Scientists from the Max Planck Institute for Molecular Cell Biology and Genetics (MPI-CBG) in Dresden, along with a colleague from the University of Florida in the United States, have been carrying out research into how transport proteins can move in cells without bumping into or sticking to anything. Using an ultra-sensitive microscopy method, the researchers have defined how the motor protein Kinesin-1 interacts with its "transport rails", the microtubules, based on a nanometer scale. The motor protein stays at a distance of 17 nanometers from the microtubules, which explains how it manages to carry its load to its destination without collisions (PNAS, 24 October 2006).

Cells are very similar to the Port of Hamburg: goods and commodities arrive, have to be classified, temporarily stored and subsequently dispatched. In both small and large cells, it is very important to avoid backups and collisions, as these transport processes are vital for every organism.

Motor proteins take care of transport in cells, carrying their goods back and forth like small containers. They need transport rails to accomplish this, otherwise they would float aimlessly in the cytoplasm. This role is performed by microtubules, among others, long thread-shaped structures about 25 nanometers in diameter and several micrometers in length, which extend through the whole of the cell. Motor proteins, of which kinesin-1 is a well-researched example, consist of a head, middle section and tail. They are considerably smaller than their transport rails.

Whether kinesin-1 is transporting individual cell organelles or other cargo, its head section moves forward step by step on a microtubule - the length of the step and the precise coordination of such steps have already been investigated in detail. It is also known how kinesin attache
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Contact: Stefan Diez
diez@mpi-cbg.de
0049-351-210-2521
Max-Planck-Gesellschaft
24-Oct-2006