One-pot semisynthesis of exon 1 of the Huntingtin protein: New tools for elucidating the role of posttranslational modifications in the pathogenesis of Huntington's disease

Annalisa Ansaloni, Zhe Ming Wang, Jae Sun Jeong, Francesco Simone Ruggeri, Giovanni Dietler, Hilal A. Lashuel

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

The natural enzymes involved in regulating many of the posttranslational modifications (PTMs) within the first 17 residues (Nt17) of Huntingtin exon 1 (Httex1) remain unknown. A semisynthetic strategy that allows the site-specific introduction of PTMs within Nt17 by using expressed protein ligation (EPL) was developed. This strategy was used to produce untagged wild-type (wt) and T3-phosphorylated (pT3) Httex1 containing 23 glutamine residues (Httex1-23Q). Our studies show that pT3 significantly slows the oligomerization and fibrillization of Httex1-23Q and that Httex1 variants containing polyQ repeats below the pathogenic threshold readily aggregate and form fibrils in vitro. These findings suggest that crossing the polyQ pathogenic threshold is not essential for Httex1 aggregation. The ability to produce wt or site-specifically modified tag-free Httex1 should facilitate determining its structure and the role of N-terminal PTMs in regulating the functions of Htt in health and disease. Tailor-made: A one-pot semisynthetic strategy that enables the site-specific introduction of posttranslational modifications within the N terminus of exon 1 of the Huntingtin protein (Httex1) is reported. This approach was applied to generate untagged wild-type and T3-phosphorylated Httex1. Httex1 with polyQ repeats below the pathogenic threshold (Httex1-23Q) was shown to aggregate in vitro and phosphorylation at T3 slows aggregation.

Original languageEnglish
Pages (from-to)1928-1933
Number of pages6
JournalAngewandte Chemie - International Edition
Volume53
Issue number7
DOIs
Publication statusPublished - 10 Feb 2014

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Keywords

  • aggregation
  • huntingtin exon 1
  • huntington's disease
  • phosphorylation
  • protein semisynthesis

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)

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