Microtubule end conversion mediated by motors and diffusing proteins with no intrinsic microtubule end-binding activity.
Nat Commun
; 10(1): 1673, 2019 04 11.
Article
in En
| MEDLINE
| ID: mdl-30975984
ABSTRACT
Accurate chromosome segregation relies on microtubule end conversion, the ill-understood ability of kinetochores to transit from lateral microtubule attachment to durable association with dynamic microtubule plus-ends. The molecular requirements for this conversion and the underlying biophysical mechanisms are elusive. We reconstituted end conversion in vitro using two kinetochore components the plus end-directed kinesin CENP-E and microtubule-binding Ndc80 complex, combined on the surface of a microbead. The primary role of CENP-E is to ensure close proximity between Ndc80 complexes and the microtubule plus-end, whereas Ndc80 complexes provide lasting microtubule association by diffusing on the microtubule wall near its tip. Together, these proteins mediate robust plus-end coupling during several rounds of microtubule dynamics, in the absence of any specialized tip-binding or regulatory proteins. Using a Brownian dynamics model, we show that end conversion is an emergent property of multimolecular ensembles of microtubule wall-binding proteins with finely tuned force-dependent motility characteristics.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Kinesins
/
Kinetochores
/
Chromosome Segregation
/
Microtubules
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Nat Commun
Journal subject:
BIOLOGIA
/
CIENCIA
Year:
2019
Document type:
Article
Affiliation country:
Estados Unidos