Yeast Nkp2 is required for accurate chromosome segregation and interacts with several components of the central kinetochore
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Kinetochores are macromolecular proteinaceous assemblies that are assembled on centromeres and attach chromosomes to the spindle fibres and regulate the accurate transmission of genetic material to daughter cells. Multiple protein sub-complexes within this supramolecular assembly are hierarchically assembled and contribute to the different aspects of kinetochore function. In this work we show that one of the components of the Saccharomyces cerevisiae kinetochore, Nkp2, plays an important role in ensuring accurate segregation of chromosomes. Although this protein is not conserved in higher organisms, we show that it interacts with highly conserved components of the kinetochore genetically and regulates chromosome segregation. We show that in kinetochore mutants like ctf19 and mcm21 the protein is mislocalized. Furthermore, removal of Nkp2 in these mutants restores normal levels of segregation.
KeywordsNKP2 Kinetochore Chromosome segregation Chromosome loss Loss of heterozygosity
This work was supported by a Department of Science and Technology (DST) Fast Track grant to KM. Facilities established under University Special Assistance Programme (UGC-SAP), DST-Fund for Infrastructure in Science and Technology (DST-FIST) and Department of Biotechnology-Centre for Research and Education in Biology and Biotechnology (DBT-CREBB) programmes of University of Hyderabad have been used for conducting of experiments. ST acknowledges fellowship support from UGC and DBT-CREBB. We thank D. Gottshling, A. Marston, M. Dresser, S. Jaspersen and P. Pryciak for strains and plasmids.
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