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. The apoptogenic cooperation between AIF and CypA did not rely on the CypA peptidyl-prolyl cis-trans isomerase activity. In Cyp-expressing cells, AIF overexpression augmented apoptotic chromatinolysis. The AIF-dependent large-scale DNA fragmentation was less pronounced in CypA knockout cells as compared to controls. AIF mutants lacking the CypA-binding domain were inefficient apoptosis sensitizers in transfection experiments. Moreover, AIF failed to sensitize CypA knockout cells to apoptosis induction, and this defect in the AIF response was reversed by reintroduction of the CypA gene into CypA-deficient cells. In summary, AIF and CypA collaborate in chromatinolysis.
Candé
Céline
C
CNRS-UMR8125, Institut Gustave Roussy, Pavillon de Recherche 1, 39 rue Camille-Desmoulins, F-94805 Villejuif, France.
Vahsen
Nicola
N
Kouranti
Ilektra
I
Schmitt
Elise
E
Daugas
Eric
E
Spahr
Chris
C
Luban
Jeremy
J
Kroemer
Romano T
RT
Giordanetto
Fabrizio
F
Garrido
Carmen
C
Penninger
Josef M
JM
Kroemer
Guido
G
D017209:Apoptosis / Q000187:drug effects*; D051033:Apoptosis Inducing Factor; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism*; D016895:Culture Media, Serum-Free; D021984:Cyclophilin A / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005420:Flavoproteins / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D019169:Jurkat Cells; D008164:Luminescent Proteins / Q000378:metabolism; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000378:metabolism*; D008958:Models, Molecular; D011994:Recombinant Proteins / Q000378:metabolism; D017384:Sequence Deletion; D019311:Staurosporine / Q000494:pharmacology; D014746:Vimentin / Q000378:metabolism
C494829:AIFM1 protein, human; D051033:Apoptosis Inducing Factor; D002843:Chromatin; D016895:Culture Media, Serum-Free; D004791:Enzyme Inhibitors; D005420:Flavoproteins; D008164:Luminescent Proteins; D008565:Membrane Proteins; D011994:Recombinant Proteins; D014746:Vimentin; D049452:Green Fluorescent Proteins; D021984:Cyclophilin A; D019311:Staurosporine