Analysis of syntaxin-1 chaperones during synaptic activity

Detalhes bibliográficos
Autor(a) principal: Santos, Tatiana Cerveira Tavares dos
Data de Publicação: 2011
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10451/8888
Resumo: Tese de mestrado em Bioquímica, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2011
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spelling Analysis of syntaxin-1 chaperones during synaptic activitySNARE complexSyntaxin-1Munc-18SNAP-25ChaperonesTeses de mestrado - 2011Tese de mestrado em Bioquímica, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2011Neuronal communication is based on synaptic vesicle exocytosis, which is strongly regulated. The release of neurotransmitters from presynaptic nerve terminals requires cycles of protein-protein interactions. SNARE and SM proteins are universally involved in all intracellular membrane fusion reactions, and reside either on the target membrane (syntaxin-1 and synaptosome-associated protein of 25kDa (SNAP-25) or on the synaptic vesicle (synaptobrevin-2). Recent studies have identified chaperones for two SNARE proteins: synaptobrevin-2 and SNAP-25 . Since these SNARE chaperones seem essential for the long-term functioning of synapses, the question arises which molecule(s) may chaperone syntaxin-1. Previous studies have suggested that Munc-18 and SNAP-25 may chaperone syntaxin-1. Furthermore, it has been shown that chemical modification of syntaxin-1 or mutation on cysteine residue 145 increases its stability. To investigate a possible chaperone function of Munc-18 and SNAP-25 for syntaxin-1, I aimed to clarify whether this chemical modification inhibits syntaxin-1 degradation, whether the C145S mutation reproduces this modification, and whether this cysteine is normally involved in ubiquitination and degradation of syntaxin-1. To approach these aims, HEK-293T cells and neuronal cultures from wild-type mice were used in combination with overexpression of syntaxin-1 full-length, several truncations and its mutant C145S. Chemical agents were used to monitor syntaxin-1 levels. These experiments were analyzed by immunoprecipitation, immunoblotting or immunocytochemistry. Results suggest that munc-18 chaperones syntaxin-1, based on the following observations: 1) it increases syntaxin-1 levels and inhibits syntaxin-1 degradation in cotransfected HEK cells; 2) C145S mutation significantly stabilizes syntaxin-1 levels and results in less degradation products. C145S also dramatically reduces ubiquitination of syntaxin-1; 3) syntaxin-1 may be degraded via the lysosome. Lysosomal inhibitors revealed a trend towards stabilization of syntaxin-1 whereas proteasomal inhibitors showed no change. Yet, further experiments are needed to understand the precise role of C145S in the degradation mechanism of syntaxin-1.Sudhof, ThomasFarinha, Carlos, 1973-Repositório da Universidade de LisboaSantos, Tatiana Cerveira Tavares dos2013-07-26T13:09:28Z20112011-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10451/8888enginfo: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:RCAAP2023-11-08T15:52:57Zoai:repositorio.ul.pt:10451/8888Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:33:15.314817Repositório 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 Analysis of syntaxin-1 chaperones during synaptic activity
title Analysis of syntaxin-1 chaperones during synaptic activity
spellingShingle Analysis of syntaxin-1 chaperones during synaptic activity
Santos, Tatiana Cerveira Tavares dos
SNARE complex
Syntaxin-1
Munc-18
SNAP-25
Chaperones
Teses de mestrado - 2011
title_short Analysis of syntaxin-1 chaperones during synaptic activity
title_full Analysis of syntaxin-1 chaperones during synaptic activity
title_fullStr Analysis of syntaxin-1 chaperones during synaptic activity
title_full_unstemmed Analysis of syntaxin-1 chaperones during synaptic activity
title_sort Analysis of syntaxin-1 chaperones during synaptic activity
author Santos, Tatiana Cerveira Tavares dos
author_facet Santos, Tatiana Cerveira Tavares dos
author_role author
dc.contributor.none.fl_str_mv Sudhof, Thomas
Farinha, Carlos, 1973-
Repositório da Universidade de Lisboa
dc.contributor.author.fl_str_mv Santos, Tatiana Cerveira Tavares dos
dc.subject.por.fl_str_mv SNARE complex
Syntaxin-1
Munc-18
SNAP-25
Chaperones
Teses de mestrado - 2011
topic SNARE complex
Syntaxin-1
Munc-18
SNAP-25
Chaperones
Teses de mestrado - 2011
description Tese de mestrado em Bioquímica, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2011
publishDate 2011
dc.date.none.fl_str_mv 2011
2011-01-01T00:00:00Z
2013-07-26T13:09:28Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/masterThesis
format masterThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10451/8888
url http://hdl.handle.net/10451/8888
dc.language.iso.fl_str_mv eng
language eng
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
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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