Protein architecture of the human kinetochore microtubule attachment site.
Cell
; 137(4): 672-84, 2009 May 15.
Article
em En
| MEDLINE
| ID: mdl-19450515
ABSTRACT
Chromosome segregation requires assembly of kinetochores on centromeric chromatin to mediate interactions with spindle microtubules and control cell-cycle progression. To elucidate the protein architecture of human kinetochores, we developed a two-color fluorescence light microscopy method that measures average label separation, Delta, at <5 nm accuracy. Delta analysis of 16 proteins representing core structural complexes spanning the centromeric chromatin-microtubule interface, when correlated with mechanical states of spindle-attached kinetochores, provided a nanometer-scale map of protein position and mechanical properties of protein linkages. Treatment with taxol, which suppresses microtubule dynamics and activates the spindle checkpoint, revealed a specific switch in kinetochore architecture. Cumulatively, Delta analysis revealed that compliant linkages are restricted to the proximity of chromatin, suggested a model for how the KMN (KNL1/Mis12 complex/Ndc80 complex) network provides microtubule attachment and generates pulling forces from depolymerization, and identified an intrakinetochore molecular switch that may function in controlling checkpoint activity.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Cinetocoros
/
Microtúbulos
Limite:
Humans
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article