MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States; Department of Physics, Massachusetts Institute of Technology, Cambridge, United States
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States
Scott R Manalis
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, United States
The extent and dynamics of animal cell biomass accumulation during mitosis are unknown, primarily because growth has not been quantified with sufficient precision and temporal resolution. Using the suspended microchannel resonator and protein synthesis assays, we quantify mass accumulation and translation rates between mitotic stages on a single-cell level. For various animal cell types, growth rates in prophase are commensurate with or higher than interphase growth rates. Growth is only stopped as cells approach metaphase-to-anaphase transition and growth resumes in late cytokinesis. Mitotic arrests stop growth independently of arresting mechanism. For mouse lymphoblast cells, growth in prophase is promoted by CDK1 through increased phosphorylation of 4E-BP1 and cap-dependent protein synthesis. Inhibition of CDK1-driven mitotic translation reduces daughter cell growth. Overall, our measurements counter the traditional dogma that growth during mitosis is negligible and provide insight into antimitotic cancer chemotherapies.
