Journal Club – June 2019

Spindle-F-Actin, Molecular Gearshifts, and Cytoplasmic Softening

 

Must Read


Spindle-F-Actin Interactions in Mitotic Spindles in an Intact Vertebrate Epithelium

Kita et al. | Molecular Biology of the Cell A compelling subject for striking microscopy images, microtubules have long been considered the major mechanical component of the mitotic spindle. But a long-standing question has been whether a second cytoskeletal system lurks beneath the surface. In this study, the Bement lab develops improved methods for preserving F-actin in embryonic epithelia and successfully visualizes F-actin associated with the mitotic spindle. The authors demonstrate that, like spindle microtubules, multiple populations of spindle-F-actin exist and reorganize as a function of the cell cycle. By providing some of the first evidence that F-actin is a component of the mitotic spindle in animal cells, this study challenges the view that F-actin is restricted to the cell periphery during cell division.

 

Methods


In Vitro BioID: Mapping the CENP-A Microenvironment with High Temporal and Spatial Resolution

Enhancements to a proximity-based labeling approach allow mapping of cell-cycle-dependent structural proteins.
Remnant et al.  |  Molecular Biology of the Cell
 

Reviews and Perspectives


 

Tools and Resources


Allen Institute for Cell Science Integrated Mitotic Stem Cell
The Allen Institute For Cell Science presents the Integrated Mitotic Stem Cell,
a holistic view of the dividing cell assembled from a vast database of microscopy images.
 

Journal Club Picks


  • Actin and myosin self-organize into active liquid droplets reminiscent of the mitotic spindle.
    Weirich et al. |  Gardel Lab |  Proceedings of the National Academy of Sciences
  • The microtubule seam is as strong as other regions of the lattice.
    Szatkowski et al. |  Dima Lab |  The Journal of Physical Chemistry
  • A dynein mutant uncouples ATPase activity and directed movement.
    Niekamp et al. |  Bhabha Lab |  The EMBO Journal
  • The kinesin-1 neck linker acts as a molecular gearshift, toggling between force and speed.
    Budaitis et al. |  Verhey Lab |  eLife
  • The biased sidestepping of kinesin-3 KIF1A causes microtubule rotation in gliding assays.
    Mitra et al. |  Casademunt Lab |  Biophysical Journal
  • Bacterial cells accumulate FtsZ to a fixed threshold to control cell-size homeostasis.
    Si et al. |  Jun Lab |  Current Biology
  • Microtubules can organize into spindle-like arrays in the absence of motor proteins.
    Edozie et al. |  Ross Lab |  Soft Matter
  • Actin filaments block the elongation of new microtubules at the centrosome.
    Inoue et al. |  Théry Lab |  The EMBO Journal
  • Actin and keratin disassembly near the spindle midzone causes local cytoplasmic softening.
    Field et al. |  Mitchison Lab |  Current Biology
  • The Ndc80 complex undergoes auto-inhibition by conformational folding.
    Scarborough et al. |  Davis and Asbury Labs |  eLife
  • Cleared Xenopus extracts are active in peroxisome protein transport.
    Romano et al. |  Rapoport Lab |  Journal of Cell Biology

Our opinions are our own and do not represent the views or endorsement of the authors cited.