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Philosophical Transactions of the Royal... Sep 2014The yeast spindle pole body (SPB) is the functional equivalent of the centrosome. Most SPB components have been identified and their functions partly established. This... (Review)
Review
The yeast spindle pole body (SPB) is the functional equivalent of the centrosome. Most SPB components have been identified and their functions partly established. This involved a large variety of techniques which are described here, and the potential use of some of these in the centrosome field is highlighted. In particular, very useful structural information on the SPB was obtained from a reconstituted complex, the γ-tubulin complex, and also from a sub-particle, SPB cores, prepared by extraction of an enriched SPB preparation. The labelling of SPB proteins with GFP at the N or C termini, using GFP tags inserted into the genome, gave informative electron microscopy localization and fluorescence resonance energy transfer data. Examples are given of more precise functional data obtained by removing domains from one SPB protein, Spc110p, without affecting its essential function. Finally, a structural model for SPB duplication is described and the differences between SPB and centrosome duplication discussed.
Topics: Calmodulin-Binding Proteins; Centrosome; Cytoskeletal Proteins; Fluorescence Resonance Energy Transfer; Green Fluorescent Proteins; Microscopy, Electron; Nuclear Proteins; Phenotype; Saccharomyces cerevisiae Proteins; Spindle Pole Bodies; Tubulin; Two-Hybrid System Techniques; Yeasts
PubMed: 25047610
DOI: 10.1098/rstb.2013.0456 -
Cells Jul 2018The centrosome is the major microtubule organizing centre (MTOC) in animal cells. The canonical centrosome is composed of two centrioles surrounded by a pericentriolar... (Review)
Review
The centrosome is the major microtubule organizing centre (MTOC) in animal cells. The canonical centrosome is composed of two centrioles surrounded by a pericentriolar matrix (PCM). In contrast, yeasts and amoebozoa have lost centrioles and possess acentriolar centrosomes—called the spindle pole body (SPB) and the nucleus-associated body (NAB), respectively. Despite the difference in their structures, centriolar centrosomes and SPBs not only share components but also common biogenesis regulators. In this review, we focus on the SPB and speculate how its structures evolved from the ancestral centrosome. Phylogenetic distribution of molecular components suggests that yeasts gained specific SPB components upon loss of centrioles but maintained PCM components associated with the structure. It is possible that the PCM structure remained even after centrosome remodelling due to its indispensable function to nucleate microtubules. We propose that the yeast SPB has been formed by a step-wise process; (1) an SPB-like precursor structure appeared on the ancestral centriolar centrosome; (2) it interacted with the PCM and the nuclear envelope; and (3) it replaced the roles of centrioles. Acentriolar centrosomes should continue to be a great model to understand how centrosomes evolved and how centrosome biogenesis is regulated.
PubMed: 29986477
DOI: 10.3390/cells7070071 -
Frontiers in Immunology 2022Tumor-associated macrophages (TAMs) are involved in the growth of prostate cancer (PrC), while the molecular mechanisms underlying the interactive crosstalk between TAM...
Tumor-associated macrophages (TAMs) are involved in the growth of prostate cancer (PrC), while the molecular mechanisms underlying the interactive crosstalk between TAM and PrC cells remain largely unknown. Platelet-derived growth factor (PDGF) is known to promote mesenchymal stromal cell chemotaxis to the tumor microenvironment. Recently, activation of spindle pole body component 25 (SPC25) has been shown to promote PrC cell proliferation and is associated with PrC stemness. Here, the relationship between SPC25 and PDGF in the crosstalk between TAM and PrC was investigated. Significant increases in both PDGF and SPC25 levels were detected in PrC specimens compared to paired adjacent normal prostate tissues. A significant correlation was detected between PDGF and SPC25 levels in PrC specimens and cell lines. SPC25 increased PDGF production and tumor cell growth in cultured PrC cells and in xenotransplantation. Mechanistically, SPC25 appeared to activate PDGF in PrC likely through Early Growth Response 1 (Egr1), while the secreted PDGF signaled to TAM through PDGFR on macrophages and polarized macrophages, which, in turn, induced the growth of PrC cells likely through their production and secretion of transforming growth factor β1 (TGFβ1). Thus, our data suggest that SPC25 triggers the crosstalk between TAM and PrC cells SPC25/PDGF/PDGFR/TGFβ1 receptor signaling to enhance PrC growth.
Topics: Cell Line, Tumor; Humans; Male; Microtubule-Associated Proteins; Platelet-Derived Growth Factor; Prostate; Prostatic Neoplasms; Receptor Cross-Talk; Receptors, Platelet-Derived Growth Factor; Signal Transduction; Spindle Pole Bodies; Transforming Growth Factor beta1; Tumor Microenvironment; Tumor-Associated Macrophages
PubMed: 35967419
DOI: 10.3389/fimmu.2022.907636 -
Philosophical Transactions of the Royal... Sep 2014Centrosomes-as well as the related spindle pole bodies (SPBs) of yeast-have been extensively studied from the perspective of their microtubule-organizing roles.... (Review)
Review
Centrosomes-as well as the related spindle pole bodies (SPBs) of yeast-have been extensively studied from the perspective of their microtubule-organizing roles. Moreover, the biogenesis and duplication of these organelles have been the subject of much attention, and the importance of centrosomes and the centriole-ciliary apparatus for human disease is well recognized. Much less developed is our understanding of another facet of centrosomes and SPBs, namely their possible role as signalling centres. Yet, many signalling components, including kinases and phosphatases, have been associated with centrosomes and spindle poles, giving rise to the hypothesis that these organelles might serve as hubs for the integration and coordination of signalling pathways. In this review, we discuss a number of selected studies that bear on this notion. We cover different processes (cell cycle control, development, DNA damage response) and organisms (yeast, invertebrates and vertebrates), but have made no attempt to be comprehensive. This field is still young and although the concept of centrosomes and SPBs as signalling centres is attractive, it remains primarily a concept-in need of further scrutiny. We hope that this review will stimulate thought and experimentation.
Topics: Animals; Cell Cycle; Centrosome; Humans; Mitosis; Models, Biological; Signal Transduction; Species Specificity; Spindle Pole Bodies; Yeasts
PubMed: 25047618
DOI: 10.1098/rstb.2013.0464 -
Annals of Translational Medicine Sep 2021Aberrant growth and polarization of microglia are critical for pathological initiation and progression of neurodegenerative conditions like Alzheimer's disease (AD)....
BACKGROUND
Aberrant growth and polarization of microglia are critical for pathological initiation and progression of neurodegenerative conditions like Alzheimer's disease (AD). However, the molecular signals that govern the outgrowth of microglia have not yet been fully determined. Spindle pole body component 25 (SPC25) is an important part for forming NDC80 complex, which plays a key role in the assembly of the microtubule-binding domain of kinetochores. Nevertheless, the role of SPC25 in microglial growth during neurodegeneration has not been described before, and was thus addressed in the current study.
METHODS
We generated an adeno-associated virus (AAV) serotype PHP.B carrying short hairpin RNA (shRNA) for SPC25 (shSPC25) under a microglia-specific TMEM119 promoter (AAV-pTMEM-shSPC25). Serotype PHP.B allowed the virus to cross blood-brain barrier, while TMEM119 promoter allowed specific targeting microglia in vitro and in vivo. We intravenously administrated AAV-pTMEM-shSPC25 to AD-prone APP/PS1 male and female mice and determined this effect on microglia proliferation and mouse behavior.
RESULTS
Depletion of SPC25 did not alter polarization of microglia cell polarization in vitro. On the other hand, AD-prone APP/PS1 mice that had received AAV-pTMEM-shSPC25 significantly decreased SPC25 levels in microglia and attenuated microglia proliferation, resulting in significant improvement of the performance of the mice in behavior tests.
CONCLUSIONS
Specific depletion of SPC25 in microglia may prevent AD development through suppression of microglia outgrowth. SPC25 may be a promising novel target for preventing AD through microglia.
PubMed: 34733984
DOI: 10.21037/atm-21-4064 -
Cold Spring Harbor Perspectives in... Feb 2015The centrosome was discovered in the late 19th century when mitosis was first described. Long recognized as a key organelle of the spindle pole, its core component, the... (Review)
Review
The centrosome was discovered in the late 19th century when mitosis was first described. Long recognized as a key organelle of the spindle pole, its core component, the centriole, was realized more than 50 or so years later also to comprise the basal body of the cilium. Here, we chart the more recent acquisition of a molecular understanding of centrosome structure and function. The strategies for gaining such knowledge were quickly developed in the yeasts to decipher the structure and function of their distinctive spindle pole bodies. Only within the past decade have studies with model eukaryotes and cultured cells brought a similar degree of sophistication to our understanding of the centrosome duplication cycle and the multiple roles of this organelle and its component parts in cell division and signaling. Now as we begin to understand these functions in the context of development, the way is being opened up for studies of the roles of centrosomes in human disease.
Topics: Animals; Centrosome; Cilia; Drosophila; Drosophila Proteins; Humans; Mice; Mitosis; Models, Biological; Protein Serine-Threonine Kinases; S Phase; Saccharomycetales; Spindle Apparatus; Xenopus laevis
PubMed: 25646378
DOI: 10.1101/cshperspect.a015800 -
Translational Andrology and Urology Apr 2022Androgen plays a critical role in the development and growth of prostate cancer (PCa) by binding to the androgen receptor, a steroid receptor for testosterone and...
BACKGROUND
Androgen plays a critical role in the development and growth of prostate cancer (PCa) by binding to the androgen receptor, a steroid receptor for testosterone and dihydrotestosterone (DHT). Androgen deprivation therapy, a clinical endocrine therapy, has resulted in increases in the occurrence of castration-resistant prostate cancer (CRPC); however, the mechanisms of CRPC have not yet fully been determined. We previously showed that spindle pole body component 25 (SPC25), a component of the NDC80 complex that is critical in kinetochore formation and chromosome segregation during the cell cycle, plays a critical role in PCa tumorigenesis and cancer stemness. However, it is not yet known whether SPC25 plays a role in CRPC; thus, we sought to address this question in the current study.
METHODS
SPC25 levels were detected in androgen-insensitive PCa cells using the public database and bioinformatics tools. In vitro, SPC25 levels were determined in androgen-sensitive and androgen-insensitive PCa cells treated with or without DHT. The growth of the PCa cells was assessed by the Cell Counting Kit-8 assay. The invasiveness and migratory potential of the PCa cells were assessed by the transwell cell invasive assay and migratory assay, respectively. Gain-of-function and loss-of-function experiments examined the transfection of androgen-sensitive and androgen-insensitive PCa cells by plasmids carrying small-interfering ribonucleic acids for SPC25 or SPC25, respectively.
RESULTS
SPC25 levels were significantly reduced in the androgen-insensitive PCa cells treated with DHT in the Public database. In vitro, PCa cell growth, invasion, and metastasis was reduced in androgen-insensitive PCa cells but increased in androgen-sensitive PCa cells treated with DHT, partially through DHT-regulated expression of SPC25 at transcriptional but not at translational levels.
CONCLUSIONS
Androgen treatment reduces CRPC growth, invasion, and metastasis partially through its regulation of SPC25. SPC25 represents a promising target in the treatment of CRPC.
PubMed: 35558271
DOI: 10.21037/tau-22-214 -
Cells May 2018The main microtubule organizing centre in the unicellular model organisms and is the spindle pole body (SPB). The SPB is a multilayer structure, which duplicates... (Review)
Review
The main microtubule organizing centre in the unicellular model organisms and is the spindle pole body (SPB). The SPB is a multilayer structure, which duplicates exactly once per cell cycle. Unlike higher eukaryotic cells, both yeast model organisms undergo mitosis without breakdown of the nuclear envelope (NE), a so-called closed mitosis. Therefore, in order to simultaneously nucleate nuclear and cytoplasmic MTs, it is vital to embed the SPB into the NE at least during mitosis, similarly to the nuclear pore complex (NPC). This review aims to embrace the current knowledge of the SPB duplication cycle with special emphasis on the critical step of the insertion of the new SPB into the NE.
PubMed: 29748517
DOI: 10.3390/cells7050042 -
Cells Nov 2018The centrosome is not only the largest and most sophisticated protein complex within a eukaryotic cell, in the light of evolution, it is also one of its most ancient...
The centrosome is not only the largest and most sophisticated protein complex within a eukaryotic cell, in the light of evolution, it is also one of its most ancient organelles. This special issue of "" features representatives of three main, structurally divergent centrosome types, i.e., centriole-containing centrosomes, yeast spindle pole bodies (SPBs), and amoebozoan nucleus-associated bodies (NABs). Here, I discuss their evolution and their key-functions in microtubule organization, mitosis, and cytokinesis. Furthermore, I provide a brief history of centrosome research and highlight recently emerged topics, such as the role of centrioles in ciliogenesis, the relationship of centrosomes and centriolar satellites, the integration of centrosomal structures into the nuclear envelope and the involvement of centrosomal components in non-centrosomal microtubule organization.
PubMed: 30413081
DOI: 10.3390/cells7110202 -
Molecular and Cellular Biology May 2016The yeast spindle pole body (SPB) is the functional equivalent of the mammalian centrosome. Centrosomes and SPBs duplicate exactly once per cell cycle by mechanisms that... (Review)
Review
The yeast spindle pole body (SPB) is the functional equivalent of the mammalian centrosome. Centrosomes and SPBs duplicate exactly once per cell cycle by mechanisms that use the mother structure as a platform for the assembly of the daughter. The conserved Sfi1 and centrin proteins are essential components of the SPB duplication process. Sfi1 is an elongated molecule that has, in its center, 20 to 23 binding sites for the Ca(2+)-binding protein centrin. In the yeastSaccharomyces cerevisiae, all Sfi1 N termini are in contact with the mother SPB whereas the free C termini are distal to it. During S phase and early mitosis, cyclin-dependent kinase 1 (Cdk1) phosphorylation of mainly serine residues in the Sfi1 C termini blocks the initiation of SPB duplication ("off" state). Upon anaphase onset, the phosphatase Cdc14 dephosphorylates Sfi1 ("on" state) to promote antiparallel and shifted incorporation of cytoplasmic Sfi1 molecules into the half-bridge layer, which thereby elongates into the bridge. The Sfi1 C termini of the two Sfi1 layers localize in the bridge center, whereas the N termini of the newly assembled Sfi1 molecules are distal to the mother SPB. These free Sfi1 N termini then assemble the new SPB in G1phase. Recruitment of Sfi1 molecules into the anaphase SPB and bridge formation were also observed inSchizosaccharomyces pombe, suggesting that the Sfi1 bridge cycle is conserved between the two organisms. Thus, restricting SPB duplication to one event per cell cycle requires only an oscillation between Cdk1 kinase and Cdc14 phosphatase activities. This clockwork regulates the "on"/"off" state of the Sfi1-centrin receiver.
Topics: Cell Cycle Proteins; Centrosome; Humans; Repressor Proteins; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Schizosaccharomyces; Schizosaccharomyces pombe Proteins; Spindle Apparatus; Spindle Pole Bodies; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 26951196
DOI: 10.1128/MCB.00048-16