Functional characterization of a cysteine protease essential for the assembly of the Clostridioides difficile spore surface layers

Detalhes bibliográficos
Autor(a) principal: Olivença, Carmen Maria Antunes
Data de Publicação: 2022
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10362/132664
Resumo: Clostridioides difficile is a Gram-positive, strict anaerobe, sporeforming organism, and the leading cause of a range of intestinal diseases linked to antibiotic therapy. C. difficile infection begins with the ingestion of spores that are also the vehicle for transmission. Proper assembly of the spore surface layers is important for the resilience of spores, their interaction with host cells and proper germination. Here, we focused on the characterization of YabG, a cysteine protease conserved among spore-formers. YabG processes substrates involved in spore germination and is required for the transcription of a gene, cdeM, which codes for a protein with a key role in the structural organization of the spore surface and required for host colonization. YabG has an N-terminal domain separated by a linker with a hinge region, from a C-terminal catalytic domain with the fold of a response regulator. We showed that unlike other cysteine proteases, YabG does not require removal of the N-terminal domain for activity. Rather, we present data suggesting that this domain is important for substrate engagement. Nevertheless, a catalytic inactive variant is cleaved in trans by the WT enzyme, at one of several arginine residues located in the hinge region. Multiple arginine to alanine substitutions in this region, result in a form of YabG able to process its substrates in vitro and in vivo but that fails to activate cdeM transcription. YabG may function by removing a cdeM repressor. Consistent with this model, we found two direct repeats in the cdeM regulatory region that function in cis to bind a repressor. Accordingly, titrating the repressor bypasses the need for YabG. Given its central role in spore assembly and its unique structural and functional features, YabG is an attractive therapeutical target to interfere with the central role of spores in infection and transmission.
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spelling Functional characterization of a cysteine protease essential for the assembly of the Clostridioides difficile spore surface layersClostridioides difficileYabGCysteine proteaseSpore surface layersRepressorDomínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e TecnologiasClostridioides difficile is a Gram-positive, strict anaerobe, sporeforming organism, and the leading cause of a range of intestinal diseases linked to antibiotic therapy. C. difficile infection begins with the ingestion of spores that are also the vehicle for transmission. Proper assembly of the spore surface layers is important for the resilience of spores, their interaction with host cells and proper germination. Here, we focused on the characterization of YabG, a cysteine protease conserved among spore-formers. YabG processes substrates involved in spore germination and is required for the transcription of a gene, cdeM, which codes for a protein with a key role in the structural organization of the spore surface and required for host colonization. YabG has an N-terminal domain separated by a linker with a hinge region, from a C-terminal catalytic domain with the fold of a response regulator. We showed that unlike other cysteine proteases, YabG does not require removal of the N-terminal domain for activity. Rather, we present data suggesting that this domain is important for substrate engagement. Nevertheless, a catalytic inactive variant is cleaved in trans by the WT enzyme, at one of several arginine residues located in the hinge region. Multiple arginine to alanine substitutions in this region, result in a form of YabG able to process its substrates in vitro and in vivo but that fails to activate cdeM transcription. YabG may function by removing a cdeM repressor. Consistent with this model, we found two direct repeats in the cdeM regulatory region that function in cis to bind a repressor. Accordingly, titrating the repressor bypasses the need for YabG. Given its central role in spore assembly and its unique structural and functional features, YabG is an attractive therapeutical target to interfere with the central role of spores in infection and transmission.Clostridioides difficile é uma bactéria Gram-positiva anaeróbia esporulante e a principal causa de doenças intestinais associadas à toma de antibióticos. A infecção por C. difficile começa com a ingestão de esporos, que são também veículos de transmissão. A montagem adequada das camadas superficiais dos esporos é importante para a sua resiliência, a interação com as células hospedeiras e germinação adequada. Neste estudo, concentrámo-nos na caracterização de YabG, uma protease de cisteína conservada entre bactérias esporulantes. YabG processa substratos envolvidos na germinação de esporos e é necessário para a transcrição de cdeM, que codifica para uma proteína com um papel fundamental na organização das camadas superficiais do esporo e necessária para a colonização do hospedeiro. YabG tem um domínio N-terminal separado por uma região flexível de um domínio catalítico C-terminal, que possui uma conformação de um regulador de resposta. Ao contrário de outras proteases de cisteína, YabG não requer a remoção do domínio N-terminal para atividade. Em vez disso, apresentamos dados que sugerem que este domínio é importante para interação com substratos. Adicionalmente, uma variante catalítica inativa é clivada em trans pela enzima WT num dos vários resíduos de arginina localizados na região flexível. Múltiplas substituições de arginina por alanina nesta região, resultam numa forma de YabG capaz de processar substratos in vitro e in vivo, mas que falha em ativar a transcrição de cdeM. YabG pode funcionar removendo um repressor de cdeM. Consistente com este modelo, encontrámos duas repetições diretas na região reguladora de cdeM, que funcionam em cis para ligar um repressor. Consequentemente, a titulação do repressor transpôs a necessidade de YabG na transcrição. Assim, dado o seu papel central na montagem de esporos e as suas características estruturais e funcionais únicas, YabG é um alvo terapêutico atraente interferindo no papel central dos esporos na infecção e transmissão.Henriques, AdrianoSerrano, MónicaRUNOlivença, Carmen Maria Antunes2023-01-01T01:31:33Z2022-01-262022-01-26T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10362/132664enginfo: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:RCAAP2024-03-11T05:11:21Zoai:run.unl.pt:10362/132664Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:47:33.568447Repositório 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 Functional characterization of a cysteine protease essential for the assembly of the Clostridioides difficile spore surface layers
title Functional characterization of a cysteine protease essential for the assembly of the Clostridioides difficile spore surface layers
spellingShingle Functional characterization of a cysteine protease essential for the assembly of the Clostridioides difficile spore surface layers
Olivença, Carmen Maria Antunes
Clostridioides difficile
YabG
Cysteine protease
Spore surface layers
Repressor
Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias
title_short Functional characterization of a cysteine protease essential for the assembly of the Clostridioides difficile spore surface layers
title_full Functional characterization of a cysteine protease essential for the assembly of the Clostridioides difficile spore surface layers
title_fullStr Functional characterization of a cysteine protease essential for the assembly of the Clostridioides difficile spore surface layers
title_full_unstemmed Functional characterization of a cysteine protease essential for the assembly of the Clostridioides difficile spore surface layers
title_sort Functional characterization of a cysteine protease essential for the assembly of the Clostridioides difficile spore surface layers
author Olivença, Carmen Maria Antunes
author_facet Olivença, Carmen Maria Antunes
author_role author
dc.contributor.none.fl_str_mv Henriques, Adriano
Serrano, Mónica
RUN
dc.contributor.author.fl_str_mv Olivença, Carmen Maria Antunes
dc.subject.por.fl_str_mv Clostridioides difficile
YabG
Cysteine protease
Spore surface layers
Repressor
Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias
topic Clostridioides difficile
YabG
Cysteine protease
Spore surface layers
Repressor
Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias
description Clostridioides difficile is a Gram-positive, strict anaerobe, sporeforming organism, and the leading cause of a range of intestinal diseases linked to antibiotic therapy. C. difficile infection begins with the ingestion of spores that are also the vehicle for transmission. Proper assembly of the spore surface layers is important for the resilience of spores, their interaction with host cells and proper germination. Here, we focused on the characterization of YabG, a cysteine protease conserved among spore-formers. YabG processes substrates involved in spore germination and is required for the transcription of a gene, cdeM, which codes for a protein with a key role in the structural organization of the spore surface and required for host colonization. YabG has an N-terminal domain separated by a linker with a hinge region, from a C-terminal catalytic domain with the fold of a response regulator. We showed that unlike other cysteine proteases, YabG does not require removal of the N-terminal domain for activity. Rather, we present data suggesting that this domain is important for substrate engagement. Nevertheless, a catalytic inactive variant is cleaved in trans by the WT enzyme, at one of several arginine residues located in the hinge region. Multiple arginine to alanine substitutions in this region, result in a form of YabG able to process its substrates in vitro and in vivo but that fails to activate cdeM transcription. YabG may function by removing a cdeM repressor. Consistent with this model, we found two direct repeats in the cdeM regulatory region that function in cis to bind a repressor. Accordingly, titrating the repressor bypasses the need for YabG. Given its central role in spore assembly and its unique structural and functional features, YabG is an attractive therapeutical target to interfere with the central role of spores in infection and transmission.
publishDate 2022
dc.date.none.fl_str_mv 2022-01-26
2022-01-26T00:00:00Z
2023-01-01T01:31:33Z
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