Growth laws for unicellular organisms from ribosome biogenesis
by Dr. Sarah Kostinski
School Of Chemistry, Tel-Aviv University
at Biological and soft-matter physics
Thu, 04 Mar 2021, 12:10
ZOOM only - Meeting ID: 874 2021 0979
Ribosomes generate all proteins in a cell, including their own ribosomal proteins. Previous work on bacteria showed that ribosomal protein production imposes a bound on cellular growth rates, since cell doubling requires a commensurate doubling of ribosomes. However, ribosomes are made not only of protein, but also of ribosomal RNA. We obtain a new speed limit on cell growth which originates in the generation of ribosomal RNA . A comparison with E. coli data reveals that the bacterial ribosome’s 1:2 protein-to-RNA mass ratio uniquely maximizes cellular growth rates as permitted by both bounds. This observation leads to a growth law involving RNA polymerases, and an invariant of bacterial growth. Similar arguments for Eukarya lead to several new growth laws . Despite the greater complexity of that domain of life, the predictions are consistent thus far with available data for the model organism S. cerevisiae.
 S. Kostinski and S. Reuveni, “Ribosome composition maximizes cellular growth rates in E. coli,” Phys. Rev. Lett. 125, 028103 (2020).
 S. Kostinski and S. Reuveni, “Growth laws and invariants from ribosome biogenesis in lower Eukarya,” Phys. Rev. Research 3, 013020 (2021).
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Meeting ID: 874 2021 0979
Created on 29-11-2020 by Granek, Rony (rgranek)
Updaded on 26-02-2021 by Granek, Rony (rgranek)