Navegando por Palavras-chave "Proteasome"
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- ItemSomente MetadadadosEffect of ionizing radiation exposure on Trypanosoma cruzi ubiquitin-proteasome system(Elsevier Science Bv, 2017) Cerqueira, Paula Gonçalves; Passos-Silva, Danielle Gomes; Vieira-da-Rocha, João Pedro; Mendes, Isabela Cecilia; Oliveira, Karla Andrade de; Oliveira, Camila Franco Batista de; Vilela, Liza Figueiredo Felicori; Nagem, Ronaldo Alves Pinto; Cardoso, Joseane; Nardelli, Sheila Cristina; Krieger, Marco Aurélio; Franco, Gloria Regina; Macedo, Andrea Mara; Pena, Sergio Danilo Junho; Schenkman, Sergio [UNIFESP]; Gomes, Dawidson A.; Guerra-Sa, Renata; Machado, Carlos Renato; Universidade Federal de São Paulo (UNIFESP)In recent years, proteasome involvement in the damage response induced by ionizing radiation (IR) became evident. However, whether proteasome plays a direct or indirect role in IR-induced damage response still unclear. Trypanosoma cruzi is a human parasite capable of remarkable high tolerance to IR, suggesting a highly efficient damage response system. Here, we investigate the role of T. cruzi proteasome in the damage response induced by IR. We exposed epimastigotes to high doses of gamma ray and we analyzed the expression and subcellular localization of several components of the ubiquitin-proteasome system. We show that proteasome inhibition increases IR-induced cell growth arrest and proteasome-mediated proteolysis is altered after parasite exposure. We observed nuclear accumulation of 19S and 20S proteasome subunits in response to IR treatments. Intriguingly, the dynamic of 19S particle nuclear accumulation was more similar to the dynamic observed for Rad51 nuclear translocation than the observed for 20S. In the other hand, 20S increase and nuclear translocation could be related with an increase of its regulator PA26 and high levels of proteasome-mediated proteolysis in vitro. The intersection between the opposed peaks of 19S and 20S protein levels was marked by nuclear accumulation of both 20S and 19S together with Ubiquitin, suggesting a role of ubiquitin-proteasome system in the nuclear protein turnover at the time. Our results revealed the importance of proteasome-mediated proteolysis in T. cruzi IR-induced damage response suggesting that proteasome is also involved in T. cruzi IR tolerance. Moreover, our data support the possible direct/signaling role of 19S in DNA damage repair. Based on these results, we speculate that spatial and temporal differences between the 19S particle and 20S proteasome controls proteasome multiple roles in IR damage response. (C) 2017 Elsevier B.V. All rights reserved.
- ItemAcesso aberto (Open Access)Envolvimento da via autofágica no envelhecimento bem-sucedido(Universidade Federal de São Paulo (UNIFESP), 2015-09-30) Chaves, Carolina Fioroto [UNIFESP]; D'Almeida, Vania [UNIFESP]; Mazzotti, Diego Robles [UNIFESP]; http://lattes.cnpq.br/6848696921553394; http://lattes.cnpq.br/7220411418339421; http://lattes.cnpq.br/2107925110083483; Universidade Federal de São Paulo (UNIFESP)O envelhecimento é um fenômeno no qual há o declínio dos processos essenciais para a sobrevivência celular. As principais vias que mantem a limpeza e a homeostase celular são a autofagia e o proteassomo. Investigamos estas vias em três diferentes grupos de indivíduos: Jovens (20-30 anos), Idosos (60-70 anos) e Longevos (80-105 anos) por meio da quantificação do proteassomo no plasma e da expressão de genes relacionados à maquinaria autofágica em sangue periférico. Nos níveis do proteassomo quantificados no plasma, não foram encontradas diferenças significativas entre os três grupos estudados, assim como não foram encontradas correlações entre os níveis de proteassomo e as idades dentro de cada grupo. Com relação à via autofágica, foi medida a expressão de 84 genes, sendo que destes, apenas 5 foram diferencialmente expressos: ATG4C (codifica proteína com atividade de protease, envolvido na formação do vacúolo autofágico; responsável pelo transporte de proteínas e; responsável pelas proteínas alvo da membrana/vacúolo) BCL2L1 (co-regulador da autofagia e apoptose), TP53 (co-regulador da autofagia e do ciclo celular; co-regulador da autofagia e apoptose), EIF2AK3 (co-regulador da autofagia e apoptose e indutor da autofagia por patógenos intracelulares) e EIF4G1 (regulador da autofagia em resposta a outros sinais intracelulares). Foi feita também análise de rede e de enriquecimento para observar as interações entre os genes diferencialmente expressos e os processos nos quais eles estão envolvidos. Observamos uma interação entre quatro dos cinco genes diferencialmente expressos, e a participação destes genes, seja direta ou indiretamente, no processo transcricional, sugerindo que a transcrição possa estar afetada pelo processo de envelhecimento. Foi verificado que os Longevos apresentaram tanto uma manutenção da expressão dos genes ligados à maquinaria autofágica, quanto uma manutenção dos níveis de proteassomo, em relação ao grupo Idoso, fatores estes que podem ser importantes para um envelhecimento bem-sucedido.
- ItemSomente MetadadadosAn extracellular proteasome releases endostatin from human collagen XVIII(Springer, 2017) Reiss-Pistilli, Maria L. V.; Schuppan, Detlef; Barroso, Madalena M. S.; Assuncao-Miranda, Iranaia; Farias, Shirley [UNIFESP]; Lery, Leticia; Bauer, Michael; Juliano, Luiz [UNIFESP]; Juliano, Maria A. [UNIFESP]; Coelho-Sampaio, TatianaEndostatin is a potent anti-angiogenic and anti-tumor protein capable of regressing tumors without inducing acquired resistance. Since it is a fragment of the parental molecule, collagen XVIII, its endogenous production depends on the activity of a specific proteolytic enzyme. While such an enzyme has been described in mice, a human counterpart has not been identified so far. Here, we searched for this enzyme by using a fluorescence resonance energy transfer peptide containing the cleavage site of human collagen XVIII. We found that the cleavage activity was present in various murine and human tumor cells but not in untransformed cells. It was ascribed to a large protein complex identified as an extracellular form of proteasome 20S. Since circulating proteasome 20S has recently emerged as an important marker of tumor progression, the possibility of proteasomes controlling the production of angiostatic endostatin may inspire the development of new anticancer therapies.
- ItemSomente MetadadadosMolecular characterization and intracellular distribution of the alpha 5 subunit of Trypanosoma cruzi 20S proteasome(Elsevier B.V., 2009-12-01) Gutierrez, Bessy; Osorio, Luis; Motta, Maria Cristina M.; Huima-Byron, Telervo; Erdjument-Bromage, Heydeie; Munoz, Christian; Sagua, Hernan; Mortara, Renato A. [UNIFESP]; Echeverria, Alex; Araya, Jorge E.; Gonzalez, Jorge; Univ Antofagasta; Universidade Federal do Rio de Janeiro (UFRJ); New York Blood Ctr; Mem Sloan Kettering Canc Ctr; Universidade Federal de São Paulo (UNIFESP); N Catholic UnivThree different monoclonal antibodies were produced against Trypanosona cruzi proteasomes. These antibodies were shown to react with a single 27-kDa hand on immunoblots of purified proteasomes. Using a 7E5 monoclonal antibody (IgG1) that recognized the alpha 5 subunit of protozoan protease we have studied the intracellular distribution of the T cruzi 20S proteasome. Contrary to all cell types described to date, T cruzi 20S proteasome was found not only in the cytoplasm and nucleus but also in the kinetoplast. As revealed by confocal microscopy, the reactivity of monoclonal antibody 7E5 was highly specific for protozoan proteasome because the antibody recognized only the proteasomes from parasites and not those from the mammalian host in T. cruzi infected cells. These findings were confirmed by immunoblots or immunoprecipitations, followed by chymotrypsin-like activity detection in kinetoplasts isolated by differential centrifugation and sucrose density gradients. Proteasome 20S was present in all T cruzi stages and only slight differences in terms of relative abundance were found. the potential role of the proteasome in kinetoplast remodeling remains to be determined. (C) 2009 Published by Elsevier Ireland Ltd.
- ItemAcesso aberto (Open Access)A novel proteasome inhibitor acting in mitochondrial dysfunction, ER stress and ROS production(Springer, 2013-06-01) Maria, Durvanei Augusto; Souza, Jean Gabriel de [UNIFESP]; Morais, Katia Luciano Pereira [UNIFESP]; Berra, Carolina Maria; Zampolli, Hamilton de Campos; Demasi, Marilene; Simons, Simone Michaela; Saito, Renata de Freitas; Chammas, Roger; Chudzinski-Tavassi, Ana Marisa [UNIFESP]; Inst Butantan; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)In cancer-treatment, potentially therapeutic drugs trigger their effects through apoptotic mechanisms. Generally, cell response is manifested by Bcl-2 family protein regulation, the impairment of mitochondrial functions, and ROS production. Notwithstanding, several drugs operate through proteasome inhibition, which, by inducing the accumulation and aggregation of misfolded or unfolded proteins, can lead to endoplasmic reticulum (ER) stress. Accordingly, it was shown that Amblyomin-X, a Kunitz-type inhibitor identified in the transcriptome of the Amblyomma cajennense tick by ESTs sequence analysis of a cDNA library, obtained in recombinant protein form, induces apoptosis in murine renal adenocarcinoma (RENCA) cells by: inducing imbalance between pro- and anti-apoptotic Bcl-2 family proteins, dysfunction/mitochondrial damage, production of reactive oxygen species (ROS), caspase cascade activation, and proteasome inhibition, all ER-stress inductive. Moreover, there was no manifest action on normal mouse-fibroblast cells (NHI3T3), suggesting an Amblyomin-X tumor-cell selectivity. Taken together, these evidences indicate that Amblyomin-X could be a promising candidate for cancer therapy.
- ItemSomente MetadadadosSpecific role of cytoplasmic dynein in the mechanism of action of an antitumor molecule, Amblyomin-X(Elsevier Inc, 2016) Pacheco, Mario T. F.; Morais, Katia L. P. [UNIFESP]; Berra, Carolina M.; Demasi, Marilene; Sciani, Juliana M.; Branco, Vania G.; Bosch, Rosemary V.; Iqbal, Asif; Chudzinski-Tavassi, Ana MarisaThe Kunitz-type recombinant protein, Amblyomin-X, is an antitumor recombinant molecule from a cDNA library prepared from the salivary glands of the tick Amblyomma cajennense. The primary target of this protein appears to be the proteasome. Amblyomin-X increased gene and protein expression of distinct subunits of the molecular motor dynein, which plays a key role in the intracellular transport. Herein, Amblyomin-X was specifically taken up by tumor cells through lipid-raft endocytic pathways, but not by fibroblasts. Moreover, dynein inhibitor, ciliobrevin A, decreased Amblyomin-X uptake by tumor cells. Furthermore, incubation of tumor cells with Amblyomin-X inhibited trypsin-like activity of the proteasome, which was restored upon pretreatment with ciliobrevin A. Only in tumor cells treated with Amblyomin-X, we identified proteins bounds to dynein that are related to aggresome formation, autophagy inhibition, and early and recycling endosome markers. In addition, Amblyomin-X was found to interact with dynein, increased Rab11A protein expression and Rab11A co-localization with the light intermediate chain 2 (LIC2) of dynein. Thereby, the results provide new insights on the antitumor mechanism of Amblyomin-X and reveal an unsuspected role of cytoplasmic dynein in its uptake, intracellular trafficking and pro-apoptotic action. (C) 2016 Published by Elsevier Inc.
- ItemSomente MetadadadosSpecific role of cytoplasmic dynein in the mechanism of action of an antitumor molecule, Amblyomin-X(Elsevier Inc, 2016) Pacheco, Mario T. F.; Morais, Katia L. P. [UNIFESP]; Berra, Carolina M.; Demasi, Marilene; Sciani, Juliana M.; Branco, Vania G.; Bosch, Rosemary V.; Iqbal, Asif; Chudzinski-Tavassi, Ana MarisaThe Kunitz-type recombinant protein, Amblyomin-X, is an antitumor recombinant molecule from a cDNA library prepared from the salivary glands of the tick Amblyomma cajennense. The primary target of this protein appears to be the proteasome. Amblyomin-X increased gene and protein expression of distinct subunits of the molecular motor dynein, which plays a key role in the intracellular transport. Herein, Amblyomin-X was specifically taken up by tumor cells through lipid-raft endocytic pathways, but not by fibroblasts. Moreover, dynein inhibitor, ciliobrevin A, decreased Amblyomin-X uptake by tumor cells. Furthermore, incubation of tumor cells with Amblyomin-X inhibited trypsin-like activity of the proteasome, which was restored upon pretreatment with ciliobrevin A. Only in tumor cells treated with Amblyomin-X, we identified proteins bounds to dynein that are related to aggresome formation, autophagy inhibition, and early and recycling endosome markers. In addition, Amblyomin-X was found to interact with dynein, increased Rab11A protein expression and Rab11A co-localization with the light intermediate chain 2 (LIC2) of dynein. Thereby, the results provide new insights on the antitumor mechanism of Amblyomin-X and reveal an unsuspected role of cytoplasmic dynein in its uptake, intracellular trafficking and pro-apoptotic action. (C) 2016 Published by Elsevier Inc.