(photo credit: Marretao22/Wikimedia Commons)
Tiny bits of proteins necessary for cells to divide have been found by Israeli
and German scientists to have an astonishing ability to go into reverse as if
they were car-like “nanoengines.”
According to a 13-page article just
published in the online edition of the EMBO (European Molecular Biology
Organization Journal) and due to be published in the December 14 print edition,
the discovery could be vital for the understanding of biological motors during
cell division, not only for basic cell science but also for cancer research and
biologically inspired nanotechnology in medicine and industry.
discoveries indicate the nanometersized molecular machines are much more
powerful and versatile than previously thought.
Scientists at Ben-Gurion
University of the Negev in Beersheba who have been working with a group from
George August University of Goettingen, Germany, made the discovery while
working on motor proteins essential for cell division.
They found these
“nanoengines” can drastically modify their speed and even switch direction when
loaded with a cargo - something that was not realized until now.
division is a key process in the development of organisms. During regular cell
division, duplicated chromosomes of the mother cell are distributed into two
daughter cells. This tightly regulated process is driven by specialized enzymes
called motor proteins; prominent among them are the families of kinesins and
dyneins. Until now, it was believed that each member of those families was
structurally programmed for a defined directionality on its track, the
microtubules of the cytoskeleton. One class of motors was believed to generate
motion toward the cell poles and another toward the cell equator.
BGU group, led by Dr. Leah (Larisa) Gheber from the clinical biochemistry and
chemistry departments and the university’s Ilse Katz Institute for Nanoscale
Science and Technology, along with German Prof. Christoph Schmidt, have now been
able to show that one type of cell division motor in yeast cells can move in
both directions. In addition, the motor protein can move toward the cell poles
10 times faster than all other known motors of the same family. The researchers
observed this phenomenon with high-resolution flourescence microscopy, which was
used to track single molecules both in model systems and living
According, to the researchers, one particularly interesting aspect
of their findings is that the bi-directional motors switch exactly into the slow
forward gear when they bind between two microtubule tracks in the middle of the
cell, where they help to push the chromosomes apart.