Phosphorylation of connexin 43 acts as a stimuli for proteasome-dependent degradation of the protein in lens epithelial cells
Autor(a) principal: | |
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Data de Publicação: | 2003 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10316/12773 |
Resumo: | Purpose: The lens is an avascular organ in which gap junctions provide a pathway for intercellular communication, which is vital to maintain lens transparency. Connexin43 (Cx43) is the main gap-junctional protein in lens epithelial cells. Phosphorylation of connexins is implicated in the regulation of intercellular communication. The objective of this report is to determine whether phosphorylation of Cx43 in lens epithelial cells alters its resistance to degradation by a proteasome dependent mechanism. Methods: Primary cultures of LEC were incubated with protein kinase activator (TPA) and allowed to recover either in the presence or absence of proteasome or lysosome inhibitors. The contribution of the proteasome for the degradation of the phosphorylated form of Cx43 was further investigated by metabolic labeling with 32P or [35S]-methionine. Subcellular distribution of Cx43 was evaluated by immunofluorescence using antibodies directed against Cx43. Gap junctional inter- cellular communication was evaluated by transfer of the dye Lucifer yellow. Results: Inhibitors of proteasome and lysosome both stabilize Cx43, while proteasome inhibitors preferentially stabilize the phosphorylated form of the protein. Pulse chase experiments with 32P or [35S]-methionine show that while phosphory- lation destabilizes Cx43, proteasome inhibitors stabilize the phosphorylated form of the protein. Intercellular communica- tion is inhibited by TPA and can be restored by proteasome inhibitors, probably by preventing loss of Cx43 from the plasma membrane following treatment with TPA. Conclusions: Our observations support a model in which the combined action of phosphorylation and protein degrada- tion by a proteasome dependent mechanism contribute to regulate Cx43 stability in plasma membrane and intercellular communication through gap junctions, thus adding a novel level of regulation to intercellular communication in lens epithelial cells |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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7160 |
spelling |
Phosphorylation of connexin 43 acts as a stimuli for proteasome-dependent degradation of the protein in lens epithelial cellsPurpose: The lens is an avascular organ in which gap junctions provide a pathway for intercellular communication, which is vital to maintain lens transparency. Connexin43 (Cx43) is the main gap-junctional protein in lens epithelial cells. Phosphorylation of connexins is implicated in the regulation of intercellular communication. The objective of this report is to determine whether phosphorylation of Cx43 in lens epithelial cells alters its resistance to degradation by a proteasome dependent mechanism. Methods: Primary cultures of LEC were incubated with protein kinase activator (TPA) and allowed to recover either in the presence or absence of proteasome or lysosome inhibitors. The contribution of the proteasome for the degradation of the phosphorylated form of Cx43 was further investigated by metabolic labeling with 32P or [35S]-methionine. Subcellular distribution of Cx43 was evaluated by immunofluorescence using antibodies directed against Cx43. Gap junctional inter- cellular communication was evaluated by transfer of the dye Lucifer yellow. Results: Inhibitors of proteasome and lysosome both stabilize Cx43, while proteasome inhibitors preferentially stabilize the phosphorylated form of the protein. Pulse chase experiments with 32P or [35S]-methionine show that while phosphory- lation destabilizes Cx43, proteasome inhibitors stabilize the phosphorylated form of the protein. Intercellular communica- tion is inhibited by TPA and can be restored by proteasome inhibitors, probably by preventing loss of Cx43 from the plasma membrane following treatment with TPA. Conclusions: Our observations support a model in which the combined action of phosphorylation and protein degrada- tion by a proteasome dependent mechanism contribute to regulate Cx43 stability in plasma membrane and intercellular communication through gap junctions, thus adding a novel level of regulation to intercellular communication in lens epithelial cellsMolecular Vision2003-01-30info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/12773http://hdl.handle.net/10316/12773engMolecular Vision. 9 (2003) 24-301090-0535Girão, HenriquePereira, Pauloinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2022-05-25T04:09:36Zoai:estudogeral.uc.pt:10316/12773Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T20:43:38.154610Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Phosphorylation of connexin 43 acts as a stimuli for proteasome-dependent degradation of the protein in lens epithelial cells |
title |
Phosphorylation of connexin 43 acts as a stimuli for proteasome-dependent degradation of the protein in lens epithelial cells |
spellingShingle |
Phosphorylation of connexin 43 acts as a stimuli for proteasome-dependent degradation of the protein in lens epithelial cells Girão, Henrique |
title_short |
Phosphorylation of connexin 43 acts as a stimuli for proteasome-dependent degradation of the protein in lens epithelial cells |
title_full |
Phosphorylation of connexin 43 acts as a stimuli for proteasome-dependent degradation of the protein in lens epithelial cells |
title_fullStr |
Phosphorylation of connexin 43 acts as a stimuli for proteasome-dependent degradation of the protein in lens epithelial cells |
title_full_unstemmed |
Phosphorylation of connexin 43 acts as a stimuli for proteasome-dependent degradation of the protein in lens epithelial cells |
title_sort |
Phosphorylation of connexin 43 acts as a stimuli for proteasome-dependent degradation of the protein in lens epithelial cells |
author |
Girão, Henrique |
author_facet |
Girão, Henrique Pereira, Paulo |
author_role |
author |
author2 |
Pereira, Paulo |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Girão, Henrique Pereira, Paulo |
description |
Purpose: The lens is an avascular organ in which gap junctions provide a pathway for intercellular communication, which is vital to maintain lens transparency. Connexin43 (Cx43) is the main gap-junctional protein in lens epithelial cells. Phosphorylation of connexins is implicated in the regulation of intercellular communication. The objective of this report is to determine whether phosphorylation of Cx43 in lens epithelial cells alters its resistance to degradation by a proteasome dependent mechanism. Methods: Primary cultures of LEC were incubated with protein kinase activator (TPA) and allowed to recover either in the presence or absence of proteasome or lysosome inhibitors. The contribution of the proteasome for the degradation of the phosphorylated form of Cx43 was further investigated by metabolic labeling with 32P or [35S]-methionine. Subcellular distribution of Cx43 was evaluated by immunofluorescence using antibodies directed against Cx43. Gap junctional inter- cellular communication was evaluated by transfer of the dye Lucifer yellow. Results: Inhibitors of proteasome and lysosome both stabilize Cx43, while proteasome inhibitors preferentially stabilize the phosphorylated form of the protein. Pulse chase experiments with 32P or [35S]-methionine show that while phosphory- lation destabilizes Cx43, proteasome inhibitors stabilize the phosphorylated form of the protein. Intercellular communica- tion is inhibited by TPA and can be restored by proteasome inhibitors, probably by preventing loss of Cx43 from the plasma membrane following treatment with TPA. Conclusions: Our observations support a model in which the combined action of phosphorylation and protein degrada- tion by a proteasome dependent mechanism contribute to regulate Cx43 stability in plasma membrane and intercellular communication through gap junctions, thus adding a novel level of regulation to intercellular communication in lens epithelial cells |
publishDate |
2003 |
dc.date.none.fl_str_mv |
2003-01-30 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10316/12773 http://hdl.handle.net/10316/12773 |
url |
http://hdl.handle.net/10316/12773 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Molecular Vision. 9 (2003) 24-30 1090-0535 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Molecular Vision |
publisher.none.fl_str_mv |
Molecular Vision |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
|
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1799133708505055232 |