Inhibition of Poly(ADP-ribose) Polymerase Activity by Bcl-2 in Association with the Ribosomal Protein S3a

• Published in: Biochemistry (Easton) 2002-01, Vol.41 (3), p.929-934
• Main Authors: Song, Demao, Sakamoto, Shuji, Taniguchi, Taketoshi
• Format: Article
• Language: English
• Subjects: Antibodies; DNA, Complementary - metabolism; Escherichia coli; Gene Library; Glutathione Transferase - metabolism; Humans; Lymphocytes - metabolism; Plasmids; Poly(ADP-ribose) Polymerase Inhibitors; Proto-Oncogene Proteins c-bcl-2 - metabolism; Recombinant Fusion Proteins - immunology; Recombinant Fusion Proteins - metabolism; Ribosomal Proteins - metabolism; Thrombin - metabolism
• ISSN: 0006-2960; 1520-4995
• DOI: 10.1021/bi015669c

We screened a human lymphocyte cDNA library using the yeast two-hybrid system and an automodification domain of PARP as a probe. The DNA sequence of an isolated clone (clone 3-9) was identical to the partial cDNA sequence of the human ribosomal protein S3a. We confirmed that PARP interacts with clone 3-9 by performing binding studies using a GST−3-9 fusion protein as bait. We also demonstrated that native S3a in nuclear extracts of HL-60 cells interacts with the automodification domain of PARP and that PARP from nuclear extracts is coprecipitated with the GST−3-9 fusion protein. Furthermore, we demonstrated that Bcl-2 interacts with PARP in association with S3a and that the interaction of S3a and Bcl-2 with PARP causes a significant decrease in PARP activity. Since Bcl-2 failed to inhibit PARP activity in the absence of S3a, we suggest that Bcl-2 together with S3a prevents apoptosis probably by inhibiting PARP activity.