1t3s
From Proteopedia
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| , resolution 2.30Å | |||||||
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| Ligands: | |||||||
| Gene: | CACNB2, CACNLB2 (Oryctolagus cuniculus) | ||||||
| Related: | 1T3L
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structural Analysis of the Voltage-Dependent Calcium Channel Beta Subunit Functional Core
Overview
Huntington's disease (HD) is initiated by an abnormally expanded polyglutamine stretch in the huntingtin protein, conferring a novel property on the protein that leads to the loss of striatal neurons. Defects in mitochondrial function have been implicated in the pathogenesis of HD. Here, we have examined the hypothesis that the mutant huntingtin protein may directly interact with the mitochondrion and affect its function. In human neuroblastoma cells and clonal striatal cells established from HdhQ7 (wild-type) and HdhQ111 (mutant) homozygote mouse knock-in embryos, huntingtin was present in a purified mitochondrial fraction. Subfractionation of the mitochondria and limited trypsin digestion of the organelle demonstrated that huntingtin was associated with the outer mitochondrial membrane. We further demonstrated that a recombinant truncated mutant huntingtin protein, but not a wild-type, directly induced mitochondrial permeability transition (MPT) pore opening in isolated mouse liver mitochondria, an effect that was prevented completely by cyclosporin A (CSA) and ATP. Importantly, the mutant huntingtin protein significantly decreased the Ca2+ threshold necessary to trigger MPT pore opening. We found a similar increased susceptibility to the calcium-induced MPT in liver mitochondria isolated from a knock-in HD mouse model. The mutant huntingtin protein-induced MPT pore opening was accompanied by a significant release of cytochrome c, an effect completely inhibited by CSA. These findings suggest that the development of specific MPT inhibitors may be an interesting therapeutic avenue to delay the onset of HD.
About this Structure
1T3S is a Single protein structure of sequence from Oryctolagus cuniculus. Full crystallographic information is available from OCA.
Reference
Mutant huntingtin directly increases susceptibility of mitochondria to the calcium-induced permeability transition and cytochrome c release., Choo YS, Johnson GV, MacDonald M, Detloff PJ, Lesort M, Hum Mol Genet. 2004 Jul 15;13(14):1407-20. Epub 2004 May 26. PMID:15163634
Page seeded by OCA on Sun Mar 30 23:50:54 2008
