The 75-99 C-Terminal Peptide of URG7 Protein Promotes α-Synuclein Disaggregation

Int J Mol Sci. 2024 Jan 17;25(2):1135. doi: 10.3390/ijms25021135.

Abstract

Up Regulation Gene seven (URG7) is the pseudogene 2 of the transporter ABCC6. The translated URG7 protein is localized with its single transmembrane α-helix in the endoplasmic reticulum (ER) membrane, orienting the N- and C-terminal regions in the lumen and cytoplasm, respectively, and it plays a crucial role in the folding of ER proteins. Previously, the C-terminal region of URG7 (PU, residues 75-99) has been shown to modify the aggregation state of α-synuclein in the lysate of HepG2 cells. PU analogs were synthesized, and their anti-aggregation potential was tested in vitro on α-synuclein obtained using recombinant DNA technology. Circular dichroism (CD), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy, and microscopic techniques were used to assess the sample's behavior. The results show that the peptides studied by themselves are prone to clathrate-like structure formation of variable stability. Aggregation of α-synuclein is accompanied by desolvation of its peptide chain and an increase in intermolecular β-sheets. The PU analogs all interact with α-synuclein aggregates and those possessing the most stable clathrate-like structures have the highest disaggregating effect. These findings suggest that the C-terminal region of URG7 may have a role in interacting and modulating α-synuclein structures and could be used to generate interesting therapeutic candidates as disaggregators of α-synuclein.

Keywords: URG7; bioinformatics; clathrate-like structures; intermolecular β-sheets; peptides; α-synuclein.

MeSH terms

  • Bridged-Ring Compounds
  • Endoplasmic Reticulum
  • Hep G2 Cells
  • Humans
  • Multidrug Resistance-Associated Proteins* / genetics
  • Peptides* / pharmacology
  • Pseudogenes
  • alpha-Synuclein* / genetics

Substances

  • alpha-Synuclein
  • Bridged-Ring Compounds
  • Peptides
  • ABCC6 protein, human
  • SNCA protein, human
  • Multidrug Resistance-Associated Proteins

Grants and funding

This research received no external funding.