Claudio E Sunkel

Claudio E Sunkel
University of Porto | UP · Instituto de Investigação e Inovação em Saúde

PhD

About

190
Publications
16,013
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
6,705
Citations
Additional affiliations
September 1997 - present
Institute for Molecular and Cell Biology
Position
  • Managing Director

Publications

Publications (190)
Preprint
Full-text available
Protein phosphatase 1 (PP1) is essential for spindle assembly checkpoint (SAC) silencing and mitotic exit, but its regulation during mitosis remains ill-defined. Here, we demonstrate in vitro and in Drosophila cells that the mitotic kinase POLO phosphorylates PP1α87B at a conserved residue (T286) within a pocket implicated in the recognition of RVx...
Preprint
Faithfull cell division relies on mitotic chromosomes becoming bioriented with each pair of sister kinetochores bound to microtubules oriented toward opposing spindle poles. Erroneous kinetochore-microtubule attachments often form during early mitosis, but are destabilized through the phosphorylation of outer kinetochore proteins by centromeric AUR...
Article
Full-text available
Barbosa et al. discuss work by Mussachio and colleagues (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202206131) finding that conformational changes in the DYNEIN adaptor SPINDLY can precisely control DYNEIN activation at kinetochores.
Article
Full-text available
Apical-basal polarity is an essential epithelial trait controlled by the evolutionarily conserved PAR-aPKC polarity network. Dysregulation of polarity proteins disrupts tissue organization during development and in disease, but the underlying mechanisms are unclear due to the broad implications of polarity loss. Here, we uncover how Drosophila aPKC...
Preprint
Full-text available
Apical-basal polarity is an essential epithelial trait controlled by the evolutionarily conserved PAR-aPKC polarity network. Deregulation of polarity proteins disrupts tissue organization during development and in disease, but the underlying mechanisms are unclear due to the broad implications of polarity loss. Here, we uncovered how Drosophila aPK...
Article
Full-text available
During mitosis, the interaction of kinetochores (KTs) with microtubules (MTs) drives chromosome congression to the spindle equator and supports the segregation of sister chromatids. Faithful genome partition critically relies on the ability of chromosomes to establish and maintain proper amphitelic end-on attachments, a configuration in which siste...
Article
Full-text available
Aneuploidy has been strongly linked to cancer development, and published evidence has suggested that aneuploidy can have an oncogenic or a tumor suppressor role depending on the tissue context. Using the Drosophila midgut as a model, we have recently described that adult intestinal stem cells (ISCs), do not activate programmed cell death upon aneup...
Article
To maintain genome stability, chromosomes must be equally distributed among daughter cells at the end of mitosis. The accuracy of chromosome segregation requires sister-kinetochores to stably attach to microtubules emanating from opposite spindle poles. However, initial kinetochore-microtubule interactions are able to turnover so that defective att...
Article
Full-text available
The spindle assembly checkpoint (SAC) relies on the recruitment of Mad1-C-Mad2 to unattached kinetochores but also on its binding to Megator/Tpr at nuclear pore complexes (NPCs) during interphase. However, the molecular underpinnings controlling the spatiotemporal redistribution of Mad1-C-Mad2 as cells progress into mitosis remain elusive. Here, we...
Article
Accurate chromosome segregation in mitosis requires sister kinetochores to bind to microtubules from opposite spindle poles. The stability of kinetochore-microtubule attachments is fine-tuned to prevent or correct erroneous attachments while preserving amphitelic interactions. Polo kinase has been implicated in both stabilizing and destabilizing ki...
Article
Full-text available
The cytoskeleton protein α-fodrin plays a major role in maintaining structural stability of membranes. It was also identified as part of the brain γ-tubulin ring complex, the major microtubule nucleator. Here, we investigated the requirement of α-fodrin for microtubule spindle assembly during mitotic progression. We found that α-fodrin depletion re...
Article
Full-text available
Alternative polyadenylation generates transcriptomic diversity, although the physiological impact and regulatory mechanisms involved are still poorly understood. The cell cycle kinase Polo is controlled by alternative polyadenylation in the 3′ untranslated region (3′UTR), with critical physiological consequences. Here, we characterized the molecula...
Article
The development of multicellular organisms and the maintenance of its tissues relies on mitosis. However, this process represents a major challenge for genomic stability as each time a cell division occurs there are multiple steps where errors can lead to an abnormal chromosomal content in daughter cells - aneuploidy. Aneuploidy was first postulate...
Preprint
Full-text available
The strength of the Spindle Assembly Checkpoint (SAC) depends on the amount of the Mad1-C-Mad2 heterotetramer at kinetochores but also on its binding to Megator/Tpr at nuclear pore complexes (NPCs) during interphase. However, the molecular underpinnings controlling the spatiotemporal redistribution of Mad1-C-Mad2 as cells progress into mitosis rema...
Article
Alternative polyadenylation generates transcriptomic diversity, although the physiological impact and regulatory mechanisms involved are still poorly understood. The cell cycle kinase Polo is controlled by alternative polyadenylation in the 3′UTR with critical physiological consequences. Here, we characterized the molecular mechanisms required for...
Article
Full-text available
Apical-basal polarity is a common trait that underlies epithelial function. Although the asymmetric distribution of cortical polarity proteins works in a functioning equilibrium, it also retains plasticity to accommodate cell division, during which the basolateral determinant Lgl is released from the cortex. Here, we investigated how Lgl restores i...
Article
Full-text available
Aneuploidy is associated with different human diseases including cancer. However, different cell types appear to respond differently to aneuploidy, either by promoting tumorigenesis or causing cell death. We set out to study the behavior of adult Drosophila melanogaster intestinal stem cells (ISCs) after induction of chromosome missegregation eithe...
Preprint
Aneuploidy is associated with different human diseases, particularly cancer, but how different cell types within tissues respond to aneuploidy is not fully understood. In some studies, aneuploidy has been shown to have a deleterious effect and lead to cell death, however it has also been shown to be a causal event of tumorigenesis in other contexts...
Data
Numerical data for Figure 1.DOI: http://dx.doi.org/10.7554/eLife.25366.003
Data
Numerical data for Figure 4.DOI: http://dx.doi.org/10.7554/eLife.25366.023
Data
Numerical data for Figure 5.DOI: http://dx.doi.org/10.7554/eLife.25366.029
Data
Numerical data for Figure 2.DOI: http://dx.doi.org/10.7554/eLife.25366.012
Data
Numerical data for Figure 3.DOI: http://dx.doi.org/10.7554/eLife.25366.018
Data
Numerical data for Figure 6.DOI: http://dx.doi.org/10.7554/eLife.25366.036
Article
Full-text available
Faithfull genome partitioning during cell division relies on the Spindle Assembly Checkpoint (SAC), a conserved signaling pathway that delays anaphase onset until all chromosomes are attached to spindle microtubules. Mps1 kinase is an upstream SAC regulator that promotes the assembly of an anaphase inhibitor through a sequential multi-target phosph...
Article
Full-text available
Kinesins are a superfamily of microtubule-based molecular motors that perform various transport needs and have essential roles in cell division. Among these, the kinesin-5 family has been shown to play a major role in the formation and maintenance of the bipolar mitotic spindle. Moreover, recent work suggests that kinesin-5 motors may have addition...
Article
Full-text available
> “On the wisdom with which we bring science to bear against the problems of the coming years depends in large measure our future…”[1] Vannevar Bush, 1945 The notion of “scientific excellence” has entered the vocabulary of scientists and funders and has embedded itself in the language of evaluation guidelines as part of a broader discourse about t...
Article
Mitotic spindle orientation is essential to control cell-fate specification and epithelial architecture [1]. The tumor suppressor Lgl localizes to the basolateral cortex of epithelial cells, where it acts together with Dlg and Scrib to organize apicobasal polarity [2]. Dlg and Scrib also control planar spindle orientation [3, 4], but how the organi...
Article
Kinetochores bind spindle microtubules and also act as signaling centers that monitor this interaction. Defects in kinetochore assembly lead to chromosome mis-segregation and aneuploidy. The interaction between microtubules and chromosomes involves a conserved super-complex of proteins, known as the KMN network, composed by the KNL1 (Spc105), Mis12...
Article
Full-text available
Maintenance of genomic stability during eukaryotic cell division relies on the Spindle Assembly Checkpoint (SAC), which has evolved as a surveillance mechanism that monitors kinetochore-microtubule attachment and prevents APC/C-mediated mitotic exit until all chromosomes are properly attached to the mitotic spindle. Reversible protein phosphorylati...
Article
Full-text available
Maintenance of genomic stability during eukaryotic cell division relies on the Spindle Assembly Checkpoint (SAC), which has evolved as a surveillance mechanism that monitors kinetochore-microtubule attachment and prevents APC/C-mediated mitotic exit until all chromosomes are properly attached to the mitotic spindle. Reversible protein phosphorylati...
Article
Full-text available
Abscission is the last step of cytokinesis that physically separates the cytoplasm of sister cells. As the final stage of cell division, abscission is poorly characterized during animal development. Here, we show that Aurora B and Survivin regulate the number of germ cells in each Drosophila egg chamber by inhibiting abscission during differentiati...
Article
Full-text available
Cytokinesis is asymmetric along the apical-basal axis of epithelial cells, positioning the midbody near the apical domain. However, little is known about the mechanism and purpose of this asymmetry. We use live imaging of Drosophila follicle cell division to show that asymmetric cytokinesis does not result from intrinsic polarization of the main co...
Article
Maintenance of genomic stability during eukaryotic cell division relies on the spindle assembly checkpoint (SAC) that prevents mitotic exit until all chromosomes are properly attached to the spindle. Polo is a mitotic kinase proposed to be involved in SAC function, but its role has remained elusive. We demonstrate that Polo and Aurora B functional...
Article
Full-text available
Most solid tumors contain aneuploid cells, indicating that the mitotic checkpoint is permissive to the proliferation of chromosomally aberrant cells. However, mutated or altered expression of mitotic checkpoint genes accounts for a minor proportion of human tumors. We describe a Drosophila melanogaster tumorigenesis model derived from knocking down...
Article
Full-text available
The first centromeric protein identified in any species was CENP-A, a divergent member of the histone H3 family that was recognised by autoantibodies from patients with scleroderma-spectrum disease. It has recently been suggested to rename this protein CenH3. Here, we argue that the original name should be maintained both because it is the basis of...
Article
Full-text available
Among all organisms, Drosophila melanogaster has the most extensive well-characterized collection of large-scale chromosome rearrangements. Compound chromosomes, rearrangements in which homologous chromosome arms share a centromere, have proven especially useful in genetic-based surveys of the entire genome. However, their potential has not been fu...
Article
Metaphase chromosome protein 1 (MCP1) is a nuclear autoantigen that is associated with condensed chromosomes throughout mitosis. During interphase, this antigen shows a speckle distribution in the nucleus, excluding the nucleolus. Additionally, MCP1 binds tightly to the scaffold/matrix component of nuclei and isolated chromosomes. In order to deter...
Article
Correct chromosome segregation during cell division requires bi-orientation at the mitotic spindle. Cells possess mechanisms to prevent and correct inappropriate chromosome attachment. Sister kinetochores assume a 'back-to-back' geometry on chromosomes that favors amphitelic orientation but the regulation of this process and molecular components ar...
Article
Full-text available
The pairing of homologous chromosomes and the intimate synapsis of the paired homologs by the synaptonemal complex (SC) are essential for subsequent meiotic processes including recombination and chromosome segregation. Here we show that the centromere clustering plays an important role in initiating homolog synapsis during meiosis in Drosophila fem...
Article
Full-text available
We have previously characterized an EMS-induced allele of the bubR1 gene (bubR1(D1326N)) that separates the two functions of BubR1, causing meiotic nondisjunction but retaining spindle assembly checkpoint activity during somatic cell division in Drosophila melanogaster. Using this allele, we demonstrate that bubR1 meiotic nondisjunction is dosage s...
Article
Full-text available
Regulated alternative polyadenylation is an important feature of gene expression, but how gene transcription rate affects this process remains to be investigated. polo is a cell-cycle gene that uses two poly(A) signals in the 3' untranslated region (UTR) to produce alternative messenger RNAs that differ in their 3'UTR length. Using a mutant Drosoph...
Data
Full-text available
List of primers used. (PDF)
Data
Overview of the meiosis-related genes studied. (PDF)
Data
Full-text available
Accession numbers for the 33 meiosis genes studied from 12 Drosophila species. (PDF)
Data
Coding sequence size and intron number (in brackets) of 33 meiosis genes from 12 Drosophila species. (PDF)
Article
Full-text available
Using a phylogenetic approach, the examination of 33 meiosis/meiosis-related genes in 12 Drosophila species, revealed nine independent gene duplications, involving the genes cav, mre11, meiS332, polo and mtrm. Evidence is provided that at least eight out of the nine gene duplicates are functional. Therefore, the rate at which Drosophila meiosis/mei...
Article
Centromeres are specialized chromosomal domains that direct mitotic kinetochore assembly and are defined by the presence of CENP-A (CID in Drosophila) and CENP-C. While the role of CENP-A appears to be highly conserved, functional studies in different organisms suggest that the precise role of CENP-C in kinetochore assembly is still under debate. P...
Article
The kinetochore is a complex molecular machine that serves as the interface between sister chromatids and the mitotic spindle. The kinetochore assembles at a particular chromosomal locus, the centromere, which is essential to maintain genomic stability during cell division. The kinetochore is a macromolecular puzzle of subcomplexes assembled in a h...
Article
A new series of 4-alkyl-1,4-dihydropyridines (1,4-DHP) were synthesized and evaluated for their ability to inhibit washed rabbit platelet aggregation induced by PAF-acether (1-O-hexadecyl/octadecyl-2-O-acetyl-sn-glycero-3-phosphorylcholine) and to reverse PAF-induced hypotension in anesthetized rats. Additionally, compounds were evaluated for their...
Article
Full-text available
Error-free chromosome segregation requires that all chromosomes biorient on the mitotic spindle. The motor protein Centromere-associated protein E (CENP-E) facilitates chromosome congression by mediating the lateral sliding of sister chromatids along existing K-fibers, while the mitotic kinase Aurora B detaches kinetochore-microtubule interactions...
Article
Full-text available
gamma-Tubulin is critical for the initiation and regulation of microtubule (MT) assembly. In Drosophila melanogaster, it acts within two main complexes: the gamma-tubulin small complex (gamma-TuSC) and the gamma-tubulin ring complex (gamma-TuRC). Proteins specific of the gamma-TuRC, although nonessential for viability, are required for efficient mi...
Article
Full-text available
Establishment and maintenance of the mitotic spindle requires the balanced activity of microtubule-associated proteins and motors. In this study we have addressed how the microtubule plus-end tracking protein mast/orbit/CLASP and cytoplasmic dynein regulate this process in Drosophila melanogaster embryos and S2 cells. We show that mast accumulates...
Article
Full-text available
A putative spindle matrix has been hypothesized to mediate chromosome motion, but its existence and functionality remain controversial. In this report, we show that Megator (Mtor), the Drosophila melanogaster counterpart of the human nuclear pore complex protein translocated promoter region (Tpr), and the spindle assembly checkpoint (SAC) protein M...
Article
Full-text available
Sgt1 was described previously in yeast and humans to be a Hsp90 co-chaperone and required for kinetochore assembly. We have identified a mutant allele of Sgt1 in Drosophila and characterized its function. Mutations in sgt1 do not affect overall kinetochore assembly or spindle assembly checkpoint. sgt1 mutant cells enter less frequently into mitosis...
Article
Full-text available
Chromosome segregation requires sister chromatid resolution. Condensins are essential for this process since they organize an axial structure where topoisomerase II can work. How sister chromatid separation is coordinated with chromosome condensation and decatenation activity remains unknown. We combined four-dimensional (4D) microscopy, RNA interf...
Data
Time-Lapse Confocal Microscopy of S2 Cells Stably Expressing CID-GFP and RFP-H2B Z-stacks were acquired every 30 s (time is shown in seconds). Each Z-stack is 10 μm and composed of ten optical sections. Anaphase onset corresponds to time 0 s. Merge color images of RFP-H2B (red) and CID-GFP (green) channels are shown on the left. The CID-GFP (white)...
Data
Time-Lapse Microscopy of S2 Cells Stably Expressing CID-GFP and RFP-H2B and Depleted for TOPO II, 72 h after the Addition of the dsRNA Z-stacks are composed of ten optical sections covering 10 μm and were acquired every 20 s. Each Z-stack is 10 μm and composed of ten optical sections. Anaphase onset corresponds to time 0 s. Merge color images of RF...
Data
Full-text available
Quantification of Sister Centromere Distance during Progression through Mitosis in TOPO II–Depleted Cells (A) Images from time-lapse recording of S2 cells stably expressing the centromere marker CID-mCherry (red and individual channel on the right) and GFP-α-tubulin. Z-stacks were collected in both control and TOPO II–depleted cells. (B) Quantifica...
Data
Full-text available
Characterization of Mitotic Exit after Depletion of TOPO II and RAD21 Progression through mitosis was determined using cyclin B to clearly determine exit from mitosis and also the earlier stages, such as prometaphase (72 h of treatment). Either (A) control or (B) TOPO II– and DRAD21-depleted cells were immunostained for cyclin B (green), CID (red),...
Data
Full-text available
Characterization of Mitotic Exit of TOPO II–Depleted Cells (A and B) Immunolocalization of cyclin B and CID in (A) control or (B) TOPO II–depleted cells. In both control and TOPO II–depleted cells, cyclin B localizes to the spindle, centromeres, and poles during prometaphase and metaphase. During anaphase, the overall level of cyclin B falls and is...
Data
Time-Lapse Microscopy of S2 cells Stably Expressing CID-GFP and RFP-H2B and Depleted for TOPO II, 96 h after the Addition of the dsRNA Z-stacks are composed of ten optical sections covering 10 μm and were acquired every 15 s. Anaphase onset corresponds to time 0 s. Merge color images for H2BRFP (red) and CID-GFP (green) is shown on the left. The se...
Data
Time-Lapse Microscopy of S2 Cells Stably Expressing GFP-α-Tubulin and CID-mCherry Z-stacks were acquired every 40 s. Each Z-stack is 10 μm and composed of ten optical sections. Anaphase onset corresponds to time 0 s. Merge color images for CID-mCherry (red) and GFP-α-tubulin (green) are shown on the left. On the right, the separated channel for CID...
Data
Time-Lapse Microscopy of S2 Cells Stably Expressing GFP-α-Tubulin and CID-mCherry That Were Depleted for TOPO II, 72 h after the Addition of the dsRNA Z-stacks were acquired every 40 s. Each Z-stack is 10 μm and is composed of ten optical sections. Anaphase onset corresponds to time 0 s. Merged color images for Cherry-CID (red) and GFP-α-tubulin (g...
Data
Time-Lapse Microscopy of S2 Cells Stably Expressing GFP-α-Tubulin and CID-mCherry Z-stacks were acquired every 30 s. Each Z-stack is 10 μm and composed of ten optical sections. Anaphase onset corresponds to time 0 s. Merge color images for CID-mCherry (red) and GFP-α-tubulin (green) is shown on the left. Separated channels for CID-GFP (black) and G...
Data
Time-Lapse Microscopy of S2 Cells Stably Expressing CID-GFP and RFP-H2B That Were Simultaneously Depleted of TOPO II and RAD21, 96 h after the Addition of the dsRNA Z-stacks were acquired every 15 s. Each Z-stack is 10 μm and is composed of ten optical sections. Anaphase onset corresponds to time 0 s. Merged color images for H2B- RFP (red) and CID-...
Data
Full-text available
In Vivo Analysis of Mitotic Progression after Depletion of RAD21 in S2 Cells (A and B) Progression through mitosis was determined using cyclin B (red) and α-tubulin and DNA (blue) for either (A) control or (B) RAD21-depleted cells. Scale bar represents 5 μm. (B) RAD21-depleted cells are delayed in mitosis, exhibiting separated sister chromatids. (C...
Data
Immunolocalization of PH3 and TOPO II in ICRF-187–Treated Cells (A) Control and (B) cells treated for 2 h with 10 μM ICRF-187, after which they were immunostained for Phospho-S10-histone H3 (green) and for TOPO II (blue). TOPO II and PH3 localized to the chromosomes both in control and treated cells, although a reduction in the levels of PH3 was de...
Data
Time-Lapse Microscopy of S2 Cells Stably Expressing CID-GFP and RFP-H2B and Depleted for TOPO II, 72 h after the Addition of the dsRNA Z-stacks are composed of ten optical sections covering 10 μm and were acquired every 15 s. Anaphase onset corresponds to time 0 s. Merge color images for H2B- RFP (red) and CID-GFP (green). (806 KB MOV)
Data
Full-text available
Analysis of Centromere Organization after Depletion of TOPO II. Immunolocalization of CID in S2 Cells Treated with Hypotonic Shock prior to Cell Fixation with two CID dots per chromosome (individual channel on the right). (B) In TOPO II–depleted cells, chromosomes are observed as larger clusters of chromatids with interconnecting chromatin and broa...
Data
Full-text available
Microtubule–Kinetochore Interaction in TOPO II–Depleted Cells (A and B) Immunofluorescence for α-tubulin (green), CID (red), and DNA (blue) in (A) control and (B) TOPO II–depleted cells subjected to the MG132-Taxol assay. (C) Quantification shows that a few chromosomes (≤3%; control, n = 35 cells; TOPO II dsRNAi, n = 38 cells), either in control or...
Data
Time-Lapse Microscopy of S2 Cells Stably Expressing GFP-α-Tubulin and CID-mCherry That Were Incubated with 50 μg/ml ICRF-187 after the Establishment of a Bipolar Attachment Z-stacks were acquired every 30 s. Each Z-stack is 10 μm and composed of ten optical sections. Merge color images for CID-mCherry (red) and GFP-α-tubulin (green) are shown on th...
Data
Time-Lapse Microscopy of S2 Cells Stably Expressing GFP-α-Tubulin and CID-mCherry That Were Incubated for 1 h with 50 μg/ml ICRF-187 before the Recording Z-stacks were acquired every 30 s. Each Z-stack is 10 μm and composed of ten optical sections. Anaphase onset corresponds to time 0 sec. Merge color images for CID-mCherry (red) and GFP-α-tubulin...