Navigation Links
Constant overlap
Date:8/5/2010

During cell division, microtubules emanating from each of the spindle poles meet and overlap in the spindle's mid zone. Scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have uncovered the molecular mechanism that determines the extent of this overlap. In a study published today in Cell, they were able to reconstruct such anti-parallel microtubule overlaps in vitro, and identify two proteins which are sufficient to control the formation and size of this important spindle feature.

Thomas Surrey and his group at EMBL found that one protein, PRC1, bundles together microtubules coming from opposite ends of the cell, attaching them to each other. It then recruits a second protein, a molecular motor from the kinesin-4 subfamily, increasing its concentration in the spindle mid zone. This motor walks along the overlapping microtubules like an officer on patrol, until it reaches one of the ends. When enough kinesin-4 molecules reach the end of the overlap, they inhibit the growth of microtubules there, thus keeping the overlap size constant without affecting microtubules elsewhere in the cell.

The spindle mid zone plays an important role not only in helping to align the chromosomes in metaphase, but also in the final stages of cell division, when it drives the physical separation of the two daughter-cells. But between these two stages, the two ends of the spindle must move away from each other, to drag half the genetic material to each side of the dividing cell. At this point, if PRC1 and kinesin-4 had stopped microtubule growth permanently in the central part of the spindle, the overlap would become smaller and smaller, until eventually the spindle itself would collapse, jeopardising cell division. But Surrey and colleagues found that PRC1 and kinesin-4 control the overlap size in an adaptive manner. As the spindle stretches and the overlap between microtubules becomes smaller, the scientists posit, the inhibitory effect of kinesin-4 diminishes, allowing the microtubule ends to grow.

"Our findings show how molecules millionths of millimetres small can control the size of a structure about a thousand times larger than themselves," Surrey concludes: "they help us to understand the fundamentals of cell division."


'/>"/>

Contact: Lena Raditsch
lena.raditsch@embl.de
European Molecular Biology Laboratory
Source:Eurekalert

Related biology news :

1. Finding the constant in bacterial communication
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/14/2016)... 14, 2016 http://www.apimages.com ) ... --> - Renvoi : image disponible via AP ... --> --> DERMALOG, le leader ... nouveaux lecteurs d,empreintes digitales pour l,enregistrement des réfugiés ... utilisé pour produire des cartes d,identité aux réfugiés. ...
(Date:3/10/2016)... 10, 2016   Unisys Corporation (NYSE: UIS ... (CBP) is testing its biometric identity solution at the ... to help identify certain non-U.S. citizens leaving the country. ... designed to help determine the efficiency and accuracy of using ... and will run until May 2016. --> ...
(Date:3/8/2016)... , March 8, 2016   Valencell , ... today announced it has secured $11M in Series ... Tech, a new venture fund being launched by ... participation from existing investors TDF Ventures and WSJ ... to continue its triple-digit growth and accelerate its ...
Breaking Biology News(10 mins):
(Date:5/6/2016)... ... May 06, 2016 , ... Crucial Life Sciences ... Version 4.1, greatly improves performance of the platform. In particular, Version 4.1 boosts ... volumes of data to be collected on a per patient basis. Clinical Studio ...
(Date:5/5/2016)... ... May 05, 2016 , ... American Process, Inc. (API) announced ... Patent Nos. 9,322,133 and 9,322,134, to API and its affiliated companies for BioPlus® ... hydrophobic nanocellulose compositions. In addition to these patents and U.S. Patent No. ...
(Date:5/4/2016)... ... May 05, 2016 , ... CereScan, the ... National Stroke Association during National Stroke Awareness Month in May. An infographic ... throughout the month. CereScan will donate $1 up to a maximum of ...
(Date:5/4/2016)... , May 4, 2016  Bayer today announced ... compound Stivarga ® (regorafenib) tablets for the ... has met its primary endpoint of a statistically ... RESORCE, evaluated the efficacy and safety of regorafenib ... after treatment with sorafenib. The safety and tolerability ...
Breaking Biology Technology: