Proteasome assembly chaperone translation upon stress requires Ede1 phase separation at the plasma membrane

Thomas D Williams; Aurellia Winaya; Ifeoluwapo Joshua; Adrien Rousseau

doi:10.1016/j.isci.2023.108732

Proteasome assembly chaperone translation upon stress requires Ede1 phase separation at the plasma membrane

iScience. 2023 Dec 14;27(1):108732. doi: 10.1016/j.isci.2023.108732. eCollection 2024 Jan 19.

Authors

Thomas D Williams¹, Aurellia Winaya¹, Ifeoluwapo Joshua¹, Adrien Rousseau¹

Affiliation

¹ MRC-PPU, School of Life Sciences, University of Dundee, Dow Street, Dundee DD5 1EH, UK.

Abstract

Proteome adaptation is key to cells surviving stresses. Increased translation of proteasome assembly chaperones (PACs) is critical for increasing proteasome assembly and cell degradative capacity. The endocytic protein Ede1 recruits PAC mRNA to cortical actin patches in Saccharomyces cerevisiae for translation upon stress. We show, through genetic and pharmacological studies, that this is mediated by the capacity of Ede1 to phase separate. PAC expression is maintained when we exchange the phase separating domains from Ede1 for those of unrelated proteins. Without these phase separating regions, PAC expression is not induced upon stress, preventing increased proteasome assembly, causing cell death. This work identifies a mechanism underpinning Ede1-mediated increased translation of specific mRNAs at a time when general translation is repressed.

Keywords: Cell biology; Molecular biology.