One-dimensional Diffusion Accelerates Molecular Motors

May 12, 2006
One-dimensional Diffusion Accelerates Molecular Motors
The movement of MCAK molecules (green) over time, along a microtubule (red). 20 points in time, from top to bottom. Credit: Max Planck Institute of Molecular Cell Biology and Genetics

Max Planck scientists have identified a new strategy which motor proteins use to move. The research was carried out by Prof. Jonathon Howard and Stefan Diez at the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden. The motor protein MCAK (Mitotic Centromere Associated Kinesin) goes into action at the end of microtubules where it disassembles them.

This is in contrast to most other motor proteins, which transport materials over long distances along microtubules. The researchers were able to show that the protein reaches the position via a random, one-dimensional diffusion movement along the microtubule, until it locks into place at its end (Nature, May 4, 2006). This discovery is important for understanding cellular life processes like cell division and nerve cell growth.

When cells divide, they build a giant apparatus - the so called the "mitotic spindle". It is made up of microtubules; which are tiny protein polymers that can be built up and torn down like scaffolding. They also make up "tracks", along which motor proteins pull the halves of chromosomes into existing daughter cells. Until now, scientists have not known how the length of microtubule gets regulated, nor how the proteins reach the end of the microtubules to be regulated.

The Max Planck researchers looked at the example of the protein MCAK, and how it locates microtubule ends. Howard and his colleagues followed single MCAK molecules under the microscope and could see that MCAK docks randomly anywhere on a microtubule, and then slides around on its surface.

This "random" strategy is surprisingly efficient and successful. It allows MCAK to localize microtubule ends very quickly. Howard says, "when it gets there, MCAK eats like a Pacman into the end of the microtubule." The chromosome halves follow this movement and are this way accurately distributed on the daughter cells.

Source: Max-Planck-Gesellschaft

Explore further: Biologists demonstrate how signals in plant roots determine the activity of stem cells

Related Stories

NSA winds down once-secret phone-records collection program

16 minutes ago

The National Security Agency has begun winding down its collection and storage of American phone records after the Senate failed to agree on a path forward to change or extend the once-secret program ahead of its expiration ...

Pipeline that leaked wasn't equipped with auto shut-off

26 minutes ago

The pipeline that leaked thousands of gallons of oil on the California coast was the only pipe of its kind in the county not required to have an automatic shut-off valve because of a court fight nearly three ...

Uber drivers fined in Hungary

1 hour ago

The Hungarian tax authority fined Uber drivers in its first probe against the ride-sharing service which the economy ministry said Saturday "ignores passenger safety" and must be made to follow regulations.

Recommended for you

Bacterial tenants in fungal quarters

5 hours ago

Ludwig Maximilian University of Munich researchers have sequenced the genome of a bacterial symbiont hosted by a mycorrhizal fungus. Analysis of the symbiont's genetic endowment reveals previously unknown ...

Natural enzyme examined as antibiotics alternative

8 hours ago

In 1921, Alexander Fleming discovered the antimicrobial powers of the enzyme lysozyme after observing diminished bacterial growth in a Petri dish where a drop from his runny nose had fallen. The famed Scottish ...

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.