Unlocking the Centromere: The Crucial Role of Proteins in Cellular Docking

In both mitosis and meiosis, the spindle fibres connect to the chromosomes at a specialized region known as the centromere, facilitating the separation of sister chromatids so that each daughter cell receives an identical set of genetic information. The centromere is made up of centromeric DNA and a multi-protein complex called the kinetochore. The kinetochore guarantees the accurate distribution of chromosomes between the two daughter cells, thus maintaining genome stability and ensuring proper gene function in eukaryotic organisms.

The two proteins, KNL2 and CENP-C, are essential for the correct segregation of chromosomes during cell division. They attach carefully to the centromeric DNA, akin to the “lock and key principle.” However, previously known regions of the two proteins, referred to as CENPC-k/CENPC motifs, are inadequate for forming a link to the centromere. Initially, they can only identify the centromere. “By using the model organism Arabidopsis thaliana, we have demonstrated that, in addition, specific DNA-binding regions adjacent to the previously identified motifs of the proteins are required,” explains Dr. Inna Lermontova, the leader of IPK’s research group “Kinetochore Biology.” “These binding regions are crucial for establishing a connection with the centromere and consequently for the interaction of the proteins with the centromeric DNA,” states Surya Prakash Yalagapati, the principal author of the research.

“These findings enhance our comprehension of centromere structure and present new opportunities in synthetic biology and chromosome engineering,” remarks Dr. Inna Lermontova. Fragments containing CENPC/CENPC-k motifs along with DNA-binding regions can accurately direct proteins that modify centromeric chromatin architecture to centromeres. This research offers new understandings of the mechanisms involved in centromere development and the function of the kinetochore complex. “In the long run, this strategy could promote plant breeding by refining the creation of double-haploid lines and therefore hastening the breeding process,” asserts the IPK researcher.