α-synuclein and phosphoinositide-binding proteins : α-synuclein inhibits the association of PX- but not FYVE-containing proteins with vesicles in vivo

Copyright © 2022 Elsevier Inc. All rights reserved..

By an unknown mechanism, alpha-synuclein (α-syn) inhibits autophagy in yeast and human cells. Herein, using the yeast Saccharomyces cerevisiae, we tested the hypothesis that α-syn disrupts autophagy by inhibiting the required association of sorting nexin 4 (Snx4) with phagophores. Snx4 contains a phox (PX) homology domain that selectively binds membranes enriched in phosphatidylinositol 3-phosphate (PI3P). Using fluorescence microscopy, we show that upon nitrogen starvation, 70% of the cells exhibited green puncta (phagophores); whereas identically treated cells expressing α-syn exhibited a significantly lower percentage of cells (30%) with such puncta. Our interpretation is that α-syn outcompetes Snx4 for binding to membranes enriched in PI3P, resulting in fewer phagophores and consequently inefficient induction of autophagy. As a control, we tested whether α-syn disrupts the binding of Vps27-GFP to late endosomes/multivesicular bodies (MVBs). Vps27 contains a PI3P-binding domain called FYVE. α-Syn did not disrupt the binding of Vps27-GFP to late endosomes. α-Syn likely inhibits the binding of PX- but not FYVE-containing proteins to PI3P because FYVE domains bind more than two-orders of magnitude tighter than PX domains. We propose that in all cells, whether yeast or human, α-syn has the potential to inhibit protein trafficking pathways that are dependent on PX-domain proteins such as sorting nexins.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:603

Enthalten in:

Biochemical and biophysical research communications - 603(2022) vom: 07. Mai, Seite 7-12

Sprache:

Englisch

Beteiligte Personen:

Rajasekaran, Santhanasabapathy [VerfasserIn]
Patel, Dhaval [VerfasserIn]
Witt, Stephan N [VerfasserIn]

Links:

Volltext

Themen:

α-synuclein
Alpha-Synuclein
Autophagy
Carrier Proteins
Endosomal Sorting Complexes Required for Transport
Journal Article
Multivesicular body
Oxazoles
Parkinson's disease
Phosphatidylinositol Phosphates
Phosphatidylinositols
Retromer
Saccharomyces cerevisiae Proteins
Sorting nexin
VPS27 protein, S cerevisiae

Anmerkungen:

Date Completed 04.04.2022

Date Revised 08.05.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.bbrc.2022.01.101

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM337945748