Number and molecular brightness analysis reveals Htt25Q protein aggregation upon the uptake of Htt97Q aggregates

Biochem Biophys Res Commun. 2020 Jan 29;522(1):133-137. doi: 10.1016/j.bbrc.2019.10.041. Epub 2019 Nov 19.

Abstract

Number and molecular Brightness (N&B) analysis is a powerful method used to monitor protein aggregation in living cells. Here, we used the N&B method to characterize the unexpanded HTT protein oligomerization after the internalization of the mutant HTT (mHTT) which contains a CAG repeat extensions encoding for long polyglutamine (polyQ) proteins resulting in misfolding and aggregation. HEK cells expressing Htt25Q-mCherry proteins were infected with Htt97Q-EGFP aggregates, by cell to cell uptake, in cultured conditions resulting in an increasing population of dimers and tetramers compared to our controls. This study shows for the first time the impact of protein aggregation in the unexpanded Htt25Q-mCherry expressing cells that occurs from cell to cell transfer of the expanded Htt97Q-EGFP. These results signify the sporadic behavior of the polyQ inclusion that gives insight into the mechanism of protein dynamics as a consequence of secreted mHTT aggregates.

Keywords: Huntingtin protein aggregation; N&B analysis; Oligomerization; mHTT.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biological Transport
  • Coculture Techniques
  • Exons
  • Green Fluorescent Proteins / metabolism
  • HEK293 Cells
  • Humans
  • Huntingtin Protein / genetics
  • Huntingtin Protein / physiology*
  • Inclusion Bodies / metabolism
  • Microscopy, Confocal
  • Mutation
  • Peptides / chemistry
  • Protein Aggregates*
  • Protein Binding
  • Protein Folding*

Substances

  • HTT protein, human
  • Huntingtin Protein
  • Peptides
  • Protein Aggregates
  • Green Fluorescent Proteins
  • polyglutamine