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: How do our muscles work? Scientists reveal important new insights into muscle protein

add to favorites email to friend print save as pdf

Related Stories

How the hummingbird achieves its aerobatic feats

20 minutes ago

(Phys.org) —The sight of a tiny hummingbird hovering in front of a flower and then darting to another with lightning speed amazes and delights. But it also leaves watchers with a persistent question: How ...

'Mind the gap' between atomically thin materials

1 hour ago

In subway stations around London, the warning to "Mind the Gap" helps commuters keep from stepping into empty space as they leave the train. When it comes to engineering single-layer atomic structures, minding ...

Seychelles poachers go nutty for erotic shaped seed

1 hour ago

Under cover of darkness in the steamy jungles of the Seychelles thieves creep out to harvest the sizeable and valuable nuts of the famous coco de mer palm, and their activities are threatening its long-term ...

Recommended for you

Genomes of malaria-carrying mosquitoes sequenced

4 hours ago

Nora Besansky, O'Hara Professor of Biological Sciences at the University of Notre Dame and a member of the University's Eck Institute for Global Health, has led an international team of scientists in sequencing ...

Bitter food but good medicine from cucumber genetics

4 hours ago

High-tech genomics and traditional Chinese medicine come together as researchers identify the genes responsible for the intense bitter taste of wild cucumbers. Taming this bitterness made cucumber, pumpkin ...

New button mushroom varieties need better protection

8 hours ago

A working group has recently been formed to work on a better protection of button mushroom varieties. It's activities are firstly directed to generate consensus among the spawn/breeding companies to consider ...

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.