Duke U. Team ‘Sees’ Motor Molecule Move

North Carolina scientists say the tiny motor molecules in cells stagger like humans as they carry their loads of vesicles or organelles through the cell.

By understanding how these intracellular motors work, researchers hope to better understand Charcot-Marie-Tooth disease and other neuromuscular conditions dependent on the transport of neurotransmitters or synaptic vesicle precursors by molecular motors.

The work by the Duke University Medical Center team has been summarized in the latest online edition of the European Molecular Biology Organization journal.

In short, the team believes it has helped settle a controversy within biology of how motor molecules, known as kinesins, step through the cytoplasm within the cell along infinitesimal tracks called microtubules.

The motor protein itself consists of a coiled-coil neck/stalk region that connects two identical motor domains or heads.

These heads move the molecule forward by binding to the microtubule. Because of these two identical heads, some researchers felt that movement should therefore be symmetrical, one head stepping after the other in an identical fashion.

The team’s work show that the molecule alternates which side the lagging head passes the leading head as the motor walks, leading to asymmetrical gait.