cellular motors at work: (Evolution)

by David Turell , Sunday, January 26, 2020, 21:38 (1761 days ago) @ David Turell

A new description of how the motors transport:

https://www.sciencedaily.com/releases/2020/01/200122150010.htm

"Researchers develop a device that parks individual molecular motors on nano scale platforms and found that two types of 'kinesin' possess different properties of coordination. In kinesin-1, neither the number nor spacing of the molecules change the transport velocity of microtubules, while kinesin-14 decreased transport velocity as the number of motors on a filament increased, but increased as the spacing of the motors increased.

"Any kind of body movement both big and small, from the muscles in your arms to the neurons transporting those signals to your brain, rely on a massive collection of proteins we call molecular motors.

"Fundamentally, molecular motors are proteins that convert chemical energy into mechanical movement, and have different functions depending on their task. However, because they are so small, the exact mechanisms on how these molecules coordinate with each other is poorly understood.

***

"The team evaluated two kinesins: kinesin-1 and kinesin-14 which are involved in intercellular transport and cell division respectively. Their results showed that in the case of kinesin-1, neither the number nor spacing of the molecules change the transport velocity of microtubules.

"In contrast, kinesin-14 decreased transport velocity as the number of motors on a filament increased, but increased as the spacing of the motors increased. The results indicate that while kinesin-1 molecules work independently, kinesin-14 interacts with each other to tune the speed of transport.

"Ryuji Yokokawa who led the team was surprised by the results, "Before we started this study, we thought that more motors led to faster transport and more force. But like most things in Biology, it's rarely that simple.'"

Comment: These motors produce directed results. The reactions do not depend on chance diffusion in cellular fluids. But delivery by design means the cells produce their products in a very organized fashion. Not by chance.