Functional interaction of poly(ADP-ribose) with the 20S proteasome in vitro.
The nuclear enzyme poly(ADP-ribosyl) transferase (pADPRT) catalyzes the formation of poly(ADP-ribose) from NAD+. Several nuclear proteins and pADPRT itself are targets for the modification by poly(ADP-ribosyl)ation. It is demonstrated here that poly(ADP-ribose) or pADPRT automodified with poly(ADP-ribose) interacts noncovalently with the 20S proteasome in vitro. The interaction of pADPRT with the 20S proteasome requires the long ADP-ribose polymers formed by automodification of the pADPRT with poly(ADP-ribose). As a result pADPRT automodified with short ADP-ribose oligomers is unable to associate with the 20S proteasome. The interaction with poly(ADP-ribose) causes a specific stimulation of the peptidase activity of the 20S proteasome. Modified pADPRT does not serve as a substrate for the degradation by the 20S proteasome. No covalent modification of the 20S proteasome by ADP-ribosylation was observed. The results may point to a functional relationship between pADPRT and the 20S proteasome in a pathway protecting the cell from oxidative damage.
Mayer-Kuckuk
P
P
Institute of Biochemistry, Free University Berlin, Thielallee 63, Berlin, 14195, Germany. kuckuk@chemie.fu-berlin.de
Ullrich
O
O
Ziegler
M
M
Grune
T
T
Schweiger
M
M
D003546:Cysteine Endopeptidases / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism*; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism* / Q000502:physiology; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding; D011993:Recombinant Fusion Proteins
D009097:Multienzyme Complexes; D011993:Recombinant Fusion Proteins; D011064:Poly Adenosine Diphosphate Ribose; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex