1
|
Khalaf A, Francis O, Blaxter ML. Genome evolution in intracellular parasites: Microsporidia and Apicomplexa. J Eukaryot Microbiol 2024:e13033. [PMID: 38785208 DOI: 10.1111/jeu.13033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/29/2024] [Accepted: 05/02/2024] [Indexed: 05/25/2024]
Abstract
Microsporidia and Apicomplexa are eukaryotic, single-celled, intracellular parasites with huge public health and economic importance. Typically, these parasites are studied separately, emphasizing their uniqueness and diversity. In this review, we explore the huge amount of genomic data that has recently become available for the two groups. We compare and contrast their genome evolution and discuss how their transitions to intracellular life may have shaped it. In particular, we explore genome reduction and compaction, genome expansion and ploidy, gene shuffling and rearrangements, and the evolution of centromeres and telomeres.
Collapse
Affiliation(s)
- Amjad Khalaf
- Tree of Life, Wellcome Sanger Institute, Cambridge, UK
| | - Ore Francis
- Tree of Life, Wellcome Sanger Institute, Cambridge, UK
| | | |
Collapse
|
2
|
Bangera M, Dungdung A, Prabhu S, Sirajuddin M. Doublet microtubule inner junction protein FAP20 recruits tubulin to the microtubule lattice. Structure 2023; 31:1535-1544.e4. [PMID: 37816351 PMCID: PMC7615566 DOI: 10.1016/j.str.2023.09.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 07/12/2023] [Accepted: 09/13/2023] [Indexed: 10/12/2023]
Abstract
Doublet microtubules of eukaryotic cilia and flagella are made up of a complete A- and an incomplete B-tubule that are fused together. Of the two fusion points, the outer junction is made of tripartite tubulin connections, while the inner junction contains non-tubulin elements. The latter includes flagellar-associated protein 20 (FAP20) and Parkin co-regulated gene protein (PACRG) that together link the A- and B-tubule at the inner junction. While structures of doublet microtubules reveal molecular details, their assembly is poorly understood. In this study, we purified recombinant FAP20 and characterized its effects on microtubule dynamics. We use in vitro reconstitution and cryo-electron microscopy to show that FAP20 recruits free tubulin to the existing microtubule lattice. Our cryo-electron microscopy reconstruction of microtubule:FAP20:tubulin complex reveals the mode of tubulin recruitment by FAP20 onto microtubules, providing insights into assembly steps of B-tubule closure during doublet microtubule formation.
Collapse
Affiliation(s)
- Mamata Bangera
- Institute for Stem Cell Science and Regenerative Medicine, GKVK Campus, Bengaluru 560065, India
| | - Archita Dungdung
- Institute for Stem Cell Science and Regenerative Medicine, GKVK Campus, Bengaluru 560065, India
| | - Sujana Prabhu
- Institute for Stem Cell Science and Regenerative Medicine, GKVK Campus, Bengaluru 560065, India
| | - Minhajuddin Sirajuddin
- Institute for Stem Cell Science and Regenerative Medicine, GKVK Campus, Bengaluru 560065, India.
| |
Collapse
|
3
|
Black CS, Bui KH. Unveiling the intriguing role of FAP20 in tubulin recruitment at the doublet microtubule inner junctions. Structure 2023; 31:1518-1519. [PMID: 38065073 DOI: 10.1016/j.str.2023.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 11/10/2023] [Accepted: 11/10/2023] [Indexed: 12/18/2023]
Abstract
In this issue of Structure, Bangera et al. investigate the role of the inner junction protein FAP20 in doublet microtubule assembly. Using cryo-EM and microtubule dynamic assays, they demonstrate that FAP20 recruits free tubulins to existing microtubule lattices, shedding light on B-tubule closure during doublet microtubule formation.
Collapse
Affiliation(s)
- Corbin S Black
- Facility for Electron Microscopy Research, McGill University, Montreal, QC, Canada.
| | - Khanh Huy Bui
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada.
| |
Collapse
|
4
|
Radhakrishnan RM, Kizhakkeduth ST, Nair VM, Ayyappan S, Lakshmi RB, Babu N, Prasannajith A, Umeda K, Vijayan V, Kodera N, Manna TK. Kinetochore-microtubule attachment in human cells is regulated by the interaction of a conserved motif of Ska1 with EB1. J Biol Chem 2023; 299:102853. [PMID: 36592928 PMCID: PMC9926122 DOI: 10.1016/j.jbc.2022.102853] [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: 07/06/2022] [Revised: 12/16/2022] [Accepted: 12/18/2022] [Indexed: 01/02/2023] Open
Abstract
The kinetochore establishes the linkage between chromosomes and the spindle microtubule plus ends during mitosis. In vertebrates, the spindle-kinetochore-associated (Ska1,2,3) complex stabilizes kinetochore attachment with the microtubule plus ends, but how Ska is recruited to and stabilized at the kinetochore-microtubule interface is not understood. Here, our results show that interaction of Ska1 with the general microtubule plus end-associated protein EB1 through a conserved motif regulates Ska recruitment to kinetochores in human cells. Ska1 forms a stable complex with EB1 via interaction with the motif in its N-terminal disordered loop region. Disruption of this interaction either by deleting or mutating the motif disrupts Ska complex recruitment to kinetochores and induces chromosome alignment defects, but it does not affect Ska complex assembly. Atomic-force microscopy imaging revealed that Ska1 is anchored to the C-terminal region of the EB1 dimer through its loop and thereby promotes formation of extended structures. Furthermore, our NMR data showed that the Ska1 motif binds to the residues in EB1 that are the binding sites of other plus end targeting proteins that are recruited to microtubules by EB1 through a similar conserved motif. Collectively, our results demonstrate that EB1-mediated Ska1 recruitment onto the microtubule serves as a general mechanism for the formation of vertebrate kinetochore-microtubule attachments and metaphase chromosome alignment.
Collapse
Affiliation(s)
- Renjith M Radhakrishnan
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Safwa T Kizhakkeduth
- School of Chemistry, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Vishnu M Nair
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Shine Ayyappan
- School of Chemistry, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - R Bhagya Lakshmi
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Neethu Babu
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Anjaly Prasannajith
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Kenichi Umeda
- Nano Life Science Institute (WPI-Nano LSI), Kanazawa University, Kakuma-machi, Kanazawa, Japan
| | - Vinesh Vijayan
- School of Chemistry, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Noriyuki Kodera
- Nano Life Science Institute (WPI-Nano LSI), Kanazawa University, Kakuma-machi, Kanazawa, Japan
| | - Tapas K Manna
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India.
| |
Collapse
|
5
|
Song GQ, He TL, Ji KJ, Duan YM, Zhang JW, Hu GQ. SKA1/2/3 is a biomarker of poor prognosis in human hepatocellular carcinoma. Front Oncol 2022; 12:1038925. [PMID: 36439516 PMCID: PMC9684634 DOI: 10.3389/fonc.2022.1038925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 10/25/2022] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND Spindle and kinetochore-associated complex subunits 1-3 (SKA1-3) stabilize the kinetochore-attached spindle microtubules in metaphase. Due to the dysregulation in multiple cancers, SKA1-3 is considered a predictor for the prognosis of the patients. However, the potential clinical applications of SKA1-3, particularly in hepatocellular carcinoma (HCC) prognosis and progression, have completely unknown yet. METHODS For the analysis of SKA1-3 expression and applications in clinics in HCC patients, several databases, such as STRING, UALCAN, GEO, and TCGA, were searched. In addition, the underlying mechanisms of SKA for the regulation of HCC occurrence, development, and progression were also explored. RESULTS Compared to the normal controls, HCC patients showed dramatically elevated SKA1-3 expression at the mRNA level, and the values of the area under the curve (AUC) were 0.982, 0.887, and 0.973, respectively. Increased SKA1-3 expression levels were associated with the clinical stage, age, body mass index, tumor grade, tissue subtype, and Tp53 mutation status in HCC patients. The analyses of Kyoto Encyclopedia of Genes and Genome (KEGG) and Gene ontology (GO) demonstrated that SKA1-3 are enriched mainly in the Fanconi anemia, homologous recombination, spliceosome, DNA replication, and cell cycle signaling pathways. The hub genes, such as CDK1, CCNB1, CCNA2, TOP2A, BUB1, AURKB, CCNB2, BUB1B, NCAPG, and KIF11, were identified in protein-protein interactions (PPIs). The expression levels of hub genes were increased in HCC patients and predictive of a poor prognosis. Finally, the expression levels of SKA1-3 were determined using the GEO database. CONCLUSIONS SKA1-3 are potential prognostic biomarkers of and targets for HCC. In addition, SKA1-3 may affect HCC prognosis via the Fanconi anemia pathway, homologous recombination, spliceosome, DNA replication, and cell cycle signaling pathway.
Collapse
Affiliation(s)
- Guo-Qiang Song
- Department of Respiratory, Changxing Hospital of Traditional Chinese Medicine, Huzhou, China
| | - Tian-Li He
- Department of Radiotherapy, Changxing People’s Hospital, Huzhou, China
| | - Ke-Jie Ji
- Department of Respiratory, Changxing Hospital of Traditional Chinese Medicine, Huzhou, China
| | - Yi-Meng Duan
- Department of Radiotherapy, Changxing People’s Hospital, Huzhou, China
| | - Jia-Wen Zhang
- Department of Respiratory, Changxing Hospital of Traditional Chinese Medicine, Huzhou, China
| | - Guo-Qiang Hu
- Department of Respiratory, Changxing Hospital of Traditional Chinese Medicine, Huzhou, China
- Department of Cancer Center, Changxing Hospital of Traditional Chinese Medicine, Huzhou, China
| |
Collapse
|
6
|
Castrogiovanni C, Inchingolo AV, Harrison JU, Dudka D, Sen O, Burroughs NJ, McAinsh AD, Meraldi P. Evidence for a HURP/EB free mixed-nucleotide zone in kinetochore-microtubules. Nat Commun 2022; 13:4704. [PMID: 35948594 PMCID: PMC9365851 DOI: 10.1038/s41467-022-32421-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 07/28/2022] [Indexed: 12/02/2022] Open
Abstract
Current models infer that the microtubule-based mitotic spindle is built from GDP-tubulin with small GTP caps at microtubule plus-ends, including those that attach to kinetochores, forming the kinetochore-fibres. Here we reveal that kinetochore-fibres additionally contain a dynamic mixed-nucleotide zone that reaches several microns in length. This zone becomes visible in cells expressing fluorescently labelled end-binding proteins, a known marker for GTP-tubulin, and endogenously-labelled HURP - a protein which we show to preferentially bind the GDP microtubule lattice in vitro and in vivo. We find that in mitotic cells HURP accumulates on the kinetochore-proximal region of depolymerising kinetochore-fibres, whilst avoiding recruitment to nascent polymerising K-fibres, giving rise to a growing "HURP-gap". The absence of end-binding proteins in the HURP-gaps leads us to postulate that they reflect a mixed-nucleotide zone. We generate a minimal quantitative model based on the preferential binding of HURP to GDP-tubulin to show that such a mixed-nucleotide zone is sufficient to recapitulate the observed in vivo dynamics of HURP-gaps.
Collapse
Affiliation(s)
- Cédric Castrogiovanni
- Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, 1211, Geneva 4, Switzerland
- Translational Research Centre in Onco-hematology, Faculty of Medicine, University of Geneva, 1211, Geneva 4, Switzerland
| | - Alessio V Inchingolo
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Jonathan U Harrison
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK
- Mathematics Institute, University of Warwick, Coventry, UK
| | - Damian Dudka
- Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, 1211, Geneva 4, Switzerland
- Translational Research Centre in Onco-hematology, Faculty of Medicine, University of Geneva, 1211, Geneva 4, Switzerland
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Onur Sen
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Nigel J Burroughs
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK
- Mathematics Institute, University of Warwick, Coventry, UK
| | - Andrew D McAinsh
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK.
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK.
| | - Patrick Meraldi
- Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, 1211, Geneva 4, Switzerland.
- Translational Research Centre in Onco-hematology, Faculty of Medicine, University of Geneva, 1211, Geneva 4, Switzerland.
| |
Collapse
|
7
|
Failure of DNA double-strand break repair by tau mediates Alzheimer's disease pathology in vitro. Commun Biol 2022; 5:358. [PMID: 35418705 PMCID: PMC9008043 DOI: 10.1038/s42003-022-03312-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 03/24/2022] [Indexed: 12/26/2022] Open
Abstract
DNA double-strand break (DSB) is the most severe form of DNA damage and accumulates with age, in which cytoskeletal proteins are polymerized to repair DSB in dividing cells. Since tau is a microtubule-associated protein, we investigate whether DSB is involved in tau pathologies in Alzheimer's disease (AD). First, immunohistochemistry reveals the frequent coexistence of DSB and phosphorylated tau in the cortex of AD patients. In vitro studies using primary mouse cortical neurons show that non-p-tau accumulates perinuclearly together with the tubulin after DSB induction with etoposide, followed by the accumulation of phosphorylated tau. Moreover, the knockdown of endogenous tau exacerbates DSB in neurons, suggesting the protective role of tau on DNA repair. Interestingly, synergistic exposure of neurons to microtubule disassembly and the DSB strikingly augments aberrant p-tau aggregation and apoptosis. These data suggest that DSB plays a pivotal role in AD-tau pathology and that the failure of DSB repair leads to tauopathy.
Collapse
|
8
|
Tripathy SK, Demidov VM, Gonchar IV, Wu S, Ataullakhanov FI, Grishchuk EL. Ultrafast Force-Clamp Spectroscopy of Microtubule-Binding Proteins. Methods Mol Biol 2022; 2478:609-650. [PMID: 36063336 PMCID: PMC9662813 DOI: 10.1007/978-1-0716-2229-2_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Optical trapping has been instrumental for deciphering translocation mechanisms of the force-generating cytoskeletal proteins. However, studies of the dynamic interactions between microtubules (MTs) and MT-associated proteins (MAPs) with no motor activity are lagging. Investigating the motility of MAPs that can diffuse along MT walls is a particular challenge for optical-trapping assays because thermally driven motions rely on weak and highly transient interactions. Three-bead, ultrafast force-clamp (UFFC) spectroscopy has the potential to resolve static and diffusive translocations of different MAPs with sub-millisecond temporal resolution and sub-nanometer spatial precision. In this report, we present detailed procedures for implementing UFFC, including setup of the optical instrument and feedback control, immobilization and functionalization of pedestal beads, and preparation of MT dumbbells. Example results for strong static interactions were generated using the Kinesin-7 motor CENP-E in the presence of AMP-PNP. Time resolution for MAP-MT interactions in the UFFC assay is limited by the MT dumbbell relaxation time, which is significantly longer than reported for analogous experiments using actin filaments. UFFC, however, provides a unique opportunity for quantitative studies on MAPs that glide along MTs under a dragging force, as illustrated using the kinetochore-associated Ska complex.
Collapse
Affiliation(s)
- Suvranta K Tripathy
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI, USA
| | - Vladimir M Demidov
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ivan V Gonchar
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Shaowen Wu
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Agro-Biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Fazly I Ataullakhanov
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Ekaterina L Grishchuk
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
9
|
Shen D, Zhao HY, Gu AD, Wu YW, Weng YH, Li SJ, Song JY, Gu XF, Qiu J, Zhao W. miRNA-10a-5p inhibits cell metastasis in hepatocellular carcinoma via targeting SKA1. Kaohsiung J Med Sci 2021; 37:784-794. [PMID: 34002462 DOI: 10.1002/kjm2.12392] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 04/19/2021] [Accepted: 04/28/2021] [Indexed: 01/17/2023] Open
Abstract
A variety of microRNAs (miRNAs) are involved in the occurrence and development of hepatocellular carcinoma (HCC). However, the role of miR-10a-5p in the progression of HCC remains unclear. Therefore, the purpose of this study was to determine the role of miR-10a-5p in the development of HCC and the possible molecular mechanism. miR-10a-5p expression in HCC tissues and plasma from patients was detected by quantitative real-time polymerase chain reaction. Migratory changes in HCC cells were detected after the overexpression of miR-10a-5p. Epithelial-mesenchymal transition (EMT)-related proteins were detected by Western blot. Finally, through luciferase assay and rescue experiments, the mechanism by which miR-10a-5p regulates its downstream gene, human spindle and kinetochore-associated complex subunit 1, SKA1 and the interaction between these molecules in the development of HCC were determined. The expression of miR-10a-5p was markedly downregulated in HCC tissues, cell lines, and plasma. The overexpression of miR-10a-5p significantly inhibited the migration, invasion, and EMT of HCC cells. Furthermore, SKA1 was shown to be a downstream gene of miR-10a-5p. SKA1 silencing had the same effect as miR-10a-5p overexpression in HCC. In particular, the overexpression of SKA1 reversed the inhibitory effects of miR-10a-5p in HCC. Taken together, low miR-10a-5p expression is associated with HCC progression. miR-10a-5p inhibits the malignant development of HCC by negatively regulating SKA1.
Collapse
Affiliation(s)
- Duo Shen
- Medical School, Southeast University, Nanjing, China
| | - Hong-Yu Zhao
- Department of Clinical Research Center, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing, China
| | - Ai-Dong Gu
- Department of Hepatobiliary and Pancreatic Surgery, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yin-Wei Wu
- Department of Clinical Research Center, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yu-Hang Weng
- Department of Hepatology, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing, China
| | - Shu-Jie Li
- Department of Hepatobiliary and Pancreatic Surgery, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing, China
| | - Jin-Yun Song
- Department of Clinical Research Center, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing, China
| | - Xue-Feng Gu
- Medical School, Southeast University, Nanjing, China
| | - Jie Qiu
- Medical School, Southeast University, Nanjing, China.,Department of Hepatology, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing, China
| | - Wei Zhao
- Medical School, Southeast University, Nanjing, China.,Department of Hepatology, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing, China
| |
Collapse
|
10
|
Leaving no-one behind: how CENP-E facilitates chromosome alignment. Essays Biochem 2021; 64:313-324. [PMID: 32347304 PMCID: PMC7475649 DOI: 10.1042/ebc20190073] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/08/2020] [Accepted: 04/14/2020] [Indexed: 02/06/2023]
Abstract
Chromosome alignment and biorientation is essential for mitotic progression and genomic stability. Most chromosomes align at the spindle equator in a motor-independent manner. However, a subset of polar kinetochores fail to bi-orient and require a microtubule motor-based transport mechanism to move to the cell equator. Centromere Protein E (CENP-E/KIF10) is a kinesin motor from the Kinesin-7 family, which localizes to unattached kinetochores during mitosis and utilizes plus-end directed microtubule motility to slide mono-oriented chromosomes to the spindle equator. Recent work has revealed how CENP-E cooperates with chromokinesins and dynein to mediate chromosome congression and highlighted its role at aligned chromosomes. Additionally, we have gained new mechanistic insights into the targeting and regulation of CENP-E motor activity at the kinetochore. Here, we will review the function of CENP-E in chromosome congression, the pathways that contribute to CENP-E loading at the kinetochore, and how CENP-E activity is regulated during mitosis.
Collapse
|
11
|
Microtubules pull the strings: disordered sequences as efficient couplers of microtubule-generated force. Essays Biochem 2020; 64:371-382. [PMID: 32502246 DOI: 10.1042/ebc20190078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/01/2020] [Accepted: 05/14/2020] [Indexed: 11/17/2022]
Abstract
Microtubules are dynamic polymers that grow and shrink through addition or loss of tubulin subunits at their ends. Microtubule ends generate mechanical force that moves chromosomes and cellular organelles, and provides mechanical tension. Recent literature describes a number of proteins and protein complexes that couple dynamics of microtubule ends to movements of their cellular cargoes. These 'couplers' are quite diverse in their microtubule-binding domains (MTBDs), while sharing similarity in function, but a systematic understanding of the principles underlying their activity is missing. Here, I review various types of microtubule couplers, focusing on their essential activities: ability to follow microtubule ends and capture microtubule-generated force. Most of the couplers require presence of unstructured positively charged sequences and multivalency in their microtubule-binding sites to efficiently convert the microtubule-generated force into useful connection to a cargo. An overview of the microtubule features supporting end-tracking and force-coupling, and the experimental methods to assess force-coupling properties is also provided.
Collapse
|
12
|
Kinetochore-microtubule coupling mechanisms mediated by the Ska1 complex and Cdt1. Essays Biochem 2020; 64:337-347. [PMID: 32844209 DOI: 10.1042/ebc20190075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/03/2020] [Accepted: 08/06/2020] [Indexed: 11/17/2022]
Abstract
The faithful segregation of duplicated sister chromatids rely on the remarkable ability of kinetochores to sustain stable load bearing attachments with the dynamic plus ends of kinetochore-microtubules (kMTs). The outer layer of the kinetochore recruits several motor and non-motor microtubule-associated proteins (MAPs) that help the kinetochores establish and maintain a load bearing dynamic attachment with kMTs. The primary kMT-binding protein, the Ndc80 complex (Ndc80c), which is highly conserved among diverse organisms from yeast to humans, performs this essential function with assistance from other MAPs. These MAPs are not an integral part of the kinetochore, but they localize to the kinetochore periodically throughout mitosis and regulate the strength of the kinetochore microtubule attachments. Here, we attempt to summarize the recent advances that have been made toward furthering our understanding of this co-operation between the Ndc80c and these MAPs, focusing on the spindle and kinetochore-associated 1 (Ska1) complex (Ska1c) and Cdc10-dependent transcript 1 (Cdt1) in humans.
Collapse
|
13
|
Zhao L, Zhang B, Li K, Sun P. SKA1 expression in oral squamous cell carcinoma and its relationship to P53 and clinicopathologic features. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2020; 13:2100-2105. [PMID: 32922606 PMCID: PMC7476955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 07/20/2020] [Indexed: 06/11/2023]
Abstract
In this study, 57 paraffin-embedded tissue specimens from patients with oral squamous cell carcinoma (OSCC) were collected and analyzed. Spindle and kinetochore-associated complex subunit 1 (SKA1) and P53 protein expression in selected samples was detected by immunohistochemistry. The positive expression rate of SKA1 and P53 was significantly higher in oral squamous cell carcinoma tissues than in normal controls. The expression of SKA1 protein was significantly associated with tumor-node-metastasis (TNM) stage, and p53 expression was significantly correlated with pathologic differentiation grade in oral squamous cell carcinoma tissues. There was a significant correlation between SKA1 and p53 protein expression in oral squamous cell carcinoma tissues. Our results indicate that the SKA1 gene might be involved in the development of oral squamous cell carcinoma and might predict its prognosis. SKA1 is expected to be a new molecular target for oral squamous cell carcinoma.
Collapse
Affiliation(s)
- Lijuan Zhao
- Department of Oral and Maxillofacial Surgery, Yantai Stomatological Hospital Affiliated to Binzhou Medical CollegeYantai 264001, China
| | - Bin Zhang
- Department of Oral and Maxillofacial Surgery, Liaocheng People’s Hospital Affiliated to Taishan Medical UniversityLiaocheng 252000, China
| | - Kun Li
- Department of Orthodontics, Yantai Stomatological Hospital Affiliated to Binzhou Medical CollegeYantai 264001, China
| | - Peng Sun
- Department of Orthodontics, Yantai Stomatological Hospital Affiliated to Binzhou Medical CollegeYantai 264001, China
| |
Collapse
|
14
|
Zhang Q, Hu L, Chen Y, Tian W, Liu H. Multisite phosphorylation determines the formation of Ska-Ndc80 macro-complexes that are essential for chromosome segregation during mitosis. Mol Biol Cell 2020; 31:1892-1903. [PMID: 32491969 PMCID: PMC7525821 DOI: 10.1091/mbc.e19-10-0569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human Ska complex (Ska) localizing to both spindle microtubules and kinetochores is essential for proper chromosome segregation during mitosis. Although several mechanisms have been proposed to explain how Ska is recruited to kinetochores, it is still not fully understood. By analyzing Ska3 phosphorylation, we identified six critical Cdk1 sites, including the previously identified Thr358 and Thr360. Mutations of these sites to phospho-deficient alanine (6A) in cells completely abolished Ska3 localization to kinetochores and Ska functions in chromosome segregation. In vitro, Cdk1 phosphorylation on Ska enhanced WT, not phospho-deficient 6A, binding to Ndc80C. Strikingly, the phosphomimetic Ska 6D complex formed a stable macro-complex with Ndc80C, but Ska WT failed to do so. These results suggest that multisite Cdk1 phosphorylation-enabled Ska–Ndc80 binding is decisive for Ska localization to kinetochores and its functions. Moreover, we found that Ska decrease at kinetochores triggered by the microtubule-depolymerizing drug nocodazole is independent of Aurora B but can be overridden by Ska3 overexpression, suggestive of a role of spindle microtubules in promoting Ska kinetochore recruitment. Thus, based on the current and previous results, we propose that multisite Cdk1 phosphorylation is critical for the formation of Ska–Ndc80 macro-complexes that are essential for chromosome segregation.
Collapse
Affiliation(s)
- Qian Zhang
- Department of Biochemistry and Molecular Biology, Tulane University Health Science Center, New Orleans, LA 70112
| | - Liqiao Hu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yujue Chen
- Department of Biochemistry and Molecular Biology, Tulane University Health Science Center, New Orleans, LA 70112
| | - Wei Tian
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hong Liu
- Department of Biochemistry and Molecular Biology, Tulane University Health Science Center, New Orleans, LA 70112
| |
Collapse
|
15
|
Kixmoeller K, Allu PK, Black BE. The centromere comes into focus: from CENP-A nucleosomes to kinetochore connections with the spindle. Open Biol 2020; 10:200051. [PMID: 32516549 PMCID: PMC7333888 DOI: 10.1098/rsob.200051] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Eukaryotic chromosome segregation relies upon specific connections from DNA to the microtubule-based spindle that forms at cell division. The chromosomal locus that directs this process is the centromere, where a structure called the kinetochore forms upon entry into mitosis. Recent crystallography and single-particle electron microscopy have provided unprecedented high-resolution views of the molecular complexes involved in this process. The centromere is epigenetically specified by nucleosomes harbouring a histone H3 variant, CENP-A, and we review recent progress on how it differentiates centromeric chromatin from the rest of the chromosome, the biochemical pathway that mediates its assembly and how two non-histone components of the centromere specifically recognize CENP-A nucleosomes. The core centromeric nucleosome complex (CCNC) is required to recruit a 16-subunit complex termed the constitutive centromere associated network (CCAN), and we highlight recent structures reported of the budding yeast CCAN. Finally, the structures of multiple modular sub-complexes of the kinetochore have been solved at near-atomic resolution, providing insight into how connections are made to the CCAN on one end and to the spindle microtubules on the other. One can now build molecular models from the DNA through to the physical connections to microtubules.
Collapse
Affiliation(s)
- Kathryn Kixmoeller
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Graduate Program in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Praveen Kumar Allu
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ben E Black
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Graduate Program in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
16
|
Li T, Liu X, Xu B, Wu W, Zang Y, Li J, Wei L, Qian Y, Xu H, Xie M, Wang Q, Wang L. SKA1 regulates actin cytoskeleton remodelling via activating Cdc42 and influences the migration of pancreatic ductal adenocarcinoma cells. Cell Prolif 2020; 53:e12799. [PMID: 32232899 PMCID: PMC7162805 DOI: 10.1111/cpr.12799] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/08/2020] [Accepted: 03/04/2020] [Indexed: 12/29/2022] Open
Abstract
Objectives Spindle and kinetochore–associated protein 1(SKA1), originally identified as a protein essential for proper chromosome segregation, has been recently linked to multiple malignancies. This study aimed to explore the biological, clinical role and molecular mechanism of SKA1 in pancreatic carcinogenesis. Materials and Methods SKA1 expression was detected in 145 pancreatic ductal adenocarcinoma (PDAC) specimens by immunohistochemistry. Biological behaviour assays were used to determine the role of SKA1 in PDAC progression in vitro and in vivo. Using isobaric tags for relative and absolute quantitation (iTRAQ), SKA1’s downstream proteins were examined. Moreover, cytochalasin B and ZCL278 were used to explore the changes of SKA1‐induced signalling and cell morphology, with further confirmation by immunoblotting and immunofluorescence assays. Results Increased SKA1 expression was significantly correlated with tumour size and cellular differentiation degree in PDAC tissues. Furthermore, elevated levels of SKA1 reflected shorter overall survival (P = .019). As for biological behaviour, SKA1 acted as a tumour promotor in PDAC, overexpression of SKA1 facilitates cell proliferation, migration and invasion in vitro and in vivo. Mechanistically, we demonstrated that SKA1 enhanced pancreatic cancer aggressiveness by inhibiting G2/M arrest and regulating actin cytoskeleton organization via activating Cdc42. Conclusions This study revealed novel roles for SKA1 as an important regulator of actin cytoskeleton organization and an oncogene in PDAC cells, which may provide insights into developing novel therapeutics.
Collapse
Affiliation(s)
- Tong Li
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xu Liu
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bin Xu
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wei Wu
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi Zang
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Juanjuan Li
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lumin Wei
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuting Qian
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hui Xu
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mingping Xie
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qi Wang
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lifu Wang
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| |
Collapse
|
17
|
Huis In 't Veld PJ, Volkov VA, Stender ID, Musacchio A, Dogterom M. Molecular determinants of the Ska-Ndc80 interaction and their influence on microtubule tracking and force-coupling. eLife 2019; 8:49539. [PMID: 31804178 PMCID: PMC6927755 DOI: 10.7554/elife.49539] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 11/26/2019] [Indexed: 12/12/2022] Open
Abstract
Errorless chromosome segregation requires load-bearing attachments of the plus ends of spindle microtubules to chromosome structures named kinetochores. How these end-on kinetochore attachments are established following initial lateral contacts with the microtubule lattice is poorly understood. Two microtubule-binding complexes, the Ndc80 and Ska complexes, are important for efficient end-on coupling and may function as a unit in this process, but precise conditions for their interaction are unknown. Here, we report that the Ska-Ndc80 interaction is phosphorylation-dependent and does not require microtubules, applied force, or several previously identified functional determinants including the Ndc80-loop and the Ndc80-tail. Both the Ndc80-tail, which we reveal to be essential for microtubule end-tracking, and Ndc80-bound Ska stabilize microtubule ends in a stalled conformation. Modulation of force-coupling efficiency demonstrates that the duration of stalled microtubule disassembly predicts whether a microtubule is stabilized and rescued by the kinetochore, likely reflecting a structural transition of the microtubule end.
Collapse
Affiliation(s)
- Pim J Huis In 't Veld
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Vladimir A Volkov
- Department of Bionanoscience, Faculty of Applied Sciences, Delft University of Technology, Delft, Netherlands
| | - Isabelle D Stender
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany.,Centre for Medical Biotechnology, Faculty of Biology, University Duisburg, Essen, Germany
| | - Marileen Dogterom
- Department of Bionanoscience, Faculty of Applied Sciences, Delft University of Technology, Delft, Netherlands
| |
Collapse
|
18
|
Amin MA, Agarwal S, Varma D. Mapping the kinetochore MAP functions required for stabilizing microtubule attachments to chromosomes during metaphase. Cytoskeleton (Hoboken) 2019; 76:398-412. [PMID: 31454167 DOI: 10.1002/cm.21559] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 08/07/2019] [Accepted: 08/22/2019] [Indexed: 12/24/2022]
Abstract
In mitosis, faithful chromosome segregation is orchestrated by the dynamic interactions between the spindle microtubules (MTs) emanating from the opposite poles and the kinetochores of the chromosomes. However, the precise mechanism that coordinates the coupling of the kinetochore components to dynamic MTs has been a long-standing question. Microtubule-associated proteins (MAPs) regulate MT nucleation and dynamics, MT-mediated transport and MT cross-linking in cells. During mitosis, MAPs play an essential role not only in determining spindle length, position, and orientation but also in facilitating robust kinetochore-microtubule (kMT) attachments by linking the kinetochores to spindle MTs efficiently. The stability of MTs imparted by the MAPs is critical to ensure accurate chromosome segregation. This review primarily focuses on the specific function of nonmotor kinetochore MAPs, their recruitment to kinetochores and their MT-binding properties. We also attempt to synthesize and strengthen our understanding of how these MAPs work in coordination with the kinetochore-bound Ndc80 complex (the key component at the MT-binding interface in metaphase and anaphase) to establish stable kMT attachments and control accurate chromosome segregation during mitosis.
Collapse
Affiliation(s)
- Mohammed A Amin
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Shivangi Agarwal
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Dileep Varma
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| |
Collapse
|
19
|
The mammalian kinetochore-microtubule interface: robust mechanics and computation with many microtubules. Curr Opin Cell Biol 2019; 60:60-67. [PMID: 31132675 DOI: 10.1016/j.ceb.2019.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 04/10/2019] [Accepted: 04/15/2019] [Indexed: 12/31/2022]
Abstract
The kinetochore drives chromosome segregation at cell division. It acts as a physical link between chromosomes and dynamic microtubules, and as a signaling hub detecting and processing microtubule attachments to control anaphase onset. The mammalian kinetochore is a large macromolecular machine that forms a dynamic interface with the many microtubules that it binds. While we know most of the kinetochore's component parts, how they work together to give rise to its robust functions remains poorly understood. Here we highlight recent findings that shed light on this question, driven by an expanding physical and molecular toolkit. We present emerging principles that underlie the kinetochore's robust microtubule grip, such as redundancy, specialization, and dynamicity, and present signal processing principles that connect this microtubule grip to robust computation. Throughout, we identify open questions, and define simple engineering concepts that provide insight into kinetochore function.
Collapse
|
20
|
Chakraborty M, Tarasovetc EV, Zaytsev AV, Godzi M, Figueiredo AC, Ataullakhanov FI, Grishchuk EL. Microtubule end conversion mediated by motors and diffusing proteins with no intrinsic microtubule end-binding activity. Nat Commun 2019; 10:1673. [PMID: 30975984 PMCID: PMC6459870 DOI: 10.1038/s41467-019-09411-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 02/28/2019] [Indexed: 01/31/2023] Open
Abstract
Accurate chromosome segregation relies on microtubule end conversion, the ill-understood ability of kinetochores to transit from lateral microtubule attachment to durable association with dynamic microtubule plus-ends. The molecular requirements for this conversion and the underlying biophysical mechanisms are elusive. We reconstituted end conversion in vitro using two kinetochore components: the plus end-directed kinesin CENP-E and microtubule-binding Ndc80 complex, combined on the surface of a microbead. The primary role of CENP-E is to ensure close proximity between Ndc80 complexes and the microtubule plus-end, whereas Ndc80 complexes provide lasting microtubule association by diffusing on the microtubule wall near its tip. Together, these proteins mediate robust plus-end coupling during several rounds of microtubule dynamics, in the absence of any specialized tip-binding or regulatory proteins. Using a Brownian dynamics model, we show that end conversion is an emergent property of multimolecular ensembles of microtubule wall-binding proteins with finely tuned force-dependent motility characteristics.
Collapse
Affiliation(s)
- Manas Chakraborty
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.,Centre for Mechanochemical Cell Biology, Warwick Medical School, Coventry, CV4 7AL, UK
| | - Ekaterina V Tarasovetc
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Anatoly V Zaytsev
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Maxim Godzi
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.,Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, 119991, Moscow, Russia
| | - Ana C Figueiredo
- Chromosome Instability & Dynamics Laboratory, Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal.,Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal
| | - Fazly I Ataullakhanov
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, 119991, Moscow, Russia.,Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, 117997, Russia.,Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, 141701, Russia
| | - Ekaterina L Grishchuk
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA. .,Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, 117997, Russia.
| |
Collapse
|
21
|
Moura M, Conde C. Phosphatases in Mitosis: Roles and Regulation. Biomolecules 2019; 9:E55. [PMID: 30736436 PMCID: PMC6406801 DOI: 10.3390/biom9020055] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/31/2019] [Accepted: 02/01/2019] [Indexed: 02/07/2023] Open
Abstract
Mitosis requires extensive rearrangement of cellular architecture and of subcellular structures so that replicated chromosomes can bind correctly to spindle microtubules and segregate towards opposite poles. This process originates two new daughter nuclei with equal genetic content and relies on highly-dynamic and tightly regulated phosphorylation of numerous cell cycle proteins. A burst in protein phosphorylation orchestrated by several conserved kinases occurs as cells go into and progress through mitosis. The opposing dephosphorylation events are catalyzed by a small set of protein phosphatases, whose importance for the accuracy of mitosis is becoming increasingly appreciated. This review will focus on the established and emerging roles of mitotic phosphatases, describe their structural and biochemical properties, and discuss recent advances in understanding the regulation of phosphatase activity and function.
Collapse
Affiliation(s)
- Margarida Moura
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
- i3S-Instituto de Investigação e Inovação em Saúde da Universidade do Porto, 4200-135, Porto, Portugal.
- Programa Doutoral em Biologia Molecular e Celular (MCbiology), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4050-313 Porto, Portugal.
| | - Carlos Conde
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
- i3S-Instituto de Investigação e Inovação em Saúde da Universidade do Porto, 4200-135, Porto, Portugal.
| |
Collapse
|
22
|
Monda JK, Cheeseman IM. The kinetochore-microtubule interface at a glance. J Cell Sci 2018; 131:131/16/jcs214577. [PMID: 30115751 DOI: 10.1242/jcs.214577] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Accurate chromosome segregation critically depends on the formation of attachments between microtubule polymers and each sister chromatid. The kinetochore is the macromolecular complex that assembles at the centromere of each chromosome during mitosis and serves as the link between the DNA and the microtubules. In this Cell Science at a Glance article and accompanying poster, we discuss the activities and molecular players that are involved in generating kinetochore-microtubule attachments, including the initial stages of lateral kinetochore-microtubule interactions and maturation to stabilized end-on attachments. We additionally explore the features that contribute to the ability of the kinetochore to track with dynamic microtubules. Finally, we examine the contributions of microtubule-associated proteins to the organization and stabilization of the mitotic spindle and the control of microtubule dynamics.
Collapse
Affiliation(s)
- Julie K Monda
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA.,Department of Biology, MIT, Cambridge, MA 02142, USA
| | - Iain M Cheeseman
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA .,Department of Biology, MIT, Cambridge, MA 02142, USA
| |
Collapse
|
23
|
Zhang Q, Chen Y, Yang L, Liu H. Multitasking Ska in Chromosome Segregation: Its Distinct Pools Might Specify Various Functions. Bioessays 2018; 40. [PMID: 29359816 DOI: 10.1002/bies.201700176] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 12/12/2017] [Indexed: 01/31/2023]
Abstract
The human spindle and kinetochore associated (Ska) complex is required for proper mitotic progression. Extensive studies have demonstrated its important functions in both stable kinetochore-microtubule interactions and spindle checkpoint silencing. We suggest a model to explain how various Ska functions might be fulfilled by distinct pools of Ska at kinetochores. The Ndc80-loop pool of Ska is recruited by the Ndc80 loop, or together with some of its flanking sequences, and the recruitment is also dependent on Cdk1-mediated Ska3 phosphorylation. This pool seems to play a more important role in silencing the spindle checkpoint than stabilizing kinetochore-microtubule interactions. In contrast, the Ndc80-N-terminus pool of Ska is recruited by the N-terminal domains of Ndc80 and appears to be more important for stabilizing kinetochore-microtubule interactions. Here, we review and discuss the evidence that supports this model and suggest further experiments to test the functioning mechanisms of the Ska complex.
Collapse
Affiliation(s)
- Qian Zhang
- Department of Biochemistry and Molecular Biology and Tulane Center for Aging, Tulane University Health Sciences Center, New Orleans, LA, 70112, USA
| | - Yujue Chen
- Department of Biochemistry and Molecular Biology and Tulane Center for Aging, Tulane University Health Sciences Center, New Orleans, LA, 70112, USA
| | - Lu Yang
- Department of Biochemistry and Molecular Biology and Tulane Center for Aging, Tulane University Health Sciences Center, New Orleans, LA, 70112, USA
| | - Hong Liu
- Department of Biochemistry and Molecular Biology and Tulane Center for Aging, Tulane University Health Sciences Center, New Orleans, LA, 70112, USA
| |
Collapse
|