ABSTRACT
The microtubule (MT) plus-end motor kinesin heavy chain (Khc) is well known for its role in long distance cargo transport. Recent evidence showed that Khc is also required for the organization of the cellular MT network by mediating MT sliding. We found that mutations in Khc and the gene of its adaptor protein, kinesin light chain (Klc) resulted in identical bristle morphology defects, with the upper part of the bristle being thinner and flatter than normal and failing to taper towards the bristle tip. We demonstrate that bristle mitochondria transport requires Khc but not Klc as a competing force to dynein heavy chain (Dhc). Surprisingly, we demonstrate for the first time that Dhc is the primary motor for both anterograde and retrograde fast mitochondria transport. We found that the upper part of Khc and Klc mutant bristles lacked stable MTs. When following dynamic MT polymerization via the use of GFP-tagged end-binding protein 1 (EB1), it was noted that at Khc and Klc mutant bristle tips, dynamic MTs significantly deviated from the bristle parallel growth axis, relative to wild-type bristles. We also observed that GFP-EB1 failed to concentrate as a focus at the tip of Khc and Klc mutant bristles. We propose that the failure of bristle tapering is due to defects in directing dynamic MTs at the growing tip. Thus, we reveal a new function for Khc and Klc in directing dynamic MTs during polarized cell growth. Moreover, we also demonstrate a novel mode of coordination in mitochondrial transport between Khc and Dhc.
Footnotes
Competing interests
The authors declare no competing or financial interests.
Author contributions
A.M., performed the experiments, analyzed the data and wrote the paper. Y.S., performed experiments. Y.A. analyzed the data. U.A., analyzed the data and wrote the paper.
Funding
This research was supported by Israel Science Foundation [grant 968/10] to U.A.
Supplementary information
Supplementary information available online at http://bio.biologists.org/lookup/suppl/doi:10.1242/bio.015206/-/DC1
- Received October 7, 2015.
- Accepted October 16, 2015.
- © 2015. Published by The Company of Biologists Ltd
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.
Article Navigation
Related articles
Cited by...
More in this TOC section
Similar articles
Other journals from The Company of Biologists
Cover article - Contribution of non-circadian neurons to the temporal organization of locomotor activity
Our cover article characterizes the impact of different putative postsynaptic partners of the small ventral lateral neurons on the control of rhythmic locomotor behavior. M. Fernanda Ceriani and team found that some of these novel neuronal clusters are relevant for the control of locomotor activity.
Featured article - Development and validation of RdRp Screen, a crystallization screen for viral RNA-dependent RNA polymerases
Frank Kozielski and colleagues have developed a 96-well crystallization screen for viral RNA-dependent RNA polymerases (RdRps). Read about this platform for streamlining the crystallisation of RdRps and implementing structure-based drug discovery programs.
First person interviews
Have you seen our interviews with the early-career first authors of our papers? Recently, we caught up with first authors Sarah Hoffman, Amani Hassan, Eriko Seo, Yunlong Li and Klytaimnistra Kiouptsi.
Why should you publish your next paper in BiO?
Biology Open has strong credentials and publishing with us is easy and fast. BiO aims to provide rapid publication for scientifically sound observations and valid conclusions in developmental, cell, experimental and translational biology. Submit your paper here; you’ll be in good company.
Recent disease mechanism highlights in BiO – Timothy Plageman and team investigate folic acid’s modification of epithelial cell shape during morphogenesis, shedding light onto the mechanism by which folic acid may prevent neural tube defects.
Transfer to Biology Open
If your submission to one of our other journals, Development, Journal of Cell Science, Journal of Experimental Biology or Disease Models & Mechanisms, is unsuccessful, did you know you can transfer your paper and any reviews directly to Biology Open? The majority of papers transferred with reviews are accepted for publication. Find out how here.
PreLights - Short-range interactions govern cellular dynamics in microbial multi-genotype systems
Connor Rosen highlights two preprints which show that microbial conversations dictate growth by measuring and modeling the crosstalk between individual microbial cells.