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Zhu X, Wang P, Wei J, Li Y, Zhai J, Zheng T, Tao Q. Lysosomal degradation of the maternal dorsal determinant Hwa safeguards dorsal body axis formation. EMBO Rep 2021; 22:e53185. [PMID: 34652064 DOI: 10.15252/embr.202153185] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 09/15/2021] [Accepted: 09/29/2021] [Indexed: 01/09/2023] Open
Abstract
The Spemann and Mangold Organizer (SMO) is of fundamental importance for dorsal ventral body axis formation during vertebrate embryogenesis. Maternal Huluwa (Hwa) has been identified as the dorsal determinant that is both necessary and sufficient for SMO formation. However, it remains unclear how Hwa is regulated. Here, we report that the E3 ubiquitin ligase zinc and ring finger 3 (ZNRF3) is essential for restricting the spatial activity of Hwa and therefore correct SMO formation in Xenopus laevis. ZNRF3 interacts with and ubiquitinates Hwa, thereby regulating its lysosomal trafficking and protein stability. Perturbation of ZNRF3 leads to the accumulation of Hwa and induction of an ectopic axis in embryos. Ectopic expression of ZNRF3 promotes Hwa degradation and dampens the axis-inducing activity of Hwa. Thus, our findings identify a substrate of ZNRF3, but also highlight the importance of the regulation of Hwa temporospatial activity in body axis formation in vertebrate embryos.
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Affiliation(s)
- Xuechen Zhu
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China.,Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, China
| | - Pan Wang
- Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.,Beijing Advanced Innovation Center for Structural Biology, Beijing, China
| | - Jiale Wei
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yongyu Li
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jiayu Zhai
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Tianrui Zheng
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Qinghua Tao
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China.,Beijing Advanced Innovation Center for Structural Biology, Beijing, China
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2
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Kim K, Yoshinaga N, Bhattacharyya S, Nakazawa H, Umetsu M, Teizer W. Large-scale chirality in an active layer of microtubules and kinesin motor proteins. SOFT MATTER 2018; 14:3221-3231. [PMID: 29670958 DOI: 10.1039/c7sm02298k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
During the early developmental process of organisms, the formation of left-right laterality requires a subtle mechanism, as it is associated with other principal body axes. Any inherent chiral feature in an egg cell can in principal trigger this spontaneous breaking of chiral symmetry. Individual microtubules, major cytoskeletal filaments, are known as chiral objects. However, to date there lacks convincing evidence of a hierarchical connection of the molecular nature of microtubules to large-scale chirality, particularly at the length scale of an entire cell. Here we assemble an in vitro active layer, consisting of microtubules and kinesin motor proteins, on a glass surface. Upon inclusion of methyl cellulose, the layered system exhibits a long-range active nematic phase, characterized by the global alignment of gliding MTs. This nematic order spans over the entire system size in the millimeter range and, remarkably, allows hidden collective chirality to emerge as counterclockwise global rotation of the active MT layer. The analysis based on our theoretical model suggests that the emerging global nematic order results from the local alignment of MTs, stabilized by methyl cellulose. It also suggests that the global rotation arises from the MTs' intrinsic curvature, leading to preferential handedness. Given its flexibility, this layered in vitro cytoskeletal system enables the study of membranous protein behavior responsible for important cellular developmental processes.
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Affiliation(s)
- Kyongwan Kim
- WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan
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3
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Beloussov LV. Morphogenesis can be driven by properly parametrised mechanical feedback. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2013; 36:132. [PMID: 24264054 DOI: 10.1140/epje/i2013-13132-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 06/23/2013] [Accepted: 10/15/2013] [Indexed: 06/02/2023]
Abstract
A fundamental problem of morphogenesis is whether it presents itself as a succession of links that are each driven by its own specific cause-effect relationship, or whether all of the links can be embraced by a common law that is possible to formulate in physical terms. We suggest that a common biophysical background for most, if not all, morphogenetic processes is based upon feedback between mechanical stresses (MS) that are imposed to a given part of a developing embryo by its other parts and MS that are actively generated within that part. The latter are directed toward hyper-restoration (restoration with an overshoot) of the initial MS values. We show that under mechanical constraints imposed by other parts, these tendencies drive forth development. To provide specificity for morphogenetic reactions, this feedback should be modulated by long-term parameters and/or initial conditions that are set up by genetic factors. The experimental and model data related to this concept are reviewed.
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Affiliation(s)
- L V Beloussov
- Laboratory of Developmental Biophysics, Faculty of Biology, Moscow State University, 119992, Moscow, Russia,
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4
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Beloussov LV. Morphogenesis as a macroscopic self-organizing process. Biosystems 2012; 109:262-79. [PMID: 22609495 DOI: 10.1016/j.biosystems.2012.05.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 04/26/2012] [Accepted: 05/09/2012] [Indexed: 01/11/2023]
Abstract
We start from reviewing different epistemological constructions used for explaining morphogenesis. Among them, we explore the explanatory power of a law-centered approach which includes top-down causation and the basic concepts of a self-organization theory. Within such a framework, we discuss the morphomechanical models based upon the presumption of feedbacks between mechanical stresses imposed onto a given embryo part from outside and those generated within the latter as a kind of active response. A number of elementary morphogenetic events demonstrating that these feedbacks are directed towards hyper-restoration (restoration with an overshoot) of the initial state of mechanical stresses are described. Moreover, we show that these reactions are bound together into the larger scale feedbacks. That permits to suggest a reconstruction of morphogenetic successions in early Metazoan development concentrated around two main archetypes distinguished by the blastopores geometry. The perspectives of applying the same approach to cell differentiation are outlined. By discussing the problem of positional information we suggest that the developmental pathway of a given embryo part depends upon its preceded deformations and the corresponding mechanical stresses rather than upon its static position at any moment of development.
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Affiliation(s)
- Lev V Beloussov
- Laboratory of Developmental Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia.
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5
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Becker BE, Gard DL. Visualization of the cytoskeleton in Xenopus oocytes and eggs by confocal immunofluorescence microscopy. Methods Mol Biol 2006; 322:69-86. [PMID: 16739717 DOI: 10.1007/978-1-59745-000-3_6] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Xelopus oocytes and eggs are popular models for studying the developmental and cellular mechanisms of RNA localization, axis specification and establishment, and nuclear envelope assembly/disassembly. However, their large size and opacity hamper application of many techniques commonly used for studying cell structure and organization, including immunofluorescence and other techniques of fluorescence microscopy. In this chapter, we describe techniques and procedures that we have used to preserve, stain, and view the cytoskeleton in Xenopus oocytes and eggs by confocal immunofluorescence microscopy.
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Affiliation(s)
- Bret E Becker
- Department of Biology, University of Utah, East Salt Lake City, USA
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6
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Abstract
A long-standing question in developmental biology is how amphibians establish a dorsoventral axis. The prevailing view has been that cortical rotation is used to move a dorsalizing activity from the bottom of the egg towards the future dorsal side. We review recent evidence that kinesin-dependent movement of particles containing components of the Wnt intracellular pathway contributes to the formation of the dorsal organizer, and suggest that cortical rotation functions to align and orient microtubules, thereby establishing the direction of particle transport. We propose a new model in which active particle transport and cortical rotation cooperate to generate a robust movement of dorsal determinants towards the future dorsal side of the embryo.
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Affiliation(s)
- Carole Weaver
- Department of Biochemistry, Box 357350, University of Washington, Seattle, WA 98195-7350, USA
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Marrari Y, Rouvière C, Houliston E. Complementary roles for dynein and kinesins in the Xenopus egg cortical rotation. Dev Biol 2004; 271:38-48. [PMID: 15196948 DOI: 10.1016/j.ydbio.2004.03.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2004] [Revised: 03/10/2004] [Accepted: 03/11/2004] [Indexed: 01/01/2023]
Abstract
Aligned vegetal subcortical microtubules in fertilized Xenopus eggs mediate the "cortical rotation", a translocation of the vegetal cortex and of dorsalizing factors toward the egg equator. Kinesin-related protein (KRP) function is essential for the cortical rotation, and dynein has been implicated indirectly; however, the role of neither microtubule motor protein family is understood. We examined the consequence of inhibiting dynein--dynactin-based transport by microinjection of excess dynamitin beneath the vegetal egg surface. Dynamitin introduced before the cortical rotation prevented formation of the subcortical array, blocking microtubule incorporation from deeper regions. In contrast, dynamitin injected after the microtubule array was fully established did not block cortical translocation, unlike inhibitory-KRP antibodies. During an early phase of cortical rotation, when microtubules showed a distinctive wavy organization, dynamitin disrupted microtubule alignment and perturbed cortical movement. These findings indicate that dynein is required for formation and early maintenance of the vegetal microtubule array, while KRPs are largely responsible for displacing the cortex once the microtubule tracks are established. Consistent with this model for the cortical rotation, photobleach analysis revealed both microtubules that translocated with the vegetal cytoplasm relative to the cortex, and ones that moved with the cortex relative to the cytoplasm.
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Affiliation(s)
- Yannick Marrari
- Unité de Biologie du Développement, UMR 7009 CNRS/Université Paris VI, Observatoire Océanologique, 06230 Villefranche sur mer, France
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Clarke EJ, Allan VJ. Cytokeratin intermediate filament organisation and dynamics in the vegetal cortex of living Xenopus laevis oocytes and eggs. CELL MOTILITY AND THE CYTOSKELETON 2003; 56:13-26. [PMID: 12905528 DOI: 10.1002/cm.10131] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Cytokeratin intermediate filaments are prominent constituents of developing Xenopus oocytes and eggs, forming radial and cortical networks. In order to investigate the dynamics of the cortical cytokeratin network, we expressed EGFP-tagged Xenopus cytokeratin 1(8) in oocytes and eggs. The EGFP-cytokeratin co-assembled with endogenous partner cytokeratin proteins to form fluorescent filaments. Using time-lapse confocal microscopy, cytokeratin filament assembly was monitored in live Xenopus oocytes at different stages of oogenesis, and in the artificially-activated mature egg during the first cell cycle. In stage III to V oocytes, cytokeratin proteins formed a loose cortical geodesic network, which became more tightly bundled in stage VI oocytes. Maturation of oocytes into metaphase II-arrested eggs induced disassembly of the EGFP-cytokeratin network. Imaging live eggs after artificial activation allowed us to observe the reassembly of cytokeratin filaments in the vegetal cortex. The earliest observable structures were loose foci, which then extended into curly filament bundles. The position and orientation of these bundles altered with time, suggesting that forces were acting upon them. During cortical rotation, the cytokeratin network realigned into a parallel array that translocated in a directed manner at 5 microm/minute, relative to stationary cortex. The cytokeratin filaments are, therefore, moving in association with the bulk cytoplasm of the egg, suggesting that they may provide a structural role at the moving interface between cortex and cytoplasm.
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Affiliation(s)
- Emma J Clarke
- School of Biological Sciences, University of Manchester, Manchester, United Kingdom
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9
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Gard DL. Confocal fluorescence microscopy of the cytoskeleton of amphibian oocytes and embryos. Methods Cell Biol 2003; 70:379-416. [PMID: 12512330 DOI: 10.1016/s0091-679x(02)70011-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Affiliation(s)
- David L Gard
- Department of Biology, University of Utah, Salt Lake City, Utah 84112, USA
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Marrari Y, Clarke EJ, Rouvière C, Houliston E. Analysis of microtubule movement on isolated Xenopus egg cortices provides evidence that the cortical rotation involves dynein as well as Kinesin Related Proteins and is regulated by local microtubule polymerisation. Dev Biol 2003; 257:55-70. [PMID: 12710957 DOI: 10.1016/s0012-1606(03)00057-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In amphibians, the cortical rotation, a translocation of the egg cortex relative to the cytoplasm, specifies the dorsoventral axis. The cortical rotation involves an array of subcortical microtubules whose alignment is mediated by Kinesin-related proteins (KRPs), and stops as M-phase promoting factor (MPF) activation propagates across the egg. To dissect the role of different motor proteins in the cortical rotation and to analyse their regulation, we have developed an open cell assay system involving reactivation of microtubule movement on isolated cortices. Microtubule movements were dependent on ATP and consisted mainly of wriggling and flailing without net displacement, consistent with a tethering of microtubules to the cortex. Reactivated movements were inhibited by anti-KRP and anti-dynein antibodies perfused together but not separately, the KRP antibody alone becoming fixed to the cortex. Neither antibody could inhibit movement in the presence of MPF, indicating that arrest of the cortical rotation is not due to MPF-dependent inhibition of motor molecules. In contrast, D(2)O treatment of live eggs to protect microtubules from progressive depolymerisation prolonged the cortical rotation. We conclude that the cortical rotation probably involves cytoplasmic dynein as well as cortical KRPs and terminates as a result of local MPF-dependent microtubule depolymerisation.
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Affiliation(s)
- Yannick Marrari
- Unité de Biologie du Développement, UMR 7009 CNRS/Université Paris VI, Observatoire Océanologique, 06230, Villefranche-Sur-Mer, France.
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11
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St Amand AL, Klymkowsky MW. Cadherins and catenins, Wnts and SOXs: embryonic patterning in Xenopus. INTERNATIONAL REVIEW OF CYTOLOGY 2001; 203:291-355. [PMID: 11131519 DOI: 10.1016/s0074-7696(01)03010-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Wnt signaling plays a critical role in a wide range of developmental and oncogenic processes. Altered gene regulation by the canonical Wnt signaling pathway involves the cytoplasmic stabilization of beta-catenin, a protein critical to the assembly of cadherin-based cell-cell adherence junctions. In addition to binding to cadherins, beta-catenin also interacts with transcription factors of the TCF-subfamily of HMG box proteins and regulates their activity. The Xenopus embryo has proven to be a particularly powerful experimental system in which to study the role of Wnt signaling components in development and differentiation. We review this literature, focusing on the role of Wnt signaling and interacting components in establishing patterns within the early embryo.
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Affiliation(s)
- A L St Amand
- Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder 80309, USA
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12
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Becker BE, Gard DL. Multiple isoforms of the high molecular weight microtubule associated protein XMAP215 are expressed during development in Xenopus. CELL MOTILITY AND THE CYTOSKELETON 2000; 47:282-95. [PMID: 11093249 DOI: 10.1002/1097-0169(200012)47:4<282::aid-cm3>3.0.co;2-e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We have cloned and sequenced cDNAs encoding two isoforms of XMAP215, a high molecular weight microtubule-associated protein identified in Xenopus eggs. XMAP215 is approximately 80% identical in amino acid sequence to the product of ch-TOG, a cDNA that is over expressed in certain human tumors [Charrasse et al., 1995: Eur J Biochem 234:406-413]. Northern and Western blots demonstrated that XMAP215 is expressed throughout development, from oogenesis to tadpole. We identified two XMAP215 transcripts differing only in the presence of a 108-bp sequence encoding a 36 amino acid insert. RT-PCR revealed that the transcripts encoding these two isoforms are expressed at distinct times during development: a transcript containing the insert (encoding XMAP215(M)) is expressed during oogenesis and is present through gastrulation. The second transcript (encoding XMAP215(Z)) lacks the 108-bp insert and is expressed from gastrulation onward. In situ hybridization demonstrated that XMAP215 transcripts are localized to the ectoderm of early embryos and in the developing nervous system during later development. These results suggest that XMAP215 plays important roles in at least two phases of development: (1) regulating the assembly of MTs during the rapid cell divisions after fertilization, and (2) regulating MT assembly during the development of the nervous system.
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Affiliation(s)
- B E Becker
- Department of Biology, University of Utah, Salt Lake City
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13
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Marrari Y, Terasaki M, Arrowsmith V, Houliston E. Local inhibition of cortical rotation in Xenopus eggs by an anti-KRP antibody. Dev Biol 2000; 224:250-62. [PMID: 10926764 DOI: 10.1006/dbio.2000.9773] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The dorsal-ventral axis of amphibian embryos is specified by the "cortical rotation," a translocation of the egg cortex relative to the vegetal yolk mass. The mechanism of cortical rotation is not understood but is thought to involve an array of aligned, commonly oriented microtubules. We have demonstrated an essential requirement for kinesin-related proteins (KRPs) in the cortical rotation by microinjection beneath the vegetal cortex of an antipeptide antibody recognising multiple Xenopus egg KRPs. Time-lapse videomicroscopy revealed a striking local inhibition of the cortical rotation around the injection site, indicating that KRP-mediated translocation of the cortex is generated by forces acting across the vegetal subcortical region. Anti-tubulin immunofluorescence showed that the antibody disrupted both formation and maintenance of the aligned microtubule array. Direct examination of rhodamine-labelled microtubules by confocal microscopy showed that the anti-KRP antibody provoked striking three-dimensional flailing movement of the subcortical microtubules. In contrast, microtubules in antibody-free regions undulated only within the plane of the cortex, a significant population exhibiting little or no net movement. These findings suggest that KRPs have a critical role during cortical rotation in tethering microtubules to the cortex and that they may not contribute significantly to the translocation force as previously thought.
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Affiliation(s)
- Y Marrari
- Unité de Biologie du Développement, UMR 7009 CNRS/, Université Paris VI, Station Zoologique, Villefranche-sur-mer, France
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Cha B, Cassimeris L, Gard DL. XMAP230 is required for normal spindle assembly in vivo and in vitro. J Cell Sci 1999; 112 ( Pt 23):4337-46. [PMID: 10564651 DOI: 10.1242/jcs.112.23.4337] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
XMAP230 is a high molecular mass microtubule-associated protein isolated from Xenopus oocytes and eggs, and has been recently shown to be a homolog of mammalian MAP4. Confocal immunofluorescence microscopy revealed that XMAP230 is associated with microtubules throughout the cell cycle of early Xenopus embryos. During interphase XMAP230 is associated with the radial arrays of microtubules and midbodies remaining from the previous division. During mitosis, XMAP230 is associated with both astral microtubules and microtubules of the central spindle. Microinjection of affinity-purified anti-XMAP230 antibody into blastomeres severely disrupted the assembly of mitotic spindles during the rapid cleavage cycles of early development. Both monopolar half spindles and bipolar spindles were assembled from XMAP230-depleted extracts in vitro. However, spindles assembled in XMAP230-depleted extracts exhibited a reduction in spindle width, reduced microtubule density, chromosome loss, and reduced acetylation of spindle MTs. Similar defects were observed in the spindles assembled in XMAP230-depleted extracts that had been cycled through interphase. Depletion of XMAP230 had no effect on the pole-to-pole length of spindles, and depletion of XMAP230 from both interphase and M-phase extracts had no effect on the rate of microtubule elongation. From these results, we conclude that XMAP230 plays an important role in normal spindle assembly, primarily by acting to stabilize spindle microtubules, and that the observed defects in spindle assembly may result from enhanced microtubule dynamics in XMAP230-depleted extracts.
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Affiliation(s)
- B Cha
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA
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