Poly(ADP-ribose) polymerase cleavage during apoptosis: when and where?
Poly(ADP-ribose) polymerase-1 (PARP-1) plays the active role of "nick sensor" during DNA repair and apoptosis, when it synthesizes ADP-ribose from NAD(+) in the presence of DNA strand breaks. Moreover, PARP-1 becomes a target of apoptotic caspases, which originate two proteolytic fragments of 89 and 24 kDa. The precise relationship between PARP-1 activation and degradation during apoptosis is still a matter of debate. In human Hep-2 cells driven to apoptosis by actinomycin D, we have monitored PARP-1 activity by the mAb 10H, which is specific for the ADP-ribose polymers, and we have observed that poly(ADP-ribose) synthesis is a very early response to the apoptotic stimulus. The analysis of the presence and fate of the p89 proteolytic fragment revealed that PARP-1 proteolysis by caspases is concomitant with poly(ADP-ribose) synthesis and that p89 migrates from the nucleus into the cytoplasm in late apoptotic cells with advanced nuclear fragmentation.
Soldani
C
C
Dipartimento di Biologia Animale, Centro di Studio per I'Istochimica del CNR, Piazza Botta 10, Pavia, I-27100, Italy.
Lazzè
M C
MC
Bottone
M G
MG
Tognon
G
G
Biggiogera
M
M
Pellicciari
C E
CE
Scovassi
A I
AI
D017209:Apoptosis; D015153:Blotting, Western; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004260:DNA Repair; D003609:Dactinomycin / Q000494:pharmacology; D004789:Enzyme Activation; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007202:Indicators and Reagents / Q000494:pharmacology; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D010718:Phosphatidylserines / Q000737:chemistry; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D011419:Propidium / Q000494:pharmacology; D011485:Protein Binding; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D013997:Time Factors; D014407:Tumor Cells, Cultured
D007202:Indicators and Reagents; D010718:Phosphatidylserines; D011500:Protein Synthesis Inhibitors; D003609:Dactinomycin; D011419:Propidium; D011065:Poly(ADP-ribose) Polymerases; D016650:Fluorescein-5-isothiocyanate