Minus-End Growth, Reconstituted Spindle Midzones, and Contorted Microtubules

Must Read

Patronin-Mediated Minus End Growth Is Required For Dendritic Microtubule Polarity

Feng et al. | Journal of Cell Biology Microtubule minus-ends are often stably capped in cells, yielding the spotlight to their more dynamic plus-end counterparts. However, dendritic neurons present a compelling case for significant minus-end growth in vivo as >90% of microtubules are arranged with their minus-ends directed outward. In this study, the Rolls Lab monitors microtubule polymerization in Drosophila and zebrafish neurons with EB1 tracking and discovers an unexpected population of slow-moving puncta (~1 μm/min) with speed and direction suggestive of growing minus-ends. Using genetic perturbations, the authors further identify Patronin as a critical proponent of minus-end growth and “minus-end-out” microtubule architecture. Overall, this study provides the first evidence of slow growing minus-ends in neurons and demonstrates a novel role for Patronin in microtubule organization.

“The finding that Drosophila Patronin facilitates, rather than reduces, minus end growth in neurons is surprising in light of its previous characterization.”

Spotlight by Heather T. Broihier

Methods

Live Cell Imaging of Meiosis in Arabidopsis thaliana

Researchers develop a novel reporter cell line combined with morphological analysis to study plant cell meiosis in real time.
Prusicki et al. | eLife

The Kinetics of Nucleotide Binding to Isolated Chlamydomonas Axonemes using UV-TIRF Microscopy

By studying the recovery of mantATP fluorescence, researchers observe the travelling wave of dynein activity in the axoneme.
Feofilova, Mahamdeh, and Howard | Biophysical Journal

Reviews and Perspectives

Tools and Resources

The Age of Living Machines – How Biology Will Build The Next Technology Revolution

Susan Hockfield, the first woman and life scientist to serve as president of MIT, writes how the next generation of disruptive technologies will stem from biological systems.

Listen to a candid interview with the author here.

Journal Club Picks

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Spindle assembly factors coalesce via phase separation in large egg cells.
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PRC1 and KIF4A tune the length of anti-parallel overlap in reconstituted spindle midzones.
Hannabuss et al. | Nédélec and Surrey Labs | Current Biology
Shrinking the overlap of midzone microtubules prevents chromosome hypersegregation.
Pamula et al. | Kapoor Lab | Journal of Cell Biology
The tubulin C-terminal tail activates spastin for microtubule severing.
Sandate et al. | Lander and Roll-Mecak Labs | Nature Structural & Molecular Biology
The microtubule polymerase action of Eg5 resides in straightening tubulin heterodimers.
Chen et al. | Hancock Lab | Current Biology
Axonemal dynein contorts microtubules to be more elliptical than round.
Lacey et al. | Carter Lab | eLife
Glucose metabolism triggers the nucleation of Golgi-derived microtubules in β cells.
Trogden et al. | Gu and Kaverina Labs | Current Biology
Actin branching amplifies B cell activation upon antigen presentation.
Bolger-Munro et al. | Gold Lab | eLife
Filament severing increases the fluidity of entangled F-actin solutions.
McCall et al. | Gardel Lab | Proceedings of the National Academy of Sciences
Local actin dynamics regulate the synaptic accumulation of neuropeptides in vivo.
Anbalagan et al. | Levkowitz Lab | eLife
A molecular clutch mediates T cell signaling across actin networks at immune synapses.
Ditlev et al. | Mayor, Jaqaman, and Rosen Labs | eLife

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