March 26, 2013

When Outkast sang that “I like the way you mooove,” I immediately figured they were talking my dancing skills.  Turns out, they were really singing about motile cells…true story*.  Today’s image is from a paper showing a link between the chemical signals that tell a cell to move and how the cell actually moves.

As an axon searches for its synaptic target, it sends out a motile extension called a growth cone.  The chemical cues that initiate mobility in the growth cone trigger major cytoskeletal rearrangements at the leading edge, specifically actin filament polymerization and an engagement with the underlying extracellular substrate.  A recent paper describes the signaling that links the chemical cues to the generation of traction forces that move the growth cone forward.  Toriyama and colleagues show that the protein shootin1 is phosphorylated following signaling from the chemoattractant netrin1.  Phosphorylated shootin1, then, triggers actin-extracellular substrate coupling and generates the forces for axonal outgrowth.  In the images above, phosphorylated shootin1 (green) is enriched at filopodial and lamellipodial extensions in growth cones (actin filaments are in red).

*not really

Toriyama, M., Kozawa, S., Sakumura, Y., & Inagaki, N. (2013). Conversion of a Signal into Forces for Axon Outgrowth through Pak1-Mediated Shootin1 Phosphorylation Current Biology, 23 (6), 529-534 DOI: 10.1016/j.cub.2013.02.017 
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