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1.
J Cancer Res Clin Oncol ; 147(8): 2187-2198, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34047821

RESUMO

BACKGROUND: Ensuring genetic integrity is essential during the cell cycle to avoid aneuploidy, one of the underlying causes of malignancies. Aurora kinases are serine/threonine kinase that play a vital role in maintaining the genomic integrity of the cells. There are three forms of aurora kinases in the mammalian cells, which are highly conserved and act together with several other proteins to control chromosome alignment and its equal distribution to daughter cells in mitosis and meiosis. METHODS: We provide here a detailed analysis of Aurora B kinase (ABK) in terms of its expression, structure, function, disease association and potential therapeutic implications. RESULTS: ABK plays an instrumental in mitotic entry, chromosome condensation, spindle assembly, cytokinesis, and abscission. Small-molecule inhibitors of ABK are designed and synthesized to control cancer progression. A detailed understanding of ABK pathophysiology in different cancers is of great significance in designing and developing effective therapeutic strategies. CONCLUSION: In this review, we have discussed the physiological significance of ABK followed by its role in cancer progression. We further highlighted available small-molecule inhibitors to control the tumor proliferation and their mechanistic insights.


Assuntos
Aurora Quinase B/fisiologia , Terapia de Alvo Molecular , Neoplasias/terapia , Animais , Antineoplásicos/uso terapêutico , Aurora Quinase B/antagonistas & inibidores , Aurora Quinase B/genética , Ciclo Celular/genética , Cromossomos/genética , Cromossomos/metabolismo , Progressão da Doença , Humanos , Mitose/genética , Terapia de Alvo Molecular/métodos , Terapia de Alvo Molecular/tendências , Neoplasias/etiologia , Neoplasias/patologia
2.
Cell Cycle ; 20(4): 345-352, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33459116

RESUMO

DNA Topoisomerase II (TopoII) uses ATP hydrolysis to decatenate chromosomes so that sister chromatids can faithfully segregate in mitosis. When the TopoII enzyme cycle stalls due to failed ATP hydrolysis, the onset of anaphase is delayed, presumably to allow extra time for decatenation to be completed. Recent evidence revealed that, unlike the spindle assembly checkpoint, this TopoII checkpoint response requires Aurora B and Haspin kinases and is triggered by SUMOylation of the C-terminal domain of TopoII.


Assuntos
Aurora Quinase B/fisiologia , DNA Topoisomerases Tipo II/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Pontos de Checagem da Fase M do Ciclo Celular/fisiologia , Metáfase/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Animais , Proteínas de Ciclo Celular/fisiologia , Genes cdc/fisiologia , Humanos , Mitose/fisiologia
3.
FASEB J ; 34(9): 12751-12767, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32738097

RESUMO

Equal segregation of chromosomes during mitosis ensures euploidy of daughter cells. Defects in this process may result in an imbalance in the chromosomal composition and cellular transformation. Proteolytic and non-proteolytic ubiquitylation pathways ensure directionality and fidelity of mitotic progression but specific mitotic functions of deubiquitylating enzymes (DUBs) remain less studied. Here we describe the role of the DUB ubiquitin carboxyl-terminal hydrolase isozyme L3 (UCHL3) in the regulation of chromosome bi-orientation and segregation during mitosis. Downregulation or inhibition of UCHL3 leads to chromosome alignment defects during metaphase. Frequent segregation errors during anaphase are also observed upon inactivation of UCHL3. Mechanistically, UCHL3 interacts with and deubiquitylates Aurora B, the catalytic subunit of chromosome passenger complex (CPC), known to be critically involved in the regulation of chromosome alignment and segregation. UCHL3 does not regulate protein levels of Aurora B or the binding of Aurora B to other CPC subunits. Instead, UCHL3 promotes localization of Aurora B to kinetochores, suggesting its role in the error correction mechanism monitoring bi-orientation of chromosomes during metaphase. Thus, UCHL3 contributes to the regulation of faithful genome segregation and maintenance of euploidy in human cells.


Assuntos
Segregação de Cromossomos , Mitose , Ubiquitina Tiolesterase/fisiologia , Aurora Quinase B/fisiologia , Células HeLa , Humanos , Ubiquitinação
4.
Essays Biochem ; 64(2): 277-287, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32406497

RESUMO

Faithful chromosome segregation in mitosis and meiosis requires that chromosomes properly attach to spindle microtubules. Initial kinetochore-microtubule attachments are often incorrect and rely on error correction mechanisms to release improper attachments, allowing the formation of new attachments. Aurora B kinase and, in mammalian germ cells, Aurora C kinase function as the enzymatic component of the Chromosomal Passenger Complex (CPC), which localizes to the inner centromere/kinetochore and phosphorylates kinetochore proteins for microtubule release during error correction. In this review, we discuss recent findings of the molecular pathways that regulate the chromosomal localization of Aurora B and C kinases in human cell lines, mice, fission yeast, and budding yeast. We also discuss differences in the importance of localization pathways between mitosis and meiosis.


Assuntos
Aurora Quinase B/fisiologia , Aurora Quinase C/fisiologia , Meiose , Mitose , Animais , Linhagem Celular , Humanos , Cinetocoros/enzimologia , Camundongos , Microtúbulos/enzimologia , Leveduras
5.
Development ; 147(1)2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31806662

RESUMO

Although cytokinesis has been intensely studied, the way it is executed during development is not well understood, despite a long-standing appreciation that various aspects of cytokinesis vary across cell and tissue types. To address this, we investigated cytokinesis during the invariant Caenorhabditis elegans embryonic divisions and found several parameters that are altered at different stages in a reproducible manner. During early divisions, furrow ingression asymmetry and midbody inheritance is consistent, suggesting specific regulation of these events. During morphogenesis, we found several unexpected alterations to cytokinesis, including apical midbody migration in polarizing epithelial cells of the gut, pharynx and sensory neurons. Aurora B kinase, which is essential for several aspects of cytokinesis, remains apically localized in each of these tissues after internalization of midbody ring components. Aurora B inactivation disrupts cytokinesis and causes defects in apical structures, even if inactivated post-mitotically. Therefore, we demonstrate that cytokinesis is implemented in a specialized way during epithelial polarization and that Aurora B has a role in the formation of the apical surface.


Assuntos
Aurora Quinase B/fisiologia , Proteínas de Caenorhabditis elegans/fisiologia , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/enzimologia , Citocinese , Morfogênese , Animais , Caenorhabditis elegans/citologia , Polaridade Celular , Citocinese/fisiologia , Dendritos/fisiologia , Embrião não Mamífero/citologia , Células Epiteliais/fisiologia , Intestinos/embriologia , Neurônios/citologia , Faringe/embriologia , Propriedades de Superfície
6.
J Neurochem ; 152(1): 72-91, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31563141

RESUMO

Peripheral nerve injury elicits spinal microgliosis, contributing to neuropathic pain. The aurora kinases A (AURKA), B (AURKB), and C (AURKC) are potential therapeutic targets in proliferating cells. However, their role has not been clarified in microglia. The aim of this study was to examine the regulation of aurora kinases and their roles and druggability in spinal microgliosis and neuropathic pain. Sprague-Dawley rats received chronic constriction injury (CCI). Gene expression of aurora kinases A-C was evaluated by quantitative RT-PCR and western blot, respectively, in spinal cords at 1, 3, 7, and 14 days after CCI. AURKB gene and protein expression was up-regulated concomitantly with the development of spinal microgliosis and neuropathic pain. Using lentiviral over-expression and adeno-associated viral knockdown approaches, the function of AURKB was further investigated by western blot, immunohistochemistry, RNA sequencing, and pain behavior tests. We found that AURKB over-expression in naive rats caused spinal microgliosis and pain hypersensitivity, whereas AURKB knockdown reduced microgliosis and alleviated CCI-induced neuropathic pain. Accordingly, RNA sequencing data revealed down-regulation of genes critically involved in signaling pathways associated with spinal microgliosis and neuropathic pain after AURKB knockdown in CCI rats. To examine its therapeutic potential for treatment of neuropathic pain, animals were treated intrathecally with the pharmacological AURKB inhibitor AZD1152-HQPA resulting in the alleviation of CCI-induced pain. Taken together, our findings indicated that AURKB plays a critical role in spinal microgliosis and neuropathic pain. Targeting AURKB may be an efficient method for treatment of neuropathic pain subsequent to peripheral nerve injury.


Assuntos
Aurora Quinase B/antagonistas & inibidores , Microglia/fisiologia , Neuralgia/terapia , Traumatismos dos Nervos Periféricos/fisiopatologia , Animais , Aurora Quinase B/genética , Aurora Quinase B/fisiologia , Modelos Animais de Doenças , Regulação para Baixo , Inibidores Enzimáticos/uso terapêutico , Expressão Gênica , Técnicas de Silenciamento de Genes , Masculino , Microglia/enzimologia , Microglia/patologia , Neuralgia/enzimologia , Traumatismos dos Nervos Periféricos/enzimologia , Ratos , Ratos Sprague-Dawley , Medula Espinal/enzimologia , Medula Espinal/patologia
7.
Artigo em Inglês | MEDLINE | ID: mdl-31699346

RESUMO

An aneuploidy workgroup was established as part of the 7th International Workshops on Genotoxicity Testing. The workgroup conducted a review of the scientific literature on the biological mechanisms of aneuploidy in mammalian cells and methods used to detect chemical aneugens. In addition, the current regulatory framework was discussed, with the objective to arrive at consensus statements on the ramifications of exposure to chemical aneugens for human health risk assessment. As part of these efforts, the workgroup explored the use of adverse outcome pathways (AOPs) to document mechanisms of chemically induced aneuploidy in mammalian somatic cells. The group worked on two molecular initiating events (MIEs), tubulin binding and binding to the catalytic domain of aurora kinase B, which result in several adverse outcomes, including aneuploidy. The workgroup agreed that the AOP framework provides a useful approach to link evidence for MIEs with aneuploidy on a cellular level. The evidence linking chemically induced aneuploidy with carcinogenicity and hereditary disease was also reviewed and is presented in two companion papers. In addition, the group came to the consensus that the current regulatory test batteries, while not ideal, are sufficient for the identification of aneugens and human risk assessment. While it is obvious that there are many different MIEs that could lead to the induction of aneuploidy, the most commonly observed mechanisms involving chemical aneugens are related to tubulin binding and, to a lesser extent, inhibition of mitotic kinases. The comprehensive review presented here should help with the identification and risk management of aneugenic agents.


Assuntos
Rotas de Resultados Adversos , Aneuploidia , Doenças Genéticas Inatas/induzido quimicamente , Mitose/efeitos dos fármacos , Testes de Mutagenicidade/métodos , Mutagênicos/toxicidade , Neoplasias/induzido quimicamente , Animais , Aurora Quinase B/antagonistas & inibidores , Aurora Quinase B/fisiologia , Carcinógenos/toxicidade , Aberrações Cromossômicas/induzido quimicamente , Segregação de Cromossomos/efeitos dos fármacos , Cromossomos/efeitos dos fármacos , Genes Reporter , Doenças Genéticas Inatas/genética , Células Germinativas/efeitos dos fármacos , Células Germinativas/ultraestrutura , Humanos , Camundongos , Testes para Micronúcleos , Microtúbulos/efeitos dos fármacos , Mitose/fisiologia , Testes de Mutagenicidade/normas , Mutagênicos/análise , Neoplasias/genética , Não Disjunção Genética/efeitos dos fármacos , Gestão de Riscos/legislação & jurisprudência , Moduladores de Tubulina/toxicidade
8.
NPJ Syst Biol Appl ; 5: 20, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31312514

RESUMO

Cancer cells with heterogeneous mutation landscapes and extensive functional redundancy easily develop resistance to monotherapies by emerging activation of compensating or bypassing pathways. To achieve more effective and sustained clinical responses, synergistic interactions of multiple druggable targets that inhibit redundant cancer survival pathways are often required. Here, we report a systematic polypharmacology strategy to predict, test, and understand the selective drug combinations for MDA-MB-231 triple-negative breast cancer cells. We started by applying our network pharmacology model to predict synergistic drug combinations. Next, by utilizing kinome-wide drug-target profiles and gene expression data, we pinpointed a synergistic target interaction between Aurora B and ZAK kinase inhibition that led to enhanced growth inhibition and cytotoxicity, as validated by combinatorial siRNA, CRISPR/Cas9, and drug combination experiments. The mechanism of such a context-specific target interaction was elucidated using a dynamic simulation of MDA-MB-231 signaling network, suggesting a cross-talk between p53 and p38 pathways. Our results demonstrate the potential of polypharmacological modeling to systematically interrogate target interactions that may lead to clinically actionable and personalized treatment options.


Assuntos
Aurora Quinase B/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Aurora Quinase B/fisiologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Simulação por Computador , Interações Medicamentosas/genética , Sinergismo Farmacológico , Feminino , Humanos , MAP Quinase Quinase Quinases/fisiologia , Modelos Biológicos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética
9.
Cell Mol Life Sci ; 76(21): 4291-4307, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31302750

RESUMO

In the presence of chromatin bridges, mammalian cells delay completion of cytokinesis (abscission) to prevent chromatin breakage or tetraploidization by regression of the cleavage furrow. This abscission delay is called "the abscission checkpoint" and is dependent on Aurora B kinase. Furthermore, cells stabilize the narrow cytoplasmic canal between the two daughter cells until the DNA bridges are resolved. Impaired abscission checkpoint signaling or unstable intercellular canals can lead to accumulation of DNA damage, aneuploidy, or generation of polyploid cells which are associated with tumourigenesis. However, the molecular mechanisms involved have only recently started to emerge. In this review, we focus on the molecular pathways of the abscission checkpoint and describe newly identified triggers, Aurora B-regulators and effector proteins in abscission checkpoint signaling. We also describe mechanisms that control intercellular bridge stabilization, DNA bridge resolution, or abscission checkpoint silencing upon satisfaction, and discuss how abscission checkpoint proteins can be targeted to potentially improve cancer therapy.


Assuntos
Cromatina/metabolismo , Cromossomos/metabolismo , Citocinese/fisiologia , Animais , Aurora Quinase B/metabolismo , Aurora Quinase B/fisiologia , Genes cdc/fisiologia , Humanos , Transdução de Sinais
10.
Cereb Cortex ; 29(3): 1280-1290, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29462287

RESUMO

Neural progenitor proliferation and cell fate decision from self-renewal to differentiation are crucial factors in determining brain size and morphology. The cytoskeletal dependent regulation of these processes is not entirely known. The actin-binding filamin A (FlnA) was shown to regulate proliferation of progenitors by directing changes in cell cycles proteins such as Cdk1 during G2/M phase. Here we report that functional loss of FlnA not only affects the rate of proliferation by altering cell cycle length but also causes a defect in early differentiation through changes in cell fate specification. FlnA interacts with Rho GTPase RhoA, and FlnA loss impairs RhoA activation. Disruption of either of these cytoskeletal associated proteins delays neurogenesis and promotes neural progenitors to remain in proliferative states. Aurora kinase B (Aurkb) has been implicated in cytokinesis, and peaks in expression during the G2/M phase. Inhibition of FlnA or RhoA impairs Aurkb degradation and alters its localization during mitosis. Overexpression of Aurkb replicates the same delay in neurogenesis seen with loss of FlnA or RhoA. Our findings suggest that shared cytoskeletal processes can direct neural progenitor proliferation by regulating the expression and localization of proteins that are implicated in the cell cycle progression and cell fate specification.


Assuntos
Córtex Cerebral/crescimento & desenvolvimento , Citoesqueleto/fisiologia , Filaminas/fisiologia , Mitose/fisiologia , Células-Tronco Neurais/fisiologia , Proteína rhoA de Ligação ao GTP/fisiologia , Animais , Aurora Quinase B/fisiologia , Diferenciação Celular , Proliferação de Células , Camundongos , Neurogênese
11.
Genetics ; 210(1): 171-187, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29986897

RESUMO

While it is known that micronuclei pose a serious risk to genomic integrity by undergoing chromothripsis, mechanisms preventing micronucleus formation remain poorly understood. Here, we investigate how late-segregating acentric chromosomes that would otherwise form micronuclei instead reintegrate into daughter nuclei by passing through Aurora B kinase-dependent channels in the nuclear envelope of Drosophila melanogaster neuroblasts. We find that localized concentrations of Aurora B preferentially phosphorylate H3(S10) on acentrics and their associated DNA tethers. This phosphorylation event prevents HP1a from associating with heterochromatin and results in localized inhibition of nuclear envelope reassembly on endonuclease- and X-irradiation-induced acentrics, promoting channel formation. Finally, we find that HP1a also specifies initiation sites of nuclear envelope reassembly on undamaged chromatin. Taken together, these results demonstrate that Aurora B-mediated regulation of HP1a-chromatin interaction plays a key role in maintaining genome integrity by locally preventing nuclear envelope assembly and facilitating the incorporation of late-segregating acentrics into daughter nuclei.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Micronúcleo Germinativo/fisiologia , Animais , Aurora Quinase B/metabolismo , Aurora Quinase B/fisiologia , Núcleo Celular/metabolismo , Cromatina/genética , Cromatina/metabolismo , Homólogo 5 da Proteína Cromobox , Proteínas Cromossômicas não Histona/genética , DNA/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/genética , Heterocromatina/metabolismo , Micronúcleos com Defeito Cromossômico , Micronúcleo Germinativo/genética , Membrana Nuclear/metabolismo
12.
Nucleic Acids Res ; 45(21): 12340-12353, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29040668

RESUMO

AURKB (Aurora Kinase B) is a serine/threonine kinase better known for its role at the mitotic kinetochore during chromosome segregation. Here, we demonstrate that AURKB localizes to the telomeres in mouse embryonic stem cells, where it interacts with the essential telomere protein TERF1. Loss of AURKB function affects TERF1 telomere binding and results in aberrant telomere structure. In vitro kinase experiments successfully identified Serine 404 on TERF1 as a putative AURKB target site. Importantly, in vivo overexpression of S404-TERF1 mutants results in fragile telomere formation. These findings demonstrate that AURKB is an important regulator of telomere structural integrity.


Assuntos
Aurora Quinase B/metabolismo , Telômero/enzimologia , Proteína 1 de Ligação a Repetições Teloméricas/metabolismo , Animais , Aurora Quinase B/fisiologia , Linhagem Celular , Células-Tronco Embrionárias/enzimologia , Humanos , Interfase/genética , Camundongos , Mitose/genética , Mutação , Ligação Proteica , Telômero/ultraestrutura , Proteína 1 de Ligação a Repetições Teloméricas/química , Proteína 1 de Ligação a Repetições Teloméricas/genética
13.
Nat Commun ; 7: 11117, 2016 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-27030108

RESUMO

Temporal regulation of microtubule dynamics is essential for proper progression of mitosis and control of microtubule plus-end tracking proteins by phosphorylation is an essential component of this regulation. Here we show that Aurora B and CDK1 phosphorylate microtubule end-binding protein 2 (EB2) at multiple sites within the amino terminus and a cluster of serine/threonine residues in the linker connecting the calponin homology and end-binding homology domains. EB2 phosphorylation, which is strictly associated with mitotic entry and progression, reduces the binding affinity of EB2 for microtubules. Expression of non-phosphorylatable EB2 induces stable kinetochore microtubule dynamics and delays formation of bipolar metaphase plates in a microtubule binding-dependent manner, and leads to aneuploidy even in unperturbed mitosis. We propose that Aurora B and CDK1 temporally regulate the binding affinity of EB2 for microtubules, thereby ensuring kinetochore microtubule dynamics, proper mitotic progression and genome stability.


Assuntos
Aurora Quinase B/fisiologia , Quinases Ciclina-Dependentes/fisiologia , Proteínas Associadas aos Microtúbulos/fisiologia , Mitose/fisiologia , Aurora Quinase B/análise , Aurora Quinase B/metabolismo , Sítios de Ligação , Proteína Quinase CDC2 , Linhagem Celular , Quinases Ciclina-Dependentes/análise , Quinases Ciclina-Dependentes/metabolismo , Instabilidade Genômica , Humanos , Cinetocoros/metabolismo , Cinetocoros/ultraestrutura , Proteínas Associadas aos Microtúbulos/análise , Proteínas Associadas aos Microtúbulos/química , Microtúbulos/metabolismo , Microtúbulos/ultraestrutura , Mitose/genética , Fosforilação
14.
Tumour Biol ; 37(3): 3071-80, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26423403

RESUMO

Colorectal adenomatous polyp (CRAP) is a major risk factor for the development of sporadic colorectal cancer (CRC). Histone modifications are one of the epigenetic mechanisms that may have key roles in the carcinogenesis of CRC. The objective of the present study is to investigate the alternations in the defined histone modification gene expression profiles in patients with CRAP and CRC. Histone modification enzyme key gene expressions of the CRC, CRAP, and control groups were evaluated and compared using the reverse transcription PCR (RT-PCR) array method. Gene expression analysis was performed in the CRAP group after dividing the patients into subgroups according to the polyp diameter, pathological results, and morphological parameters which are risk factors for developing CRC in patients with CRAP. PAK1, NEK6, AURKA, AURKB, HDAC1, and HDAC7 were significantly more overexpressed in CRC subjects compared to the controls (p < 0.05). PAK1, NEK6, AURKA, AURKB, and HDAC1 were significantly more overexpressed in the CRAP group compared to the controls (p < 0.005). There were no significant differences between the CRAP and CRC groups with regards to PAK1, NEK6, AURKA, or AURKB gene overexpression. PAK1, NEK6, AURKA, and AURKB were significantly in correlation with the polyp diameter as they were more overexpressed in polyps with larger diameters. In conclusion, overexpressions of NEK6, AURKA, AURKB, and PAK1 genes can be used as predictive markers to decide the colonoscopic surveillance intervals after the polypectomy procedure especially in polyps with larger diameters.


Assuntos
Adenocarcinoma/genética , Polipose Adenomatosa do Colo/genética , Aurora Quinase A/genética , Aurora Quinase B/genética , Neoplasias Colorretais/genética , Quinases Ativadas por p21/genética , Adenocarcinoma/patologia , Polipose Adenomatosa do Colo/patologia , Adulto , Idoso , Aurora Quinase A/fisiologia , Aurora Quinase B/fisiologia , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Quinases Relacionadas a NIMA/genética , Quinases Relacionadas a NIMA/fisiologia , Quinases Ativadas por p21/fisiologia
15.
J Cell Biochem ; 117(2): 351-60, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26177583

RESUMO

The cohesin complex holds sister chromatids together until all chromosomes are properly attached to the mitotic spindle. Cleavage of the cohesin subunit Rad21 at the metaphase to anaphase transition allows separation of sister chromatids and is fundamental for the creation of identical daughter cells. Sororin blocks removal of cohesin from chromosomes from S phase until mitosis. In mitosis, Sororin is phosphorylated by Cdk1 releasing it from the cohesin complex. Aurora B phosphorylation of Sororin may play a similar role as Cdk1. Using PhosTag electrophoresis, we detect multiple Sororin species suggesting that phosphorylation of Sororin in mitosis is heterogeneous. Mutating the Cdk1 consensus site S21 to alanine eliminates many of the phosphorylated species suggesting that S21 is a key site of phosphorylation in vivo. Inhibiting Aurora B reduces phosphorylation of Sororin in cells, but only if Cdk1 sites are intact suggesting that some phosphorylation events on Sororin may be sequential. Surprisingly, mutating Aurora B consensus sites in Sororin causes it to relocalize to the nucleolus during interphase and blocks its interaction with chromosomes in Aurora B-inhibited cells. These observations indicate that phosphorylation plays unexpected roles in regulating the subcellular localization of Sororin.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Aurora Quinase B/fisiologia , Proteínas de Ciclo Celular/metabolismo , Quinases Ciclina-Dependentes/fisiologia , Processamento de Proteína Pós-Traducional , Sequência de Aminoácidos , Sítios de Ligação , Proteína Quinase CDC2 , Nucléolo Celular/metabolismo , Sequência Consenso , Células HeLa , Humanos , Dados de Sequência Molecular , Fosforilação , Transporte Proteico , Especificidade por Substrato
16.
Cancer Gene Ther ; 22(9): 438-44, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26272026

RESUMO

Oncolytic measles virus (MV) strains have demonstrated broad spectrum preclinical anti-tumor efficacy, including breast cancer. Aurora A kinase controls mitotic spindle formation and has a critical role in malignant transformation. We hypothesized that the Aurora A kinase inhibitor MLN8237 (alisertib) can increase MV oncolytic effect and efficacy by causing mitotic arrest. Alisertib enhanced MV oncolysis in vitro and significantly improved outcome in vivo against breast cancer xenografts. In a disseminated MDA-231-lu-P4 lung metastatic model, the MV/alisertib combination treatment markedly increased median survival to 82.5 days with 20% of the animals being long-term survivors versus 48 days median survival for the control animals. Similarly, in a pleural effusion model of advanced breast cancer, the MV/alisertib combination significantly improved outcome with a 74.5 day median survival versus the single agent groups (57 and 40 days, respectively). Increased viral gene expression and IL-24 upregulation were demonstrated, representing possible mechanisms for the observed increase in anti-tumor effect. Inhibiting Aurora A kinase with alisertib represents a novel approach to enhance MV-mediated oncolysis and antitumor effect. Both oncolytic MV strains and alisertib are currently tested in clinical trials, this study therefore provides the basis for translational applications of this combinatorial strategy in the treatment of patients with advanced breast cancer.


Assuntos
Antineoplásicos/uso terapêutico , Aurora Quinase B/antagonistas & inibidores , Azepinas/uso terapêutico , Neoplasias da Mama/terapia , Vírus do Sarampo , Terapia Viral Oncolítica , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Adenocarcinoma/secundário , Adenocarcinoma/terapia , Animais , Aurora Quinase B/fisiologia , Azepinas/farmacologia , Proteínas de Bactérias/genética , Neoplasias da Mama/patologia , Chlorocebus aethiops , Terapia Combinada , Feminino , Regulação da Expressão Gênica , Humanos , Cadeias lambda de Imunoglobulina/genética , Interleucinas/biossíntese , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/terapia , Camundongos , Camundongos Nus , Pirimidinas/farmacologia , Transgenes , Células Vero , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Mol Cell Biol ; 35(20): 3566-78, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26240282

RESUMO

Aurora kinase B, one of the three members of the mammalian Aurora kinase family, is the catalytic component of the chromosomal passenger complex, an essential regulator of chromosome segregation in mitosis. Aurora B is overexpressed in human tumors although whether this kinase may function as an oncogene in vivo is not established. Here, we report a new mouse model in which expression of the endogenous Aurkb locus can be induced in vitro and in vivo. Overexpression of Aurora B in cultured cells induces defective chromosome segregation and aneuploidy. Long-term overexpression of Aurora B in vivo results in aneuploidy and the development of multiple spontaneous tumors in adult mice, including a high incidence of lymphomas. Overexpression of Aurora B also results in a reduced DNA damage response and decreased levels of the p53 target p21(Cip1) in vitro and in vivo, in line with an inverse correlation between Aurora B and p21(Cip1) expression in human leukemias. Thus, overexpression of Aurora B may contribute to tumor formation not only by inducing chromosomal instability but also by suppressing the function of the cell cycle inhibitor p21(Cip1).


Assuntos
Aneuploidia , Aurora Quinase B/fisiologia , Inibidor de Quinase Dependente de Ciclina p21/genética , Animais , Carcinogênese/genética , Carcinogênese/metabolismo , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Fibroblastos/metabolismo , Expressão Gênica , Inativação Gênica , Camundongos Endogâmicos C57BL , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética
18.
Cell Cycle ; 14(23): 3755-67, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26148251

RESUMO

Mitotic centromere-associated kinesin (MCAK) is the best characterized member of the kinesin-13 family and plays important roles in microtubule dynamics during mitosis. Its activity and subcellular localization is tightly regulated by an orchestra of mitotic kinases, such as Aurora B. It is well known that serine 196 of MCAK is the major phosphorylation site of Aurora B in Xenopus leavis extracts and that this phosphorylation regulates its catalytic activity and subcellular localization. In the current study, we have addressed the conserved phosphorylation site serine 192 in human MCAK to characterize its function in more depth in human cancer cells. Our data confirm that S192 is the major phosphorylation site of Aurora B in human MCAK and that this phosphorylation has crucial roles in regulating its catalytic activity and localization at the kinetochore/centromere region in mitosis. Interfering with this phosphorylation leads to a delayed progression through prometa- and metaphase associated with mitotic defects in chromosome alignment and segregation. We show further that MCAK is involved in directional migration and invasion of tumor cells, and interestingly, interference with the S192 phosphorylation affects this capability of MCAK. These data provide the first molecular explanation for clinical observation, where an overexpression of MCAK was associated with lymphatic invasion and lymph node metastasis in gastric and colorectal cancer patients.


Assuntos
Aurora Quinase B/fisiologia , Cinesinas/química , Aurora Quinase B/metabolismo , Sítios de Ligação , Linhagem Celular Tumoral , Movimento Celular/genética , Células HeLa , Humanos , Cinesinas/fisiologia , Mitose/genética , Invasividade Neoplásica/genética , Metástase Neoplásica/genética , Fosforilação , Processamento de Proteína Pós-Traducional , Estrutura Terciária de Proteína
19.
Mol Biol Cell ; 26(12): 2227-41, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25877868

RESUMO

To determine how chromosome segregation is coordinated with nuclear envelope formation (NEF), we examined the dynamics of NEF in the presence of lagging acentric chromosomes in Drosophila neuroblasts. Acentric chromosomes often exhibit delayed but ultimately successful segregation and incorporation into daughter nuclei. However, it is unknown whether these late-segregating acentric fragments influence NEF to ensure their inclusion in daughter nuclei. Through live analysis, we show that acentric chromosomes induce highly localized delays in the reassembly of the nuclear envelope. These delays result in a gap in the nuclear envelope that facilitates the inclusion of lagging acentrics into telophase daughter nuclei. Localized delays of nuclear envelope reassembly require Aurora B kinase activity. In cells with reduced Aurora B activity, there is a decrease in the frequency of local nuclear envelope reassembly delays, resulting in an increase in the frequency of acentric-bearing, lamin-coated micronuclei. These studies reveal a novel role of Aurora B in maintaining genomic integrity by promoting the formation of a passageway in the nuclear envelope through which late-segregating acentric chromosomes enter the telophase daughter nucleus.


Assuntos
Aurora Quinase B/fisiologia , Segregação de Cromossomos , Proteínas de Drosophila/fisiologia , Membrana Nuclear/metabolismo , Animais , Aurora Quinase B/genética , Drosophila/genética , Drosophila/fisiologia , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Expressão Gênica , Laminas/metabolismo , Micronúcleos com Defeito Cromossômico
20.
J Cell Biol ; 207(2): 201-11, 2014 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-25332165

RESUMO

Drosophila melanogaster Polo and its human orthologue Polo-like kinase 1 fulfill essential roles during cell division. Members of the Polo-like kinase (Plk) family contain an N-terminal kinase domain (KD) and a C-terminal Polo-Box domain (PBD), which mediates protein interactions. How Plks are regulated in cytokinesis is poorly understood. Here we show that phosphorylation of Polo by Aurora B is required for cytokinesis. This phosphorylation in the activation loop of the KD promotes the dissociation of Polo from the PBD-bound microtubule-associated protein Map205, which acts as an allosteric inhibitor of Polo kinase activity. This mechanism allows the release of active Polo from microtubules of the central spindle and its recruitment to the site of cytokinesis. Failure in Polo phosphorylation results in both early and late cytokinesis defects. Importantly, the antagonistic regulation of Polo by Aurora B and Map205 in cytokinesis reveals that interdomain allosteric mechanisms can play important roles in controlling the cellular functions of Plks.


Assuntos
Aurora Quinase B/fisiologia , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/citologia , Proteínas Associadas aos Microtúbulos/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Aurora Quinase B/metabolismo , Células Cultivadas , Citocinese , Proteínas de Drosophila/análise , Drosophila melanogaster/enzimologia , Drosophila melanogaster/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Modelos Biológicos , Modelos Moleculares , Fosforilação , Proteínas Serina-Treonina Quinases/análise , Proteínas Serina-Treonina Quinases/fisiologia
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