If you're the motor protein up front, be prepared to do the heavy pulling.
That's one conclusion from a Rice University-led study of the mechanisms that drive kinesins, motor proteins that carry cargo inside cells. The study shows it takes a lot of counterforce to slow down a determined kinesin. Nor does the protein get much help from colleagues that bring up the rear.
The theoretical study detailed in the Proceedings of the National Academy of Sciences and led by Rice postdoctoral researcher Qian Wang was a collaborative effort by the labs of three professors at Rice and one at the University of Houston, all working under the umbrella of Rice's Center for Theoretical Biological Physics (CTBP).
They hope to add to knowledge about the little-understood workhorses inside cells that are critical to cell division as well as cargo transport.
Qian Wang, Michael R. Diehl, Biman Jana, Margaret S. Cheung, Anatoly B. Kolomeisky, José N. Onuchic. Molecular origin of the weak susceptibility of kinesin velocity to loads and its relation to the collective behavior of kinesins. Proceedings of the National Academy of Sciences, 2017; 201710328 DOI: 10.1073/pnas.1710328114
An illustration shows two load-bearing kinesins as they carry cargo along a microtubule (cyan). Rice University and University of Houston researchers determined that motor proteins respond best to strong forces and hardly at all to weak ones, even those applied by motors attached to the same cargo. In this example, the leading kinesin (LK) carries most of the load, with motor heads (blue) activated by a neck linker (yellow) that connects to the stalk (red) and senses the presence of the cargo. Click on the image for a larger version.Credit: Courtesy of the Center for Theoretical Biological Physics
