scholarly journals The C-terminal helix of BubR1 is essential for CENP-E-dependent chromosome alignment

2020 ◽  
Author(s):  
Thibault Legal ◽  
Daniel Hayward ◽  
Agata Gluszek-Kustusz ◽  
Elizabeth A. Blackburn ◽  
Christos Spanos ◽  
...  
Keyword(s):  
Cell Division ◽  
Molecular Basis ◽  
Spindle Checkpoint ◽  
Checkpoint Protein ◽  
Molecular Determinants ◽  
Chromosome Alignment

AbstractDuring cell division, misaligned chromosomes are captured and aligned by motors before their segregation. The CENP-E motor is recruited to polar unattached kinetochores, to facilitate chromosome alignment. The spindle checkpoint protein BubR1 has been reported as a CENP-E interacting partner, but to what extent, if at all, BubR1 contributes to CENP-E localization at kinetochores, has remained controversial. Here we define the molecular determinants that specify the interaction between BubR1 and CENP-E. The basic C-terminal helix of BubR1 is necessary but not sufficient for CENP-E interaction, while a minimal key acidic patch on the kinetochore-targeting domain of CENP-E, is also essential. We then demonstrate that BubR1 is required for the recruitment of CENP-E to kinetochores to facilitate chromosome alignment. This BubR1-CENP-E axis is critical to align chromosomes that have failed to congress through other pathways and recapitulates the major known function of CENP-E. Overall, our studies define the molecular basis and the function for CENP-E recruitment to BubR1 at kinetochores during mammalian mitosis.

scholarly journals The C-terminal helix of BubR1 is essential for CENP-E-dependent chromosome alignment

2020 ◽  
Vol 133 (16) ◽  
pp. jcs246025 ◽  
Author(s):  
Thibault Legal ◽  
Daniel Hayward ◽  
Agata Gluszek-Kustusz ◽  
Elizabeth A. Blackburn ◽  
Christos Spanos ◽  
...  
Keyword(s):  
Cell Division ◽  
Molecular Basis ◽  
Spindle Checkpoint ◽  
First Person ◽  
Checkpoint Protein ◽  
Molecular Determinants ◽  
Chromosome Alignment

ABSTRACTDuring cell division, misaligned chromosomes are captured and aligned by motors before their segregation. The CENP-E motor is recruited to polar unattached kinetochores to facilitate chromosome alignment. The spindle checkpoint protein BubR1 (also known as BUB1B) has been reported as a CENP-E interacting partner, but the extent to which BubR1 contributes to CENP-E localization at kinetochores has remained controversial. Here we define the molecular determinants that specify the interaction between BubR1 and CENP-E. The basic C-terminal helix of BubR1 is necessary but not sufficient for CENP-E interaction, and a minimal key acidic patch on the kinetochore-targeting domain of CENP-E is also essential. We then demonstrate that BubR1 is required for the recruitment of CENP-E to kinetochores to facilitate chromosome alignment. This BubR1–CENP-E axis is critical for alignment of chromosomes that have failed to congress through other pathways and recapitulates the major known function of CENP-E. Overall, our studies define the molecular basis and the function for CENP-E recruitment to BubR1 at kinetochores during mammalian mitosis.This article has an associated First Person interview with the first author of the paper.

Spindle Assembly Checkpoint Protein Dynamics and Roles in Plant Cell Division

2011 ◽  
pp. 142-153
Author(s):  
Marie-Cécile Caillaud ◽  
Laetitia Paganelli ◽  
Philippe Lecomte ◽  
Laurent Deslandes ◽  
Michaël Quentin ◽  
...  
Keyword(s):  
Cell Division ◽  
Protein Dynamics ◽  
Plant Cell ◽  
Spindle Assembly Checkpoint ◽  
Spindle Assembly ◽  
Checkpoint Protein ◽  
Plant Cell Division ◽  
Spindle Assembly Checkpoint Protein

scholarly journals c-di-GMP heterogeneity is generated by the chemotaxis machinery to regulate flagellar motility

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Bridget R Kulasekara ◽  
Cassandra Kamischke ◽  
Hemantha D Kulasekara ◽  
Matthias Christen ◽  
Paul A Wiggins ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Division ◽  
Histidine Kinase ◽  
Molecular Basis ◽  
Individual Cell ◽  
Cell Heterogeneity ◽  
Flagellar Motility ◽  
Bacterial Populations ◽  
Phosphorylation State ◽  
Asymmetric Partitioning

Individual cell heterogeneity is commonly observed within populations, although its molecular basis is largely unknown. Previously, using FRET-based microscopy, we observed heterogeneity in cellular c-di-GMP levels. In this study, we show that c-di-GMP heterogeneity in Pseudomonas aeruginosa is promoted by a specific phosphodiesterase partitioned after cell division. We found that subcellular localization and reduction of c-di-GMP levels by this phosphodiesterase is dependent on the histidine kinase component of the chemotaxis machinery, CheA, and its phosphorylation state. Therefore, individual cell heterogeneity in c-di-GMP concentrations is regulated by the activity and the asymmetrical inheritance of the chemotaxis organelle after cell division. c-di-GMP heterogeneity results in a diversity of motility behaviors. The generation of diverse intracellular concentrations of c-di-GMP by asymmetric partitioning is likely important to the success and survival of bacterial populations within the environment by allowing a variety of motility behaviors.

scholarly journals Wnt signaling recruits KIF2A to the spindle to ensure chromosome congression and alignment during mitosis

2021 ◽  
Vol 118 (34) ◽  
pp. e2108145118
Author(s):  
Anja Bufe ◽  
Ana García del Arco ◽  
Magdalena Hennecke ◽  
Anchel de Jaime-Soguero ◽  
Matthias Ostermaier ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Division ◽  
Wnt Signaling ◽  
Pluripotent Stem Cells ◽  
Target Genes ◽  
Genome Maintenance ◽  
Spindle Poles ◽  
Chromosome Congression ◽  
Chromosome Alignment ◽  
Canonical Wnt

Canonical Wnt signaling plays critical roles in development and tissue renewal by regulating β-catenin target genes. Recent evidence showed that β-catenin–independent Wnt signaling is also required for faithful execution of mitosis. However, the targets and specific functions of mitotic Wnt signaling still remain uncharacterized. Using phosphoproteomics, we identified that Wnt signaling regulates the microtubule depolymerase KIF2A during mitosis. We found that Dishevelled recruits KIF2A via its N-terminal and motor domains, which is further promoted upon LRP6 signalosome formation during cell division. We show that Wnt signaling modulates KIF2A interaction with PLK1, which is critical for KIF2A localization at the spindle. Accordingly, inhibition of basal Wnt signaling leads to chromosome misalignment in somatic cells and pluripotent stem cells. We propose that Wnt signaling monitors KIF2A activity at the spindle poles during mitosis to ensure timely chromosome alignment. Our findings highlight a function of Wnt signaling during cell division, which could have important implications for genome maintenance, notably in stem cells.

scholarly journals Separase cleaves the kinetochore protein Meikin to direct the meiosis I/II transition

2020 ◽  
Author(s):  
Nolan K Maier ◽  
Jun Ma ◽  
Michael A Lampson ◽  
Iain M Cheeseman
Keyword(s):  
Cell Division ◽  
Germ Cells ◽  
Molecular Switch ◽  
Specific Protein ◽  
Cleavage Product ◽  
Regulatory Mechanisms ◽  
Kinetochore Protein ◽  
Chromosome Alignment ◽  
Activity State ◽  
Meiosis I

SummaryTo generate haploid gametes, germ cells undergo two consecutive meiotic divisions requiring key changes to the cell division machinery. Here, we explore the regulatory mechanisms that differentially control meiotic events. We demonstrate that the protease Separase rewires key cell division processes at the meiosis I/II transition by cleaving the meiosis-specific protein Meikin. In contrast to cohesin, which is inactivated by Separase proteolysis, cleaved Meikin remains functional, but results in a distinct activity state. Full-length Meikin and the C-terminal Meikin Separase-cleavage product both localize to kinetochores, bind to Plk1 kinase, and promote Rec8 cleavage, but our results reveal distinct roles for these proteins in controlling meiosis. Mutations that prevent Meikin cleavage or that conditionally inactivate Meikin at anaphase I both result in defective meiosis II chromosome alignment. Thus, Separase cleavage of Meikin creates an irreversible molecular switch to rewire the cell division machinery at the meiosis I/II transition.

scholarly journals Plasmodium Kinesin-8X associates with mitotic spindles and is essential for oocyst development during parasite proliferation and transmission

2019 ◽  
Author(s):  
Mohammad Zeeshan ◽  
Fiona Shilliday ◽  
Tianyang Liu ◽  
Steven Abel ◽  
Tobias Mourier ◽  
...  
Keyword(s):  
Life Cycle ◽  
Cell Division ◽  
Gene Targeting ◽  
Intracellular Transport ◽  
Regulation Of Gene Expression ◽  
Microtubule Depolymerization ◽  
Expression Of Genes ◽  
Genome Wide ◽  
Spindle Dynamics ◽  
Chromosome Alignment

AbstractKinesin-8 proteins are microtubule motors that are often involved in regulation of mitotic spindle length and chromosome alignment. They move towards the ends of spindle microtubules and regulate the dynamics of these ends due, at least in some species, to their microtubule depolymerization activity. Plasmodium spp. exhibit an atypical endomitotic cell division in which chromosome condensation and spindle dynamics are not well understood in the different proliferative stages. Genome-wide homology analysis of Plasmodium spp. revealed the presence of two Kinesin-8 motor proteins (Kinesin-8X and Kinesin-8B). Here we have studied the biochemical properties of Kinesin-8X and its role in parasite proliferation. In vitro, Kinesin-8X showed motile and depolymerization activities like other Kinesin-8 motors. To understand its role in cell division, we have used protein tagging and live cell imaging to define the location of Plasmodium Kinesin-8X during all proliferative stages of the P berghei life cycle. Furthermore, we have used gene targeting to analyse the function of Kinesin-8X. The results reveal a spatio-temporal involvement of Kinesin-8X in spindle dynamics and its association with both mitotic and meiotic spindles and the putative microtubule organising centre (MTOC). Deletion of the Kinesin-8X gene showed that this protein is required for endomitotic division during oocyst development and is therefore necessary for parasite replication within the mosquito gut, and for transmission to the vertebrate host. Consistently, transcriptome analysis of Δkinesin-8X parasites reveals modulated expression of genes involved mainly in microtubule-based processes, chromosome organisation and the regulation of gene expression supporting a role in cell division.Author SummaryKinesins are microtubule-based motors that play key roles in intracellular transport, cell division and motility. Members of the Kinesin-8 family contribute to chromosome alignment during cell division in many eukaryotes. However, the roles of kinesins in the atypical cell division in Plasmodium, the causative agent of malaria, is not known. In contrast to many other eukaryotes, Plasmodium proliferates by endomitosis, in which genome replication and division occur within a nucleus bounded by a persistent nuclear envelope. We show that the Plasmodium genome encodes only nine kinesins and we further investigate the role of Kinesin-8X throughout the Plasmodium life cycle using biochemical and gene targeting approaches. We show that Plasmodium Kinesin-8X has microtubule-based motility and depolymerization activity. We also show that Kinesin-8X is probably localized on putative MTOCs and spindles during cell division in most of the stages of P. berghei life cycle. By gene deletion we demonstrate that Kinesin-8X is essential for normal oocyst development and sporozoite formation. Genome-wide RNA analysis of Δkinesin-8X parasites reveals modulated expression of genes involved in microtubule-based processes. Overall, the data suggest that Kinesin-8X is a molecular motor that plays essential roles during endomitosis in oocyst development in the mosquito, contributing to parasite transmission.

scholarly journals DNA Replication Checkpoint Control Mediated by the Spindle Checkpoint Protein Mad2p in Fission Yeast

2004 ◽  
Vol 279 (45) ◽  
pp. 47372-47378 ◽  
Author(s):  
Izumi Sugimoto ◽  
Hiroshi Murakami ◽  
Yuko Tonami ◽  
Akihiko Moriyama ◽  
Makoto Nakanishi
Keyword(s):  
Dna Replication ◽  
Fission Yeast ◽  
Spindle Checkpoint ◽  
Checkpoint Control ◽  
Replication Checkpoint ◽  
Checkpoint Protein ◽  
Dna Replication Checkpoint

scholarly journals Cytoskeletal Control and Wnt Signaling—APC’s Dual Contributions in Stem Cell Division and Colorectal Cancer

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3811
Author(s):  
M. Angeles Juanes
Keyword(s):  
Colorectal Cancer ◽  
Stem Cell ◽  
Cell Division ◽  
Asymmetric Cell Division ◽  
Extracellular Signals ◽  
Integrative View ◽  
Molecular Determinants ◽  
Stem Cell Division ◽  
Outstanding Question ◽  
Stem Cell Pool

Intestinal epithelium architecture is sustained by stem cell division. In principle, stem cells can divide symmetrically to generate two identical copies of themselves or asymmetrically to sustain tissue renewal in a balanced manner. The choice between the two helps preserve stem cell and progeny pools and is crucial for tissue homeostasis. Control of spindle orientation is a prime contributor to the specification of symmetric versus asymmetric cell division. Competition for space within the niche may be another factor limiting the stem cell pool. An integrative view of the multiple links between intracellular and extracellular signals and molecular determinants at play remains a challenge. One outstanding question is the precise molecular roles of the tumour suppressor Adenomatous polyposis coli (APC) for sustaining gut homeostasis through its respective functions as a cytoskeletal hub and a down regulator in Wnt signalling. Here, we review our current understanding of APC inherent activities and partners in order to explore novel avenues by which APC may act as a gatekeeper in colorectal cancer and as a therapeutic target.

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