Glucose restriction in Saccharomyces cerevisiae modulates the phosphorylation pattern of the 20S proteasome and increases its activity

Author(s)

Bicev, Renata Naporano ; Degenhardt, Maximilia Frazao de Souza ; de Oliveira, Cristiano Luis Pinto ; da Silva, Emerson Rodrigo ; Degrouard, Jeril ; Tresset, Guillaume ; Ronsein, Graziella Eliza ; Demasi, Marilene ; da Cunha, Fernanda Marques

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 13, n. 1, p. 14-pg., 2023-11-08.

Abstract

Caloric restriction is known to extend the lifespan and/or improve diverse physiological parameters in a vast array of organisms. In the yeast Saccharomyces cerevisiae, caloric restriction is performed by reducing the glucose concentration in the culture medium, a condition previously associated with increased chronological lifespan and 20S proteasome activity in cell extracts, which was not due to increased proteasome amounts in restricted cells. Herein, we sought to investigate the mechanisms through which glucose restriction improved proteasome activity and whether these activity changes were associated with modifications in the particle conformation. We show that glucose restriction increases the ability of 20S proteasomes, isolated from Saccharomyces cerevisiae cells, to degrade model substrates and whole proteins. In addition, threonine 55 and/or serine 56 of the alpha 5-subunit, were/was consistently found to be phosphorylated in proteasomes isolated from glucose restricted cells, which may be involved in the increased proteolysis capacity of proteasomes from restricted cells. We were not able to observe changes in the gate opening nor in the spatial conformation in 20S proteasome particles isolated from glucose restricted cells, suggesting that the changes in activity were not accompanied by large conformational alterations in the 20S proteasome but involved allosteric activation of proteasome catalytic site. (AU)

• FAPESP's process: 16/11724-8 - Calorie Restriction effects on the proteasome of yeast Saccharomyces cerevisiae
• Grantee: Renata Naporano Bicev
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 19/09732-0 - Deciphering the starvation-induced effects on mitochondria phenotype
• Grantee: Fernanda Marques da Cunha
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/07937-8 - Redoxome - Redox Processes in Biomedicine
• Grantee: Ohara Augusto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 19/27044-4 - Effect of calorie restriction on the structure of 20S proteasome: a cryo-EM study
• Grantee: Renata Naporano Bicev
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate