Coupling of Ribosome Synthesis and Translational Capacity with Cell Growth

Ribosome and protein synthesis lie at the core of cell growth and are major consumers of the cellular budget. Here we review recent progress in the coupling of ribosome synthesis and translational capacity with cell growth in bacteria. We elaborate on the different strategies of bacteria to modulate the protein synthesis rate at fast and slow growth rates. In particular, bacterial cells maintain translational potential at very slow growth as a strategy to keep fitness in fluctuating environments. We further discuss the important role of ribosome synthesis in rapidly proliferating eukaryotic cells such as yeast cells and cancer cells. The tight relation between ribosome and cell growth provides a broad research avenue for researchers from various disciplines. At fast growth rates, cellular ribosome synthesis is tightly coupled with cell growth by guanosine tetra- or pentaphosphate [(p)ppGpp] to attain optimal proteome resource allocation in bacterial cells.Under slow growth conditions, bacterial cells adopt an ingenious strategy to keep translational potential through maintaining both a basal inactive ribosome pool and a moderate translational elongation rate; such a design reflects an adaptive mechanism to fluctuating environments.Ribosome synthesis is also tightly coupled with growth rate in yeast cells, being similar to that in bacterial cells.Excessive ribosome synthesis is crucial for cancer cells to support rapid proliferation and a high protein synthesis rate, and upregulation of ribosome synthesis promotes cancer progression.