MIT engineers show how tiny cell proteins generate force to 'walk'

Nov 24, 2008 By Anne Trafton
Kinesin, a small motor protein found in cells, walks stepwise on microtubules to perform cellular processes. In each step, a power stroke is generated when two mechanical elements (neck linker, in red, and cover strand, in blue) form a beta-sheet that folds to drive the protein forward. Image courtesy / Ahmad S. Khalil; Kathleen M. Flynn; and Wonmuk Hwang

(PhysOrg.com) -- MIT researchers have shown how a cell motor protein exerts the force to move, enabling functions such as cell division.

Kinesin, a motor protein that also carries neurotransmitters, "walks" along cellular beams known as microtubules. For the first time, the MIT team has shown at a molecular level how kinesin generates the force needed to step along the microtubules.

The researchers, led by Matthew Lang, associate professor of biological and mechanical engineering, report their findings in the Nov. 24 online early issue of the Proceedings of the National Academy of Sciences.

Because kinesin is involved in organizing the machinery of cell division, understanding how it works could one day be useful in developing therapies for diseases involving out-of-control cell division, such as cancer.

The protein consists of two "heads," which walk along the microtubule, and a long "tail," which carries cargo. The heads take turns stepping along the microtubule, at a rate of up to 100 steps (800 nanometers) per second.

In the PNAS paper, Lang and his colleagues offer experimental evidence for a model they reported in January in the journal Structure. Their model suggests — and the new experiments confirm — that a small region of the protein, part of which joins the head and tail is responsible for generating the force needed to make kinesin walk. Two protein subunits, known as the N-terminal cover strand and neck linker, line up next to each other to form a sheet, forming the cover-neck bundle that drives the kinesin head forward.

"This is the kinesin power stroke," said Lang.

Next, Lang's team plans to investigate how the two kinesin heads communicate with each other to coordinate their steps.

Source: Massachusetts Institute of Technology

Explore further: Researchers collect soil samples from around the globe in effort to conduct fungi survey

add to favorites email to friend print save as pdf

Related Stories

Some motor proteins cooperate better than others

Jan 09, 2014

Rice University researchers have engineered cells to characterize how sensitively altering the cooperative functions of motor proteins can regulate the transport of organelles.

RNA on the move

Nov 26, 2009

In the fruit fly Drosophila, oskar mRNA, which is involved in defining the animal’s body axes, is produced in the nuclei of nurse cells neighbouring the oocyte, and must be transported to the oocyte and ...

Dartmouth researchers find new protein function

Jan 09, 2009

A group of Dartmouth researchers has found a new function for one of the proteins involved with chromosome segregation during cell division. Their finding adds to the growing knowledge about the fundamental ...

Hitchhiking nanotubes show how cells stir themselves

May 30, 2014

(Phys.org) —Chemical engineers from Rice University and biophysicists from Georg-August Universität Göttingen in Germany and the VU University Amsterdam in the Netherlands have successfully tracked single ...

Kinesin-5 structure opens cancer drug targets

Apr 08, 2014

The structure of a key part of the machinery that allows cells to divide has been identified by researchers at the University of California, Davis—opening new possibilities for throwing a wrench in the machine and blocking ...

Recommended for you

Parasitic worm genomes: largest-ever dataset released

16 hours ago

The largest collection of helminth genomic data ever assembled has been published in the new, open-access WormBase-ParaSite. Developed jointly by EMBL-EBI and the Wellcome Trust Sanger Institute, this new ...

Male sex organ distinguishes 30 millipede species

17 hours ago

The unique shapes of male sex organs have helped describe thirty new millipede species from the Great Western Woodlands in the Goldfields, the largest area of relatively undisturbed Mediterranean climate ...

How can we avoid kelp beds turning into barren grounds?

21 hours ago

Urchins are marine invertebrates that mould the biological richness of marine grounds. However, an excessive proliferation of urchins may also have severe ecological consequences on marine grounds as they ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.