CENP-E combines a slow, processive motor and a flexible coiled coil to produce an essential motile kinetochore tether.
The mitotic kinesin centromere protein E (CENP-E) is an essential kinetochore component that directly contributes to the capture and stabilization of spindle microtubules by kinetochores. Although reduction in CENP-E leads to high rates of whole chromosome missegregation, neither its properties as a microtubule-dependent motor nor how it contributes to the dynamic linkage between kinetochores and microtubules is known. Using single-molecule assays, we demonstrate that CENP-E is a very slow, highly processive motor that maintains microtubule attachment for long periods. Direct visualization of full-length Xenopus laevis CENP-E reveals a highly flexible 230-nm coiled coil separating its kinetochore-binding and motor domains. We also show that full-length CENP-E is a slow plus end-directed motor whose activity is essential for metaphase chromosome alignment. We propose that the highly processive microtubule-dependent motor activity of CENP-E serves to power chromosome congression and provides a flexible, motile tether linking kinetochores to dynamic spindle microtubules.
Kim
Yumi
Y
Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA.
Heuser
John E
JE
Waterman
Clare M
CM
Cleveland
Don W
DW
D000818:Animals; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020090:Chromosome Segregation; D018386:Kinetochores / Q000737:chemistry* / Q000378:metabolism; D008870:Microtubules / Q000737:chemistry* / Q000378:metabolism; D008954:Models, Biological; D020409:Molecular Motor Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008941:Spindle Apparatus / Q000737:chemistry* / Q000378:metabolism; D029867:Xenopus Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis
D002868:Chromosomal Proteins, Non-Histone; D020409:Molecular Motor Proteins; D011993:Recombinant Fusion Proteins; D029867:Xenopus Proteins; C068688:centromere protein E