Specific role of the cyanobacterial pipX factor in the heterocysts of Anabaena sp. strain PCC 7120

The PipX factor is a regulatory protein that seems to occur only in cyanobacteria. In the filamentous, heterocyst-forming Anabaena sp. strain PCC 7120, open reading frame (ORF) asr0485, identified as the pipX gene, is expressed mainly under conditions of combined-nitrogen deprivation dependent on th...

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Autores: Valladares Ruiz, Ana, Rodríguez, Virginia, Camargo Bernal, Sergio, Martínez Noël, Giselle M. A., Herrero Moreno, Antonia, Luque Romero, Ignacio
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2011
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/62805
Acceso en línea:http://hdl.handle.net/11441/62805
https://doi.org/10.1128/JB.01202-10
Access Level:acceso abierto
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spelling Specific role of the cyanobacterial pipX factor in the heterocysts of Anabaena sp. strain PCC 7120Valladares Ruiz, AnaRodríguez, VirginiaCamargo Bernal, SergioMartínez Noël, Giselle M. A.Herrero Moreno, AntoniaLuque Romero, IgnacioThe PipX factor is a regulatory protein that seems to occur only in cyanobacteria. In the filamentous, heterocyst-forming Anabaena sp. strain PCC 7120, open reading frame (ORF) asr0485, identified as the pipX gene, is expressed mainly under conditions of combined-nitrogen deprivation dependent on the global N regulator NtcA and the heterocyst-specific regulator HetR. Primer extension and 5′ rapid amplification of cDNA ends (RACE) analyses detected three transcription start points corresponding to a canonical NtcA-activated promoter (to which direct binding of NtcA was observed), an NtcA- and HetR-dependent promoter, and a consensus-type promoter, the last with putative -35 and -10 determinants. Activation of pipX took place in cells differentiating into heterocysts at intermediate to late stages of the process. Accordingly, disruption of pipX led to impaired diazotrophic growth, reduced nitrogenase activity, and impaired activation of the nitrogenase structural genes. The nitrogenase activity of the mutant was low under oxic conditions, likely resulting from inefficient protection against oxygen. In line with this, the activation of the coxB2A2C2 and coxB3A3C3 operons, encoding heterocyst-specific terminal respiratory oxidases responsible for internal oxygen removal, was deficient in the pipX mutant. Therefore, the Anabaena PipX factor shows a spatiotemporal specificity contributing to normal heterocyst function, including full activation of the nitrogenase structural genes and genes of the nitrogenase-protective features of the heterocyst.Ministerio de Ciencia e Innovación y FEDER BFU2007-60457 BFU2007-66589 BFU2010-17980American Society for MicrobiologyBioquímica Vegetal y Biología MolecularMinisterio de Ciencia e Innovación (MICIN). España2011info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfapplication/pdfhttp://hdl.handle.net/11441/62805https://doi.org/10.1128/JB.01202-10reponame:idUS. Depósito de Investigación de la Universidad de Sevillainstname:Universidad de Sevilla (US)InglésJournal of Bacteriology, 193 (5), 1172-1182.BFU2007-60457BFU2007-66589BFU2010-17980http://dx.doi.org/10.1128/JB.01202-10info:eu-repo/semantics/openAccessoai:idus.us.es:11441/628052026-06-17T12:51:07Z
dc.title.none.fl_str_mv Specific role of the cyanobacterial pipX factor in the heterocysts of Anabaena sp. strain PCC 7120
title Specific role of the cyanobacterial pipX factor in the heterocysts of Anabaena sp. strain PCC 7120
spellingShingle Specific role of the cyanobacterial pipX factor in the heterocysts of Anabaena sp. strain PCC 7120
Valladares Ruiz, Ana
title_short Specific role of the cyanobacterial pipX factor in the heterocysts of Anabaena sp. strain PCC 7120
title_full Specific role of the cyanobacterial pipX factor in the heterocysts of Anabaena sp. strain PCC 7120
title_fullStr Specific role of the cyanobacterial pipX factor in the heterocysts of Anabaena sp. strain PCC 7120
title_full_unstemmed Specific role of the cyanobacterial pipX factor in the heterocysts of Anabaena sp. strain PCC 7120
title_sort Specific role of the cyanobacterial pipX factor in the heterocysts of Anabaena sp. strain PCC 7120
dc.creator.none.fl_str_mv Valladares Ruiz, Ana
Rodríguez, Virginia
Camargo Bernal, Sergio
Martínez Noël, Giselle M. A.
Herrero Moreno, Antonia
Luque Romero, Ignacio
author Valladares Ruiz, Ana
author_facet Valladares Ruiz, Ana
Rodríguez, Virginia
Camargo Bernal, Sergio
Martínez Noël, Giselle M. A.
Herrero Moreno, Antonia
Luque Romero, Ignacio
author_role author
author2 Rodríguez, Virginia
Camargo Bernal, Sergio
Martínez Noël, Giselle M. A.
Herrero Moreno, Antonia
Luque Romero, Ignacio
author2_role author
author
author
author
author
dc.contributor.none.fl_str_mv Bioquímica Vegetal y Biología Molecular
Ministerio de Ciencia e Innovación (MICIN). España
description The PipX factor is a regulatory protein that seems to occur only in cyanobacteria. In the filamentous, heterocyst-forming Anabaena sp. strain PCC 7120, open reading frame (ORF) asr0485, identified as the pipX gene, is expressed mainly under conditions of combined-nitrogen deprivation dependent on the global N regulator NtcA and the heterocyst-specific regulator HetR. Primer extension and 5′ rapid amplification of cDNA ends (RACE) analyses detected three transcription start points corresponding to a canonical NtcA-activated promoter (to which direct binding of NtcA was observed), an NtcA- and HetR-dependent promoter, and a consensus-type promoter, the last with putative -35 and -10 determinants. Activation of pipX took place in cells differentiating into heterocysts at intermediate to late stages of the process. Accordingly, disruption of pipX led to impaired diazotrophic growth, reduced nitrogenase activity, and impaired activation of the nitrogenase structural genes. The nitrogenase activity of the mutant was low under oxic conditions, likely resulting from inefficient protection against oxygen. In line with this, the activation of the coxB2A2C2 and coxB3A3C3 operons, encoding heterocyst-specific terminal respiratory oxidases responsible for internal oxygen removal, was deficient in the pipX mutant. Therefore, the Anabaena PipX factor shows a spatiotemporal specificity contributing to normal heterocyst function, including full activation of the nitrogenase structural genes and genes of the nitrogenase-protective features of the heterocyst.
publishDate 2011
dc.date.none.fl_str_mv 2011
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11441/62805
https://doi.org/10.1128/JB.01202-10
url http://hdl.handle.net/11441/62805
https://doi.org/10.1128/JB.01202-10
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Journal of Bacteriology, 193 (5), 1172-1182.
BFU2007-60457
BFU2007-66589
BFU2010-17980
http://dx.doi.org/10.1128/JB.01202-10
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv American Society for Microbiology
publisher.none.fl_str_mv American Society for Microbiology
dc.source.none.fl_str_mv reponame:idUS. Depósito de Investigación de la Universidad de Sevilla
instname:Universidad de Sevilla (US)
instname_str Universidad de Sevilla (US)
reponame_str idUS. Depósito de Investigación de la Universidad de Sevilla
collection idUS. Depósito de Investigación de la Universidad de Sevilla
repository.name.fl_str_mv
repository.mail.fl_str_mv
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