FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W1529156770> ?p ?o ?g. }

• W1529156770 endingPage "2546" @default.
• W1529156770 startingPage "2545" @default.
• W1529156770 abstract "Defects in cell division can lead to genomic instability and aneuploidy, both hallmarks of many cancers. During mitosis, sister chromatids are segregated on a microtubule-based spindle. Concomitant to spindle assembly, proteinaceous structures termed kinetochores are assembled on sister chromatids. In metaphase, kinetochores allow chromosome alignment and bi-orientation by interacting with microtubules coming from opposite spindle poles. At anaphase onset, microtubules organize between the separating chromosomes to form an array of antiparallel microtubules with their plus-ends overlapping at the center, called the central spindle. Once formed, the central spindle acts as a localization hub for key proteins required for cytokinesis, the physical division of one cell into 2. Importantly, the mechanisms that coordinate central spindle assembly with anaphase onset and chromosome segregation are unclear.In HeLa cells, de novo microtubule nucleation by the Augmin complex participates in central spindle assembly.1 However, this complex is missing in some species that assemble central spindles in anaphase, including yeast and Caenorhabditis elegans. In most species, central spindle organization relies on the microtubule bundling activity of the conserved Ase1/PRC1 family of microtubule-associated proteins (MAPs), as well as on the microtubule motor of the kinesin-6 family MKLP1.2 Microtubule motors of the kinesin-4 and -5 families also regulate central spindle integrity. However, none of these proteins display microtubule assembly or nucleation activities. Therefore, the relative contribution of pre-existing and/or de novo-assembled microtubules is unclear.To study the mechanisms of central spindle assembly, we combined RNAi-mediated depletion of key proteins with quantitative fluorescence live-cell microscopy.3 We capitalized on 2 transgenic C. elegans strains expressing fluorescent markers for chromosomes and microtubules or the kinase AIR-2AuroraB, a component of the Chromosomal Passenger Complex that specifically localizes to the central spindle. We then developed an assay to track and quantify central spindle intensity over time, and extract the chromosome segregation profile, which is a read-out of central spindle mechanical integrity. In the one-cell C. elegans embryo, chromosome segregation is primarily driven by astral microtubule pulling forces generated by the cortically anchored microtubule motor dynein. The anaphase central spindle acts as a brake that counteracts these dynein-driven astral pulling forces, limiting the extent and velocity of sister chromatid segregation4. Thus we can quantify the mechanical integrity of the central spindle by monitoring the rate and extent of chromosome segregation with and without astral pulling forces. We first confirmed the contribution of SPD-1PRC1 and ZEN-4MKLP1 in central spindle integrity. However, while these 2 proteins are often presented in the literature as being required for central spindle assembly, our analysis suggested that their primary function is to provide mechanical integrity to the central spindle during its elongation but not to promote de novo central spindle microtubule assembly. Interestingly, reducing astral pulling forces (by preventing cortical targeting of dynein) restored central spindle integrity in the absence of SPD-1PRC1 and ZEN-4MKLP1. These results show that these 2 proteins are dispensible for initial central spindle assembly but are essential for mechanical integrity during central spindle elongation, when normal cortical pulling forces are exerted.We next set out to identify components involved in initial central spindle microtubule assembly. We focused on the potential contribution of the kinetochore, which participates in pre-anaphase spindle microtubule formation in most systems and is associated with microtubule assembly promoting activities.5 We identified a kinetochore sub-branch essential for central spindle formation and comprised of the conserved kinase BUB-1, the 2 redundant CENP-F orthologs HCP-1 and -2, and the CLASP ortholog CLS-2. RNAi-mediated depletion of any one of these components led to impaired central spindle assembly. Interestingly, a role for CLASP in central spindle formation had already been described in Drosophila spermatocytes.6 We then followed the dynamic localization of these kinetochore components and showed that during metaphase HCP-1/2CENP-F and CLS-2CLASP are recruited to kinetochores by BUB-1 and then translocate to the central spindle region upon anaphase onset. By analyzing 2 mutants of the upstream kinetochore scaffold protein KNL-1 that led to decreased or excess BUB-1 at the metaphase kinetochore, we demonstrated that the level of kinetochore BUB-1 directly controls central spindle microtubule density. Further, pre-anaphase levels of BUB-1 at the kinetochores control overall central spindle mechanical robustness by modulating the levels of HCP-1/2CENP-F and CLS-2CLASP that translocate between the separating chromosomes in anaphase.CLASP proteins contain TOGL (Tumor Overexpressed Gene Like) domains, which are characteristic of proteins with microtubule assembling activity.7 Secondary structure analysis of CLS-2CLASP revealed 3 potential TOGL domains. We thus purified recombinant CLS-2CLASP and tested its potential activity as a microtubule polymerase. We showed that in vitro recombinant CLS-2CLASP led to an increase in the rate of microtubule polymerization and in the total amount of assembled microtubules. Furthermore, replacing endogenous CLS-2CLASP with a mutant version that has impaired microtubule polymerase activity completely disrupted central spindle assembly in vivo.Altogether our results led us to propose a new model for central spindle formation and elongation based on a 2-step mechanism (Fig. 1).3 In the first step, metaphase kinetochore recruitment of BUB-1, HCP-1/2CENP-F and CLS-2CLASP is essential to trigger their anaphase translocation between the separating chromosomes, which then promotes central spindle microtubule assembly through CLS-2CLASP activity. During the second step, central spindle elongation, anti-parallel microtubules are organized and cross-linked by SPD-1PRC1 and ZEN-4MKLP1, which provides additional mechanical integrity.Overall, we propose that by promoting central spindle assembly, kinetochores coordinate the 2 critical events of cell division: chromosome segregation and cytokinesis. As kinetochore components are conserved across metazoans, this previously unknown function of the kinetochore is also likely to be conserved.Figure 1.A 2-step model for anaphase central spindle organization. During metaphase, BUB-1, HCP-1/2Cenp-F and CLS-2CLASP are localized at the kinetochore. At anaphase onset, their translocation between the segregating sister chromatids promotes initiation of central ..." @default.
• W1529156770 created "2016-06-24" @default.
• W1529156770 creator A5002172208 @default.
• W1529156770 creator A5055992265 @default.
• W1529156770 creator A5083127536 @default.
• W1529156770 date "2015-06-26" @default.
• W1529156770 modified "2023-10-18" @default.
• W1529156770 title "Versatile kinetochore components control central spindle assembly" @default.
• W1529156770 cites W1980166711 @default.
• W1529156770 cites W2002669560 @default.
• W1529156770 cites W2031873527 @default.
• W1529156770 cites W2035190974 @default.
• W1529156770 cites W2049288819 @default.
• W1529156770 cites W2097664711 @default.
• W1529156770 cites W2115708035 @default.
• W1529156770 doi "https://doi.org/10.1080/15384101.2015.1062329" @default.
• W1529156770 hasPubMedCentralId "https://www.ncbi.nlm.nih.gov/pmc/articles/4614393" @default.
• W1529156770 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/26083054" @default.
• W1529156770 hasPublicationYear "2015" @default.
• W1529156770 type Work @default.
• W1529156770 sameAs 1529156770 @default.
• W1529156770 citedByCount "3" @default.
• W1529156770 countsByYear W15291567702022 @default.
• W1529156770 countsByYear W15291567702023 @default.
• W1529156770 crossrefType "journal-article" @default.
• W1529156770 hasAuthorship W1529156770A5002172208 @default.
• W1529156770 hasAuthorship W1529156770A5055992265 @default.
• W1529156770 hasAuthorship W1529156770A5083127536 @default.
• W1529156770 hasBestOaLocation W15291567701 @default.
• W1529156770 hasConcept C104317684 @default.
• W1529156770 hasConcept C192838845 @default.
• W1529156770 hasConcept C30481170 @default.
• W1529156770 hasConcept C54355233 @default.
• W1529156770 hasConcept C86803240 @default.
• W1529156770 hasConcept C95444343 @default.
• W1529156770 hasConceptScore W1529156770C104317684 @default.
• W1529156770 hasConceptScore W1529156770C192838845 @default.
• W1529156770 hasConceptScore W1529156770C30481170 @default.
• W1529156770 hasConceptScore W1529156770C54355233 @default.
• W1529156770 hasConceptScore W1529156770C86803240 @default.
• W1529156770 hasConceptScore W1529156770C95444343 @default.
• W1529156770 hasIssue "16" @default.
• W1529156770 hasLocation W15291567701 @default.
• W1529156770 hasLocation W15291567702 @default.
• W1529156770 hasLocation W15291567703 @default.
• W1529156770 hasLocation W15291567704 @default.
• W1529156770 hasOpenAccess W1529156770 @default.
• W1529156770 hasPrimaryLocation W15291567701 @default.
• W1529156770 hasRelatedWork W1527499364 @default.
• W1529156770 hasRelatedWork W2079987996 @default.
• W1529156770 hasRelatedWork W2085955403 @default.
• W1529156770 hasRelatedWork W2096509200 @default.
• W1529156770 hasRelatedWork W2168908838 @default.
• W1529156770 hasRelatedWork W2170396038 @default.
• W1529156770 hasRelatedWork W2272268972 @default.
• W1529156770 hasRelatedWork W2314181693 @default.
• W1529156770 hasRelatedWork W2780728884 @default.
• W1529156770 hasRelatedWork W2899676732 @default.
• W1529156770 hasVolume "14" @default.
• W1529156770 isParatext "false" @default.
• W1529156770 isRetracted "false" @default.
• W1529156770 magId "1529156770" @default.
• W1529156770 workType "article" @default.