| Structural highlights
Function
[B2CL1_HUMAN] Potent inhibitor of cell death. Inhibits activation of caspases (By similarity). Appears to regulate cell death by blocking the voltage-dependent anion channel (VDAC) by binding to it and preventing the release of the caspase activator, CYC1, from the mitochondrial membrane. Also acts as a regulator of G2 checkpoint and progression to cytokinesis during mitosis.[1] [2] Isoform Bcl-X(S) promotes apoptosis.[3] [4] [BAK_HUMAN] In the presence of an appropriate stimulus, accelerates programmed cell death by binding to, and antagonizing the anti-apoptotic action of BCL2 or its adenovirus homolog E1B 19k protein. Low micromolar levels of zinc ions inhibit the promotion of apoptosis.[5] [6]
Publication Abstract from PubMed
The Bcl-2 family of proteins includes the major regulators and effectors of the intrinsic apoptosis pathway. Cancers are frequently formed when activation of the apoptosis mechanism is compromised either by misregulated expression of prosurvival family members or, more frequently, by damage to the regulatory pathways that trigger intrinsic apoptosis. Short peptides derived from the pro-apoptotic members of the Bcl-2 family can activate mechanisms that ultimately lead to cell death. The recent development of photocontrolled peptides that are able to change their conformation and activity upon irradiation with an external light source has provided new tools to target cells for apoptosis induction with temporal and spatial control. Here, we report the first NMR solution structure of a photoswitchable peptide derived from the proapoptotic protein Bak in complex with the antiapoptotic protein Bcl-x(L). This structure provides insight into the molecular mechanism, by which the increased affinity of such photopeptides compared to their native forms is achieved, and offers a rationale for the large differences in the binding affinities between the helical and nonhelical states.
NMR Solution Structure of a Photoswitchable Apoptosis Activating Bak Peptide Bound to Bcl-x(L).,Wysoczanski P, Mart RJ, Loveridge EJ, Williams C, Whittaker SB, Crump MP, Allemann RK J Am Chem Soc. 2012 Apr 25. PMID:22515821[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Terrano DT, Upreti M, Chambers TC. Cyclin-dependent kinase 1-mediated Bcl-xL/Bcl-2 phosphorylation acts as a functional link coupling mitotic arrest and apoptosis. Mol Cell Biol. 2010 Feb;30(3):640-56. doi: 10.1128/MCB.00882-09. Epub 2009 Nov, 16. PMID:19917720 doi:10.1128/MCB.00882-09
- ↑ Wang J, Beauchemin M, Bertrand R. Bcl-xL phosphorylation at Ser49 by polo kinase 3 during cell cycle progression and checkpoints. Cell Signal. 2011 Dec;23(12):2030-8. doi: 10.1016/j.cellsig.2011.07.017. Epub, 2011 Aug 5. PMID:21840391 doi:10.1016/j.cellsig.2011.07.017
- ↑ Terrano DT, Upreti M, Chambers TC. Cyclin-dependent kinase 1-mediated Bcl-xL/Bcl-2 phosphorylation acts as a functional link coupling mitotic arrest and apoptosis. Mol Cell Biol. 2010 Feb;30(3):640-56. doi: 10.1128/MCB.00882-09. Epub 2009 Nov, 16. PMID:19917720 doi:10.1128/MCB.00882-09
- ↑ Wang J, Beauchemin M, Bertrand R. Bcl-xL phosphorylation at Ser49 by polo kinase 3 during cell cycle progression and checkpoints. Cell Signal. 2011 Dec;23(12):2030-8. doi: 10.1016/j.cellsig.2011.07.017. Epub, 2011 Aug 5. PMID:21840391 doi:10.1016/j.cellsig.2011.07.017
- ↑ Chittenden T, Flemington C, Houghton AB, Ebb RG, Gallo GJ, Elangovan B, Chinnadurai G, Lutz RJ. A conserved domain in Bak, distinct from BH1 and BH2, mediates cell death and protein binding functions. EMBO J. 1995 Nov 15;14(22):5589-96. PMID:8521816
- ↑ Moldoveanu T, Liu Q, Tocilj A, Watson M, Shore G, Gehring K. The X-ray structure of a BAK homodimer reveals an inhibitory zinc binding site. Mol Cell. 2006 Dec 8;24(5):677-88. PMID:17157251 doi:10.1016/j.molcel.2006.10.014
- ↑ Wysoczanski P, Mart RJ, Loveridge EJ, Williams C, Whittaker SB, Crump MP, Allemann RK. NMR Solution Structure of a Photoswitchable Apoptosis Activating Bak Peptide Bound to Bcl-x(L). J Am Chem Soc. 2012 Apr 25. PMID:22515821 doi:10.1021/ja302390a
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