Intracellular Mass Density Increase Is Accompanying but Not Sufficient for Stiffening and Growth Arrest of Yeast Cells
Journal article, 2018

Many organisms, including yeast cells, bacteria, nematodes, and tardigrades, endure harsh environmental conditions, such as nutrient scarcity, or lack of water and energy for a remarkably long time. The rescue programs that these organisms launch upon encountering these adverse conditions include reprogramming their metabolism in order to enter a quiescent or dormant state in a controlled fashion. Reprogramming coincides with changes in the macromolecular architecture and changes in the physical and mechanical properties of the cells. However, the cellular mechanisms underlying the physical-mechanical changes remain enigmatic. Here, we induce metabolic arrest of yeast cells by lowering their intracellular pH. We then determine the differences in the intracellular mass density and stiffness of active and metabolically arrested cells using optical diffraction tomography (ODT) and atomic force microscopy (AFM). We show that an increased intracellular mass density is associated with an increase in stiffness when the growth of yeast is arrested. However, increasing the intracellular mass density alone is not sufficient for maintenance of the growth-arrested state in yeast cells. Our data suggest that the cytoplasm of metabolically arrested yeast displays characteristics of a solid. Our findings constitute a bridge between the mechanical behavior of the cytoplasm and the physical and chemical mechanisms of metabolically arrested cells with the ultimate aim of understanding dormant organisms.

atomic force microscopy

optical diffraction tomography

stiffness

refractive index

yeast

liquid solid transition

Author

Shada Abuhattum

JPK Instruments AG

Technische Universität Dresden

Kyoohyun Kim

Technische Universität Dresden

Titus M. Franzmann

Max Planck Institute

Anne Esslinger

Max Planck Institute

Daniel Midtvedt

Chalmers, Physics, Biological Physics

Raimund Schluessler

Technische Universität Dresden

Stephanie Mollmert

Technische Universität Dresden

Hui-Shun Kuan

University of Erlangen-Nuremberg (FAU)

Max Planck Institute

Simon Alberti

Max Planck Institute

Vasily Zaburdaev

University of Erlangen-Nuremberg (FAU)

Max Planck Institute

Jochen Guck

Technische Universität Dresden

Frontiers in Physics

2296-424x (eISSN)

Vol. 6 NOV 131

Subject Categories

Cell Biology

Other Chemistry Topics

Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)

DOI

10.3389/fphy.2018.00131

More information

Latest update

3/18/2019