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How are chromosomes moved during mitosis? Biophysics at the kinetochore‐microtubule interface
Author(s) -
Asbury Charles,
Powers Andrew,
Franck Andrew,
Gestaut Daniel,
Gonen Tamir,
Davis Trisha
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.537.2
Subject(s) - kinetochore , chromosome segregation , microtubule , mitosis , microbiology and biotechnology , biology , centromere , spindle apparatus , chromosome , cell division , biophysics , cell , genetics , gene
During cell division, chromosome movements are coupled to the growth and shortening of microtubule (MT) filaments, the tips of which transmit tension to specialized sites on each chromosome, called kinetochores. Recent work suggests that the Dam1 complex, a component of yeast kinetochores, participates in kinetochore‐MT attachment, force production, and regulation of attached MTs, perhaps by forming a ring encircling the MT. To test these hypotheses, we developed an in vitro motility assay where Dam1‐coated beads attach the tips of individual MTs. Like kinetochores, the beads remain tip‐bound and undergo movements driven by MT growth and shortening. By using a feedback‐controlled optical trap, we found that tension applied continuously through Dam1 decreases the likelihood that growing tips will begin to shorten, slows shortening, and increases the likelihood that shortening tips will resume growth. These findings demonstrate how Dam1 can contribute directly to MT‐driven force production and chromosome movement. They also show that tension can modulate filament dynamics directly, without need for additional MT‐modifying factors.