Kinetics of Formation and Asymmetrical Distribution of Hsp104-Bound Protein Aggregates in Yeast.
Fiche publication
Date publication
avril 2016
Journal
Biophysical journal
Auteurs
Membres identifiés du Cancéropôle Est :
Dr CHARVIN Gilles
Tous les auteurs :
Paoletti C, Quintin S, Matifas A, Charvin G
Lien Pubmed
Résumé
Budding yeast cells have a finite replicative life span; that is, a mother cell produces only a limited number of daughter cells before it slows division and dies. Despite the gradual aging of the mother cell, all daughters are born rejuvenated and enjoy a full replicative lifespan. It has been proposed that entry of mother cells into senescence is driven by the progressive accumulation and retention of damaged material, including protein aggregates. This additionally allows the daughter cells to be born damage free. However, the mechanism underlying such asymmetrical segregation of protein aggregates by mother and daughter cells remains controversial, in part because of the difficulties inherent in tracking the dynamics and fate of protein aggregates in vivo. To overcome such limitations, we have developed single-cell real-time imaging methodology to track the formation of heat-induced protein aggregates in otherwise unperturbed dividing cells. By combining the imaging data with a simple computational model of protein aggregation, we show that the establishment of asymmetrical partitioning of protein aggregates upon division is driven by the large bud-specific dilution rate associated with polarized growth and the absence of significant mother/bud exchange of protein aggregates during the budded phase of the cell cycle. To our knowledge, this study sheds new light on the mechanism of establishment of a segregation bias, which can be accounted for by simple physical arguments.
Mots clés
Cell Division, Heat-Shock Proteins, chemistry, Kinetics, Protein Aggregates, Protein Transport, Saccharomyces cerevisiae, cytology, Saccharomyces cerevisiae Proteins, chemistry, Temperature
Référence
Biophys. J.. 2016 Apr 12;110(7):1605-1614