Molecular basis of the interaction between the antiapoptotic Bcl-2 family proteins and the proapoptotic protein ASPP2
| Autor: | Mario Lebendiker, Tsafrir Bravman, Hadar Refaely, Stefan G.D. Rüdiger, Chen Katz, Deborah E. Shalev, Assaf Friedler, Monica Dines, Tsafi Danieli, Anat Iosub, Shahar Rotem, Hadar Benyamini, Vered Bronner |
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| Přispěvatelé: | Eiwitvouwing en cellulaire factoren, Dep Scheikunde |
| Rok vydání: | 2008 |
| Předmět: |
Models
Molecular chemistry.chemical_classification Binding Sites Multidisciplinary Bcl-2 family Sequence alignment Peptide Biological Sciences Biology Molecular biology SH3 domain Cell biology Proto-Oncogene Proteins c-bcl-2 chemistry Docking (molecular) Mutation Humans Computer Simulation Ankyrin repeat Binding site Apoptosis Regulatory Proteins Carrier Proteins Protein Binding Binding domain |
| Zdroj: | Proceedings of the National Academy of Sciences. 105:12277-12282 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.0711269105 |
| Popis: | We have characterized the molecular basis of the interaction between ASPP2 and Bcl-2, which are key proteins in the apoptotic pathway. The C-terminal ankyrin repeats and SH3 domain of ASPP2 (ASPP2 Ank-SH3 ) mediate its interactions with the antiapoptotic protein Bcl-2. We used biophysical and computational methods to identify the interaction sites of Bcl-2 and its homologues with ASPP2. Using peptide array screening, we found that ASPP2 Ank-SH3 binds two homologous sites in all three Bcl proteins tested: ( i ) the conserved BH4 motif, and ( ii ) a binding site for proapoptotic regulators. Quantitative binding studies revealed that binding of ASPP2 Ank-SH3 to the Bcl-2 family members is selective at two levels: ( i ) interaction with Bcl-2-derived peptides is the tightest compared to peptides from the other family members, and ( ii ) within Bcl-2, binding of ASPP2 Ank-SH3 to the BH4 domain is tightest. Sequence alignment of the ASPP2-binding peptides combined with binding studies of mutated peptides revealed that two nonconserved positions where only Bcl-2 contains positively charged residues account for its tighter binding. The experimental binding results served as a basis for docking analysis, by which we modeled the complexes of ASPP2 Ank-SH3 with the full-length Bcl proteins. Using peptide arrays and quantitative binding studies, we found that Bcl-2 binds three loops in ASPP2 Ank-SH3 with similar affinity, in agreement with our predicted model. Based on our results, we propose a mechanism in which ASPP2 induces apoptosis by inhibiting functional sites of the antiapoptotic Bcl-2 proteins. |
| Databáze: | OpenAIRE |
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