Polar Ejection Forces Promote the Conversion from Lateral to End-on Kinetochore-Microtubule Attachments on Mono-oriented Chromosomes
| Autor: | Marin Barisic, Thomas J. Maresca, Helder Maiato, António J. Pereira, Danica Drpic |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Kinesins
Spindle Apparatus Biology Microtubules General Biochemistry Genetics and Molecular Biology Cell Line spindle assembly checkpoint Kinetochore microtubule 03 medical and health sciences 0302 clinical medicine Microtubule Report Animals Kinetochores Mitosis lcsh:QH301-705.5 030304 developmental biology mitosis 0303 health sciences Kinetochore Biomechanical Phenomena Chromosomes Insect Spindle apparatus Cell biology kinetochore Spindle checkpoint chromokinesins lcsh:Biology (General) Kinesin Drosophila Chromatid 030217 neurology & neurosurgery Protein Binding mitosis with unreplicated genomes |
| Zdroj: | Cell Reports, Vol 13, Iss 3, Pp 460-468 (2015) Cell Reports |
| ISSN: | 2211-1247 |
| Popis: | Summary Chromosome bi-orientation occurs after conversion of initial lateral attachments between kinetochores and spindle microtubules into stable end-on attachments near the cell equator. After bi-orientation, chromosomes experience tension from spindle forces, which plays a key role in the stabilization of correct kinetochore-microtubule attachments. However, how end-on kinetochore-microtubule attachments are first stabilized in the absence of tension remains a key unanswered question. To address this, we generated Drosophila S2 cells undergoing mitosis with unreplicated genomes (SMUGs). SMUGs retained single condensed chromatids that attached laterally to spindle microtubules. Over time, laterally attached kinetochores converted into end-on attachments and experienced intra-kinetochore stretch/structural deformation, and SMUGs eventually exited a delayed mitosis with mono-oriented chromosomes after satisfying the spindle-assembly checkpoint (SAC). Polar ejection forces (PEFs) generated by Chromokinesins promoted the conversion from lateral to end-on kinetochore-microtubule attachments that satisfied the SAC in SMUGs. Thus, PEFs convert lateral to stable end-on kinetochore-microtubule attachments, independently of chromosome bi-orientation. Graphical Abstract Highlights • Spindle assembly checkpoint (SAC) can be satisfied after a delay in cells with mono-oriented chromosomes • Mono-oriented chromosomes experience intra-kinetochore stretch • Polar ejection forces promote SAC satisfaction independently of bi-orientation • Polar ejection forces promote the conversion from lateral to end-on attachments Tension on bi-oriented chromosomes plays a role in the stabilization of kinetochore-microtubule attachments. However, how kinetochore-microtubule attachments on mono-oriented chromosomes are first stabilized in the absence of tension remained unknown. Drpic et al. now show that polar ejection forces promote the transition from lateral to end-on attachments on mono-oriented chromosomes. |
| Databáze: | OpenAIRE |
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