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Ranaivoson FM, Crozet V, Benoit MPMH, Abdalla Mohammed Khalid A, Kikuti C, Sirkia H, El Marjou A, Miserey-Lenkei S, Asenjo AB, Sosa H, Schmidt CF, Rosenfeld SS, Houdusse A. Nucleotide-free structures of KIF20A illuminate atypical mechanochemistry in this kinesin-6. Open Biol 2023; 13:230122. [PMID: 37726093 PMCID: PMC10508983 DOI: 10.1098/rsob.230122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/18/2023] [Indexed: 09/21/2023] Open
Abstract
KIF20A is a critical kinesin for cell division and a promising anti-cancer drug target. The mechanisms underlying its cellular roles remain elusive. Interestingly, unusual coupling between the nucleotide- and microtubule-binding sites of this kinesin-6 has been reported, but little is known about how its divergent sequence leads to atypical motility properties. We present here the first high-resolution structure of its motor domain that delineates the highly unusual structural features of this motor, including a long L6 insertion that integrates into the core of the motor domain and that drastically affects allostery and ATPase activity. Together with the high-resolution cryo-electron microscopy microtubule-bound KIF20A structure that reveals the microtubule-binding interface, we dissect the peculiarities of the KIF20A sequence that influence its mechanochemistry, leading to low motility compared to other kinesins. Structural and functional insights from the KIF20A pre-power stroke conformation highlight the role of extended insertions in shaping the motor's mechanochemical cycle. Essential for force production and processivity is the length of the neck linker in kinesins. We highlight here the role of the sequence preceding the neck linker in controlling its backward docking and show that a neck linker four times longer than that in kinesin-1 is required for the activity of this motor.
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Affiliation(s)
- Fanomezana Moutse Ranaivoson
- Structural Motility, CNRS UMR144, Institut Curie, Université Paris Sciences et Lettres, Sorbonne Université, 75248 Paris, France
| | - Vincent Crozet
- Structural Motility, CNRS UMR144, Institut Curie, Université Paris Sciences et Lettres, Sorbonne Université, 75248 Paris, France
| | | | | | - Carlos Kikuti
- Structural Motility, CNRS UMR144, Institut Curie, Université Paris Sciences et Lettres, Sorbonne Université, 75248 Paris, France
| | - Helena Sirkia
- Structural Motility, CNRS UMR144, Institut Curie, Université Paris Sciences et Lettres, Sorbonne Université, 75248 Paris, France
| | - Ahmed El Marjou
- Structural Motility, CNRS UMR144, Institut Curie, Université Paris Sciences et Lettres, Sorbonne Université, 75248 Paris, France
| | - Stéphanie Miserey-Lenkei
- Structural Motility, CNRS UMR144, Institut Curie, Université Paris Sciences et Lettres, Sorbonne Université, 75248 Paris, France
| | - Ana B. Asenjo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Hernando Sosa
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Christoph F. Schmidt
- Third Institute of Physics-Biophysics, Georg August University Göttingen, 37077 Göttingen, Germany
- Department of Physics and Soft Matter Center, Duke University, Durham, NC 27708, USA
| | | | - Anne Houdusse
- Structural Motility, CNRS UMR144, Institut Curie, Université Paris Sciences et Lettres, Sorbonne Université, 75248 Paris, France
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Ota R, Watanabe T, Wazawa Y, Kuwajima H, Honda T, Soeda S, Saito Y, Yuki R, Fukumoto Y, Yamaguchi N, Yamaguchi N, Nakayama Y. V-Src delocalizes Aurora B by suppressing Aurora B kinase activity during monopolar cytokinesis. Cell Signal 2023:110764. [PMID: 37315749 DOI: 10.1016/j.cellsig.2023.110764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 06/08/2023] [Accepted: 06/08/2023] [Indexed: 06/16/2023]
Abstract
c-Src tyrosine kinase plays roles in a wide range of signaling events and its increased activity is frequently observed in a variety of epithelial and non-epithelial cancers. v-Src, an oncogene first identified in the Rous sarcoma virus, is an oncogenic version of c-Src and has constitutively active tyrosine kinase activity. We previously showed that v-Src induces Aurora B delocalization, resulting in cytokinesis failure and binucleated cell formation. In the present study, we explored the mechanism underlying v-Src-induced Aurora B delocalization. Treatment with the Eg5 inhibitor (+)-S-trityl-L-cysteine (STLC) arrested cells in a prometaphase-like state with a monopolar spindle; upon further inhibition of cyclin-dependent kinase (CDK1) by RO-3306, cells underwent monopolar cytokinesis with bleb-like protrusions. Aurora B was localized to the protruding furrow region or the polarized plasma membrane 30 min after RO-3306 addition, whereas inducible v-Src expression caused Aurora B delocalization in cells undergoing monopolar cytokinesis. Delocalization was similarly observed in monopolar cytokinesis induced by inhibiting Mps1, instead of CDK1, in the STLC-arrested mitotic cells. Importantly, western blotting analysis and in vitro kinase assay revealed that v-Src decreased the levels of Aurora B autophosphorylation and its kinase activity. Furthermore, like v-Src, treatment with the Aurora B inhibitor ZM447439 also caused Aurora B delocalization at concentrations that partially inhibited Aurora B autophosphorylation. Given that phosphorylation of Aurora B by v-Src was not observed, these results suggest that v-Src causes Aurora B delocalization by indirectly suppressing Aurora B kinase activity.
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Affiliation(s)
- Ryoko Ota
- Laboratory of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Takumi Watanabe
- Laboratory of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Yuuki Wazawa
- Laboratory of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Hiroki Kuwajima
- Laboratory of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Takuya Honda
- Laboratory of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan; Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Shuhei Soeda
- Laboratory of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan; Laboratory of Neurochemistry, College of Pharmaceutical Sciences, Ritsumeikan University, Shiga 525-8577, Japan
| | - Youhei Saito
- Laboratory of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Ryuzaburo Yuki
- Laboratory of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Yasunori Fukumoto
- Laboratory of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan; Laboratory of Toxicology and Environmental Health, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Noritaka Yamaguchi
- Laboratory of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan; Department of Molecular Cardiovascular Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Naoto Yamaguchi
- Laboratory of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Yuji Nakayama
- Laboratory of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
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Wang H, Ma X, Li S, Su J, Fan B, Liu B, Ni X. KIF20A as a potential biomarker of renal and bladder cancers based on bioinformatics and experimental verification. Aging (Albany NY) 2023; 15:204736. [PMID: 37310408 DOI: 10.18632/aging.204736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 05/03/2023] [Indexed: 06/14/2023]
Abstract
BACKGROUND Bladder cancer (BC) is a malignant tumor that occurs in the bladder wall and often appears in elderly individuals. Renal cancer (RC) arises from the renal tubular epithelium, but its molecular mechanism remains unclear. METHODS We downloaded RC datasets (GSE14762 and GSE53757) and a BC dataset (GSE121711) to screen differentially expressed genes (DEGs). We also performed weighted gene coexpression network analysis (WGCNA). We created a protein-protein interaction (PPI) network and performed functional enrichment analysis, such as gene set enrichment analysis (GSEA). Heatmaps were made for gene expression. Survival analysis and immunoinfiltration analysis were performed. Comparative toxicogenomics database (CTD) analysis was performed to find the relationship between disease and hub genes. Western blotting was performed to verify the role of KIF20A in apoptosis. RESULTS A total of 764 DEGs were identified. The GSEA showed that the DEGs were mainly enriched in organic acid metabolism, drug metabolism, mitochondria, and metabolism of cysteine and methionine. The PPI network in GSE121711 showed that KIF20A was a hub gene of renal clear cell carcinoma. Where the expression level of KIF20A was higher, the prognosis of patients was worse. CTD analysis showed that KIF20A was associated with inflammation, proliferation, and apoptosis. KIF20A expression in the RC group was upregulated, as shown by western blotting. The core proteins (including pRB Ser 780, CyclinA, E2F1, CCNE1, and CCNE2) in the pRB Ser 780/CyclinA signaling pathway were also upregulated in the RC group. CONCLUSIONS KIF20A might be a novel biomarker for researching renal and bladder cancers.
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Affiliation(s)
- Haoyuan Wang
- Department of Urology Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei, P.R. China
| | - Xiaopeng Ma
- School of Basic Medical Sciences, Hebei Medical University, Shijiazhuang 050000, Hebei, P.R. China
| | - Sijie Li
- School of Basic Medical Sciences, Hebei Medical University, Shijiazhuang 050000, Hebei, P.R. China
| | - Jianzhi Su
- Department of Urology Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei, P.R. China
| | - Bo Fan
- Department of Urology Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei, P.R. China
| | - Bin Liu
- Department of Urology Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei, P.R. China
| | - Xiaochen Ni
- Department of Urology Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei, P.R. China
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Liu B, Su J, Fan B, Ni X, Jin T. High expression of KIF20A in bladder cancer as a potential prognostic target for poor survival of renal cell carcinoma. Medicine (Baltimore) 2023; 102:e32667. [PMID: 36637953 PMCID: PMC9839245 DOI: 10.1097/md.0000000000032667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Urinary system tumors are malignant tumors, including renal cancer and bladder cancer. however, molecular target of them remains unclear. GSE14762 and GSE53757 were downloaded from GEO database to screen differentially expressed genes (DEGs). Weighted gene co-expression network analysis was performed. Gene Ontology (GO) and Kyoto encyclopedia of genes and genomes were used for enrichment analysis. Gene ontology and Kyoto encyclopedia of genes and genomes analyses were performed on whole genome, as formulated by gene set enrichment analysis. Survival analysis was also performed. Comparative toxicogenomics database was used to identify diseases most associated with hub genes. A total of 1517 DEGs were identified. DEGs were mainly enriched in cancer pathway, HIF-1 signaling pathway, organic acid metabolism, glyoxylate and dicarboxylate metabolism, and protein homodimerization activity. Ten hub genes (TPX2, ASPM, NUSAP1, RAD51AP1, CCNA2, TTK, PBK, MELK, DTL, kinesin family member 20A [KIF20A]) were obtained, which were up-regulated in tumor tissue. The expression of KIF20A was related with the overall survival of renal and bladder cancer. KIF20A was up-regulated in the tumor tissue, and might worsen the overall survival of bladder and kidney cancer. KIF20A could be a novel biomarker of bladder and kidney cancer.
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Affiliation(s)
- Bin Liu
- Department of Urology Surgery, The Fourth Hospital of Hebei Medical University, Hebei, PR China
- * Correspondence: Bin Liu, Department of Urology Surgery, The Fourth Hospital of Hebei Medical University, No.12 Jiankang Road, Hebei 050000, PR China (e-mail: )
| | - Jianzhi Su
- Department of Urology Surgery, The Fourth Hospital of Hebei Medical University, Hebei, PR China
| | - Bo Fan
- Department of Urology Surgery, The Fourth Hospital of Hebei Medical University, Hebei, PR China
| | - Xiaochen Ni
- Department of Urology Surgery, The Fourth Hospital of Hebei Medical University, Hebei, PR China
| | - Tingting Jin
- Department of Urology Surgery, The Fourth Hospital of Hebei Medical University, Hebei, PR China
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Andrade V, Echard A. Mechanics and regulation of cytokinetic abscission. Front Cell Dev Biol 2022; 10:1046617. [PMID: 36506096 PMCID: PMC9730121 DOI: 10.3389/fcell.2022.1046617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 10/31/2022] [Indexed: 11/25/2022] Open
Abstract
Cytokinetic abscission leads to the physical cut of the intercellular bridge (ICB) connecting the daughter cells and concludes cell division. In different animal cells, it is well established that the ESCRT-III machinery is responsible for the constriction and scission of the ICB. Here, we review the mechanical context of abscission. We first summarize the evidence that the ICB is initially under high tension and explain why, paradoxically, this can inhibit abscission in epithelial cells by impacting on ESCRT-III assembly. We next detail the different mechanisms that have been recently identified to release ICB tension and trigger abscission. Finally, we discuss whether traction-induced mechanical cell rupture could represent an ancient alternative mechanism of abscission and suggest future research avenues to further understand the role of mechanics in regulating abscission.
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Affiliation(s)
- Virginia Andrade
- CNRS UMR3691, Membrane Traffic and Cell Division Unit, Institut Pasteur, Université Paris Cité, Paris, France,Collège Doctoral, Sorbonne Université, Paris, France
| | - Arnaud Echard
- CNRS UMR3691, Membrane Traffic and Cell Division Unit, Institut Pasteur, Université Paris Cité, Paris, France,*Correspondence: Arnaud Echard,
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Tae H, Park S, Kim SO, Yorulmaz Avsar S, Cho NJ. Selective Recognition of Phosphatidylinositol Phosphate Receptors by C-Terminal Tail of Mitotic Kinesin-like Protein 2 (MKlp2). J Phys Chem B 2022; 126:2345-2352. [PMID: 35316051 DOI: 10.1021/acs.jpcb.1c10534] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The mitotic kinesin-like protein 2 (MKlp2) plays a key role in the proper completion of cytokinetic abscission. Specifically, the C-terminal tail of MKlp2 (CTM peptides) offers a stable tethering on the plasma membrane and microtubule cytoskeleton in the midbody during abscission. However, little is known about the underlying mechanism of how the CTM peptides bind to the plasma membrane of the intercellular bridge. Herein, we identify the specific molecular interaction between the CTM peptides and phosphatidylinositol phosphate (PIP) receptors using quartz crystal microbalance-dissipation and atomic force microscopy force spectroscopic measurements. To systematically examine the effects of amino acids, we designed a series of synthetic 33-mer peptides derived from the wild-type (CTM1). First, we evaluated the peptide binding amount caused by electrostatic interactions based on 100% zwitterionic and 30% negatively charged model membranes, whereby the nonspecific attractions were nearly proportional to the net charge of peptides. Upon incubating with PIP-containing model membranes, the wild-type CTM1 and its truncated mutation showed significant PI(3)P-specific binding, which was evidenced by a 15-fold higher binding mass and 6-fold stronger adhesion force compared to other negatively charged membranes. The extent of the specific binding was predominantly dependent on the existence of S21, whereby substitution or deletion of S21 significantly hindered the binding affinity. Taken together, our findings based on a correlative measurement platform enabled the quantification of the nonelectrostatic, selective binding interactions of the C-terminal of MKlp2 to certain PIP receptors and contributed to understanding the molecular mechanisms on complete cytokinetic abscission in cells.
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Affiliation(s)
- Hyunhyuk Tae
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore
| | - Soohyun Park
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore
| | - Seong-Oh Kim
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore
| | - Saziye Yorulmaz Avsar
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore
| | - Nam-Joon Cho
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore.,China-Singapore International Joint Research Institute (CSIJRI), Guangzhou 510000, China
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McKim KS. Highway to hell-thy meiotic divisions: Chromosome passenger complex functions driven by microtubules: CPC interactions with both the chromosomes and microtubules are important for spindle assembly and function: CPC interactions with both the chromosomes and microtubules are important for spindle assembly and function. Bioessays 2022; 44:e2100202. [PMID: 34821405 PMCID: PMC8688318 DOI: 10.1002/bies.202100202] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 01/03/2023]
Abstract
The chromosome passenger complex (CPC) localizes to chromosomes and microtubules, sometimes simultaneously. The CPC also has multiple domains for interacting with chromatin and microtubules. Interactions between the CPC and both the chromatin and microtubules is important for spindle assembly and error correction. Such dual chromatin-microtubule interactions may increase the concentration of the CPC necessary for efficient kinase activity while also making it responsive to specific conditions or structures in the cell. CPC-microtubule dependent functions are considered in the context of the first meiotic division. Acentrosomal spindle assembly is a process that depends on transfer of the CPC from the chromosomes to the microtubules. Furthermore, transfer to the microtubules is not only to position the CPC for a later role in cytokinesis; metaphase I error correction and subsequent bi-orientation of bivalents may depend on microtubule associated CPC interacting with the kinetochores.
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Affiliation(s)
- Kim S McKim
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey, USA
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The Abscission Checkpoint: A Guardian of Chromosomal Stability. Cells 2021; 10:cells10123350. [PMID: 34943860 PMCID: PMC8699595 DOI: 10.3390/cells10123350] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 11/25/2021] [Accepted: 11/26/2021] [Indexed: 12/11/2022] Open
Abstract
The abscission checkpoint contributes to the fidelity of chromosome segregation by delaying completion of cytokinesis (abscission) when there is chromatin lagging in the intercellular bridge between dividing cells. Although additional triggers of an abscission checkpoint-delay have been described, including nuclear pore defects, replication stress or high intercellular bridge tension, this review will focus only on chromatin bridges. In the presence of such abnormal chromosomal tethers in mammalian cells, the abscission checkpoint requires proper localization and optimal kinase activity of the Chromosomal Passenger Complex (CPC)-catalytic subunit Aurora B at the midbody and culminates in the inhibition of Endosomal Sorting Complex Required for Transport-III (ESCRT-III) components at the abscission site to delay the final cut. Furthermore, cells with an active checkpoint stabilize the narrow cytoplasmic canal that connects the two daughter cells until the chromatin bridges are resolved. Unsuccessful resolution of chromatin bridges in checkpoint-deficient cells or in cells with unstable intercellular canals can lead to chromatin bridge breakage or tetraploidization by regression of the cleavage furrow. In turn, these outcomes can lead to accumulation of DNA damage, chromothripsis, generation of hypermutation clusters and chromosomal instability, which are associated with cancer formation or progression. Recently, many important questions regarding the mechanisms of the abscission checkpoint have been investigated, such as how the presence of chromatin bridges is signaled to the CPC, how Aurora B localization and kinase activity is regulated in late midbodies, the signaling pathways by which Aurora B implements the abscission delay, and how the actin cytoskeleton is remodeled to stabilize intercellular canals with DNA bridges. Here, we review recent progress toward understanding the mechanisms of the abscission checkpoint and its role in guarding genome integrity at the chromosome level, and consider its potential implications for cancer therapy.
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Petsalaki E, Zachos G. An ATM-Chk2-INCENP pathway activates the abscission checkpoint. J Cell Biol 2021; 220:211635. [PMID: 33355621 PMCID: PMC7769160 DOI: 10.1083/jcb.202008029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/29/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023] Open
Abstract
During cell division, in response to chromatin bridges, the chromosomal passenger complex (CPC) delays abscission to prevent chromosome breakage or tetraploidization. Here, we show that inhibition of ATM or Chk2 kinases impairs CPC localization to the midbody center, accelerates midbody resolution in normally segregating cells, and correlates with premature abscission and chromatin breakage in cytokinesis with trapped chromatin. In cultured human cells, ATM activates Chk2 at late midbodies. In turn, Chk2 phosphorylates human INCENP-Ser91 to promote INCENP binding to Mklp2 kinesin and CPC localization to the midbody center through Mklp2 association with Cep55. Expression of truncated Mklp2 that does not bind to Cep55 or nonphosphorylatable INCENP-Ser91A impairs CPC midbody localization and accelerates abscission. In contrast, expression of phosphomimetic INCENP-Ser91D or a chimeric INCENP protein that is targeted to the midbody center rescues the abscission delay in Chk2-deficient or ATM-deficient cells. Furthermore, the Mre11–Rad50–Nbs1 complex is required for ATM activation at the midbody in cytokinesis with chromatin bridges. These results identify an ATM–Chk2–INCENP pathway that imposes the abscission checkpoint by regulating CPC midbody localization.
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Affiliation(s)
- Eleni Petsalaki
- Department of Biology, University of Crete, Heraklion, Greece
| | - George Zachos
- Department of Biology, University of Crete, Heraklion, Greece
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McNeely KC, Dwyer ND. Cytokinetic Abscission Regulation in Neural Stem Cells and Tissue Development. CURRENT STEM CELL REPORTS 2021; 7:161-173. [PMID: 36303610 PMCID: PMC9603694 DOI: 10.1007/s40778-021-00193-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Purpose of Review How stem cells balance proliferation with differentiation, giving rise to specific daughter cells during development to build an embryo or tissue, remains an open question. Here, we discuss recent evidence that cytokinetic abscission regulation in stem cells, particularly neural stem cells (NSCs), is part of the answer. Abscission is a multi-step process mediated by the midbody, a microtubule-based structure formed in the intercellular bridge between daughter cells after mitosis. Recent Findings Human mutations and mouse knockouts in abscission genes reveal that subtle disruptions of NSC abscission can cause brain malformations. Experiments in several epithelial systems have shown that midbodies serve as scaffolds for apical junction proteins and are positioned near apical membrane fate determinants. Abscission timing is tightly controlled and developmentally regulated in stem cells, with delayed abscission in early embryos and faster abscission later. Midbody remnants (MBRs) contain over 400 proteins and may influence polarity, fate, and ciliogenesis. Summary As NSCs and other stem cells build tissues, they tightly regulate three aspects of abscission: midbody positioning, duration, and MBR handling. Midbody positioning and remnants establish or maintain cell polarity. MBRs are deposited on the apical membranes of epithelia, can be released or internalized by surrounding cells, and may sequester fate determinants or transfer information between cells. Work in cell lines and simpler systems has shown multiple roles for abscission regulation influencing stem cell polarity, potency, and daughter fates during development. Elucidating how the abscission process influences cell fate and tissue growth is important for our continued understanding of brain development and stem cell biology.
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Aurora-B phosphorylates the myosin II heavy chain to promote cytokinesis. J Biol Chem 2021; 297:101024. [PMID: 34343568 PMCID: PMC8385403 DOI: 10.1016/j.jbc.2021.101024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/21/2021] [Accepted: 07/29/2021] [Indexed: 12/22/2022] Open
Abstract
Cytokinesis, the final step of mitosis, is mediated by an actomyosin contractile ring, the formation of which is temporally and spatially regulated following anaphase onset. Aurora-B is a member of the chromosomal passenger complex, which regulates various processes during mitosis; it is not understood, however, how Aurora-B is involved in cytokinesis. Here, we show that Aurora-B and myosin-IIB form a complex in vivo during telophase. Aurora-B phosphorylates the myosin-IIB rod domain at threonine 1847 (T1847), abrogating the ability of myosin-IIB monomers to form filaments. Furthermore, phosphorylation of myosin-IIB filaments by Aurora-B also promotes filament disassembly. We show that myosin-IIB possessing a phosphomimetic mutation at T1847 was unable to rescue cytokinesis failure caused by myosin-IIB depletion. Cells expressing a phosphoresistant mutation at T1847 had significantly longer intercellular bridges, implying that Aurora-B-mediated phosphorylation of myosin-IIB is important for abscission. We propose that myosin-IIB is a substrate of Aurora-B and reveal a new mechanism of myosin-IIB regulation by Aurora-B in the late stages of mitosis.
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Jang JK, Gladstein AC, Das A, Shapiro JG, Sisco ZL, McKim KS. Multiple pools of PP2A regulate spindle assembly, kinetochore attachments and cohesion in Drosophila oocytes. J Cell Sci 2021; 134:jcs254037. [PMID: 34297127 PMCID: PMC8325958 DOI: 10.1242/jcs.254037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 06/14/2021] [Indexed: 01/06/2023] Open
Abstract
Meiosis in female oocytes lacks centrosomes, the microtubule-organizing centers. In Drosophila oocytes, meiotic spindle assembly depends on the chromosomal passenger complex (CPC). To investigate the mechanisms that regulate Aurora B activity, we examined the role of protein phosphatase 2A (PP2A) in Drosophila oocyte meiosis. We found that both forms of PP2A, B55 and B56, antagonize the Aurora B spindle assembly function, suggesting that a balance between Aurora B and PP2A activity maintains the oocyte spindle during meiosis I. PP2A-B56, which has a B subunit encoded by two partially redundant paralogs, wdb and wrd, is also required for maintenance of sister chromatid cohesion, establishment of end-on microtubule attachments, and metaphase I arrest in oocytes. WDB recruitment to the centromeres depends on BUBR1, MEI-S332 and kinetochore protein SPC105R. Although BUBR1 stabilizes microtubule attachments in Drosophila oocytes, it is not required for cohesion maintenance during meiosis I. We propose at least three populations of PP2A-B56 regulate meiosis, two of which depend on SPC105R and a third that is associated with the spindle.
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Affiliation(s)
| | | | | | | | | | - Kim S. McKim
- Waksman Institute, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
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Muniesh MS, Barmaver SN, Huang HY, Bayansan O, Wagner OI. PTP-3 phosphatase promotes intramolecular folding of SYD-2 to inactivate kinesin-3 UNC-104 in neurons. Mol Biol Cell 2020; 31:2932-2947. [PMID: 33147118 PMCID: PMC7927192 DOI: 10.1091/mbc.e19-10-0591] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
UNC-104 is the Caenorhabditis elegans homolog of kinesin-3 KIF1A known for its fast shuffling of synaptic vesicle protein transport vesicles in axons. SYD-2 is the homolog of liprin-α in C. elegans known to activate UNC-104; however, signals that trigger SYD-2 binding to the motor remain unknown. Because SYD-2 is a substrate of PTP-3/LAR PTPR, we speculate a role of this phosphatase in SYD–2-mediated motor activation. Indeed, coimmunoprecipitation assays revealed increased interaction between UNC-104 and SYD-2 in ptp-3 knockout worms. Intramolecular FRET analysis in living nematodes demonstrates that SYD-2 largely exists in an open conformation state in ptp-3 mutants. These assays also revealed that nonphosphorylatable SYD-2 (Y741F) exists predominately in folded conformations, while phosphomimicking SYD-2 (Y741E) primarily exists in open conformations. Increased UNC-104 motor clustering was observed along axons likely as a result of elevated SYD-2 scaffolding function in ptp-3 mutants. Also, both motor velocities as well as cargo transport speeds were visibly increased in neurons of ptp-3 mutants. Lastly, epistatic analysis revealed that PTP-3 is upstream of SYD-2 to regulate its intramolecular folding.
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Affiliation(s)
| | - Syed Nooruzuha Barmaver
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Hsin-Yi Huang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Odvogmed Bayansan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Oliver Ingvar Wagner
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan
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14
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McNeely KC, Dwyer ND. Cytokinesis and postabscission midbody remnants are regulated during mammalian brain development. Proc Natl Acad Sci U S A 2020; 117:9584-9593. [PMID: 32273386 PMCID: PMC7197019 DOI: 10.1073/pnas.1919658117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Building a brain of the proper size and structure requires neural stem cells (NSCs) to divide with tight temporal and spatial control to produce different daughter cell types in proper numbers and sequence. Mammalian NSCs in the embryonic cortex must maintain their polarized epithelial structure as they undergo both early proliferative divisions and later neurogenic divisions. To do this, they undergo a polarized form of cytokinesis at the apical membrane that is not well understood. Here, we investigate whether polarized furrowing and abscission in mouse NSCs are regulated differently at earlier and later stages and in a cytokinesis mutant, Kif20b This mutant was previously shown to have microcephaly and elevated apoptosis of NSCs. We developed methods to live image furrow ingression and midbody abscission in NSCs within cortical explants. We find that polarized furrow ingression occurs at a steady rate and completes in ∼15 min at two different ages. However, ingression is slower in a subset of Kif20b mutant NSCs. Abscission is usually observed on both sides of the midbody and takes 65 to 75 min to complete. Surprisingly, abscission is accelerated in the Kif20b mutant NSCs. Postabscission midbody remnants are observed at the apical membranes of daughter cells and are much more abundant in early-stage cortices. After NSC divisions in vitro, midbody remnants are more often retained on the daughter cells of early proliferative divisions. Altogether, these results suggest that regulation of abscission timing and midbody remnants in embryonic NSCs may influence proper brain growth and structure.
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Affiliation(s)
- Katrina C McNeely
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 22908
- Neuroscience Graduate Program, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Noelle D Dwyer
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 22908;
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15
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Kinesin-6 family motor KIF20A regulates central spindle assembly and acrosome biogenesis in mouse spermatogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1867:118636. [PMID: 31884069 DOI: 10.1016/j.bbamcr.2019.118636] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/15/2019] [Accepted: 12/23/2019] [Indexed: 11/21/2022]
Abstract
Kinesin-6 KIF20A is essential for microtubule organization and central spindle assembly during cytokinesis. However, the functions of KIF20A in meiotic division and spermatogenesis remain elusive. Here, we report that kinesin-6 KIF20A locates at the microtubules in mouse spermatogenic cells and co-localizes with the spindle midzone and midbody. We demonstrate that central spindle organization and chromosomal stability are regulated by KIF20A in male meiotic division. KIF20A inhibition leads to the defects in central spindle assembly and cytokinetic abscission, and finally results in the increase of aneuploid cells and the alteration of cell populations in the spermatogenic cells. Furthermore, we have revealed that kinesin-6 KIF20A is associated with the formation and maturation of the acrosomes during spermatogenesis. Our findings have identified the specific roles of KIF20A in central spindle organization in meiotic division.
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16
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Feng H, Raasholm M, Moosmann A, Campsteijn C, Thompson EM. Switching of INCENP paralogs controls transitions in mitotic chromosomal passenger complex functions. Cell Cycle 2019; 18:2006-2025. [PMID: 31306061 PMCID: PMC6681789 DOI: 10.1080/15384101.2019.1634954] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 01/29/2023] Open
Abstract
A single inner centromere protein (INCENP) found throughout eukaryotes modulates Aurora B kinase activity and chromosomal passenger complex (CPC) localization, which is essential for timely mitotic progression. It has been proposed that INCENP might act as a rheostat to regulate Aurora B activity through mitosis, with successively higher activity threshold levels for chromosome alignment, the spindle checkpoint, anaphase spindle transfer and finally spindle elongation and cytokinesis. It remains mechanistically unclear how this would be achieved. Here, we reveal that the urochordate, Oikopleura dioica, possesses two INCENP paralogs, which display distinct localizations and subfunctionalization in order to complete M-phase. INCENPa was localized on chromosome arms and centromeres by prometaphase, and modulated Aurora B activity to mediate H3S10/S28 phosphorylation, chromosome condensation, spindle assembly and transfer of the CPC to the central spindle. Polo-like kinase (Plk1) recruitment to CDK1 phosphorylated INCENPa was crucial for INCENPa-Aurora B enrichment on centromeres. The second paralog, INCENPb was enriched on centromeres from prometaphase, and relocated to the central spindle at anaphase onset. In the absence of INCENPa, meiotic spindles failed to form, and homologous chromosomes did not segregate. INCENPb was not required for early to mid M-phase events but became essential for the activity and localization of Aurora B on the central spindle and midbody during cytokinesis in order to allow abscission to occur. Together, our results demonstrate that INCENP paralog switching on centromeres modulates Aurora B kinase localization, thus chronologically regulating CPC functions during fast embryonic divisions in the urochordate O. dioica. Abbreviations: CCAN: constitutive centromere-associated network; CENPs: centromere proteins; cmRNA: capped messenger RNA; CPC: chromosomal passenger complex; INCENP: inner centromere protein; Plk1: polo-like kinase 1; PP1: protein phosphatase 1; PP2A: protein phosphatase 2A; SAC: spindle assembly checkpoint; SAH: single α-helix domain.
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Affiliation(s)
- Haiyang Feng
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Martina Raasholm
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
| | - Alexandra Moosmann
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
| | - Coen Campsteijn
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
- Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Eric M. Thompson
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
- Department of Biological Sciences, University of Bergen, Bergen, Norway
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17
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Wu WD, Yu KW, Zhong N, Xiao Y, She ZY. Roles and mechanisms of Kinesin-6 KIF20A in spindle organization during cell division. Eur J Cell Biol 2019; 98:74-80. [DOI: 10.1016/j.ejcb.2018.12.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/10/2018] [Accepted: 12/11/2018] [Indexed: 12/21/2022] Open
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18
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Kinesin 6 Regulation in Drosophila Female Meiosis by the Non-conserved N- and C- Terminal Domains. G3-GENES GENOMES GENETICS 2018. [PMID: 29514846 PMCID: PMC5940148 DOI: 10.1534/g3.117.300571] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bipolar spindle assembly occurs in the absence of centrosomes in the oocytes of most organisms. In the absence of centrosomes in Drosophila oocytes, we have proposed that the kinesin 6 Subito, a MKLP-2 homolog, is required for establishing spindle bipolarity and chromosome biorientation by assembling a robust central spindle during prometaphase I. Although the functions of the conserved motor domains of kinesins is well studied, less is known about the contribution of the poorly conserved N- and C- terminal domains to motor function. In this study, we have investigated the contribution of these domains to kinesin 6 functions in meiosis and early embryonic development. We found that the N-terminal domain has antagonistic elements that regulate localization of the motor to microtubules. Other parts of the N- and C-terminal domains are not required for microtubule localization but are required for motor function. Some of these elements of Subito are more important for either mitosis or meiosis, as revealed by separation-of-function mutants. One of the functions for both the N- and C-terminals domains is to restrict the CPC to the central spindle in a ring around the chromosomes. We also provide evidence that CDK1 phosphorylation of Subito regulates its activity associated with homolog bi-orientation. These results suggest the N- and C-terminal domains of Subito, while not required for localization to the central spindle microtubules, have important roles regulating Subito, by interacting with other spindle proteins and promoting activities such as bipolar spindle formation and homologous chromosome bi-orientation during meiosis.
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19
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Landino J, Norris SR, Li M, Ballister ER, Lampson MA, Ohi R. Two mechanisms coordinate the recruitment of the chromosomal passenger complex to the plane of cell division. Mol Biol Cell 2017; 28:3634-3646. [PMID: 28954866 PMCID: PMC5706991 DOI: 10.1091/mbc.e17-06-0399] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/18/2017] [Accepted: 09/22/2017] [Indexed: 11/11/2022] Open
Abstract
Proper positioning of the chromosomal passenger complex (CPC) at the cell division plane is required for cytokinesis. We show here that CPC targeting to the equatorial cortex depends on both the kinesin MKlp2 and a direct interaction with actin. These recruitment mechanisms converge to promote successful cleavage furrow ingression. During cytokinesis, the chromosomal passenger complex (CPC) promotes midzone organization, specifies the cleavage plane, and regulates furrow contractility. The localizations of the CPC are coupled to its cytokinetic functions. At the metaphase-to-anaphase transition, the CPC dissociates from centromeres and localizes to midzone microtubules and the equatorial cortex. CPC relocalization to the cell middle is thought to depend on MKlp2-driven, plus end–directed transport. In support of this idea, MKlp2 depletion impairs cytokinesis; however, cytokinesis failure stems from furrow regression rather than failed initiation of furrowing. This suggests that an alternative mechanism(s) may concentrate the CPC at the division plane. We show here that direct actin binding, via the inner centromere protein (INCENP), enhances CPC enrichment at the equatorial cortex, thus acting in tandem with MKlp2. INCENP overexpression rescues furrowing in MKlp2-depleted cells in an INCENP-actin binding–dependent manner. Using live-cell imaging, we also find that MKlp2-dependent targeting of the CPC is biphasic. MKlp2 targets the CPC to the anti-parallel microtubule overlap of the midzone, after which the MKlp2-CPC complex moves in a nondirected manner. Collectively, our work suggests that both actin binding and MKlp2-dependent midzone targeting cooperate to precisely position the CPC during mitotic exit, and that these pathways converge to ensure successful cleavage furrow ingression.
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Affiliation(s)
- Jennifer Landino
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Stephen R Norris
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Muyi Li
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Edward R Ballister
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Michael A Lampson
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Ryoma Ohi
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232 .,Department of Cell and Developmental Biology and Life Sciences Institute, University of Michigan Medical School, Ann Arbor, MI 48109
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20
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Stoten CL, Carlton JG. ESCRT-dependent control of membrane remodelling during cell division. Semin Cell Dev Biol 2017; 74:50-65. [PMID: 28843980 PMCID: PMC6015221 DOI: 10.1016/j.semcdb.2017.08.035] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 08/07/2017] [Accepted: 08/18/2017] [Indexed: 12/16/2022]
Abstract
The Endosomal Sorting Complex Required for Transport (ESCRT) proteins form an evolutionarily conserved membrane remodelling machinery. Identified originally for their role in cargo sorting and remodelling of endosomal membranes during yeast vacuolar sorting, an extensive body of work now implicates a sub-complex of this machinery (ESCRT-III), as a transplantable membrane fission machinery that is dispatched to various cellular locations to achieve a topologically unique membrane separation. Surprisingly, several ESCRT-III-regulated processes occur during cell division, when cells undergo a dramatic and co-ordinated remodelling of their membranes to allow the physical processes of division to occur. The ESCRT machinery functions in regeneration of the nuclear envelope during open mitosis and in the abscission phase of cytokinesis, where daughter cells are separated from each other in the last act of division. Roles for the ESCRT machinery in cell division are conserved as far back as Archaea, suggesting that the ancestral role of these proteins was as a membrane remodelling machinery that facilitated division and that was co-opted throughout evolution to perform a variety of other cell biological functions. Here, we will explore the function and regulation of the ESCRT machinery in cell division.
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21
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Atherton J, Yu IM, Cook A, Muretta JM, Joseph A, Major J, Sourigues Y, Clause J, Topf M, Rosenfeld SS, Houdusse A, Moores CA. The divergent mitotic kinesin MKLP2 exhibits atypical structure and mechanochemistry. eLife 2017; 6:27793. [PMID: 28826477 PMCID: PMC5602324 DOI: 10.7554/elife.27793] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 08/07/2017] [Indexed: 01/17/2023] Open
Abstract
MKLP2, a kinesin-6, has critical roles during the metaphase-anaphase transition and cytokinesis. Its motor domain contains conserved nucleotide binding motifs, but is divergent in sequence (~35% identity) and size (~40% larger) compared to other kinesins. Using cryo-electron microscopy and biophysical assays, we have undertaken a mechanochemical dissection of the microtubule-bound MKLP2 motor domain during its ATPase cycle, and show that many facets of its mechanism are distinct from other kinesins. While the MKLP2 neck-linker is directed towards the microtubule plus-end in an ATP-like state, it does not fully dock along the motor domain. Furthermore, the footprint of the MKLP2 motor domain on the MT surface is altered compared to motile kinesins, and enhanced by kinesin-6-specific sequences. The conformation of the highly extended loop6 insertion characteristic of kinesin-6s is nucleotide-independent and does not contact the MT surface. Our results emphasize the role of family-specific insertions in modulating kinesin motor function. Cells constantly replicate to provide new cells for growing tissues, and to replace ageing or defective cells around the body. Each new cell needs a copy of the genetic material, and a cellular structure called the mitotic spindle makes sure that this material is shared correctly when a cell divides in two. The spindle is built from protein filaments called microtubules, and the protein filaments grow and shrink as the mitotic spindle carries out its role. Many of these changes in the spindle are driven by proteins called molecular motors, which break down energy-rich molecules of ATP to power them as they walk along the filaments. Kinesins, for example, are molecular motors that can move along microtubules and there are over 40 different kinesins encoded in the human genome. More than half of the human kinesins are involved in cell division including one called MKLP2. Little is known about MKLP2 but some earlier findings had suggested that it would behave very differently compared to other kinesins. Understanding how a kinesin motor works requires studying it in complex with its microtubule tracks. Atherton, Yu et al. have now used a technique called cryo-electron microscopy – which is uniquely suited to looking at large and complicated samples in three dimensions – to observe how the motor in MKLP2 changes shape as it works. This revealed that, while MKLP2 works in a fundamentally similar way to other kinesins, many aspects of its molecular mechanism are highly unusual. These include how it binds to the microtubule, how it interacts with ATP and how it generates force. These findings show that there is much greater diversity in the molecular mechanisms of the kinesins involved in cell division than was previously thought. Several anticancer drugs target kinesins to stop cells dividing and so this diversity may make it easier to target only certain kinesins with drugs, which in turn would have fewer side effects. First, though, it will be important to find out how the unusual mechanism of MKLP2 coordinates and influences other components of the spindle to reveal a fuller picture of what happens when cells replicate.
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Affiliation(s)
- Joseph Atherton
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | - I-Mei Yu
- Structural Motility, Institut Curie, Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Paris, France
| | - Alexander Cook
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | - Joseph M Muretta
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, United Sates
| | - Agnel Joseph
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | - Jennifer Major
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, United States
| | - Yannick Sourigues
- Structural Motility, Institut Curie, Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Paris, France
| | - Jeffrey Clause
- Structural Motility, Institut Curie, Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Paris, France
| | - Maya Topf
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | - Steven S Rosenfeld
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, United States
| | - Anne Houdusse
- Structural Motility, Institut Curie, Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Paris, France
| | - Carolyn A Moores
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
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