Immunobiology, Harvard Medical School, New England Deaconess Hospital Boston 02215
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
865
|
Mackman N. Protease inhibitors block lipopolysaccharide induction of tissue factor gene expression in human monocytic cells by preventing activation of c-Rel/p65 heterodimers. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)47202-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
866
|
Wiegmann K, Schütze S, Machleidt T, Witte D, Krönke M. Functional dichotomy of neutral and acidic sphingomyelinases in tumor necrosis factor signaling. Cell 1994; 78:1005-15. [PMID: 7923351 DOI: 10.1016/0092-8674(94)90275-5] [Citation(s) in RCA: 593] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Ceramide produced by sphingomyelinases (SMases) has been recognized as an important second messenger in growth factor receptor signaling. Tumor necrosis factor (TNF), through binding to the 55 kDa TNF receptor (TNF-R55), rapidly activates two distinct types of SMase, a membrane-associated neutral (N-)SMase, and an endosomal acidic (A)-SMase. N-SMase and A-SMase are activated independently by different cytoplasmic domains of TNF-R55. Each type of SMase specifically couples to select pathways of TNF signaling. Ceramide generated by N-SMase directs the activation of proline-directed serine/threonine protein kinase(s) and phospholipase A2. In contrast, A-SMase triggers the activation of NF-kappa B. No apparent crosstalk was detected between N-SMase and A-SMase pathways, indicating that ceramide action depends on the topology of its production. These results suggest that N-SMase and A-SMase control important yet dissociable and nonoverlapping pathways of TNF receptor signal transduction.
Collapse
Affiliation(s)
- K Wiegmann
- Institut für Medizinische Mikrobiologie und Hygiene, Technische Universität München, Federal Republic of Germany
| | | | | | | | | |
Collapse
|
867
|
Palombella VJ, Rando OJ, Goldberg AL, Maniatis T. The ubiquitin-proteasome pathway is required for processing the NF-kappa B1 precursor protein and the activation of NF-kappa B. Cell 1994; 78:773-85. [PMID: 8087845 DOI: 10.1016/s0092-8674(94)90482-0] [Citation(s) in RCA: 1657] [Impact Index Per Article: 55.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We demonstrate an essential role for the proteasome complex in two proteolytic processes required for activation of the transcription factor NF-kappa B. The p105 precursor of the p50 subunit of NF-kappa B is processed in vitro by an ATP-dependent process that requires proteasomes and ubiquitin conjugation. The C-terminal region of p105 is rapidly degraded, leaving the N-terminal p50 domain. p105 processing can be blocked in intact cells with inhibitors of the proteasome or in yeast with proteasome mutants. These inhibitors also block the activation of NF-kappa B and the rapid degradation of I kappa B alpha induced by tumor necrosis factor alpha. Thus, the ubiquitin-proteasome pathway functions not only in the complete degradation of polypeptides, but also in the regulated processing of precursors into active proteins.
Collapse
Affiliation(s)
- V J Palombella
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138
| | | | | | | |
Collapse
|
868
|
Albrecht H, Tschopp J, Jongeneel CV. Bcl-2 protects from oxidative damage and apoptotic cell death without interfering with activation of NF-kappa B by TNF. FEBS Lett 1994; 351:45-8. [PMID: 8076691 DOI: 10.1016/0014-5793(94)00817-5] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The recent demonstration of the anti-oxidant properties of the Bcl-2 gene product suggested that expression of Bcl-2 may interfere with the nuclear migration of the NF-kappa B transcription factor, which is thought to depend on the presence of reactive oxygen intermediates. In mouse L cells, overexpression of Bcl-2 interfered with the activation of NF-kappa B by H2O2. However, Bcl-2 had no effect on the activation of NF-kappa B by TNF, even though it protected cells from TNF-induced apoptosis. The effects of exogenous pyrrolidine dithiocarbamate were very similar to those of Bcl-2 overexpression. We conclude that the protective effects of anti-oxidants against induced apoptotic cell death are unrelated to their ability to interfere with NF-kappa B activation.
Collapse
Affiliation(s)
- H Albrecht
- Ludwig Institute for Cancer Research, University of Lausanne, Epalinges, Switzerland
| | | | | |
Collapse
|
869
|
McGeehan GM, Becherer JD, Bast RC, Boyer CM, Champion B, Connolly KM, Conway JG, Furdon P, Karp S, Kidao S. Regulation of tumour necrosis factor-alpha processing by a metalloproteinase inhibitor. Nature 1994; 370:558-61. [PMID: 8052311 DOI: 10.1038/370558a0] [Citation(s) in RCA: 459] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Tumour necrosis factor-alpha (TNF-alpha) is a potent pro-inflammatory agent produced primarily by activated monocytes and macrophages. TNF-alpha is synthesized as a precursor protein of M(r) 26,000 (26K) which is processed to a secreted 17K mature form by cleavage of an Ala-Val bond between residues 76-77. The enzyme(s) responsible for processing pro-TNF-alpha has yet to be identified. Here, we describe the capacity of a metalloproteinase inhibitor, GI 129471, to block TNF-alpha secretion both in vitro and in vivo. The inhibition is specific to TNF-alpha; the production of other secreted cytokines, such as the interleukins IL-1 beta, IL-2, or IL-6, is not inhibited. The mechanism of inhibition occurs at a post-translational step in TNF-alpha production. Our data suggest that TNF-alpha processing is mediated by a unique Zn2+ endopeptidase which is inhibited by GI 129471 and would represent a novel target for therapeutic intervention in TNF-alpha associated pathologies.
Collapse
Affiliation(s)
- G M McGeehan
- Glaxo Inc. Research Institute, Research Triangle Park, North Carolina 27709
| | | | | | | | | | | | | | | | | | | |
Collapse
|
870
|
Sequential induction of NF-kappa B/Rel family proteins during B-cell terminal differentiation. Mol Cell Biol 1994. [PMID: 8035813 DOI: 10.1128/mcb.14.8.5349] [Citation(s) in RCA: 167] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The NF-kappa B/Rel family of at least five transcription factor polypeptides is thought to function both as a developmental regulator in B cells and as a rapid response system in all cells. To examine this notion in more detail, we determined the protein contents of both the inducible and constitutive NF-kappa B/Rel activities in a pre-B-cell line, 70Z/3, and a mature B-cell line, WEHI 231. NF-kappa B p50/p65 is the major inducible nuclear complex after lipopolysaccharide or phorbol myristate acetate treatment of 70Z/3 cells. The constitutive and inducible complexes in WEHI 231 cells are mainly composed of p50 and Rel. The constitutive or induced activities are all sensitive to I kappa B-alpha, but this inhibitor is very short-lived in WEHI 231 cells, suggesting that the balance between synthesis and degradation of I kappa B-alpha determines whether a particular cell lineage has constitutive activity. A patterned expression of the NF-kappa B/Rel activator proteins emerges from an analysis of other B-lineage cell lines and splenic B cells: mainly p50 and p65 in pre-B (and non-B) cells, a predominance of Rel and p50 in mature B cells, and expression of p52 and RelB in plasmacytoma lines. This ordered pattern of regulators may reflect the requirement for expression of different genes during terminal B-cell differentiation because different combinations of NF-kappa B/Rel family members preferentially activate distinct kappa B sites in reporter constructs.
Collapse
|
871
|
Liou HC, Sha WC, Scott ML, Baltimore D. Sequential induction of NF-kappa B/Rel family proteins during B-cell terminal differentiation. Mol Cell Biol 1994; 14:5349-59. [PMID: 8035813 PMCID: PMC359054 DOI: 10.1128/mcb.14.8.5349-5359.1994] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The NF-kappa B/Rel family of at least five transcription factor polypeptides is thought to function both as a developmental regulator in B cells and as a rapid response system in all cells. To examine this notion in more detail, we determined the protein contents of both the inducible and constitutive NF-kappa B/Rel activities in a pre-B-cell line, 70Z/3, and a mature B-cell line, WEHI 231. NF-kappa B p50/p65 is the major inducible nuclear complex after lipopolysaccharide or phorbol myristate acetate treatment of 70Z/3 cells. The constitutive and inducible complexes in WEHI 231 cells are mainly composed of p50 and Rel. The constitutive or induced activities are all sensitive to I kappa B-alpha, but this inhibitor is very short-lived in WEHI 231 cells, suggesting that the balance between synthesis and degradation of I kappa B-alpha determines whether a particular cell lineage has constitutive activity. A patterned expression of the NF-kappa B/Rel activator proteins emerges from an analysis of other B-lineage cell lines and splenic B cells: mainly p50 and p65 in pre-B (and non-B) cells, a predominance of Rel and p50 in mature B cells, and expression of p52 and RelB in plasmacytoma lines. This ordered pattern of regulators may reflect the requirement for expression of different genes during terminal B-cell differentiation because different combinations of NF-kappa B/Rel family members preferentially activate distinct kappa B sites in reporter constructs.
Collapse
Affiliation(s)
- H C Liou
- Rockfeller University, New York, New York 10021
| | | | | | | |
Collapse
|
872
|
Kelly KA, Hill MR, Youkhana K, Wanker F, Gimble JM. Dimethyl sulfoxide modulates NF-kappa B and cytokine activation in lipopolysaccharide-treated murine macrophages. Infect Immun 1994; 62:3122-8. [PMID: 8039880 PMCID: PMC302936 DOI: 10.1128/iai.62.8.3122-3128.1994] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Antioxidants are protective against septic shock in animal models. Recently, free radical scavengers have been found to inhibit the activation of the NF-kappa B protein in a number of cell lines. This transcriptional regulatory protein binds to the promoters of the proinflammatory cytokines tumor necrosis factor, interleukin-6, and the macrophage inflammatory proteins. The current work examined lipopolysaccharide-induced NF-kappa B activation in the J774 macrophage-like cell line and primary peritoneal macrophages from lipopolysaccharide-responsive (C3HeB/Fej) and -nonresponsive (C3H/HeJ) murine strains. The DNA-binding activity of the NF-kappa B protein directly correlated with mRNA expression for the genes encoding the proinflammatory cytokines and the free radical scavenging enzyme, superoxide dismutase. Both the p50 and p65 NF-kappa B subunits were detected on gel supershift assays. Minimal NF-kappa B activity was observed following exposure of C3H/HeJ macrophages to lipopolysaccharide. The antioxidant dimethyl sulfoxide decreased the level of NF-kappa B activation in the J774 cells. This correlated with decreased expression of cytokine mRNAs and tumor necrosis factor bioactivity. These results suggest that modulation of NF-kappa B activation may provide a mechanism through which antioxidants protect against endotoxemia in murine models.
Collapse
Affiliation(s)
- K A Kelly
- Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, Oklahoma City 73104
| | | | | | | | | |
Collapse
|
873
|
Kumar A, Haque J, Lacoste J, Hiscott J, Williams BR. Double-stranded RNA-dependent protein kinase activates transcription factor NF-kappa B by phosphorylating I kappa B. Proc Natl Acad Sci U S A 1994; 91:6288-92. [PMID: 7912826 PMCID: PMC44186 DOI: 10.1073/pnas.91.14.6288] [Citation(s) in RCA: 455] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The induction of interferon (IFN) genes by viruses or double-stranded RNA (dsRNA) requires the assembly of a complex set of transcription factors on responsive DNA elements of IFN gene promoters. One of the factors necessary for regulating IFN-beta gene transcription is nuclear factor NF-kappa B, the activation of which is triggered by dsRNA. It has previously been suggested that the dsRNA-activated p68 protein kinase (PKR) may act as an inducer-receptor, transducing the signal from dsRNA to NF-kappa B through phosphorylation of the inhibitor I kappa B. We present direct evidence that PKR can phosphorylate I kappa B-alpha (MAD-3) and activate NF-kappa B DNA binding activity in vitro. We further show that dsRNA induces an unusual phosphorylated form of I kappa B-alpha. The expression of a transdominant mutant PKR is able to perturb the dsRNA-mediated signaling pathway in vivo, suggesting a role for this kinase in IFN-beta gene induction.
Collapse
Affiliation(s)
- A Kumar
- Department of Cancer Biology, Cleveland Clinic Foundation, OH 44195
| | | | | | | | | |
Collapse
|
874
|
Abstract
The respiration of oxygen, while essential to aerobic organisms for the generation of energy, leads to the formation of reactive oxygen intermediates (ROIs) as harmful byproducts. ROIs damage nucleic acids, lipids and proteins. Therefore, protective mechanisms against elevated intracellular ROI levels, referred to as oxidative stress, have evolved. These include the activation of transcription factors which elevate the expression of protective enzymes. Eukaryotic cells have also evolved the ability to specifically generate ROIs following stimulation with various agents. In these cases, ROIs are used as second messengers to activate gene expression. Here we will discuss both prokaryotic and eukaryotic transcription factors that respond to ROIs. In addition, transcription factors will be described that are activated by either exposure to antioxidants, which reduce the intracellular ROI concentration, or by hypoxia, the absence of oxygen.
Collapse
Affiliation(s)
- H L Pahl
- Institute of Biochemistry, University of Freiburg, Germany
| | | |
Collapse
|
875
|
Affiliation(s)
- R A Heller
- Institute of Biochemistry and Cell Biology, Syntex Discovery Research, Palo Alto, California 94304
| | | |
Collapse
|
876
|
Abstract
Recent discoveries have led to a better understanding of how signals generated by growth factors, cytokines and hormones elicit changes in gene expression in mammalian cells. Three general strategies of information pathways from the cell surface to the nucleus can be defined, all of which involve protein phosphorylation: (1) activation and translocation of cytoplasmic kinases to the nucleus, leading to changes in transcription-factor functions; (2) direct activation of latent cytoplasmic transcription factors by phosphorylation; and (3) release of transcription factors from cytoplasmic anchor proteins. These information conduits are illustrated by the mitogen-activated protein (MAP) kinase pathway, signal transducer and activator of transcription (Stat) proteins and nuclear factor-kappa B (NF-kappa B), respectively, and are discussed in this article by Dylan Edwards. Regulation of nucleo-cytoplasmic compartmentation emerges as a key aspect of signal transfer.
Collapse
Affiliation(s)
- D R Edwards
- Department of Pharmacology and Therapeutics, University of Calgary, Alberta, Canada
| |
Collapse
|
877
|
Bacterial lipopolysaccharide has structural similarity to ceramide and stimulates ceramide-activated protein kinase in myeloid cells. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)32484-5] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
878
|
Abstract
NF-kappa B is inducible transcription factor present in many cell types in a latent cytoplasmic form. So far, only immune cells including mature B cells, thymocytes, and adherent macrophages have been reported to contain constitutively active forms of NF-kappa B in the nucleus. A recent study showed that the human immunodeficiency virus type 1 (HIV-1) promoter is highly active in several brain regions of transgenic mice (J. R. Corboy, J. M. Buzy, M. C. Zink, and J. E. Clements, Science 258:1804-1807, 1992). Since the activity of this viral enhancer is governed mainly by two binding sites for NF-kappa B, we were prompted to investigate the state of NF-kappa B activity in neurons. Primary neuronal cultures derived from rat hippocampus and cerebral cortex showed a high constitutive expression of an HIV-1 long terminal repeat-driven luciferase reporter gene, which was primarily dependent on intact NF-kappa B binding sites and was abolished upon coexpression of the NF-kappa B-specific inhibitor I kappa B-alpha. Indirect immunofluorescence and confocal laser microscopy showed that the activity of NF-kappa B correlated with the presence of the NF-kappa B subunits p50 and RelA (p65) in nuclei of cultured neurons. NF-kappa B was also constitutively active in neurons in vivo. As investigated by electrophoretic mobility shift assays, constitutive NF-kappa B DNA-binding activity was highly enriched in fractions containing neuronal nuclei prepared from rat cerebral cortex. Nuclear NF-kappa B-specific immunostaining was also seen in cryosections from mouse cerebral cortex and hippocampus. Only a subset of neurons was stained. Activated NF-kappa B in the brain is likely to participate in normal brain function and to reflect a distinct state of neuronal activity or differentiation. Furthermore, it may explain the high level of activity of the HIV-1 enhancer in neurons, an observation potentially relevant for the etiology of the AIDS dementia complex caused by HIV infection of the central nervous system.
Collapse
|
879
|
Isoda K, Nüsslein-Volhard C. Disulfide cross-linking in crude embryonic lysates reveals three complexes of the Drosophila morphogen dorsal and its inhibitor cactus. Proc Natl Acad Sci U S A 1994; 91:5350-4. [PMID: 8202491 PMCID: PMC43992 DOI: 10.1073/pnas.91.12.5350] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
In Drosophila embryos dorsoventral polarity is determined by a concentration gradient of dorsal (dl) protein in the nuclei formed by the differential regulation of nuclear localization of dl protein. cactus (cact) represses the nuclear localization of dl protein. By introducing intermolecular disulfide bonds in homogenates of embryos, we detected three complexes of dl and/or cact proteins. Complex 1 (190 kDa) is a dl protein homodimer (dl2). Complex 2 (270 kDa) consists of one complex 1 and one cact molecule (dl2cact). Complex 3 (200 kDa) is a cact protein complex that does not contain dl protein. In wild-type embryos dl2cact was detected as the major form of dl protein, and dl2 was minor. With this assay virtually no dl monomer is detected. Analysis of the dl protein complexes in ventralized and dorsalized mutant embryos indicates that dl2cact is a cytoplasmic form, whereas dl2 is localized mainly in the nuclei. It seems that a small amount of dl2 is also present in the cytoplasm.
Collapse
Affiliation(s)
- K Isoda
- Max-Planck-Institut für Entwicklungsbiologie, Tübingen, Germany
| | | |
Collapse
|
880
|
Kaltschmidt C, Kaltschmidt B, Neumann H, Wekerle H, Baeuerle PA. Constitutive NF-kappa B activity in neurons. Mol Cell Biol 1994; 14:3981-92. [PMID: 8196637 PMCID: PMC358764 DOI: 10.1128/mcb.14.6.3981-3992.1994] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
NF-kappa B is inducible transcription factor present in many cell types in a latent cytoplasmic form. So far, only immune cells including mature B cells, thymocytes, and adherent macrophages have been reported to contain constitutively active forms of NF-kappa B in the nucleus. A recent study showed that the human immunodeficiency virus type 1 (HIV-1) promoter is highly active in several brain regions of transgenic mice (J. R. Corboy, J. M. Buzy, M. C. Zink, and J. E. Clements, Science 258:1804-1807, 1992). Since the activity of this viral enhancer is governed mainly by two binding sites for NF-kappa B, we were prompted to investigate the state of NF-kappa B activity in neurons. Primary neuronal cultures derived from rat hippocampus and cerebral cortex showed a high constitutive expression of an HIV-1 long terminal repeat-driven luciferase reporter gene, which was primarily dependent on intact NF-kappa B binding sites and was abolished upon coexpression of the NF-kappa B-specific inhibitor I kappa B-alpha. Indirect immunofluorescence and confocal laser microscopy showed that the activity of NF-kappa B correlated with the presence of the NF-kappa B subunits p50 and RelA (p65) in nuclei of cultured neurons. NF-kappa B was also constitutively active in neurons in vivo. As investigated by electrophoretic mobility shift assays, constitutive NF-kappa B DNA-binding activity was highly enriched in fractions containing neuronal nuclei prepared from rat cerebral cortex. Nuclear NF-kappa B-specific immunostaining was also seen in cryosections from mouse cerebral cortex and hippocampus. Only a subset of neurons was stained. Activated NF-kappa B in the brain is likely to participate in normal brain function and to reflect a distinct state of neuronal activity or differentiation. Furthermore, it may explain the high level of activity of the HIV-1 enhancer in neurons, an observation potentially relevant for the etiology of the AIDS dementia complex caused by HIV infection of the central nervous system.
Collapse
Affiliation(s)
- C Kaltschmidt
- Institute of Biochemistry, Albert-Ludwigs-Universität, Freiburg, Germany
| | | | | | | | | |
Collapse
|
881
|
Enhanced I kappa B alpha degradation is responsible for constitutive NF-kappa B activity in mature murine B-cell lines. Mol Cell Biol 1994. [PMID: 8164680 DOI: 10.1128/mcb.14.5.3276] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nuclear factor kappa B (NF-kappa B) is a ubiquitous transcription factor which binds to decameric DNA sequences (kappa B sites) and regulates transcription of multiple genes. The activity of NF-kappa B is regulated by an inhibitor protein, I kappa B, which sequesters NF-kappa B in the cytoplasm. Release of I kappa B and subsequent nuclear translocation of NF-kappa B generally require activating signals. However, in mature murine B cells, the DNA-binding activity of NF-kappa B is constitutively nuclear and activates the Ig kappa gene, a marker for mature B cells. To understand the basis for the constitutive NF-kappa B activation, we examined the properties of NF-kappa B and I kappa B in both pre-B and mature B cells, the regulated and constitutive states, respectively. We found that expression of I kappa B alpha and p105, members of the I kappa B family, and Rel, a member of the NF-kappa B family, is augmented in mature B cells. Both I kappa B alpha and p 105 are associated with NF-kappa B proteins and sequester most of these proteins in the cytoplasm of mature B cells. However, rapid I kappa B alpha dissociation and degradation lead to continuous nuclear translocation of a small fraction of NF-kappa B proteins, which represent the constitutively active NF-kappa B in mature B cells. We estimate that the protease activity is at least 35-fold greater in mature B cells than in pre-B cells. Rapid degradation of I kappa B alpha is directly involved in constitutive NF-kappa B activation, because stabilization of I kappa B alpha by a protease inhibitor causes loss of NF-kappa B activity in mature B cells. These results provide evidence that continuous and rapid degradation of I kappa B alpha in the absence pf external stimuli is causally involved in the constitutive activation of NF-kappa B in mature murine B cells.
Collapse
|
882
|
Miyamoto S, Chiao PJ, Verma IM. Enhanced I kappa B alpha degradation is responsible for constitutive NF-kappa B activity in mature murine B-cell lines. Mol Cell Biol 1994; 14:3276-82. [PMID: 8164680 PMCID: PMC358694 DOI: 10.1128/mcb.14.5.3276-3282.1994] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Nuclear factor kappa B (NF-kappa B) is a ubiquitous transcription factor which binds to decameric DNA sequences (kappa B sites) and regulates transcription of multiple genes. The activity of NF-kappa B is regulated by an inhibitor protein, I kappa B, which sequesters NF-kappa B in the cytoplasm. Release of I kappa B and subsequent nuclear translocation of NF-kappa B generally require activating signals. However, in mature murine B cells, the DNA-binding activity of NF-kappa B is constitutively nuclear and activates the Ig kappa gene, a marker for mature B cells. To understand the basis for the constitutive NF-kappa B activation, we examined the properties of NF-kappa B and I kappa B in both pre-B and mature B cells, the regulated and constitutive states, respectively. We found that expression of I kappa B alpha and p105, members of the I kappa B family, and Rel, a member of the NF-kappa B family, is augmented in mature B cells. Both I kappa B alpha and p 105 are associated with NF-kappa B proteins and sequester most of these proteins in the cytoplasm of mature B cells. However, rapid I kappa B alpha dissociation and degradation lead to continuous nuclear translocation of a small fraction of NF-kappa B proteins, which represent the constitutively active NF-kappa B in mature B cells. We estimate that the protease activity is at least 35-fold greater in mature B cells than in pre-B cells. Rapid degradation of I kappa B alpha is directly involved in constitutive NF-kappa B activation, because stabilization of I kappa B alpha by a protease inhibitor causes loss of NF-kappa B activity in mature B cells. These results provide evidence that continuous and rapid degradation of I kappa B alpha in the absence pf external stimuli is causally involved in the constitutive activation of NF-kappa B in mature murine B cells.
Collapse
Affiliation(s)
- S Miyamoto
- Molecular Biology and Virology Laboratory, Salk Institute, San Diego, California 92186-5800
| | | | | |
Collapse
|
883
|
Bandres JC, Ratner L. Human immunodeficiency virus type 1 Nef protein down-regulates transcription factors NF-kappa B and AP-1 in human T cells in vitro after T-cell receptor stimulation. J Virol 1994; 68:3243-9. [PMID: 8151786 PMCID: PMC236815 DOI: 10.1128/jvi.68.5.3243-3249.1994] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) negative factor (Nef) has been shown to down-regulate the transcription factors NF-kappa B and AP-1 in vitro. To define the mechanism of action of the Nef protein, the signal transduction pathways which may be affected in T cells by constitutive expression of the nef gene were examined. Stimulation of T cells with tumor necrosis factor, interleukin-1, or lipopolysaccharide resulted in the recruitment of transcriptional factors to a similar level whether or not the cells expressed the nef gene. On the other hand, stimulation of T cells by mitogens or antibodies to the T-cell receptor (TCR)-CD3 complex resulted in the down-regulation of transcriptional factors NF-kappa B and AP-1 in cells expressing the nef gene compared with cells not expressing the nef gene. Because the Nef protein does not affect the surface expression of the CD3-TCR complex, we conclude that the Nef protein down-regulates the transcriptional factors NF-kappa B and AP-1 in T cells in vitro through an effect on the TCR-dependent signal transduction pathway.
Collapse
Affiliation(s)
- J C Bandres
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | | |
Collapse
|
884
|
Mallardo M, Giordano V, Dragonetti E, Scala G, Quinto I. DNA damaging agents increase the stability of interleukin-1 alpha, interleukin-1 beta, and interleukin-6 transcripts and the production of the relative proteins. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36550-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
885
|
Machleidt T, Wiegmann K, Henkel T, Schütze S, Baeuerle P, Krönke M. Sphingomyelinase activates proteolytic I kappa B-alpha degradation in a cell-free system. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36712-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
886
|
Hirai H, Suzuki T, Fujisawa J, Inoue J, Yoshida M. Tax protein of human T-cell leukemia virus type I binds to the ankyrin motifs of inhibitory factor kappa B and induces nuclear translocation of transcription factor NF-kappa B proteins for transcriptional activation. Proc Natl Acad Sci U S A 1994; 91:3584-8. [PMID: 8170951 PMCID: PMC43624 DOI: 10.1073/pnas.91.9.3584] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Human T-cell leukemia virus type I causes adult T-cell leukemia and tropical spastic paraparesis, and its regulator protein Tax has been implicated in the pathogenic activity of human T-cell leukemia virus type I. Tax activates transcription of viral and cellular genes through specific enhancers: the 21-bp enhancer of human T-cell leukemia virus type I, the nuclear factor kappa B (NF-kappa B)-binding site of the interleukin 2 receptor alpha gene, and the serum-responsive element of c-fos. Tax binds to enhancer-binding proteins including cAMP-responsive element-binding protein, cAMP-responsive element modulator, transcription factor NF-kappa B p50 and p67SRF, and associates with each enhancer DNA indirectly. In addition to this mechanism, we report here that Tax binds to inhibitory factor kappa B gamma (I-kappa B) gamma, which forms a complex with NF-kappa B protein heterodimer p50-p65 or homodimer p50-p50 and retains them in the cytoplasm. Tax binding to I-kappa B gamma induces nuclear translocation of NF-kappa B p65. In association with this nuclear translocation of p65, transcription directed by the kappa B enhancer is strongly activated. Tax binds to the ankyrin motifs of I-kappa B gamma, suggesting its possible interaction with many other proteins carrying ankyrin motifs contributing to various regulatory processes. This is a different mechanism of transcriptional activation by the oncoprotein Tax and seems to be independent from the trans-activation through indirect binding to enhancer DNAs.
Collapse
Affiliation(s)
- H Hirai
- Department of Cellular and Molecular Biology, University of Tokyo, Japan
| | | | | | | | | |
Collapse
|
887
|
Klug CA, Gerety SJ, Shah PC, Chen YY, Rice NR, Rosenberg N, Singh H. The v-abl tyrosine kinase negatively regulates NF-kappa B/Rel factors and blocks kappa gene transcription in pre-B lymphocytes. Genes Dev 1994; 8:678-87. [PMID: 7926758 DOI: 10.1101/gad.8.6.678] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Transformation of B-lineage precursors by the Abelson murine leukemia virus appears to arrest development at the pre-B stage. Abelson-transformed pre-B cell lines generally retain transcriptionally inactive, unrearranged immunoglobulin kappa alleles. We demonstrate that nontransformed pre-B cells expanded from the mouse bone marrow efficiently transcribe unrearranged kappa alleles. In addition, they contain activated complexes of the NF-kappa B/Rel transcription factor family, in contrast with their Abelson-transformed counterparts. Using conditionally transformed pre-B cell lines, we show that the v-abl viral transforming protein, a tyrosine kinase, blocks germ-line kappa gene transcription and negatively regulates NF-kappa B/Rel activity. An active v-abl kinase specifically inhibits the NF-kappa B/Rel-dependent kappa intron enhancer, which is implicated in promoting both transcription and rearrangement of the kappa locus. v-abl inhibits the activated state of NF-kappa B/Rel complexes in a pre-B cell via a post-translational mechanism that results in increased stability of the inhibitory subunit I kappa B alpha. This analysis suggests a molecular pathway by which v-abl inhibits kappa locus transcription and rearrangement.
Collapse
Affiliation(s)
- C A Klug
- Howard Hughes Medical Institute, University of Chicago, Illinois 60637
| | | | | | | | | | | | | |
Collapse
|
888
|
Beyaert R, Fiers W. Molecular mechanisms of tumor necrosis factor-induced cytotoxicity. What we do understand and what we do not. FEBS Lett 1994; 340:9-16. [PMID: 8119415 DOI: 10.1016/0014-5793(94)80163-0] [Citation(s) in RCA: 193] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Although TNF plays an important role in several physiological and pathological conditions, the hallmark of this important cytokine has been its selective cytotoxic activity on tumor cells. Since its cloning in 1984, understanding of how TNF selectively kills tumor cells has been the subject of research in many laboratories. Here we review TNF-induced post-receptor signaling mechanisms which seem to be involved in the pathway to cytotoxicity.
Collapse
Affiliation(s)
- R Beyaert
- Laboratory of Molecular Biology, Gent University, Belgium
| | | |
Collapse
|
889
|
Laduron PM. From receptor internalization to nuclear translocation. New targets for long-term pharmacology. Biochem Pharmacol 1994; 47:3-13. [PMID: 8311843 DOI: 10.1016/0006-2952(94)90431-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Receptors involved in intercellular communication at the cell surface share the capacity to desensitize through molecular and cellular mechanisms. Cellular desensitization is a rapid and dynamic process whereby membrane receptors internalize in response to an excess of agonists. The internalized receptors may recycle rapidly or undergo down-regulation when following a degradative pathway. However, receptor internalization does not necessarily mean degradation; it also represents the initial step of a retrograde signalling system whereby an "interiorized" message, the ligand-receptor complex, can be transported in contrast to second messengers, along axons or in the cytoplasm leading to long-term effects in the nucleus. Such "third messengers" have to undergo nuclear translocation to serve as transcriptional regulators in the control of gene expression. The "third messengers" are thus cytoplasmic proteins, including the receptor itself, which may be associated with internalized vesicles and released by mechanisms which have not yet been elucidated. They represent already good targets for the development of new drugs, and multi-targeting and synergistic approaches are likely to increase their usefulness.
Collapse
Affiliation(s)
- P M Laduron
- School of Pharmacy, University of Louvain, Brussels, Belgium
| |
Collapse
|
890
|
Manning AM, Anderson DC. Chapter 24. Transcription Factor NF-κB: An Emerging Regulator of Inflammation. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 1994. [DOI: 10.1016/s0065-7743(08)60737-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
891
|
Welsh N, Eizirik DL, Sandler S. Nitric oxide and pancreatic beta-cell destruction in insulin dependent diabetes mellitus: don't take NO for an answer. Autoimmunity 1994; 18:285-90. [PMID: 7858114 DOI: 10.3109/08916939409009530] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A major surge of interest has recently focused upon nitric oxide (NO) as a mediator of autoimmune destruction of beta-cells in insulin-dependent diabetes mellitus (IDDM). It has been proposed that insulin producing cells in response to cytokines are induced to produce self destructing amounts of NO, and that endothelial cells or islet infiltrating macrophages may induce beta-cell death by releasing cytotoxic levels of NO within the islet. Recent findings in this field are presently discussed and we conclude that although NO might have a role in rodent IDDM, any putative role of NO in the pathogenesis of human IDDM remains to be clarified.
Collapse
Affiliation(s)
- N Welsh
- Department of Medical Cell Biology, Uppsala University, Sweden
| | | | | |
Collapse
|
892
|
Bolander FF. Hormonally Regulated Transcription Factors. Mol Endocrinol 1994. [DOI: 10.1016/b978-0-12-111231-8.50017-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
|
893
|
Abstract
The I kappa B proteins bind to Rel/NF-kappa B transcription factors and modulate their activities. Although originally described only as cytoplasmic inhibitors of Rel/NF-kappa B transcription complexes, it is now clear that I kappa B proteins also have other functions.
Collapse
Affiliation(s)
- T D Gilmore
- Department of Biology, Boston University, MA 02215
| | | |
Collapse
|
894
|
Beg AA, Baldwin AS. The I kappa B proteins: multifunctional regulators of Rel/NF-kappa B transcription factors. Genes Dev 1993; 7:2064-70. [PMID: 8224838 DOI: 10.1101/gad.7.11.2064] [Citation(s) in RCA: 639] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- A A Beg
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill 27599
| | | |
Collapse
|
895
|
Kaltschmidt B, Baeuerle PA, Kaltschmidt C. Potential involvement of the transcription factor NF-kappa B in neurological disorders. Mol Aspects Med 1993; 14:171-90. [PMID: 8264332 DOI: 10.1016/0098-2997(93)90004-w] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Reactive oxygen intermediates (ROIs) are involved in many neurological diseases. Despite the toxic nature of these compounds, low concentrations of ROIs can function as signaling molecules. One target for their signaling function is the inducible transcription factor NF-kappa B. Predominantly in lymphoid cells, induction of NF-kappa B in response to oxidative stress leads to transcriptional activation of many genes which are relevant for pathogen defense. These include the TNF, IL-6, IL-8, GM-CSF, beta-interferon, MHC class I and V-CAM genes. However, NF-kappa B is also abundant in various cell types of the nervous system, including neurons. We propose that NF-kappa B plays a role as a redox-controlled transcriptional activator also in cells of the nervous system and in that property may contribute to neurological disorders. Our finding that some neurons from healthy brain contain constitutively active NF-kappa B suggests a role of NF-kappa B in normal brain function as well.
Collapse
Affiliation(s)
- B Kaltschmidt
- Institute for Biochemistry, University of Freiburg, Germany
| | | | | |
Collapse
|
896
|
Zuber C, Lackie P, Catterall W, Roth J. Polysialic acid is associated with sodium channels and the neural cell adhesion molecule N-CAM in adult rat brain. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)50186-7] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|