The adult human body consists of trillions of cells. Cell proliferation is accomplished by means of cell division in which an existing cell serves as the exact blueprint for its progeny. This process follows the same basic principles in all higher organisms. First, the genetic information is precisely copied and subsequently equally distributed between the mother and daughter.
Dividing human cancer cell in Metaphase. The DNA (gray) is attached to the spindle apparatus (pseudocolored). Copyright: IMP/Ladurner
The major task for the dividing cell is to drag two complete sets of chromosomes to the opposite sides of the nucleus, respectively. A logistic challenge accomplished by the interplay of two factors: the spindle apparatus that acts as the molecular motor driving chromosome movements, and the kinetochore that constitutes the physical platform between the DNA and the mitotic spindle.
The attachment site formed by the kinetochore is an intricate protein network. While its components providing the direct contact point for the spindle are very well preserved from yeast to human, evolution of the DNA-binding proteins remained puzzling given that the underlying DNA template is highly variable.
Now, a novel study published in the June edition of Nature Cell Biology sheds light onto the cryptic molecular relationship between the yeast and human kinetochore. Principal investigator Stefan Westermann and his team tracked the missing evolutionary link and opened up new insights into the architecture and function of the key division organelle.
The correct shape pieces the puzzle together
“The clue was to take a close look at the protein sequence as well as specific sequence motifs that get an amino acid chain into its particular shape.” says Stefan Westermann. “In this way, our bioinformatician Alexander Schleiffer was able to predict a number of novel DNA-binding kinetochore proteins and assigned them to the respective human homolog.” Follow-up experiments strongly supported analogous function of the proteins. “Yeast is still an informative model organism and very easy to handle. Our current findings can now direct similar studies in more complex systems. There erroneous chromosome segregation is deleterious for the cell and a common cause of cancer” explains the scientist.
Dr. Heidemarie Hurtl | idw
Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences
Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences