Proteostasis collapse, a hallmark of aging, hinders the chaperone-Start network and arrests cells in G1.
Fiche publication
Date publication
septembre 2019
Journal
eLife
Auteurs
Membres identifiés du Cancéropôle Est :
Dr CHARVIN Gilles
Tous les auteurs :
Moreno DF, Jenkins K, Morlot S, Charvin G, Csikasz-Nagy A, Aldea M
Lien Pubmed
Résumé
Loss of proteostasis and cellular senescence are key hallmarks of aging, but direct cause-effect relationships are not well understood. We show that most yeast cells arrest in G1 before death with low nuclear levels of Cln3, a key G1 cyclin extremely sensitive to chaperone status. Chaperone availability is seriously compromised in aged cells, and the G1 arrest coincides with massive aggregation of a metastable chaperone-activity reporter. Moreover, G1-cyclin overexpression increases lifespan in a chaperone-dependent manner. As a key prediction of a model integrating autocatalytic protein aggregation and a minimal Start network, enforced protein aggregation causes a severe reduction in lifespan, an effect that is greatly alleviated by increased expression of specific chaperones or cyclin Cln3. Overall, our data show that proteostasis breakdown, by compromising chaperone activity and G1-cyclin function, causes an irreversible arrest in G1, configuring a molecular pathway postulating proteostasis decay as a key contributing effector of cell senescence.
Mots clés
G1 cyclin, S. cerevisiae, Start, aging, cell biology, chaperone, proliferation, proteostasis
Référence
Elife. 2019 09 13;8: