2017/11/13 by Tian Zhang, Clara Wolfe, Andrew Pierle +3 · 1 voice · 1 citation
Biochemistry, Genetics and Molecular Biology · Medicine · #Autophagy in Disease and Therapy #Cellular transport and secretion #Endoplasmic Reticulum Stress and Disease
paper · pdf · doi:10.1073/pnas.1710238114
openalex publication_date 2017/11/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/04
In dividing cells, cytoplasmic dilution is the dominant route of clearance for long-lived proteins whose inherent degradation is slower than the cellular growth rate. Thus, as cells transition from a dividing to a nondividing state, there is a propensity for long-lived proteins to become stabilized relative to short-lived proteins, leading to alterations in the abundance distribution of the proteome. However, it is not known if cells mount a compensatory response to counter this potentially deleterious proteostatic disruption. We used a proteomic approach to demonstrate that fibroblasts selectively increase degradation rates of long-lived proteins as they transition from a proliferating to a quiescent state. The selective degradation of long-lived proteins occurs by the concurrent activation of lysosomal biogenesis and up-regulation of macroautophagy. Through this mechanism, quiescent cells avoid the accumulation of aged long-lived proteins that would otherwise result from the absence of cytoplasmic dilution by cell division.