Centrosome replication in hydroxyurea-arrested CHO cells expressing GFP-tagged centrin2

Kuriyama, Ryoko; Terada, Yasuhiko; Lee, Kyung S.; Wang, Christopher L. C.

doi:10.1242/jcs.008938

Cited by 33 publications

(32 citation statements)

References 35 publications

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“…5) and centrosome and nuclear defects. This suggests that RFP-DdCenB is functionally active and is concordant with previous reports on functionally active N-terminal GFP fusions of centrins in other organisms (2,27,54,60).…”

Section: Discussionsupporting

confidence: 92%

Dictyostelium discoideum CenB Is a Bona Fide Centrin Essential for Nuclear Architecture and Centrosome Stability

2009

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Centrins are a family of proteins within the calcium-binding EF-hand superfamily. In addition to their archetypical role at the microtubule organizing center (MTOC), centrins have acquired multiple functionalities throughout the course of evolution. For example, centrins have been linked to different nuclear activities, including mRNA export and DNA repair. Dictyostelium discoideum centrin B is a divergent member of the centrin family. At the amino acid level, DdCenB shows 51% identity with its closest relative and only paralog, DdCenA. Phylogenetic analysis revealed that DdCenB and DdCenA form a well-supported monophyletic and divergent group within the centrin family of proteins. Interestingly, fluorescently tagged versions of DdCenB were not found at the centrosome (in whole cells or in isolated centrosomes). Instead, DdCenB localized to the nuclei of interphase cells. This localization disappeared as the cells entered mitosis, although Dictyostelium cells undergo a closed mitosis in which the nuclear envelope (NE) does not break down. DdCenB knockout cells exhibited aberrant nuclear architecture, characterized by enlarged and deformed nuclei and loss of proper centrosome-nucleus anchoring (observed as NE protrusions). At the centrosome, loss of DdCenB resulted in defects in the organization and morphology of the MTOC and supernumerary centrosomes and centrosomerelated bodies. The multiple defects that the loss of DdCenB generated at the centrosome can be explained by its atypical division cycle, transitioning into the NE as it divides at mitosis. On the basis of these findings, we propose that DdCenB is required at interphase to maintain proper nuclear architecture, and before delocalizing from the nucleus, DdCenB is part of the centrosome duplication machinery.

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Section: Discussionsupporting

confidence: 92%

Dictyostelium discoideum CenB Is a Bona Fide Centrin Essential for Nuclear Architecture and Centrosome Stability

2009

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“…The presence of multiple centrosomes can then lead to the formation of multipolar spindles and, consequently, a defect in chromosome segregation. This significantly impairs progression through mitosis (owing to the activation of the SAC) (Kuriyama et al, 2007). A similar effect can be observed in Xenopus laevis egg extracts arrested with an inhibitor of DNA synthesis (Hinchcliffe et al, 1999).…”

Section: Chromosomal Instability In Tetraploid Cellsmentioning

confidence: 66%

The consequences of tetraploidy and aneuploidy

Storchová

Kuffer

2008

Journal of Cell Science

327

323

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Polyploidy, an increased number of chromosome sets, is a surprisingly common phenomenon in nature, particularly in plants and fungi. In humans, polyploidy often occurs in specific tissues as part of terminal differentiation. Changes in ploidy can also result from pathophysiological events that are caused by viral-induced cell fusion or erroneous cell division. Tetraploidization can initiate chromosomal instability (CIN), probably owing to supernumerary centrosomes and the doubled chromosome mass. CIN, in turn, might persist or soon give way to a stably propagating but aneuploid karyotype. Both CIN and stable aneuploidy are commonly observed in cancers. Recently, it has been proposed that an increased number of chromosome sets can promote cell transformation and give rise to an aneuploid tumor. Here, we review how tetraploidy can occur and describe the cellular responses to increased ploidy. Furthermore, we discuss how the specific physiological changes that are triggered by polyploidization might be used as novel targets for cancer therapy. Tetraploid cells can also be created after an aberrant cell division. During mitosis, the chromosomes attach via proteinaceous structures called kinetochores to spindle microtubules that emanate from MTOCs (Box 1). This enables cells to segregate their chromosomes evenly into two daughter cells. Spindle-assembly checkpoint (SAC) activity holds back the onset of anaphase until all kinetochores are properly attached (Musacchio and Salmon, 2007). If there is a persistent error, the cell can escape SAC arrest (Brito and Rieder, 2006) and exit from mitosis without undergoing anaphase or cytokinesis, thereby producing a tetraploid cell with a single nucleus and two centrosomes (Azeddine et al., 1998;Lanni and Jacks, 1998). This so-called 'mitotic slippage' also occurs in cells that have an altered SAC, such as mouse embryonic fibroblasts (MEFs), which overexpress the SAC gene Mad2 (mitotic-arrest deficient 2) (Sotillo et al., 2007).In addition, cells that have entered anaphase might fail to finalize cell division. Cytokinesis might fail owing to a disturbance of cleavage-furrow formation, which occurs when bulk chromatin (Mullins and Biesele, 1977), or even a single lagging chromosome, is trapped in the cleavage furrow (Shi and King, 2005). The result is a single binucleated cell with two centrosomes. Abnormal spindle positioning and movements might also interfere with cytokinesis and lead to the accumulation of tetraploid cells, as has been observed, for example, in cells with deregulated integrin functions that inhibited spindle assembly (Reverte et al., 2006).The list of mechanisms that lead to tetraploidy is growing, and raises the issue of how frequently unscheduled tetraploidization occurs in normal tissues. Although difficult to estimate, tetraploid cells can be found with variable frequencies (0.5-20%) in nearly every human tissue (Biesterfeld et al., 1994), suggesting that tetraploidization is a more common process than was previously thought. In fact, spontaneous unsched...

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“…The Cep57 depletion increased the percentage of cells with unduplicated centrioles (≤ 2 per cell) compared with the controls (Supplementary information, Figure S3A). Moreover, depletion of Cep57 markedly suppressed the centriole over-amplification induced by hydroxyurea (HU) (Supplementary information, Figure S3B and S3C), which could uncouple the centrosome duplication cycle from the cell cycle [23]. Furthermore, the majority of Cep57-depleted cells did not show extra centrosomes during interphase (Supplementary information, Figure S3A), indicating that multipolar spindle formation was not a consequence of centriole over-duplication and cytokinesis failure.…”

Section: Depletion Of Cep57 Causes Spindle Pole Fragmentationmentioning

confidence: 98%

Cep57, a NEDD1-binding pericentriolar material component, is essential for spindle pole integrity

Zhou

et al. 2012

Cell Res

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Formation of a bipolar spindle is indispensable for faithful chromosome segregation and cell division. Spindle integrity is largely dependent on the centrosome and the microtubule network. Centrosome protein Cep57 can bundle microtubules in mammalian cells. Its related protein (Cep57R) in Xenopus was characterized as a stabilization factor for microtubule-kinetochore attachment. Here we show that Cep57 is a pericentriolar material (PCM) component. Its interaction with NEDD1 is necessary for the centrosome localization of Cep57. Depletion of Cep57 leads to unaligned chromosomes and a multipolar spindle, which is induced by PCM fragmentation. In the absence of Cep57, centrosome microtubule array assembly activity is weakened, and the spindle length and microtubule density decrease. As a spindle microtubule-binding protein, Cep57 is also responsible for the proper organization of the spindle microtubule and localization of spindle pole focusing proteins. Collectively, these results suggest that Cep57, as a NEDD1-binding centrosome component, could function as a spindle pole-and microtubule-stabilizing factor for establishing robust spindle architecture.

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Centrosome replication in hydroxyurea-arrested CHO cells expressing GFP-tagged centrin2

Cited by 33 publications

References 35 publications

Dictyostelium discoideum CenB Is a Bona Fide Centrin Essential for Nuclear Architecture and Centrosome Stability

Dictyostelium discoideum CenB Is a Bona Fide Centrin Essential for Nuclear Architecture and Centrosome Stability

The consequences of tetraploidy and aneuploidy

Cep57, a NEDD1-binding pericentriolar material component, is essential for spindle pole integrity

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