1 CNRS-UMR8125, Institut Gustave Roussy, 39 rue Camille-Desmoulins, 94805 Villejuif, France
2 CNRS-UMR5535, Université de Montpellier II, 34293 Montpellier CEDEX 5, France
3 INSERM U-517, Faculty of Medicine and Pharmacy, 7 Boulevard Jeanne d'Arc, 21033 Dijon, France
* Author for correspondence (e-mail: kroemer{at}igr.fr)
Accepted 10 June 2004
![]() |
Summary |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Key words: G3BP, TIA-1, Mitochondria, Programmed cell death
![]() |
Introduction |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Stress defense mechanisms include the activation of DNA repair, as well as increased expression of inducible heat shock proteins (HSPs), a class of molecular chaperones that renaturate denatured proteins. Increased transcription of hsp genes is in part due to the activation of heat shock factor 1 (HSF-1), a transcription factor that redistributes to discrete nuclear structures, thus forming `nuclear stress granules' or `HSF-1 granules' (Jolly et al., 2004; Jolly et al., 1999
; Sandqvist and Sistonen, 2004
). In addition, cells can generate cytoplasmic `stress granules' (SGs) in response to environmental stress (Kedersha and Anderson, 2002
). Such SGs are dynamic cytoplasmic foci at which stalled translation initiation complexes accumulate. SGs appear when translation occurs in the absence of eIF2-GTP-tRNAiMet, the ternary complex that normally loads tRNAiMet onto the small ribosomal subunit (Kedersha et al., 2002
). Stress-induced depletion of eIF2-GTP-tRNAiMet, for instance as a result of inhibitor eIF-2 phosphorylation by PKR and other kinases (e.g. PERK/PEK, GCN2, HR1) or due to the lack of energy-rich phosphates (ATP in equilibrium with GTP), allows the RNA-binding proteins TIA-1 and TIAR to promote the assembly of eIF2eIF5-deficient pre-initiation complexes, the core constituents of SGs (Kedersha et al., 2000
; Kedersha et al., 1999
). As such, SGs are the morphological expression of abortive translational initiation (Kedersha and Anderson, 2002
). They can be detected by following the subcellular redistribution of TIA-1 and the related protein TIAR (both normally in the nucleus), PABP-1 (the poly A-binding protein that accompanies mRNA), and small ribosomal subunits (eIF3, eIF4E, EIF4G), all of which condense into cytoplasmic foci. Another protein that redistributes into SGs (and which can induce SG formation by virtue of its RasGAP-binding activity) is G3BP, an endoribonuclease that may participate in the degradation of SG-associated RNA (Tourriere et al., 2003
; Tourriere et al., 2001
).
Apoptosis is morphologically defined by cellular and nuclear shrinkage (pyknosis), chromatin condensation, blebbing, nuclear fragmentation (karyorrhexis) and formation of apoptotic bodies (Kerr et al., 1972). At the biochemical level, apoptosis of mammalian cells is characterized by mitochondrial membrane permeabilization (MMP) and/or massive caspase activation (Adams, 2003
; Danial and Korsmeyer, 2004
; Green and Kroemer, 1998
; Wang, 2002
). The intrinsic (or stress) pathway leading to apoptosis involves MMP as a rate-limiting event. MMP is regulated, at least in part, by proteins of the Bcl-2 family (Zamzami and Kroemer, 2001
) that are prominent apoptosis regulators. MMP causes bioenergetic failure as well as the release of potentially lethal proteins from the mitochondrial intermembrane space. Such lethal proteins include caspase activators such as cytochrome c, which activates the apoptosome caspase activation complex, once in the cytosol (Wang, 2002
). In addition, MMP causes the release of caspase-independent death effectors such as apoptosis-inducing factor (AIF) (Susin et al., 1999
), a flavoprotein NADH oxidase (Miramar et al., 2001
) that translocates to the nucleus, where it interacts with DNA (Ye et al., 2002
) and forms the cyclophilin-dependent `degradeosome', a DNA degradation complex (Cande et al., 2004
; Cregan et al., 2004
; Parrish and Xue, 2003
).
Importantly, stress defense and apoptotic dismantling tend to occur in a mutually exclusive fashion. Thus, HSPs act as potent apoptosis inhibitors (Garrido et al., 2001; Mosser and Morimoto, 2004
) whereas caspases actively destroy proteins involved in DNA repair (Creagh and Martin, 2001
). Nonetheless, no information was available on the crosstalk between apoptosis and SGs. Here, we report that AIF functions as a negative regulator of stress granules. Removal of AIF by knock-out or RNA interference exacerbates SG formation. SG inhibition by AIF is mediated by the hitherto undetermined effects of AIF on GSH levels.
![]() |
Materials and Methods |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Experimental conditions
Cells were treated with sodium arsenate heptahydrate (NaHAsO4, 1 mM, 3 hours), S-nitroso-N-acetyl-penicillamine (SNAP, 1 mM, 3 hours) sodium nitroprusside (SNP, 1 mM, 3 hours for HeLa cells and 0.1 mM for ES cells), paraquat (2 mM, 3 hours), tert-butyl-hydroperoxide and/or Z-VAD.fmk (100 µM, Bachem, Torrance, CA). Cells were also pretreated for 1 hour before stimulation with gluthathione ethyl ester (10 mM) or N-acetyl-L-cysteine (15 mM). To deplete glutathione (GSH), cells were incubated with buthionine-(S,R)-sulfoxamine (BSO, 100 µM, 24 hours), an irreversible inhibitor of -glutamylcysteine synthetase. All pro- and anti-oxidants were purchased from Sigma.
Cytofluorometric determination of mitochondrial parameters
The GSH content was determined using monochlorobimane (MCB, 50 µM) (Macho et al., 1997). The mitochondrial membrane potential (
m) was determined with 3,3-dihexyl-oxacarbocyanine (DiOC(6)3, 20 nM) (Zamzami et al., 1995
). Autofluorescence (424 nm emission) was measured after UV excitation at 360 nm to evaluate the NAD(P)H content (Gendron et al., 2001
). These fluorochromes were purchased from Molecular Probes (Eugene, OR). Cells were also stained for the detection of phosphatidylserine exposure with an annexin-V detection kit (Bender Medsystems, Vienna, Austria).
Transfection
HeLa cells were transfected with the pcDNA3.1 vector expressing enhanced V5/HIS (Invitrogen, Carlsbad, CA), different AIF constructs fused at their C-terminus to V5/HIS (Garrido et al., 2003; Schmitt et al., 2003
), G3BP-GFP (Tourriere et al., 2003
), TIA-1GFP or PABP-GFP (Kedersha et al., 2000
), using Lipofectamin 2000 (Invitrogen). TIA-1GFP and PABP-GFP vectors were kindly provided by Nancy Kedersha (Harvard Medical School, Boston, MA).
Knock-down of AIF by siRNA
HeLa cells were transfected with a small interfering RNA (siRNA) double-stranded oligonucleotide designed to interfere with the expression of human AIF (sense strain: 5'-GAUCCUCCCCGAAUACCUCTT-3', Proligo, Boulder, CO), using an Oligofectamine procedure (Invitrogen). As a control, we used an oligonucleotide designed to downregulate the non-essential gene emerin (Harborth et al., 2001) or an oligonucleotide specific for mouse AIF (sense strain: 5'-AUGCAGAACUCCAAGCACGTT-3') that does not affect human AIF.
Immunofluorescence
Cells were fixed with paraformaldehyde (4% w/v) in PBS. Cells were then stained for the detection of AIF (monoclonal from Santa Cruz Biotechnology, Santa Cruz, CA) or TIA-1 (goat antiserum from Santa Cruz Biotechnology), or cytochrome c (monoclonal from Pharmingen, San Diego, CA) or HSF1 (rat monoclonal from Upstate Biotechnology, Charlottesville, VA) and revealed with suitable anti-IgG conjugates [donkey anti-goat Alexa568 and anti-mouse Alexa488 (or 568) and donkey anti-rat Alexa568 from Molecular Probes] and counterstained with Hoechst 33342 (Castedo et al., 2002; Perfettini et al., 2004
). AIF constructs were detected with V5 antibody (monoclonal from Invitrogen). Cells were viewed with a Leika DMIRE2 microscope, and images were digitally captured using a CCD-DC 300F digital camera and compiled using Adobe Photoshop® software (v5.5).
Immunoblot
Western blot was done with HeLa sonicated extract (15 µg) in an isotonic buffer (250 mM sucrose, 10 mM KCl, 1.5 mM MgCl2, 1 mM EDTA, 1 mM dithiothreitol, 0.1 mM PMSF, 10 mM Tris-HCl, pH 7.4). Protein concentration was measured by means of the Bradford protein assay (BioRad, Hercules, CA). Proteins were separated in 12% SDS-polyacrylamide gel. Immunoblot analysis was realized using specific antibodies and enhanced chemoluminescence (ECL)-based detection (Pierce, Rockford, IL). The antibodies used were the mouse monoclonal anti-human HSP27 and polyclonal anti-human HSP70, (StressGen, Victoria, Canada) and mouse antibodies raised against human AIF (Pharmingen,) and raised against human GAPDH (Chemicon, Temecula, CA).
![]() |
Results and Discussion |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
|
|
SG formation occurs independently from apoptosis
Based on the facts that AIF participates in cell death execution (Cande et al., 2002) and that arsenate can induce apoptosis (Larochette et al., 1999
), we addressed the temporary and functional relationship between SG formation and apoptosis. In conditions in which arsenate (1 mM) induced massive SG formation (that is within 1-3 hours, in cells in which AIF is depleted by siRNA), mitochondria were still retaining cytochrome c (Fig. 3A) and maintained a near-to-normal transmembrane potential (
m), as quantified with the
m-sensitive fluorochrome DiOC(6)3 (Fig. 3B). Accordingly, such SG-positive cells lacked one of the hallmarks of apoptosis, namely phosphatidylserine exposure on the plasma membrane surface (Fig. 3C). This indicates that, when SGs are elicited by arsenate combined with siRNA of AIF, they are formed well before apoptosis is induced. In accordance with this interpretation, we found that addition of the caspase inhibitor Z-VAD.fmk did not reduce the frequency of SG-containing cells (Fig. 3D), although Z-VAD.fmk did reduce the induction of nuclear apoptosis by arsenite as an internal control of its efficacy (Fig. 3E). Similarly, no inhibitory effect of Bcl-2 overexpression on SG formation was detected (not shown). In summary, it appears that AIF functions as an endogenous repressor of SG formation independently from its capacity to modulate apoptosis.
|
To study further the role of AIF in SG assembly independently of its role in apoptosis we decided to induce SGs by transfection with G3BP (or a G3B-GFP fusion protein) (Tourriere et al., 2003), a protein that has been shown to have a phosphorylation-dependent RNase activity upon binding to myc mRNA (Tourriere et al., 2001
), and actually acts as an endoribonuclease in stress granules (Tourriere et al., 2003
). G3BP aggregates and leads to the accumulation of the 48S preinitiation complex within SGs, but does not induce apoptosis. Upon G3BP-GFP transfection, HeLa cells that were depleted of AIF formed more SGs than control cells expressing AIF did (Fig. 4). This difference persisted when different deletion and phosphorylation mutants affecting the SG-inducing capacity of G3BP (as regulated by arsenate) were assessed. In particular, mutant S149E, which is less effective at inducing SG formation, was also sensitive to AIF depletion (Fig. 4). Together these data suggest that SG formation and apoptosis are unrelated phenomena, although both are influenced by AIF.
|
AIF domains involved in SG regulation
When human AIF was downregulated with specifically designed RNA oligonucleotide heteroduplexes in HeLa cells, it was possible to re-transfect the cells with murine AIF constructs (which are not affected by the human AIF-specific siRNA). Although G3BP-GFP transfection induced SGs in AIF siRNA-pretreated HeLa cells cotransfected with a ß-galactosidase (ß-Gal)-expressing control vector, it was much less efficient in inducing SGs in cells cotransfected with full length mouse AIF, which is imported into mitochondria (Susin et al., 1999; Loeffler et al., 2001
) (Fig. 5A). The SG-suppressive effect of re-transfected AIF disappeared upon removal of the mitochondrial localization sequence (
1-100), indicating that only mitochondrial AIF can suppress SG. To map the functional region of AIF required for SG suppression, we transfected HeLa cells lacking endogenous AIF expression (as a result of human AIF-specific siRNA) with a battery of different mouse AIF deletion constructs affecting the binding domains for flavine adenine nucleotide (FAD), nicotine adenine dinucleotide (NAD) or the C-terminus, which is required for the apoptogenic function of AIF (Loeffler et al., 2001
; Mate et al., 2002
; Ye et al., 2002
) (Fig. 5B). In contrast to wild-type AIF, two deletion mutants effecting the NAD-binding capacity of AIF (AIF
228-347 and
322-333) (Loeffler et al., 2001
; Mate et al., 2002
) partially lost their SG-suppressing potential (Fig. 5C), suggesting that the redox function of AIF, which is largely determined by this region (Mate et al., 2002
; Miramar et al., 2001
), is important for SG inhibition. By contrast, deletion of the C-terminal region (AIF
567-609), which abolishes apoptosis induction by AIF (Schmitt et al., 2003
), did not affect its SG-inhibitory potential. Similar results were obtained when SGs were induced by arsenate (Fig. 5D). Thus, the SG-inhibitory effect of AIF is related to the mitochondrial, non-apoptotic function of AIF and is likely to involve the protein's redox activity.
|
Redox effects of AIF and their impact on SG formation
Arsenate treatment had major effects on the cellular redox metabolism. In AIF-sufficient ES cells, arsenate caused a shift in the autofluorescence, elicited at 354 nm, indicating a depletion of the pool of reduced NADH or NADPH. This arsenate-triggered NAD(P)H depletion was much attenuated in AIF-deficient ES cells (Fig. 6A). In stark contrast, the absence of AIF sensitized cells to the depletion of non-oxidized glutathione (GSH) (Fig. 6B). Thus, the absence of AIF shifts the cellular response to oxidative stress from NAD(P)H oxidation to GSH depletion, in line with the fact that the protein has an NADH oxidase activity (Mate et al., 2002; Miramar et al., 2001
). This AIF effect was also observed in response to other inducers of oxidative stress, namely the two NO donors SNAP (S-nitroso-N-acetyl-penicillamine) and sodium nitroprusside, as well as paraquat, which induces mitochondrial oxidative stress (Costantini et al., 1995
). These AIF effects on the redox balance were found both in HeLa cells subjected to AIF knock-down and in ES cells subjected to AIF knock-out (Fig. 6C-F). Next, we determined whether the maintenance of elevated GSH levels by addition of a cell-permeable GSH ester or N-acetylcysteine (NAC) (Droge et al., 1994
) would suppress the induction of SGs. The stimulation of SG formation by AIF was blunted by either GSH ester or NAC. This was found both when SGs were induced by arsenate (Fig. 7A) and when SGs were stimulated by G3BP-GFP (Fig. 7B). Thus, it is likely that GSH is (one of) the endogenous repressor(s) of SG formation and that AIF acts indirectly to repress SG aggregation, by maintaining normal GSH levels.
|
|
![]() |
Concluding remarks |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Together, these data point to a hitherto unexpected crosstalk between apoptosis and the stress response. Although the execution of apoptotic cell death and SG formation are mechanistically unrelated, AIF can be placed in the intersection of the two phenomena. When present in the nucleus, AIF actively participates in the formation of the `degradosome' to digest DNA (Cande et al., 2004; Parrish and Xue, 2003
) and to seal the cell's irreversible fate. When present in mitochondria, AIF catalyzes redox reactions whose optimal and physiologically relevant electron donors and acceptors remain elusive. Nonetheless, AIF determines the balance between NAD(P)H and GSH under stress conditions and (directly and indirectly) maintains the levels of non-oxidized GSH, which in turn determines the level of SG formation. Both functions of AIF, the pro-apoptotic function and the redox-active, SG-modulatory one, can be separated because they rely on distinct molecular domains. Nonetheless, it remains intriguing that the same molecule can regulate apoptosis as well as the defense against stress, depending on its subcellular localization. Future studies will have to address the possibility that other pro-apoptotic proteins, similarly to AIF, have a second function that blunts adaptive stress responses such as SG formation. If so, it could be postulated that apoptosis regulators not only determine the probability of fulminant self-execution but also modulate the cell's capacity to respond to environmental challenges and to mount a slow, adaptive response against stress.
![]() |
Acknowledgments |
---|
![]() |
References |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Adams, J. M. (2003). Ways of dying: multiple pathways to apoptosis. Genes Dev. 17, 2481-2495.
Cande, C., Cecconi, F., Dessen, P. and Kroemer, G. (2002). Apoptosis-inducing factor (AIF): key to the conserved caspase-independent pathways of cell death? J. Cell Sci. 115, 4727-4734.[CrossRef][Medline]
Cande, C., Vahsen, N., Kouranti, I., Schmitt, E., Daugas, E., Spahr, C., Luban, J., Kroemer, R. T., Giordanetto, F., Garrido, C. et al. (2004). AIF and cyclophilin A cooperate in apoptosis-associated chromatinolysis. Oncogene 23, 1514-1521.[CrossRef][Medline]
Castedo, M., Roumier, T., Blanco, J., Ferri, K. F., Barretina, J., Andreau, K., Perfettini, J.-L., Armendola, A., Nardacci, R., LeDuc, P. et al. (2002). Sequential involvement of Cdk1, mTOR and p53 in apoptosis induced by the human immunodeficiency virus-1 envelope. EMBO J. 21, 4070-4080.
Costantini, P., Petronilli, V., Colonna, R. and Bernardi, P. (1995). On the effects of paraquat on isolated mitochondria. Evidence that paraquat causes opening of the cyclosporin A-sensitive permeability transition pore synergistically with nitric oxide. Toxicology 99, 77-88.[CrossRef][Medline]
Creagh, E. M. and Martin, S. J. (2001). Caspases: cellular demolition experts. Biochem. Soc. Trans. 29, 696-702.[CrossRef][Medline]
Cregan, S. P., Dawson, V. L. and Slack, R. S. (2004). Role of AIF in caspase-dependent and caspase-independent cell death. Oncogene 23, 2785-2796.[CrossRef][Medline]
Danial, N. N. and Korsmeyer, S. (2004). Cell death: critical control points. Cell 116, 205-219.[CrossRef][Medline]
Droge, W., Schulze-Osthoff, K., Mihm, S., Galter, D., Schenk, H., Eck, H. P., Roth, S. and Gmunder, H. (1994). Functions of glutathione and glutathione disulfide in immunology and immunopathology. FASEB J. 8, 1131-1138.
Garrido, C., Gurbuxani, S., Ravagnan, L. and Kroemer, G. (2001). Heat shock proteins: endogenous modulators of apoptotic cell death. Biochem. Biophys. Res. Commun. 286, 433-442.[CrossRef][Medline]
Garrido, C., Schmitt, E., Cande, C., Vahsen, N., Parcellier, A. and Kroemer, G. (2003). HSP27 and HSP70: potentially oncogenic apoptosis inhibitors. Cell Cycle 2, 579-584.[Medline]
Gendron, M. C., Schrantz, N., Metivier, D., Kroemer, G., Maciorowska, Z., Sureau, F., Koester, S. and Petit, P. X. (2001). Oxidation of pyridine nucleotides during Fas- and ceramide-induced apoptosis in Jurkat cells: correlation with changes in mitochondria, glutathione depletion, intracellular acidification and caspase 3 activation. Biochem. J. 353, 357-367.[CrossRef][Medline]
Green, D. R. and Kroemer, G. (1998). The central executioner of apoptosis: mitochondria or caspases? Trends Cell Biol. 8, 267-271.[CrossRef][Medline]
Gurbuxani, S., Schmitt, E., Cande, C., Parcellier, A., Hamman, A., Daugas, E., Kouranti, I., Spahr, C., Pance, A., Kroemer, G. et al. (2003). Heat shock protein 70-binding inhibits the nuclear import of apoptosis inducing factor. Oncogene 22, 6669-6678.[CrossRef][Medline]
Harborth, J., Elbashir, S. M., Bechert, K., Tuschl, T. and Weber, K. (2001). Identification of essential genes in cultured mammalian cells using small interfering RNAs. J. Cell Sci. 114, 4557-4565.[Medline]
Jolly, C., Usson, Y. and Morimoto, R. I. (1999). Rapid and reversible relocalization of heat shock factor 1 within seconds to nuclear stress granules. Proc. Natl. Acad. Sci. USA 96, 6769-6774.
Jolly, C., Metz, A., Govin, J., Vigneron, M., Turner, B. M., Khochbin, S. and Vourc'h, C. (2004). Stress-induced transcription of satellite III repeats. J. Cell Biol. 164, 25-33.
Joza, N., Susin, S. A., Daugas, E., Stanford, W. L., Cho, S. K., Li, C. Y. J., Sasaki, T., Elia, A. J., Cheng, H.-Y. M., Ravagnan, L. et al. (2001). Essential role of the mitochondrial apoptosis inducing factor in programmed cell death. Nature 410, 549-554.[CrossRef][Medline]
Kedersha, N. and Anderson, P. (2002). Stress granules: sites of mRNA triage that regulate mRNA stability and translatability. Biochem. Soc. Trans. 30, 963-969.[Medline]
Kedersha, N. L., Gupta, M., Li, W., Miller, I. and Anderson, P. (1999). RNA-binding proteins TIA-1 and TIAR link the phosphorylation of eIF-2 alpha to the assembly of mammalian stress granules. J. Cell Biol. 147, 1431-1442.
Kedersha, N., Cho, M. R., Li, W., Yacono, P. W., Chen, S., Gilks, N., Golan, D. E. and Anderson, P. (2000). Dynamic shuttling of TIA-1 accompanies the recruitment of mRNA to mammalian stress granules. J. Cell Biol. 151, 1257-1268.
Kedersha, N., Chen, S., Gilks, N., Li, W., Miller, I. J., Stahl, J. and Anderson, P. (2002). Evidence that ternary complex (eIF2-GTP-tRNA(i)(Met))-deficient preinitiation complexes are core constituents of mammalian stress granules. Mol. Biol. Cell 13, 195-210.
Kerr, J. F. R., Wyllie, A. H. and Currie, A. R. (1972). Apoptosis: a basic biological phenomenon with wide-ranging implications in tissue kinetics. Br. J. Cancer 26, 239-257.[Medline]
Larochette, N., Decaudin, D., Jacotot, E., Brenner, C., Marzo, I., Susin, S. A., Zamzami, N., Xie, Z., Reed, J. C. and Kroemer, G. (1999). Arsenite induces apoptosis via a direct effect on the mitochondrial permeability transition pore. Exp. Cell Res. 249, 413-421.[CrossRef][Medline]
Loeffler, M., Daugas, E., Susin, S. A., Zamzami, N., Métivier, D., Nieminen, A.-L., Brothers, G., Penninger, J. M. and Kroemer, G. (2001). Dominant cell death induction by extramitochondrially targeted apoptosis inducing factor. FASEB J. 15, 758-767.
Macho, A., Hirsch, T., Marzo, I., Marchetti, P., Dallaporta, B., Susin, S. A., Zamzami, N. and Kroemer, G. (1997). Glutathione depletion is an early and calcium elevation a late event of thymocyte apoptosis. J. Immunol. 158, 4612-4619.[Abstract]
Mate, M. J., Ortiz-Lombardia, M., Boitel, B., Haouz, A., Tello, D., Susin, S. A., Penninger, J., Kroemer, G. and Alzari, P. M. (2002). The crystal structure of the mouse apoptosis-inducing factor AIF. Nat. Struct. Biol. 9, 442-446.[CrossRef][Medline]
Miramar, M. D., Costantini, P., Ravagnan, L., Saraiva, L. M., Haouzi, D., Brothers, G., Penninger, J. M., Peleato, M. L., Kroemer, G. and Susin, S. A. (2001). NADH-oxidase activity of mitochondrial apoptosis inducing factor (AIF). J. Biol. Chem. 276, 16391-16398.
Mosser, D. D. and Morimoto, R. I. (2004). Molecular chaperones and the stress of oncogenesis. Oncogene 23, 2907-2918.[CrossRef][Medline]
Parrish, J. Z. and Xue, D. (2003). Functional genomic analysis of apoptotic DNA degradation in C. elegans. Mol. Cell 11, 987-996.[Medline]
Perfettini, J.-L., Roumier, T., Castedo, M., Larochette, N., Boya, P., Reynal, B., Lazar, V., Ciccosanti, F., Nardacci, R., Penninger, J. M. et al. (2004). NF-kB and p53 are the dominant apoptosis-inducing transcription factors elicited by the HIV-1 envelope. J. Exp. Med. 199, 629-640.
Sandqvist, A. and Sistonen, L. (2004). Nuclear stress granules: the awakening of a sleeping beauty? J. Cell Biol. 164, 15-17.
Schmitt, E., Gurbuxani, S., Cande, C., Parcellier, A., Hamman, A., Morales, M. C., Kroemer, G., Giordanetto, F., Jaattela, M., Pance, A. et al. (2003). Chemosensitization by a non-apoptogenic heat shock protein 70-binding apoptosis inducing factor mutant. Cancer Res. 63, 8233-8240.
Susin, S. A., Lorenzo, H. K., Zamzami, N., Marzo, I., Snow, B. E., Brothers, G. M., Mangion, J., Jacotot, E., Costantini, P., Loeffler, M. et al. (1999). Molecular characterization of mitochondrial apoptosis-inducing factor. Nature 397, 441-446.[CrossRef][Medline]
Thompson, C. B. (1995). Apoptosis in the pathogenesis and treatment of disease. Science 267, 1456-1462.[Medline]
Tourriere, H., Gallouzi, I., Chebli, K., Capony, J. P., Mouaikel, J., van der Geer, P. and Tazi, J. (2001). RasGAP-associated endoribonuclease G3Bp: selective RNA degradation and phosphorylation-dependent localization. Mol. Cell. Biol. 21, 7747-7760.
Tourriere, H., Chebli, K., Zekri, L., Courselaud, B., Blanchard, J. M., Bertrand, E. and Tazi, J. (2003). The RasGAP-associated endoribonuclease G3BP assembles stress granules. J. Cell Biol. 160, 823-831.
Wang, X. (2002). The expanding role of mitochondria in apoptosis. Genes Dev. 15, 2922-2933.
Ye, H., Cande, C., Stephanou, N. C., Jiang, S., Gurbuxani, S., Larochette, N., Daugas, E., Garrido, C., Kroemer, G. and Wu, H. (2002). DNA binding as a structural requirement for the apoptogenic action of AIF. Nat. Struct. Biol. 9, 680-684.[CrossRef][Medline]
Zamzami, N. and Kroemer, G. (2001). Mitochondria in apoptosis. How Pandora's box opens. Nat. Rev. Mol. Cell Biol. 2, 67-71.[CrossRef][Medline]
Zamzami, N., Marchetti, P., Castedo, M., Zanin, C., Vayssière, J.-L., Petit, P. X. and Kroemer, G. (1995). Reduction in mitochondrial potential constitutes an early irreversible step of programmed lymphocyte death in vivo. J. Exp. Med. 181, 1661-1672.[Abstract]
Related articles in JCS: