| First Author | Leon R | Year | 2010 |
| Journal | Eur J Neurosci | Volume | 31 |
| Issue | 11 | Pages | 1915-25 |
| PubMed ID | 20497470 | Mgi Jnum | J:163791 |
| Mgi Id | MGI:4829748 | Doi | 10.1111/j.1460-9568.2010.07215.x |
| Citation | Leon R, et al. (2010) BimEL as a possible molecular link between proteasome dysfunction and cell death induced by mutant huntingtin. Eur J Neurosci 31(11):1915-25 |
| abstractText | Huntington's disease (HD) is a devastating neurodegenerative disorder caused by an expanded polyglutamine repeat within the N-terminus of the huntingtin protein. It is characterized by a selective loss of medium spiny neurons in the striatum. It has been suggested that impaired proteasome function and endoplasmic reticulum (ER) stress play important roles in mutant huntingtin (mHtt)-induced cell death. However, the molecular link involved is poorly understood. In the present study, we identified the essential role of the extra long form of Bim (Bcl-2 interacting mediator of cell death), BimEL, in mHtt-induced cell death. BimEL protein expression level was significantly increased in cell lines expressing the N-terminus of mHtt and in a mouse model of HD. Although quantitative RT-PCR analysis indicated that BimEL mRNA was increased in cells expressing mHtt, we provided evidence showing that, at the post-translational level, phosphorylation of BimEL played a more important role in regulating BimEL expression. Up-regulation of BimEL facilitated the translocation of Bax to the mitochondrial membrane, which further led to cytochrome c release and cell death. On the other hand, knocking down BimEL expression prevented mHtt-induced cell death. Taken together, these findings suggest that BimEL is a key element in regulating mHtt-induced cell death. A model depicting the role of BimEL in linking mHtt-induced ER stress and proteasome dysfunction to cell death is proposed. |
