ScienceDaily (July 13, 2009) — Lars Jansen* has described the formation of the centromere, a key cellular structure in powering and controlling chromosome segregation and accurate cell division.

A new Nature Cell Biology paper, published in collaboration with a group at Stanford University School of Medicine, provides 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 recognised 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 shows the applicability of this new assay and open doors to future studies into centromere assembly and structure.

*Lars Jansen moved from California to the Instituto Gulbenkian de Ciência (IGC), in Portugal, last year to head the Epigenetic Mechanisms group.

An EMBO installation grant, of 50,000 euro per year, for a maximum of five years has been awarded.

enlarge

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))

Related Stories

Researchers Determine Composition Of Centromeric Chromatin (Oct. 4, 2009) — Researchers have provided new evidence to clarify the structure of nucleosomes containing Cse4, a centromere-specific histone protein required for proper kinetochore function, which plays a critical ...  > read more

Centromeres Cross Over, A Lot (June 17, 2008) — Recombination at centromeres is higher than anywhere else on the chromosome, even though methyltransferases do their best to prevent it, according to new research. Centromeric recombination has been ...  > read more

Mutations Help Clarify Processes In Cell Division (Dec. 5, 2007) — The architecture of cell division -- a fundamental process about which little is known, but when something goes wrong, it can cause cell death -- is the focus of a new study. Researchers are ...  > read more

Researchers Identify Potential Cancer Target (Jan. 18, 2009) — Researchers have found two proteins that work in concert to ensure proper chromosome segregation during cell division. The finding is relevant for treating solid cancerous tumors that lose the ...  > read more

Search ScienceDaily

Traffic Reports From Your Cell Phone