2013/01/01 by Abhishek Kumar, Ananyo Maitra, Madhuresh Sumit +3 · 41 citations
Biochemistry, Genetics and Molecular Biology · Chemistry · Physics and Astronomy · #Actin #Biology #Biophysics #Cell #Cell biology #Cellular Mechanics and Interactions #Chemistry #Classical mechanics #Contractility #Cytoskeleton #Micro and Nano Robotics #Microtubule and mitosis dynamics #Myosin #Nucleus #Physics #Rotation around a fixed axis #cond-mat.soft #cond-mat.stat-mech #physics.bio-ph
paper · pdf · doi:10.1016/j.bpj.2012.11.3237
published in Biophysical Journal 104(2), 583a (Elsevier BV)
openalex publication_date 2013/01/01 · arxiv created 2013/09/14 · arxiv updated 2017/08/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The nucleus of the eukaryotic cell functions amidst active cytoskeletal filaments, but its response to the stresses carried by these filaments is largely unexplored. We report here the results of studies of the translational and rotational dynamics of the nuclei of single fibroblast cells, with the effects of cell migration suppressed by plating onto fibronectin-coated micro-fabricated patterns. Patterns of the same area but different shapes and/or aspect ratio were used to study the effect of cell geometry on the dynamics. On circles, squares and equilateral triangles, the nucleus undergoes persistent rotational motion, while on high-aspect-ratio rectangles of the same area it moves only back and forth. The circle and the triangle showed respectively the largest and the smallest angular speed. We show that our observations can be understood through a hydrodynamic approach in which the nucleus is treated as a highly viscous inclusion residing in a less viscous fluid of orientable filaments endowed with active stresses. Lowering actin contractility selectively by introducing blebbistatin at low concentrations drastically reduced the speed and persistence time of the angular motion of the nucleus. Time-lapse imaging of actin revealed a correlated hydrodynamic flow around the nucleus, with profile and magnitude consistent with the results of our theoretical approach. Coherent intracellular flows and consequent nuclear rotation thus appear to be a generic property that cells must balance by specific mechanisms in order to maintain nuclear homeostasis.