Structural basis for the conserved binding mechanism of MDM2-inhibiting peptides and anti-apoptotic Bcl-2 family proteins.
The interaction between tumor suppressor p53 and the anti-apoptotic Bcl-2 family proteins serves a critical role in the transcription-independent apoptosis mechanism of p53. Our previous studies showed that an MDM2-inhibiting motif (residues 15-29) in the p53 transactivation domain (p53TAD) mediates the interaction with anti-apoptotic Bcl-2 family proteins. In this study, we provided structural models of the complexes between the MDM2-inhibiting p53TAD peptide and Mcl-1, Bcl-w, and Kaposi sarcoma-associated herpes virus (KSHV) Bcl-2 using NMR chemical shift perturbation data. The binding mode of the MDM2-inhibiting p53TAD peptide is highly conserved among the anti-apoptotic Bcl-2 family proteins despite their distinct specificities for pro-apoptotic Bcl-2 family proteins. We also identified the binding of a phage-display-derived MDM2-inhibiting peptide 12-1 to anti-apoptotic Bcl-XL protein by using NMR spectroscopy. The structural model of the Bcl-XL/12-1 peptide complex revealed that the conserved residues Phe4, Trp8, and Leu11 in the MDM2-inhibiting peptide fit into a hydrophobic cleft of Bcl-XL in a manner similar to that of pro-apoptotic Bcl-2 homology 3 (BH3) peptides. Our results shed light on the mechanism underlying dual-targeting of the FxxxWxxL-based α-helical motif to MDM2 and anti-apoptotic Bcl-2 family proteins for anticancer therapy.
Medical Proteomics Research Center, KRIBB, Daejeon 305-806, Republic of Korea; Department of Bio-Analytical Science, University of Science and Technology, Daejeon 305-350, Republic of Korea.
Min-Sung
MS
Lee
Medical Proteomics Research Center, KRIBB, Daejeon 305-806, Republic of Korea; College of Pharmacy, Chungbuk National University, Cheongju 361-763, Republic of Korea.
Ji-Hyang
JH
Ha
Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore 637511, Singapore.
Ho Sup
HS
Yoon
College of Pharmacy, Chungbuk National University, Cheongju 361-763, Republic of Korea.
Chong-Kil
CK
Lee
Medical Proteomics Research Center, KRIBB, Daejeon 305-806, Republic of Korea; Department of Bio-Analytical Science, University of Science and Technology, Daejeon 305-350, Republic of Korea. Electronic address: swchi@kribb.re.kr.
Seung-Wook
SW
Chi
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D051017:Apoptosis Regulatory Proteins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D064549:Myeloid Cell Leukemia Sequence 1 Protein / Q000737:chemistry / Q000378:metabolism; D015513:Oncogene Proteins / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000737:chemistry* / Q000378:metabolism; D051736:Proto-Oncogene Proteins c-mdm2 / Q000737:chemistry* / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism; D051020:bcl-X Protein / Q000737:chemistry / Q000378:metabolism
D051017:Apoptosis Regulatory Proteins; C491073:BCL2L2 protein, human; C452184:Bcl-2 protein, Human herpesvirus 8; C579095:MCL1 protein, human; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D015513:Oncogene Proteins; D010455:Peptides; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D014764:Viral Proteins; D051020:bcl-X Protein; D051736:Proto-Oncogene Proteins c-mdm2
Bcl-2 family proteins; Cancer therapy; Dual-targeting; MDM2-inhibiting peptide; NMR spectroscopy; p53 transactivation domain