Villanueva San Martín, Maite

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https://academica-e.unavarra.es/handle/2454/50167

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Villanueva San Martín

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Maite

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Producción Agraria

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0000-0002-3894-0060

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750801

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810427

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2013 - 20183
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Author: Ruiz de los Mozos Aliaga, Igor × Subject: Staphylococcus aureus ×

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Now showing 1 - 3 of 3
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    PublicationOpen Access
    Base pairing interaction between 5′- and 3′-UTRs controls icaR mRNA translation in Staphylococcus aureus
    (Public Library of Science, 2013) Ruiz de los Mozos Aliaga, Igor; Vergara Irigaray, Marta; Segura, Víctor; Villanueva San Martín, Maite; Bitarte Manzanal, Nerea; Saramago, Margarida; Domingues, Susana; Arraiano, Cecilia M.; Fechter, Pierre; Romby, Pascale; Valle Turrillas, Jaione; Solano Goñi, Cristina; Lasa Uzcudun, Íñigo; Toledo Arana, Alejandro; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
    The presence of regulatory sequences in the 39 untranslated region (39-UTR) of eukaryotic mRNAs controlling RNA stability and translation efficiency is widely recognized. In contrast, the relevance of 39-UTRs in bacterial mRNA functionality has been disregarded. Here, we report evidences showing that around one-third of the mapped mRNAs of the major human pathogen Staphylococcus aureus carry 39-UTRs longer than 100-nt and thus, potential regulatory functions. We selected the long 39-UTR of icaR, which codes for the repressor of the main exopolysaccharidic compound of the S. aureus biofilm matrix, to evaluate the role that 39-UTRs may play in controlling mRNA expression. We showed that base pairing between the 39- UTR and the Shine-Dalgarno (SD) region of icaR mRNA interferes with the translation initiation complex and generates a double-stranded substrate for RNase III. Deletion or substitution of the motif (UCCCCUG) within icaR 39-UTR was sufficient to abolish this interaction and resulted in the accumulation of IcaR repressor and inhibition of biofilm development. Our findings provide a singular example of a new potential post-transcriptional regulatory mechanism to modulate bacterial gene expression through the interaction of a 39-UTR with the 59-UTR of the same mRNA.
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    PublicationOpen Access
    The regulon of the RNA chaperone CspA and its auto-regulation in Staphylococcus aureus
    (Oxford University Press, 2018) Caballero Sánchez, Carlos; Menéndez Gil, Pilar; Catalán Moreno, Arancha; Vergara Irigaray, Marta; García Martínez, Begoña; Segura, Víctor; Irurzun Domínguez, Naiara; Villanueva San Martín, Maite; Ruiz de los Mozos Aliaga, Igor; Solano Goñi, Cristina; Lasa Uzcudun, Íñigo; Toledo Arana, Alejandro; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
    RNA-binding proteins (RBPs) are essential to finetune gene expression. RBPs containing the coldshock domain are RNA chaperones that have been extensively studied. However, the RNA targets and specific functions for many of them remain elusive. Here, combining comparative proteomics and RBPimmunoprecipitation- microarray profiling, we have determined the regulon of the RNA chaperone CspA of Staphylococcus aureus. Functional analysis revealed that proteins involved in carbohydrate and ribonucleotide metabolism, stress response and virulence gene expression were affected by cspA deletion. Stress-associated phenotypes such as increased bacterial aggregation and diminished resistance to oxidative-stress stood out. Integration of the proteome and targetome showed that CspA posttranscriptionally modulates both positively and negatively the expression of its targets, denoting additional functions to the previously proposed translation enhancement. One of these repressed targets was its own mRNA, indicating the presence of a negative post-transcriptional feedback loop. CspA bound the 5 UTR of its own mRNA disrupting a hairpin, which was previously described as an RNase III target. Thus, deletion of the cspA 5 UTR abrogated mRNA processing and auto-regulation. We propose that CspA interacts through a U-rich motif, which is located at the RNase III cleavage site, portraying CspA as a putative RNase III-antagonist.
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    PublicationOpen Access
    Sensory deprivation in Staphylococcus aureus
    (Springer Nature, 2018) Villanueva San Martín, Maite; García Martínez, Begoña; Valle Turrillas, Jaione; Rapún Araiz, Beatriz; Ruiz de los Mozos Aliaga, Igor; Solano Goñi, Cristina; Martí, Miguel; Penadés, José R.; Toledo Arana, Alejandro; Lasa Uzcudun, Íñigo; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
    Bacteria use two-component systems (TCSs) to sense and respond to environmental changes. The core genome of the major human pathogen Staphylococcus aureus encodes 16 TCSs, one of which (WalRK) is essential. Here we show that S. aureus can be deprived of its complete sensorial TCS network and still survive under growth arrest conditions similarly to wild-type bacteria. Under replicating conditions, however, the WalRK system is necessary and sufficient to maintain bacterial growth, indicating that sensing through TCSs is mostly dispensable for living under constant environmental conditions. Characterization of S. aureus derivatives containing individual TCSs reveals that each TCS appears to be autonomous and self-sufficient to sense and respond to specific environmental cues, although some level of cross-regulation between non-cognate sensor-response regulator pairs occurs in vivo. This organization, if confirmed in other bacterial species, may provide a general evolutionarily mechanism for flexible bacterial adaptation to life in new niches.