Clusterin (CLU) is a multifunctional glycoprotein that is overexpressed in prostate and breast cancers. Although CLU is known to be involved in the regulation of apoptosis and cell survival, the precise molecular mechanism underlying the pro-apoptotic function of nuclear CLU (nCLU) remains unclear. In this study, we identified a conserved BH3 motif in C-terminal coiled coil (CC2) region of nCLU by sequence analysis and characterized the molecular interaction of the putative nCLU BH3 domain with anti-apoptotic Bcl-2 family proteins by nuclear magnetic resonance (NMR) spectroscopy. The chemical shift perturbation data demonstrated that the nCLU BH3 domain binds to pro-apoptotic BH3 peptide-binding grooves in both Bcl-XL and Bcl-2. A structural model of the Bcl-XL/nCLU BH3 peptide complex reveals that the binding mode is remarkably similar to those of other Bcl-XL/BH3 peptide complexes. In addition, mutational analysis confirmed that Leu323 and Asp328 of nCLU BH3 domain, absolutely conserved in the BH3 motifs of BH3-only protein family, are critical for binding to Bcl-XL. Taken altogether, our results suggest a molecular basis for the pro-apoptotic function of nCLU by elucidating the residue specific interactions of the BH3 motif in nCLU with anti-apoptotic Bcl-2 family proteins.
|Number of pages||7|
|Journal||Biochemical and biophysical research communications|
|Publication status||Published - 2011 May 20|
Bibliographical noteFunding Information:
This work was supported by Basic Science Research Program (No. 2009-0075665) and Mid-career Researcher Program through NRF grant funded by the MEST (No. 2008-0061624). This study was also supported by a grant from the National R&D Program for Cancer Control (0720130) and a grant of the Korean Health Technology R&D Project, Ministry for Health and Welfare, Republic of Korea (A100089). This study made use of the NMR facility at Korea Basic Science Institute, which is supported by Advanced Bio-MR technology Program of the MEST.
- BH3 domain
- Bcl-2 family protein
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology