The centromere is vital for chromosomes during cell division. An international research team, led by the Leibniz Institute IPK, examined how two critical proteins—KNL2 and CENP-C—attach to the centromere, which is essential for this process. Their findings were published in the journal Nucleic Acids Research.
During both mitotic and meiotic cell division, spindle fibers connect to chromosomes at a specific area known as the centromere, pulling sister chromatids apart to ensure each daughter cell inherits identical genetic material. The centromere is made up of centromeric DNA and a complex of proteins called the kinetochore. The kinetochore plays a crucial role in the accurate distribution of chromosomes to daughter cells, thereby maintaining genome stability and ensuring proper gene function in eukaryotic organisms.
The proteins KNL2 and CENP-C are essential for the correct separation of chromosomes in cell division. They attach to centromeric DNA based on a “lock and key principle.” However, previously known parts of these proteins, referred to as CENPC-k/CENPC motifs, are not enough to create a connection to the centromere. Initially, they are only able to identify the centromere. “Our research using the model organism Arabidopsis thaliana has demonstrated that additional regions called DNA-binding regions, located next to the known motifs, are necessary,” explains Dr. Inna Lermontova, who leads the “Kinetochore Biology” research group at IPK. “These binding regions are critical for establishing a connection with the centromere and for the proteins to interact with the centromeric DNA,” adds Surya Prakash Yalagapati, the study’s lead author.
“These findings enhance our knowledge of centromere structure and present new opportunities in synthetic biology and chromosome engineering,” states Dr. Inna Lermontova. Fragments containing CENPC/CENPC-k motifs and DNA-binding regions can accurately target proteins that modify centromere chromatin to the centromeres themselves. This research offers new insights into how centromeres are formed and the function of the kinetochore complex. “In the long run, this strategy could improve plant breeding by optimizing the production of double-haploid lines, thus speeding up the breeding process,” concludes the IPK researcher.
