July 17, 2013

We don’t need to reinvent the wheel (even if someone tried to in 2001...click here).  We use the wheel for so many things ranging from transport to energy.  Cells have proven clever at co-opting machinery for multiple processes, as the paper from today’s image describes.  This recent paper shows the use of specific machinery in both cytokinesis and neuronal migration.

When neurons migrate, there is a leading process in the front of the cell body and a trailing process.  The leading process contains actin filaments that enable the cell body of the neuron to move forward.  A recent paper describes how the microtubule-based motor kinesin-6 plays an important role in neuronal migration.  Kinesin-6 is best known for its role in cytokinesis, the physical division of a cell after mitosis.  Falnikar and colleagues found that kinesin-6 concentrates in the same region as actin filaments in the leading process of a migrating neuron.  Without kinesin-6, neurons lose their bipolar leading-trailing process morphology, concentrate actin filaments in more than one process, and either remain stationary or continually change the direction of migration.  In addition, Falnikar and colleagues found that kinesin-6 signals through the GTPase activating protein MgcRacGAP to regulate the actin cytoskeleton, as it does during cytokinesis.  In the images above, control neurons (top time-lapse series) moved in a single direction, while neurons depleted of kinesin-6 bottom) frequently changed directions.

BONUS!!  Check out a movie of a wandering, migrating kinesin-6-depleted neuron below.

Aditi Falnikar, Shubha Tole, Mei Liu, Judy S. Liu, & Peter W. Baas (2013). Polarity in Migrating Neurons Is Related to a Mechanism Analogous to Cytokinesis Current Biology, 23 (13), 1215-1220 DOI: 10.1016/j.cub.2013.05.027 Copyright ©2013 Elsevier Ltd. All rights reserved.