Huntingtin exon 1 deletion does not alter the subcellular distribution of huntingtin and gene transcription in mice

Xianxian Zhao; Yize Sun; Zhifu Wang; Laiqiang Chen; Shihua Li; Xiao-Jiang Li

doi:10.3389/fncel.2022.1021592

Huntingtin exon 1 deletion does not alter the subcellular distribution of huntingtin and gene transcription in mice

Front Cell Neurosci. 2022 Nov 10:16:1021592. doi: 10.3389/fncel.2022.1021592. eCollection 2022.

Authors

Xianxian Zhao¹, Yize Sun¹, Zhifu Wang¹, Laiqiang Chen¹, Shihua Li¹, Xiao-Jiang Li¹

Affiliation

¹ Guangdong Key Laboratory of Non-human Primate Research, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China.

Abstract

Huntington disease (HD) is caused by the expansion of CAG triplet repeats in exon 1 of the huntingtin (HTT) gene, which also encodes the first 17 amino acids (N-17) that can modulate the toxicity of the expanded polyQ repeat. N-17 are conserved in a wide range of species and are found to influence the subcellular distribution of mutant Htt. Moreover, N-17 is subject to many posttranslational modifications that may regulate the function, stability, and distribution of HTT. However, the function of Htt exon 1 and its influence on the normal Htt remains to be fully investigated. By investigating a knock-in mouse model that lacks Htt exon1, we found that deletion of Htt exon1 does not affect the survival of mice and differentiation of cultured mouse neurons. Furthermore, the lack of Htt exon 1 does not alter the subcellular distribution of Htt, autophagy protein expression, and global gene transcription in the mouse brain. These results suggest that removing the entire exon 1 of Htt could be a therapeutic approach to eliminate expanded polyQ toxicity.

Keywords: Huntington; autophagy; gene expression; polyglutamine; subcellular distribution.