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Stimulation of the catalytic activity of poly(ADP‐ribosyl) transferase by transcription factor Yin Yang 1
Author(s) -
Griesenbeck Joachim,
Ziegler Mathias,
Tomilin Nikolai,
Schweiger Manfred,
Oei Shiao Li
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)01671-8
Subject(s) - enzyme , biology , transcription (linguistics) , biochemistry , poly adp ribose polymerase , transcription factor , recombinant dna , microbiology and biotechnology , gene , polymerase , philosophy , linguistics
The transcriptional regulator Yin Yang 1 (YY1) has previously been demonstrated to physically interact with poly(ADP‐ribosyl) transferase (ADPRT). This nuclear enzyme catalyzes the synthesis of ADP‐ribose polymers and their attachment to target proteins. It is reported here that YY1 associates preferably with the extensively auto(ADP‐ribosyl)ated form of ADPRT, but not with deproteinized ADP‐ribose polymers. In the presence of YY1 the catalytic rate of ADPRT is enhanced about 10‐fold. This stimulation is in part due to modification of YY1, thus serving as a substrate of the reaction. In addition, automodification of ADPRT is also substantially increased. The activation by YY1 is most pronounced at low concentrations of ADPRT suggesting that the presence of YY1 may either facilitate the formation of catalytically active dimers of ADPRT or lead to the occurrence of active heterooligomers. The potential significance of these observations was verified by analyzing the activity of ADPRT in HeLa nuclear extracts. The endogenous enzyme exhibited an about 10‐fold higher activity as compared to the isolated recombinant protein. It is likely that the heat‐stable transcription factor YY1 contributed to the increased activity of ADPRT detected in the nuclear extracts, because heated extracts had a similar stimulatory effect on isolated ADPRT as isolated YY1 used at comparable concentrations. It is concluded that YY1 may be an important regulator of ADPRT and, therefore, could support the function of ADPRT to facilitate DNA repair.