Regulation of Intracellular Accumulation of Mutant Huntingtin by Beclin 1

Mamoru Shibata, Tao Lu, Tsuyoshi Furuya, Alexei Degterev, Noboru Mizushima, Tamotsu Yoshimori, Marcy MacDonald, Bruce Yankner, Junying Yuan
2006 Journal of Biological Chemistry  
Intracellular accumulation of mutant Huntingtin with expanded polyglutamine provides a context-dependent cytotoxicity critical for the pathogenesis of Huntington disease (Everett, C. M., and Wood, N. W. (2004) Brain 127, 2385-2405). Here we demonstrate that the accumulation of mutant Huntingtin is highly sensitive to the expression of beclin 1, a gene essential for autophagy. Moreover, we show that the accumulated mutant Huntingtin recruits Beclin 1 and impairs the Beclin 1-mediated long lived
more » ... ediated long lived protein turnover. Thus, sequestration of Beclin 1 in the vulnerable neuronal population of Huntington disease patients might further reduce Beclin 1 function and autophagic degradation of mutant Huntingtin. Finally, we demonstrate that the expression of beclin 1 decreases in an age-dependent fashion in human brains. Because beclin 1 gene is haploid insufficient in regulating autophagosome function (propose that the age-dependent decrease of beclin 1 expression may lead to a reduction of autophagic activity during aging, which in turn promotes the accumulation of mutant Htt and the progression of the disease.
doi:10.1074/jbc.m600364200 pmid:16522639 fatcat:2w5x2so2wveurlsvteqsruchrm