#ScienceSaturday posts share exciting scientific developments and educational resources with the KAND community. Each week, Dr. Dominique Lessard and Dr. Dylan Verden of KIF1A.ORG summarize newly published KIF1A-related research and highlight progress in rare disease research and therapeutic development.
KIF1A in the News
Earlier this month our founder Luke Rosen participated in NewYorkBIO’s Patient Engagement Summit to discuss the “Future of Patient Centric” care. Luke speaks to the ethos guiding KIF1A.ORG’s relentless efforts to find new therapeutics for KAND families. Watch the discussion below, and check out the rest of NewYorkBIO’s lineup!
Selective axonal transport through branch junctions is directed by growth cone signaling and mediated by KIF1/kinesin-3 motors
When looking at an image of KIF1A on a microtubule, it is easy to imagine that the “road” stretches on forever in a straight line. But not all roads lead to the same terminal! Axons have branches that allow signals to travel downstream to multiple neurons. So how does a kinesin molecule decide which road to take?
This week’s study looked at cultured neurons from rat spinal cord to investigate what factors bias kinesins to carry cargo to one axon terminal or the other. These neurons have one primary axon that tends to be longer, as well as multiple branches. By watching cargo “choose” where to go at the point where branches break off from the main axon, researchers were able to learn more about what impacted this choice. They found that the kinesin-bound cargo synaptophysin, which regulates synaptic growth, was more likely to travel along the main axon, especially when the branches were shorter. When branches were closer to the main axon in length, a larger proportion of the cargo went into those branches.
During development, axons and their branches actively grow, with ends called “growth cones” moving forward. The researchers found that whether an axon was growing had a much bigger impact on the cargo’s direction than the axon length. They demonstrated this by activating growth cones in either the main axon or an axon branch and found that they could “push” a kinesin’s decision toward active growth cones.
Lastly, the researchers found that kinesin-3 (of which KIF1A is a family member) was more responsive to these factors than other kinesins. Because growth cones are active when the nervous system is growing, this speaks to a possible developmental role of kinesin-3, directing cargo toward the growing axon terminals that need materials the most.