• Medientyp: E-Artikel
  • Titel: KNL-1 directs assembly of the microtubule-binding interface of the kinetochore in C. elegans
  • Beteiligte: Desai, Arshad; Rybina, Sonja; Müller-Reichert, Thomas; Shevchenko, Andrej; Shevchenko, Anna; Hyman, Anthony; Oegema, Karen
  • Quelle: Genes & Development ; 17 ( 2003 ) S. 2421-2435
  • Erschienen: Cold Spring Harbor Laboratory, 2003
  • Sprache: Englisch
  • DOI: 10.1101/gad.1126303
  • ISSN: 0890-9369; 1549-5477
  • Schlagwörter: Developmental Biology ; Genetics
  • Zusammenfassung: <jats:p>Segregation of the replicated genome during cell division requires kinetochores, mechanochemical organelles that assemble on mitotic chromosomes to connect them to spindle microtubules. CENP-A, a histone H3 variant, and CENP-C, a conserved structural protein, form the DNA-proximal foundation for kinetochore assembly. Using RNA interference-based genomics in <jats:italic>Caenorhabditis elegans</jats:italic>, we identified KNL-1, a novel kinetochore protein whose depletion, like that of CeCENP-A or CeCENP-C, leads to a “kinetochore-null” phenotype. KNL-1 is downstream of CeCENP-A and CeCENP-C in a linear assembly hierarchy. In embryonic extracts, KNL-1 exhibits substoichiometric interactions with CeCENP-C and forms a near-stoichiometric complex with CeNDC-80 and HIM-10, the <jats:italic>C. elegans</jats:italic> homologs of Ndc80p/HEC1p and Nuf2p—two widely conserved outer kinetochore components. However, CeNDC-80 and HIM-10 are not functionally equivalent to KNL-1 because their inhibition, although preventing formation of a mechanically stable kinetochore-microtubule interface and causing chromosome missegregation, does not result in a kinetochore-null phenotype. The greater functional importance of KNL-1 may be due to its requirement for targeting multiple components of the outer kinetochore, including CeNDC-80 and HIM-10. Thus, KNL-1 plays a central role in translating the initiation of kinetochore assembly by CeCENP-A and CeCENP-C into the formation of a functional microtubule-binding interface.</jats:p>
  • Beschreibung: <jats:p>Segregation of the replicated genome during cell division requires kinetochores, mechanochemical organelles that assemble on mitotic chromosomes to connect them to spindle microtubules. CENP-A, a histone H3 variant, and CENP-C, a conserved structural protein, form the DNA-proximal foundation for kinetochore assembly. Using RNA interference-based genomics in <jats:italic>Caenorhabditis elegans</jats:italic>, we identified KNL-1, a novel kinetochore protein whose depletion, like that of CeCENP-A or CeCENP-C, leads to a “kinetochore-null” phenotype. KNL-1 is downstream of CeCENP-A and CeCENP-C in a linear assembly hierarchy. In embryonic extracts, KNL-1 exhibits substoichiometric interactions with CeCENP-C and forms a near-stoichiometric complex with CeNDC-80 and HIM-10, the <jats:italic>C. elegans</jats:italic> homologs of Ndc80p/HEC1p and Nuf2p—two widely conserved outer kinetochore components. However, CeNDC-80 and HIM-10 are not functionally equivalent to KNL-1 because their inhibition, although preventing formation of a mechanically stable kinetochore-microtubule interface and causing chromosome missegregation, does not result in a kinetochore-null phenotype. The greater functional importance of KNL-1 may be due to its requirement for targeting multiple components of the outer kinetochore, including CeNDC-80 and HIM-10. Thus, KNL-1 plays a central role in translating the initiation of kinetochore assembly by CeCENP-A and CeCENP-C into the formation of a functional microtubule-binding interface.</jats:p>