Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.281
Filtrar
1.
Life Sci ; 236: 116933, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31614146

RESUMO

AIMS: Hepatocellular carcinoma (HCC) pathogenesis involves the interplay of multiple signalling pathways. Notch and Hedgehog (Hh) are two major developmental pathways that act in concert to regulate adult cell repair. CK2α -serine-threonine kinase-down-regulation enhanced apoptotic activity and was proven beneficial for HCC patients. Quercetin is a bioactive flavonoid and has been shown to protect against HCC through its antioxidant activity. This study was carried out to elucidate the antineoplastic effect of quercetin through regulating both Notch and Hh pathways, apoptosis, cell proliferation and CK2α activity. MAIN METHODS: Hepatocellular carcinoma was induced in male Sprague Dawley rats by thioacetamide. Quercetin was administered in both protective and curative doses. Parameters of liver function and oxidative stress were assessed. CK2α, Notch and Hh pathways were evaluated using RT-PCR and ELISA. Apoptosis was investigated by detecting caspase-3, caspase-8 and p53. Proliferative and cell cycle markers as cyclin D1 and Ki-67 were detected immunohistochemically. KEY FINDINGS: Quercetin inhibited CK2α and downregulated mRNA and protein expression of Notch1 and Gli2. Quercetin also suppressed caspase-3 expression but not caspase-8. Quercetin elevated p53 expression whereas proliferative and cell cycle markers cyclin D1 and Ki-67 were downregulated. Markers of hepatic cellular integrity such as AST, ALT, ALP, GGT, albumin and bilirubin were significantly ameliorated. This was confirmed by histological examination. Quercetin also alleviated oxidative stress as shown by SOD, GSH, MDA and NO levels. SIGNIFICANCE: We can conclude that in addition to its antioxidant power, quercetin blocked Notch, Hedgehog, regulated the apoptotic and proliferative pathways and inhibited CK2α in HCC.


Assuntos
Antioxidantes/farmacologia , Carcinoma Hepatocelular/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Hepáticas/metabolismo , Quercetina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Caseína Quinase II/antagonistas & inibidores , Caseína Quinase II/metabolismo , Proliferação de Células/efeitos dos fármacos , Proteínas Hedgehog/antagonistas & inibidores , Proteínas Hedgehog/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Masculino , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley , Receptores Notch/antagonistas & inibidores , Receptores Notch/metabolismo
2.
Eur J Med Chem ; 181: 111581, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31400711

RESUMO

Casein kinase (CK) is a type of conserved serine/threonine protein kinase that phosphorylates many important proteins in body. Researchers found that CK is involved in a variety of signaling pathways, and also plays an important role in inflammation, cancer, and nervous system diseases. Thus, it is considered to be a promising target for the treatment of related diseases. Many CK small molecule inhibitors have been reported so far, and most are ATP competitive inhibitors. However, these CK inhibitors lack the basic properties required for in vivo use, such as selectivity, cell permeability, metabolic stability, correct pharmacokinetic characteristics, and cellular environment. But small molecule inhibitors still have an advantage in drug research due to their controllable pharmacological and pharmacokinetic properties. CX-4945 discovered by Cylene Pharmaceutical is the only one CK2 inhibitor entering into Phase II clinical trials till now. In recent years, significant advances have been made in the design of non-competitive inhibitors of CK and in the application of multi-target inhibition strategies. Here, we review the published CK inhibitors and analyze their structure-activity relationships (SAR). We also summarized the eutectic structure with identified hot spots to provide a reference for future drug discovery.


Assuntos
Caseína Quinase II/antagonistas & inibidores , Caseína Quinase I/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Caseína Quinase I/química , Caseína Quinase I/metabolismo , Caseína Quinase II/química , Caseína Quinase II/metabolismo , Descoberta de Drogas , Humanos , Simulação de Acoplamento Molecular
3.
Cell Physiol Biochem ; 53(2): 366-387, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31385665

RESUMO

BACKGROUND/AIMS: The extracellular signal-regulated kinases (ERK) 1 and 2 (ERK1/2) are members of the mitogen-activated protein kinase (MAPK) family. Upon stimulation, these kinases translocate from the cytoplasm to the nucleus, where they induce physiological processes such as proliferation and differentiation. The mechanism of translocation of this kinase involves phosphorylation of two Ser residues within a nuclear translocation signal (NTS), which allows binding to importin7 and a subsequent penetration via nuclear pores. However, the regulation of this process and the protein kinases involved are not yet clear. METHODS: To answer this point we developed specific anti phospho-SPS antibody, used this and other antibodies in Western blots and crystalized the phospho-mimetic mutated ERK. RESULTS: Here we show that the phosphorylation of both Ser residues is mediated mainly by casein kinase 2 (CK2) and that active ERK may assist in the phosphorylation of the N-terminal Ser. We also demonstrate that the phosphorylation is dependent on the release of ERK from cytoplasmic anchoring proteins. Crystal structure of the phosphomimetic ERK revealed that the NTS phosphorylation creates an acidic patch in ERK. Our model is that in resting cells ERK is bound to cytoplasmic anchors, which prevent its NTS phosphorylation. Upon stimulation, phosphorylation of the ERK TEY domain releases ERK and allows phosphorylation of its NTS by CK2 and active ERK to generate a negatively charged patch in ERK, binding to importin 7 and nuclear translocation. CONCLUSION: These results provide an important role of CK2 in regulating nuclear ERK activities.


Assuntos
Núcleo Celular/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Transporte Ativo do Núcleo Celular , Caseína Quinase II/metabolismo , Linhagem Celular , Humanos , Carioferinas/metabolismo , Fosforilação , Ligação Proteica , Receptores Citoplasmáticos e Nucleares/metabolismo
4.
Chin J Physiol ; 62(2): 63-69, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31243176

RESUMO

One of the principal signaling pathway outcomes from brain-derived neurotrophic factor (BDNF) is the activation of antiapoptotic pathways. In addition to the role of extracellular signal-regulated kinase 1/2 and phosphatidylinositol-3 kinase, BDNF activates protein kinase CK2 to mediate its neuroprotective effect. The inhibition of CK2 activity has been shown to induce apoptosis. Although serum response element (SRE)-mediated transcription has been reported to be activated by BDNF and that the phosphorylation of serum response factor (SRF) by CK2 has been shown to enhance its DNA binding activity, the biological relevance of these interactions remains largely unclear. In the present study, we found that SRE-mediated transcription, CK2 activity, and SRF phosphorylation increased in PC12 cells under BDNF treatment. The transfection of CK2α siRNA blocked the enhancing effect of BDNF on SRE-mediated transcription, SRF phosphorylation, and Mcl-1 gene expression. Moreover, the blockade of CK2 diminished the antiapoptotic effects of BDNF on SRE-mediated transcription, Mcl-1 gene expression, and cell viability under rotenone-induced cytotoxicity. Our data may assist in the development of therapeutic strategies for inhibiting apoptosis during neurodegeneration.


Assuntos
Caseína Quinase II/metabolismo , Animais , Fator Neurotrófico Derivado do Encéfalo , Proteína Quinase 3 Ativada por Mitógeno , Fosforilação , Ratos , Elemento de Resposta Sérica , Transdução de Sinais
5.
J Biochem ; 166(1): 3-6, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31198932

RESUMO

Heterochromatin is a condensed and transcriptionally silent chromatin structure and that plays important roles in epigenetic regulation of the genome. Two types of heterochromatin exist: constitutive heterochromatin is primarily associated with trimethylation of histone H3 at lysine 9 (H3K9me3), and facultative heterochromatin with trimethylation of H3 at lysine 27 (H3K27me3). The methylated histones are bound by the chromodomain of histone code 'reader' proteins: HP1 family proteins for H3K9me3 and Polycomb family proteins for H3K27me3. Each repressive reader associates with various 'effector' proteins that provide the functional basis of heterochromatin. Heterochromatin regulation is primarily achieved by controlling histone modifications. However, recent studies have revealed that the repressive readers are phosphorylated, like other regulatory proteins, suggesting that phosphorylation also participates in heterochromatin regulation. Detailed studies have shown that phosphorylation of readers affects the binding specificities of chromodomains for methylated histone H3, as well as the binding of effector proteins. Thus, phosphorylation adds another layer to heterochromatin regulation. Interestingly, casein kinase 2, a strong and predominant kinase within the cell, is responsible for phosphorylation of repressive readers. In this commentary, I summarize the regulation of repressive readers by casein kinase 2-dependent phosphorylation and discuss the functional meaning of this modification.


Assuntos
Caseína Quinase II/metabolismo , Heterocromatina/metabolismo , Código das Histonas/fisiologia , Histonas/química , Histonas/metabolismo , Animais , Heterocromatina/química , Heterocromatina/genética , Histonas/genética , Humanos , Fosforilação
6.
J Biosci ; 44(2)2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31180068

RESUMO

Laminins are a major constituent of the extracellular matrix (ECM). Laminin-111, the most extensively studied laminin isoform, consists of the α1, the ß1 and the γ1 chain, and is involved in many cellular processes, like adhesion, migration and differentiation. Given the regulatory role of phosphorylation in protein function, it is important to identify the phosphorylation sites of human laminin ß1-chain sequence (LAMB1). Therefore, we computationally predicted all possible phosphorylation sites in LAMB1. For the first time, we identified the possibly responsible kinases for already in vitro experimentally observed phosphorylated residues in LAMB1. All known functional (active) sites of LAMB1, were recorded after an extensive literature search and combined with the experimentally observed and our predicted phosphorylated residues. This generated a detailed phosphorylation map of LAMB1. Five kinases (PKA, PKC, CKII, CKI and GPCR1) were indicated important, while the role of PKA, PKC and CKII, kinases known for ectophosphorylation activity, was highlighted. The activity of PKA and PKC was associated with the active site RIQNLLKITNLRIKFVKLHTLGDNLLDS. Also, predicted phosphorylations inside two amyloidogenic (DSITKYFQMSLE, VILQHSAADIAR) and two anti-cancerous (YIGSR and PDSGR) sites suggested a possible role in the development of the corresponding diseases.


Assuntos
Biologia Computacional/métodos , Laminina/química , Mapeamento de Peptídeos/métodos , Processamento de Proteína Pós-Traducional , Sequência de Aminoácidos , Caseína Quinase I/química , Caseína Quinase I/metabolismo , Caseína Quinase II/química , Caseína Quinase II/metabolismo , Domínio Catalítico , Proteínas Quinases Dependentes de AMP Cíclico/química , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Receptor Quinase 1 Acoplada a Proteína G/química , Receptor Quinase 1 Acoplada a Proteína G/metabolismo , Expressão Gênica , Humanos , Laminina/genética , Laminina/metabolismo , Fosforilação , Proteína Quinase C/química , Proteína Quinase C/metabolismo
7.
PLoS Pathog ; 15(5): e1007788, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31091289

RESUMO

Inhibition of human papillomavirus (HPV) replication is a promising therapeutic approach for intervening with HPV-related pathologies. Primary targets for interference are two viral proteins, E1 and E2, which are required for HPV replication. Both E1 and E2 are phosphoproteins; thus, the protein kinases that phosphorylate them might represent secondary targets to achieve inhibition of HPV replication. In the present study, we show that CX4945, an ATP-competitive small molecule inhibitor of casein kinase 2 (CK2) catalytic activity, suppresses replication of different HPV types, including novel HPV5NLuc, HPV11NLuc and HPV18NLuc marker genomes, but enhances the replication of HPV16 and HPV31. We further corroborate our findings using short interfering RNA (siRNA)-mediated knockdown of CK2 α and α' subunits in U2OS and CIN612 cells; we show that while both subunits are expressed in these cell lines, CK2α is required for HPV replication, but CK2α' is not. Furthermore, we demonstrate that CK2α acts in a kinase activity-dependent manner and regulates the stability and nuclear retention of endogenous E1 proteins of HPV11 and HPV18. This unique feature of CK2α makes it an attractive target for developing antiviral agents.


Assuntos
Papillomaviridae/fisiologia , Infecções por Papillomavirus/virologia , Fosfoproteínas/metabolismo , Proteínas Virais/metabolismo , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Neoplasias Ósseas/virologia , Caseína Quinase II/genética , Caseína Quinase II/metabolismo , Humanos , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Osteossarcoma/virologia , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/metabolismo , Fosfoproteínas/genética , Fosforilação , Células Tumorais Cultivadas , Proteínas Virais/genética
8.
PLoS Pathog ; 15(5): e1007769, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31116803

RESUMO

The Human Papillomavirus E7 oncoprotein plays an essential role in the development and maintenance of malignancy, which it achieves through targeting a number of critical cell control pathways. An important element in the ability of E7 to contribute towards cell transformation is the presence of a Casein Kinase II phospho-acceptor site within the CR2 domain of the protein. Phosphorylation is believed to enhance E7 interaction with a number of different cellular target proteins, and thereby increase the ability of E7 to enhance cell proliferation and induce malignancy. However, there is little information on how important this site in E7 is, once the tumour cells have become fully transformed. In this study, we have performed genome editing of the HPV-18 E7 CKII recognition site in C4-1 cervical tumour-derived cells. We first show that mutation of HPV18 E7 S32/S34 to A32/A34 abolishes CKII phosphorylation of E7, and subsequently we have isolated C4-1 clones containing these mutations in E7. The cells continue to proliferate, but are somewhat more slow-growing than wild type cells, reach lower saturation densities, and are also more susceptible to low nutrient conditions. These cells are severely defective in matrigel invasion assays, partly due to downregulation of matrix metalloproteases (MMPs). Mechanistically, we find that phosphorylation of E7 plays a direct role in the ability of E7 to activate AKT signaling, which in turn is required for optimal levels of MMP secretion. These results demonstrate that the E7 CKII phospho-acceptor site thus continues to play an important role for E7's activity in cells derived from cervical cancers, and suggests that blocking this activity of E7 could be expected to have therapeutic potential.


Assuntos
Caseína Quinase II/metabolismo , Proliferação de Células , Transformação Celular Viral , Proteínas de Ligação a DNA/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Neoplasias do Colo do Útero/patologia , Caseína Quinase II/genética , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 13 da Matriz/metabolismo , Proteínas Oncogênicas Virais/genética , Fenótipo , Fosforilação , Células Tumorais Cultivadas , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo
9.
J Exp Clin Cancer Res ; 38(1): 131, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30885251

RESUMO

BACKGROUND: Dysfunction of p53 is a key cause of cancer development, while CCDC106 can reduce p53 stability and is associated with lung cancer. However, the roles of CCDC106 in other cancer types and its upstream regulators have not been investigated. METHODS: The phosphorylation status was investigated by in vitro kinase assay and Western blotting using phosphorylation-specific antibodies. Co-immunoprecipitation assay and GST-pulldown were used to detect protein interaction. Cell viability, apoptosis, colony formation, wound-healing and invasion assays were measured for in vitro functional analyses. The in vivo effect of CCDC106 on tumor growth was investigated using a subcutaneous xenograft tumor mouse model. RESULTS: We demonstrated that CCDC106 knockdown enhanced apoptosis by stabilizing p53 and suppressed cell viability, colony formation, migration and invasion in cervical cancer HeLa and breast cancer MCF7 cells with wild-type p53 (wtp53), whereas CCDC106 overexpression exerted the opposite effects in normal breast epithelial HBL100 and cervical cancer SiHa cells with wtp53. However, CCDC106 had no similar effects on p53-mutant cervical and breast cancer cells (C33A and MDA-MB-231). Further study showed that CK2 interacts with CCDC106 through its regulatory ß subunit and then phosphorylates CCDC106 at Ser-130 and Ser-147. The phosphorylation of CCDC106 at Ser-130 and Ser-147 is required for its interaction with p53 and nuclear localization, respectively. Inhibiting CCDC106 phosphorylation by substituting both Ser-130 and Ser-147 with alanine or treating cells with the CK2 inhibitor CX-4945 abrogated CCDC106-induced p53 degradation and its oncogenic function in cells with wtp53. Wildtype CCDC106, but not Ser-130/- 147 mutant CCDC106, enhanced tumor growth and p53 degradation in a xenograft mouse model. Moreover, suppression of CCDC106 increased CX-4945 sensitivity of cancer cells with wtp53. CONCLUSION: This study revealed a CK2/CCDC106/p53 signaling axis in the progression of breast and cervical cancers, which may provide a new therapeutic target for cancer treatment.


Assuntos
Neoplasias da Mama/metabolismo , Proteínas de Transporte/metabolismo , Caseína Quinase II/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Neoplasias do Colo do Útero/metabolismo , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/genética , Caseína Quinase II/genética , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Progressão da Doença , Feminino , Técnicas de Silenciamento de Genes , Células HEK293 , Células HeLa , Xenoenxertos , Humanos , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosforilação , Transfecção , Proteína Supressora de Tumor p53/antagonistas & inibidores , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia
10.
Org Biomol Chem ; 17(4): 916-929, 2019 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-30629065

RESUMO

In this article, we describe our efforts in the search of MMP2/CK2 dual targeting inhibitors. We have followed a rational drug design approach based on our experience in the selective inhibition of these two enzymes. We have successfully obtained highly active MMP2 (10, IC50 = 70 nM; 11, IC50 = 100 nM) and CK2 (16a, IC50 = 500 nM) inhibitors. However, structural fine tuning of these small molecules to simultaneously target both enzymes turned out to be an unattainable goal. Unexpectedly, we were lucky to identify new and selective MMP13 inhibitors (10, IC50 = 3.7 nM and 11, IC50 = 5.6 nM) with a novel TBB-derived scaffold. These compounds constitute an interesting starting point for further optimization.


Assuntos
Caseína Quinase II/antagonistas & inibidores , Metaloproteinase 13 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Caseína Quinase II/metabolismo , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/química , Relação Estrutura-Atividade
11.
J Biol Chem ; 294(7): 2365-2374, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30617183

RESUMO

The mammalian lipin 1 phosphatidate phosphatase is a key regulatory enzyme in lipid metabolism. By catalyzing phosphatidate dephosphorylation, which produces diacylglycerol, the enzyme plays a major role in the synthesis of triacylglycerol and membrane phospholipids. The importance of lipin 1 to lipid metabolism is exemplified by cellular defects and lipid-based diseases associated with its loss or overexpression. Phosphorylation of lipin 1 governs whether it is associated with the cytoplasm apart from its substrate or with the endoplasmic reticulum membrane where its enzyme reaction occurs. Lipin 1ß is phosphorylated on multiple sites, but less than 10% of them are ascribed to a specific protein kinase. Here, we demonstrate that lipin 1ß is a bona fide substrate for casein kinase II (CKII), a protein kinase that is essential to viability and cell cycle progression. Phosphoamino acid analysis and phosphopeptide mapping revealed that lipin 1ß is phosphorylated by CKII on multiple serine and threonine residues, with the former being major sites. Mutational analysis of lipin 1ß and its peptides indicated that Ser-285 and Ser-287 are both phosphorylated by CKII. Substitutions of Ser-285 and Ser-287 with nonphosphorylatable alanine attenuated the interaction of lipin 1ß with 14-3-3ß protein, a regulatory hub that facilitates the cytoplasmic localization of phosphorylated lipin 1. These findings advance our understanding of how phosphorylation of lipin 1ß phosphatidate phosphatase regulates its interaction with 14-3-3ß protein and intracellular localization and uncover a mechanism by which CKII regulates cellular physiology.


Assuntos
Caseína Quinase II/química , Fosfatidato Fosfatase/química , Fosfoproteínas/química , Proteínas 14-3-3 , Substituição de Aminoácidos , Animais , Caseína Quinase II/genética , Caseína Quinase II/metabolismo , Retículo Endoplasmático/química , Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Membranas Intracelulares/química , Membranas Intracelulares/metabolismo , Camundongos , Mutação de Sentido Incorreto , Fosfatidato Fosfatase/genética , Fosfatidato Fosfatase/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Fosforilação/genética , Serina/química , Serina/genética , Serina/metabolismo
12.
Curr Protein Pept Sci ; 20(6): 547-562, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30659536

RESUMO

Substrate pleiotropicity, a very acidic phosphorylation consensus sequence, and an apparent uncontrolled activity, are the main features of CK2, a Ser/Thr protein kinase that is required for a plethora of cell functions. Not surprisingly, CK2 appears to affect cytoskeletal structures and correlated functions such as cell shape, mechanical integrity, cell movement and division. This review outlines our current knowledge of how CK2 regulates cytoskeletal structures, and discusses involved pathways and molecular mechanisms.


Assuntos
Caseína Quinase II/metabolismo , Citoesqueleto/metabolismo , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Animais , Caseína Quinase II/química , Divisão Celular , Movimento Celular , Forma Celular , Humanos , Fosforilação , Conformação Proteica , Processamento de Proteína Pós-Traducional , Septinas/metabolismo , Transdução de Sinais , Tubulina (Proteína)/metabolismo
13.
J Biol Chem ; 294(10): 3772-3782, 2019 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-30635402

RESUMO

DNA topoisomerase II (topo II) regulates the topological state of DNA and is necessary for DNA replication, transcription, and chromosome segregation. Topo II has essential functions in cell proliferation and therefore is a critical target of anticancer drugs. In this study, using Phos-tag SDS-PAGE analysis in fission yeast (Schizosaccharomyces pombe), we identified casein kinase II (Cka1/CKII)-dependent phosphorylation at the C-terminal residues Ser1363 and Ser1364 in topo II. We found that this phosphorylation decreases the inhibitory effect of an anticancer catalytic inhibitor of topo II, ICRF-193, on mitosis. Consistent with the constitutive activity of Cka1/CKII, Ser1363 and Ser1364 phosphorylation of topo II was stably maintained throughout the cell cycle. We demonstrate that ICRF-193-induced chromosomal mis-segregation is further exacerbated in two temperature-sensitive mutants, cka1-372 and cka1/orb5-19, of the catalytic subunit of CKII or in the topo II nonphosphorylatable alanine double mutant top2-S1363A,S1364A but not in cells of the phosphomimetic glutamate double mutant top2-S1363E,S1364E Our results suggest that Ser1363 and Ser1364 in topo II are targeted by Cka1/CKII kinase and that their phosphorylation facilitates topo II ATPase activity in the N-terminal region, which regulates protein turnover on chromosome DNA. Because CKII-mediated phosphorylation of the topo II C-terminal domain appears to be evolutionarily conserved, including in humans, we propose that attenuation of CKII-controlled topo II phosphorylation along with catalytic topo II inhibition may promote anticancer effects.


Assuntos
Biocatálise/efeitos dos fármacos , Caseína Quinase II/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Piperazinas/farmacologia , Schizosaccharomyces/enzimologia , Inibidores da Topoisomerase II/farmacologia , Segregação de Cromossomos/efeitos dos fármacos , DNA Topoisomerases Tipo II/genética , Mitose/efeitos dos fármacos , Mitose/genética , Mutação , Fosforilação/efeitos dos fármacos , Schizosaccharomyces/citologia , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo
14.
Int J Mol Med ; 43(2): 1033-1040, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30535443

RESUMO

Protein kinase casein kinase 2 (CK2) is important in the regulation of cell proliferation and death, even under pathological conditions. Previously, we reported that CK2 regulates the expression of heme oxygenase­1 (HO­1) in stress­induced chondrocytes. In the present study, it was shown that CK2 is involved in the dedifferentiation and cellular senescence of chondrocytes. Treatment of primary articular chondrocytes with CK2 inhibitors, 4,5,6,7­terabromo­2­azabenzimidazole (TBB) or 5,6­dichlorobenzimidazole 1­ß­D­ribofuranoside (DRB), induced an increase in senescence­associated ß­galactosidase (SA­ß­gal) staining. In addition, TBB reduced the expression of type II collagen and stimulated the accumulation of ß­catenin, phenotypic markers of chondrocyte differentiation and dedifferentiation, respectively. It was also observed that the abrogation of CK2 activity by CK2 small interfering RNA induced phenotypes of chondrocyte senescence. The association between HO­1 and cellular senescence was also examined in CK2 inhibitor­treated chondrocytes. Pretreatment with 3­morpholinosydnonimine hydrochloride, an inducer of the HO­1 expression, or overexpression of the HO­1 gene significantly delayed chondrocyte senescence. These results show that CK2 is associated with chondrocyte differentiation and cellular senescence and that this is due to regulation of the expression of HO­1. Furthermore, the findings suggest that CK2 is crucial as an anti­aging factor during chondrocyte senescence.


Assuntos
Cartilagem Articular/citologia , Cartilagem Articular/metabolismo , Caseína Quinase II/antagonistas & inibidores , Caseína Quinase II/metabolismo , Condrócitos/metabolismo , Regulação da Expressão Gênica , Heme Oxigenase-1/genética , Animais , Caseína Quinase II/genética , Senescência Celular/genética , Heme Oxigenase-1/metabolismo , Masculino , Ratos , Triazóis/farmacologia
15.
Cell Rep ; 25(12): 3476-3489.e5, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30566871

RESUMO

Spt6 is a histone chaperone that associates with RNA polymerase II and deposits nucleosomes in the wake of transcription. Although Spt6 has an essential function in nucleosome deposition, it is not known whether this function is influenced by post-translational modification. Here, we report that casein kinase II (CKII) phosphorylation of Spt6 is required for nucleosome occupancy at the 5' ends of genes to prevent aberrant antisense transcription and enforce transcriptional directionality. Mechanistically, we show that CKII phosphorylation of Spt6 promotes the interaction of Spt6 with Spn1, a binding partner required for chromatin reassembly and full recruitment of Spt6 to genes. Our study defines a function for CKII phosphorylation in transcription and highlights the importance of post-translational modification in histone chaperone function.


Assuntos
Caseína Quinase II/metabolismo , Chaperonas de Histonas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Transcrição Genética , Fatores de Elongação da Transcrição/metabolismo , Cromatina/metabolismo , Genoma Fúngico , Chaperonas de Histonas/química , Modelos Biológicos , Nucleossomos/metabolismo , Fosforilação , Ligação Proteica , Proteínas de Saccharomyces cerevisiae/química , Fatores de Elongação da Transcrição/química
16.
Semin Oncol ; 45(1-2): 58-67, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-30318085

RESUMO

Protein kinase CK2, formerly referred to as casein kinase II, is a serine/threonine kinase often found overexpressed in solid tumors and hematologic malignancies that phosphorylates many substrates integral to the hallmarks of cancer. CK2 has emerged as a viable oncology target having been experimentally validated with different kinase inhibitors, including small molecule ATP-competitors, synthetic peptides, and antisense oligonucleotides. To date only two CK2 inhibitors, CIGB-300 and CX-4945, have entered the clinic in phase 1-2 trials. This review provides information on CIGB-300, a cell-permeable cyclic peptide that inhibits CK2-mediated phosphorylation by targeting the substrate phosphoacceptor domain. We review data that support the concept of CK2 as an anticancer target, address the mechanism of action, and summarize preclinical studies showing antiangiogenic and antimetastatic effects as well as synergism with anticancer drugs in preclinical models. We also summarize early clinical research (phase 1/2 trials) of CIGB-300 in cervical cancer, including data in combination with chemoradiotherapy. The clinical data demonstrate the safety, tolerability, and clinical effects of intratumoral injections of CIGB-300 and provide the foundation for future phase 3 clinical trials in locally advanced cervical cancer in combination with standard chemoradiotherapy.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Peptídeos Cíclicos/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Antineoplásicos/farmacologia , Caseína Quinase II/antagonistas & inibidores , Caseína Quinase II/metabolismo , Ensaios Clínicos como Assunto , Humanos , Neoplasias/metabolismo , Peptídeos Cíclicos/farmacologia , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia
17.
Biochemistry (Mosc) ; 83(6): 746-754, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30195331

RESUMO

The role of protein kinases p38 and CK2 (casein kinase II) in the response of RAW 264.7 macrophages to the lipopolysaccharide (LPS) from gram-negative bacteria was studied. Using specific p38 and CK2 inhibitors (p38 MAP kinase Inhibitor XI and casein kinase II Inhibitor III, respectively), we investigated the effects of these protein kinases on (i) LPS-induced activation of signaling pathways involving nuclear factor κB (NF-κB), stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), p38, and interferon regulatory factor 3 (IRF3); (ii) expression of Toll-like receptor 4 (TLR4) and inducible heat-shock proteins HSP72 and HSP90; and (iii) production of interleukins IL-1α, IL-1ß, IL-6, tumor necrosis factor α, and IL-10. Activation of the proapoptotic signaling in the macrophages was evaluated from the ratio between the active and inactive caspase-3 forms and p53 phosphorylation. Six hours after LPS addition (2.5 µg/ml) to RAW 264.7 cells, activation of the TLR4 signaling pathways was observed that was accompanied by a significant increase in phosphorylation of IκB kinase α/ß, NF-κB (at both Ser536 and Ser276), p38, JNK, and IRF3. Other effects of macrophage incubation with LPS were an increase in the contents of TLR4, inducible heat-shock proteins (HSPs), and pro- and anti-inflammatory cytokines, as well as slight activation of the pro-apoptotic signaling in the cells. Using inhibitor analysis, we found that during the early response of macrophages to the LPS, both CK2 and p38 modulate activation of MAP kinase and NF-κB signaling pathways and p65 phosphorylation at Ser276/Ser536 and cause accumulation of HSP72, HSP90 and the LPS-recognizing receptor TLR4. Suppression of the p38 MAP kinase and CK2 activities by specific inhibitors (Inhibitor XI and Inhibitor III, respectively) resulted in the impairment of the macrophage effector function manifested as a decrease in the production of the early-response proinflammatory cytokines and disbalance between the pro- and anti-apoptotic signaling pathways leading presumably to apoptosis development. Taken together, our data indicate the inefficiency of therapeutic application of p38 and CK2 inhibitors during the early stages of inflammatory response.


Assuntos
Caseína Quinase II/metabolismo , Lipopolissacarídeos/toxicidade , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Caseína Quinase II/antagonistas & inibidores , Citocinas/metabolismo , Proteínas de Choque Térmico HSP72/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Fator Regulador 3 de Interferon/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , NF-kappa B/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Células RAW 264.7 , Receptor 4 Toll-Like/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores
18.
Proc Natl Acad Sci U S A ; 115(30): E7081-E7090, 2018 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-29987005

RESUMO

The huntingtin N17 domain is a modulator of mutant huntingtin toxicity and is hypophosphorylated in Huntington's disease (HD). We conducted high-content analysis to find compounds that could restore N17 phosphorylation. One lead compound from this screen was N6-furfuryladenine (N6FFA). N6FFA was protective in HD model neurons, and N6FFA treatment of an HD mouse model corrects HD phenotypes and eliminates cortical mutant huntingtin inclusions. We show that N6FFA restores N17 phosphorylation levels by being salvaged to a triphosphate form by adenine phosphoribosyltransferase (APRT) and used as a phosphate donor by casein kinase 2 (CK2). N6FFA is a naturally occurring product of oxidative DNA damage. Phosphorylated huntingtin functionally redistributes and colocalizes with CK2, APRT, and N6FFA DNA adducts at sites of induced DNA damage. We present a model in which this natural product compound is salvaged to provide a triphosphate substrate to signal huntingtin phosphorylation via CK2 during low-ATP stress under conditions of DNA damage, with protective effects in HD model systems.


Assuntos
Adenina , Adutos de DNA/metabolismo , Dano ao DNA , Doença de Huntington/tratamento farmacológico , Neurônios/metabolismo , Transdução de Sinais/efeitos dos fármacos , Adenina/análogos & derivados , Adenina/farmacocinética , Adenina/farmacologia , Adenina Fosforribosiltransferase/genética , Adenina Fosforribosiltransferase/metabolismo , Animais , Caseína Quinase II/genética , Caseína Quinase II/metabolismo , Linhagem Celular Transformada , Adutos de DNA/genética , Modelos Animais de Doenças , Humanos , Doença de Huntington/genética , Doença de Huntington/metabolismo , Doença de Huntington/patologia , Camundongos , Camundongos Transgênicos , Neurônios/patologia , Fosforilação/efeitos dos fármacos , Fosforilação/genética , Transdução de Sinais/genética
19.
Biochem Biophys Res Commun ; 501(4): 1080-1084, 2018 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-29778533

RESUMO

A DNA double strand break (DSB) is one of the most cytotoxic DNA lesions, but it can be repaired by non-homologous end joining (NHEJ) or by homologous recombination. The choice between these two repair pathways depends on the cell cycle stage. Although NHEJ constitutes a simple re-ligation reaction, the regulatory mechanism(s) controlling its activity has not been fully characterized. Lif1 is a regulatory subunit of the NHEJ-specific DNA ligase IV and interacts with Xrs2 of the MRX complex which is a key factor in DSB repair. Specifically, the C-terminal region of Lif1, which contains a CK2-specific phosphorylation motif, interacts with the FHA domain of Xrs2 during canonical- NHEJ (C-NHEJ). Herein, we show that Lif1 and Cka2, a catalytic subunit of yeast CK2, interact and that the C-terminal phosphorylation consensus motif in Lif1 is phosphorylated by recombinant CK2. These observations suggest that phosphorylation of Lif1 by CK2 at a DSB site promotes the Lif1-Xrs2 interaction and facilitates C-NHEJ.


Assuntos
Caseína Quinase II/metabolismo , Reparo do DNA por Junção de Extremidades , Proteínas de Ligação a DNA/química , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Sequência de Aminoácidos , Domínio Catalítico , Proteínas de Ligação a DNA/metabolismo , Fosforilação , Ligação Proteica , Domínios Proteicos , Proteínas Recombinantes/metabolismo
20.
Planta ; 248(3): 571-578, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29799081

RESUMO

MAIN CONCLUSION: Our transient gene expression analyses in Arabidopsis protoplasts support the view that CK2αs and CK2ßs positively and negatively modulate ABRE-dependent gene expression, respectively. The phytohormone abscisic acid (ABA) regulates the expression of thousands of genes via ABA-responsive elements (ABREs), and has a crucial role in abiotic stress response. Casein kinase II (CK2), a conserved Ser/Thr protein kinase in eukaryotes, is essential for plant viability. Although the CK2 has been known as a tetrameric holoenzyme comprised of two catalytic α and two regulatory ß subunits, each of the two types of subunits has been proposed to have independent functions. The Arabidopsis genome encodes four α subunits (CK2α1, CK2α2, CK2α3, CK2α4) and four ß subunits (CK2ß1, CK2ß2, CK2ß3, CK2ß4). There is a growing body of evidence linking CK2 to ABA signaling and abiotic stress responses. However, the roles of each CK2 subunit in ABA signaling remain largely elusive. Using the transient expression system with the core ABA signaling components in Arabidopsis leaf mesophyll protoplasts, we show here that CK2α1 and CK2α2 (CK2α1/2) positively modulate ABRE-dependent gene expression as ABA signal output in ABA signaling, whereas all four CK2ßs negatively modulate the ABRE-dependent gene expression mediated by subclass III SnRK2-AREB/ABF pathway and by CK2α1/2. These data indicate that CK2α1/2 and CK2ßs positively and negatively modulate ABA signal output, respectively, suggesting that the quantitative balance of CK2 subunits determines the ABA signal output in plants. Given that CK2s act as pleiotropic enzymes involved in multiple developmental and stress-responsive processes, our findings suggest that CK2 subunits may be involved in integration and coordination of ABA-dependent and -independent signaling.


Assuntos
Ácido Abscísico/metabolismo , Arabidopsis/metabolismo , Caseína Quinase II/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Caseína Quinase II/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Filogenia , Folhas de Planta/metabolismo , Protoplastos/metabolismo , Transdução de Sinais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA