The Ndc80 kinetochore complex forms load-bearing attachments to dynamic microtubule tips via biased diffusion.
Kinetochores couple chromosomes to the assembling and disassembling tips of microtubules, a dynamic behavior that is fundamental to mitosis in all eukaryotes but poorly understood. Genetic, biochemical, and structural studies implicate the Ndc80 complex as a direct point of contact between kinetochores and microtubules, but these approaches provide only a static view. Here, using techniques for manipulating and tracking individual molecules in vitro, we demonstrate that the Ndc80 complex is capable of forming the dynamic, load-bearing attachments to assembling and disassembling tips required for coupling in vivo. We also establish that Ndc80-based coupling likely occurs through a biased diffusion mechanism and that this activity is conserved from yeast to humans. Our findings demonstrate how an ensemble of Ndc80 complexes may provide the combination of plasticity and strength that allows kinetochores to maintain load-bearing tip attachments during both microtubule assembly and disassembly.
Powers
Andrew F
AF
Department of Physiology and Biophysics, University of Washington, Seattle, 98195, USA.
Franck
Andrew D
AD
Gestaut
Daniel R
DR
Cooper
Jeremy
J
Gracyzk
Beth
B
Wei
Ronnie R
RR
Wordeman
Linda
L
Davis
Trisha N
TN
Asbury
Charles L
CL
D018386:Kinetochores / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
C112472:NDC80 protein, S cerevisiae; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins