Minus-End Growth, Reconstituted Spindle Midzones, and Contorted Microtubules
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
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
Rockets, Gauges, and Pendulums: Applying Engineering Principles to Cell Biology
Considering the spindle checkpoint as a faulty gauge may unlock new insights into the perplexities of mitotic slippage.
William Sullivan | Molecular Biology of the Cell
Tools and Resources
Listen to a candid interview with the author here.
Journal Club Picks
- Branched microtubule nucleation contributes majorly to kinetochore-fiber assembly.
David et al. | Gerlich Lab | Journal of Cell Biology
- Spindle assembly factors coalesce via phase separation in large egg cells.
So et al. | Schuh Lab | Science
- 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
Our opinions are our own and do not represent the views or endorsement of the authors cited.