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 [1]. 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 [2]. Despite the greater complexity of that domain of life, the predictions are consistent thus far with available data for the model organism S. cerevisiae.

[1] S. Kostinski and S. Reuveni, “Ribosome composition maximizes cellular growth rates in E. coli,” Phys. Rev. Lett. 125, 028103 (2020).
[2] 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)