TY - JOUR
T1 - Post-translational modifications clustering within proteolytic domains decrease mutant huntingtin toxicity
AU - Arbez, Nicolas
AU - Ratovitski, Tamara
AU - Roby, Elaine
AU - Chighladze, Ekaterine
AU - Stewart, Jacqueline C.
AU - Ren, Mark
AU - Wang, Xiaofang
AU - Lavery, Daniel J.
AU - Ross, Christopher A.
N1 - Publisher Copyright:
© 2017 by The American Society for Biochemistry and Molecular Biology, Inc.
PY - 2017/11/24
Y1 - 2017/11/24
N2 - Huntington’s disease (HD) is caused in large part by a polyglutamine expansion within the huntingtin (Htt) protein. Post-translational modifications (PTMs) control and regulate many protein functions and cellular pathways, and PTMs of mutant Htt are likely important modulators of HD pathogenesis. Alterations of selected numbers of PTMs of Htt fragments have been shown to modulate Htt cellular localization and toxicity. In this study, we systematically introduced site-directed alterations in individual phosphorylation and acetylation sites in full-length Htt constructs. The effects of each of these PTM alteration constructs were tested on cell toxicity using our nuclear condensation assay and on mitochondrial viability by measuring mitochondrial potential and size. Using these functional assays in primary neurons, we identified several PTMs whose alteration can block neuronal toxicity and prevent potential loss and swelling of the mitochondria caused by mutant Htt. These PTMs included previously described sites such as serine 116 and newly found sites such as serine 2652 throughout the protein. We found that these functionally relevant sites are clustered in protease-sensitive domains throughout full-length Htt. These findings advance our understanding of the Htt PTM code and its role in HD pathogenesis. Because PTMs are catalyzed by enzymes, the toxicity-modulating Htt PTMs identified here may be promising therapeutic targets for managing HD.
AB - Huntington’s disease (HD) is caused in large part by a polyglutamine expansion within the huntingtin (Htt) protein. Post-translational modifications (PTMs) control and regulate many protein functions and cellular pathways, and PTMs of mutant Htt are likely important modulators of HD pathogenesis. Alterations of selected numbers of PTMs of Htt fragments have been shown to modulate Htt cellular localization and toxicity. In this study, we systematically introduced site-directed alterations in individual phosphorylation and acetylation sites in full-length Htt constructs. The effects of each of these PTM alteration constructs were tested on cell toxicity using our nuclear condensation assay and on mitochondrial viability by measuring mitochondrial potential and size. Using these functional assays in primary neurons, we identified several PTMs whose alteration can block neuronal toxicity and prevent potential loss and swelling of the mitochondria caused by mutant Htt. These PTMs included previously described sites such as serine 116 and newly found sites such as serine 2652 throughout the protein. We found that these functionally relevant sites are clustered in protease-sensitive domains throughout full-length Htt. These findings advance our understanding of the Htt PTM code and its role in HD pathogenesis. Because PTMs are catalyzed by enzymes, the toxicity-modulating Htt PTMs identified here may be promising therapeutic targets for managing HD.
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U2 - 10.1074/jbc.M117.782300
DO - 10.1074/jbc.M117.782300
M3 - Article
C2 - 28972180
AN - SCOPUS:85034999144
SN - 0021-9258
VL - 292
SP - 19238
EP - 19254
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 47
ER -