July 1, 2009
Scientists Working On Chromosome Segregation
Lars Jansen's work on the formation of the centromere, a key cellular structure in powering and controlling chromosome segregation and accurate cell division, has just earned him a paper in Nature Cell Biology and a prestigious EMBO installation grant, of 50,000 euro per year, for a maximum of five years.
Lars Jansen moved from California to the Instituto Gulbenkian de CiÃªncia (IGC), in Portugal, last year to head the Epigenetic Mechanisms group. The Nature Cell Biology paper, published online this week, in collaboration with a group at Stanford University School of Medicine, provides new insights into the scaffold of proteins that ensures accurate segregation of chromosomes during cell division - a fundamental step to ensure that daughter cells have the same genetic information as their mother, with reduced risk of cancer.
When segregating, chromosomes attach and move along proteins tracks (the mitotic spindle), from the centre of the cell to the poles. The centromere is the area of the chromosome that directs this attachment by controlling the assembly of a scaffold of proteins (called the kinetochore), which tether the chromosome to the spindle, and power its movement along the protein track. The location of the centromere on the chromosome is marked by the presence of a protein, called CENP-A, but how this protein is recognized by the other components of the cell to orchestrate the assembly of the centromere was not understood - until now.
Using a newly developed assay, Lars and his colleagues were able to identify the protein that triggers the assembly of the centromere. It's called CENP-N. According to Mariana Silva, a PhD student in the lab, 'When we depleted CENP-N in cells, the centromere did not assemble correctly and chromosomes segregated abnormally, leading to situations similar to cancer'.
This study, the first paper from Lars and his PhD student Mariana since arriving at the IGC a year ago, proves the applicability of this new assay and open doors to future studies into centromere assembly and structure. Indeed, Lars' proposal to further explore centromere assembly and function, was awarded an EMBO installation grant and entrance into the prestigious network of some of Europe's best young group leaders.
According to Lars, the award "will be a huge boost to our research! Apart from the direct monetary benefit this grant is a great recognition of the relevance of our work and the science we propose in this project. Moreover, entry into the EMBO Young Investigator Program allows me to fully integrate our emerging laboratory in the larger European scientific community. The IGC has been extremely supportive of our efforts and remains critically important in creating the conditions that help our laboratory and work to come to full fruition."
Portugal is a member state participating in the EMBC, the EMBO intergovernmental funding body and, as such, hosts and fully finances the grants awarded to scientists who wish to establish themselves in this country. This award will be jointly financed by the Portuguese government funding agency, FundaÃ§Ã£o para a CiÃªncia e a Tecnologia (FCT) and the host institution, the Instituto Gulbenkian de CiÃªncia (IGC), through an agreement established between the Calouste Gulbenkian Foundation and FCT.
This is second time that EMBO rewards projects developed by IGC scientists with this kind of funding. In 2007, M³nica Dias was also awarded an EMBO Installation Grant to pursue her research in regulation of cell cycle progression in normal development and cancer.
Image 1: A cell seen through a microscope: the chromosomes (in blue) are attached to the microtubule tracks (in red) in the region of the centromere -- green spots mark the protein CENP-A on the centromere.
Credit: Lars Jansen (IGC)
Image 2: This is a cartoon showing the chromosomes in a cell (blue) attached to the microtubule tracks (in green) through the kinetochore (in red).
Credit: Mariana Silva (IGC)
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