RT Journal Article SR Electronic T1 TORC1 and PKA activity towards ribosome biogenesis oscillates in synchrony with the budding yeast cell cycle JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.05.31.446450 DO 10.1101/2021.05.31.446450 A1 Paolo Guerra A1 Luc-Alban P.E. Vuillemenot A1 Marije Been A1 Andreas Milias-Argeitis YR 2021 UL http://biorxiv.org/content/early/2021/06/01/2021.05.31.446450.abstract AB Recent studies have revealed that the growth rate of budding yeast and mammalian cells varies during the cell cycle. By linking a multitude of signals to cell growth, the highly conserved Target of Rapamycin Complex 1 (TORC1) and Protein Kinase A (PKA) pathways are prime candidates for mediating the dynamic coupling between growth and division. However, measurements of TORC1 and PKA activity during the cell cycle are still lacking. Following the localization dynamics of two TORC1 and PKA targets via time-lapse microscopy in hundreds of yeast cells, we found that the activity of these pathways towards ribosome biogenesis fluctuates in synchrony with the cell cycle even under constant external conditions. Mutations of upstream TORC1 and PKA regulators suggested that internal metabolic signals partially mediate these activity changes. Our study reveals a new aspect of TORC1 and PKA signaling, which will be important for understanding growth regulation during the cell cycle.Competing Interest StatementThe authors have declared no competing interest.