Protein aggregates: an aging factor involved in cell death.
In a previous study, we demonstrated the presence of protein aggregates in an exponentially grown Escherichia coli culture. In light of these observations, protein aggregates could be considered damage to cells that is able to pass from one generation to the next. Based on the assumption that the amount of aggregate protein could represent an aging factor, we monitored this amount in a bacterial culture during senescence. In doing so, we observed (i) a significant increase in the amount of aggregate protein over time, (ii) a proportional relationship between the amount of aggregate protein and the level of dead cells, (iii) a larger amount in dead cells than in culturable cells, (iv) a heterogeneous distribution of different amounts within a homogenous population of culturable cells entering stasis, and (v) that the initial amount of aggregate protein within a culturable population conditioned the death rate of the culture. Together, the results presented in this study suggest that protein aggregates indeed represent one aging factor leading to bacterial cell death.
Maisonneuve
Etienne
E
Laboratoire de Chimie Bactérienne, UPR 9043-CNRS/Université de la Méditerranée, 31, Chemin Joseph Aiguier, 13402, Marseille, France.
Ezraty
Benjamin
B
Dukan
Sam
S
D018407:Bacterial Physiological Phenomena; D018929:Cell Culture Techniques; D004926:Escherichia coli / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D050296:Microbial Viability; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors
D029968:Escherichia coli Proteins; D017382:Reactive Oxygen Species