AIF deficiency compromises oxidative phosphorylation.

Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein that, after apoptosis induction, translocates to the nucleus where it participates in apoptotic chromatinolysis. Here, we show that human or mouse cells lacking AIF as a result of homologous recombination or small interfering RNA exhibit high lactate production and enhanced dependency on glycolytic ATP generation, due to severe reduction of respiratory chain complex I activity. Although AIF itself is not a part of complex I, AIF-deficient cells exhibit a reduced content of complex I and of its components, pointing to a role of AIF in the biogenesis and/or maintenance of this polyprotein complex.

An AIF orthologue regulates apoptosis in yeast.

Apoptosis-inducing factor (AIF), a key regulator of cell death, is essential for normal mammalian development and participates in pathological apoptosis. The proapoptotic nature of AIF and its mode of action are controversial. Here, we show that the yeast AIF homologue Ynr074cp controls yeast apoptosis.

Nuclear localization of apoptosis protease activating factor-1 predicts survival after tumor resection in early-stage non-small cell lung cancer.

The proapoptotic protein apoptosis protein activating factor-1 (Apaf-1), which is normally located in the cytoplasm, can translocate to the nucleus before non-small cell lung carcinoma (NSCLC) cells manifest signs of apoptosis such as mitochondrial damage, caspase activation, or chromatin condensation. This may indicate a stage of imminent apoptosis. Importantly, we found that 24% (15 of 62) of resected stage I NSCLC (T(1)N(0)M(0) or T(2)N(0)M(0)), manifested a marked nuclear localization of Apaf-1 (Apaf-1(Nuc)), as compared with the mostly cytoplasmic localization of Apaf-1 found in the remaining tumors (Apaf-1(Cyt)).

Regulation of cytoplasmic stress granules by apoptosis-inducing factor.

Stress granules (SG) are dynamic cytoplasmic foci in which stalled translation initiation complexes accumulate. In conditions of acute cellular redox, stress cells manipulated to lose the expression of apoptosis-inducing factor (AIF) nucleate SG signature proteins (e.g.

AIF and cyclophilin A cooperate in apoptosis-associated chromatinolysis.

Cyclophilin A (CypA) was determined to interact with apoptosis-inducing factor (AIF) by mass spectroscopy, coimmunoprecipitation, pull-down assays, and molecular modeling. During the initial, caspase-independent stage of chromatin condensation that accompanies apoptosis, AIF and CypA were found to coimmunolocalize in the nucleus. Recombinant AIF and CypA proteins synergized in vitro in the degradation of plasmid DNA, as well as in the capacity to induce DNA loss in purified nuclei.

Chemosensitization by a non-apoptogenic heat shock protein 70-binding apoptosis-inducing factor mutant.

Heat shock protein 70 (HSP70) inhibits apoptosis and thereby increases the survival of cells exposed to a wide range of lethal stimuli. HSP70 has also been shown to increase the tumorigenicity of cancer cells in rodent models. The protective function of this chaperone involves interaction and neutralization of the caspase activator apoptotic protease activation factor-1 and the mitochondrial flavoprotein apoptosis-inducing factor (AIF).

Heat shock protein 70 binding inhibits the nuclear import of apoptosis-inducing factor.

Heat shock protein 70 (HSP70) can inhibit apoptosis by neutralizing and interacting with apoptosis-inducing factor (AIF), a mitochondrial flavoprotein that translocates upon apoptosis induction to the nucleus, via the cytosol. Here, we show that only members of the HSP70 family interact with AIF. Systematic deletion mapping revealed the existence of three distinct functional regions in the AIF protein: (1) a region between amino acids 150 and 228 that binds HSP70, (2) a domain between residues 367 and 459 that includes a nuclear localization sequence (NLS) and (3) a C-terminal domain beyond residue 567 required for its chromatin-condensing activity.

HSP27 and HSP70: potentially oncogenic apoptosis inhibitors.

Stress or heat shock proteins (HSPs) such as HSP27 and HSP70 are expressed in response to a wide variety of physiological and environmental insults including heat, reactive oxygen species or anticancer drugs. Their overexpression allows cells to survive to otherwise lethal conditions. Several different mechanisms may account for the cytoprotective activity of HSP27 and HSP70.

Involvement of apoptosis-inducing factor in neuronal death after hypoxia-ischemia in the neonatal rat brain.

Apoptosis-inducing factor (AIF) triggers apoptosis in a caspase-independent manner. Here we report for the first time involvement of AIF in neuronal death induced by cerebral ischemia. Unilateral cerebral hypoxia-ischemia (HI) was induced in 7-day-old rats by ligation of the left carotid artery and hypoxia (7.

Proteinase-activated receptor-2 and human lung epithelial cells: disarming by neutrophil serine proteinases.

Proteinase-activated receptor (PAR)-2 is cleaved within its aminoterminal extracellular domain by serine proteinases such as trypsin, unmasking a new aminoterminus starting with the sequence SLIGKV, which binds intramolecularly and activates the receptor. PAR-2 has been reported to be involved in inflammation within the lungs. We show that PAR-2 is expressed not only by human alveolar (A549), but also by bronchial (16HBE) epithelial cell lines, using RT-PCR and flow cytometry with a PAR-2 antibody whose epitope maps over the trypsin cleavage site.

Apoptosis-inducing factor (AIF): key to the conserved caspase-independent pathways of cell death?

Numerous pro-apoptotic signal transducing molecules act on mitochondria and provoke the permeabilization of the outer mitochondrial membrane, thereby triggering the release of potentially toxic mitochondrial proteins. One of these proteins, apoptosis-inducing factor (AIF), is a phylogenetically old flavoprotein which, in healthy cells, is confined to the mitochondrial intermembrane space. Upon lethal signaling, AIF translocates, via the cytosol, to the nucleus where it binds to DNA and provokes caspase-independent chromatin condensation.

DNA binding is required for the apoptogenic action of apoptosis inducing factor.

The execution of apoptosis or programmed cell death comprises both caspase-dependent and caspase-independent processes. Apoptosis inducing factor (AIF) was identified as a major player in caspase-independent cell death. It induces chromatin condensation and initial DNA cleavage via an unknown molecular mechanism.

Apoptosis-inducing factor (AIF): a novel caspase-independent death effector released from mitochondria.

Apoptosis-inducing factor (AIF) is a phylogenetically ancient mitochondrial intermembrane flavoprotein endowed with the unique capacity to induce caspase-independent peripheral chromatin condensation and large-scale DNA fragmentation when added to purified nuclei. In addition to its apoptogenic activity on nuclei, AIF can also participate in the regulation of apoptotic mitochondrial membrane permeabilization and exhibits an NADH oxidase activity. Under normal circumstances, AIF is secluded behind the outer mitochondrial membrane.