A WblA-Binding Protein, SpiA, Involved in Streptomyces Oxidative Stress Response

2013 ◽  
Vol 23 (10) ◽  
pp. 1365-1371 ◽  
Author(s):  
Jin-Su Kim
2020 ◽  
Vol 295 (41) ◽  
pp. 14236-14247
Author(s):  
Janani Prahlad ◽  
Yifeng Yuan ◽  
Jiusheng Lin ◽  
Chou-Wei Chang ◽  
Dirk Iwata-Reuyl ◽  
...  

DUF328 family proteins are present in many prokaryotes; however, their molecular activities are unknown. The Escherichia coli DUF328 protein YaaA is a member of the OxyR regulon and is protective against oxidative stress. Because uncharacterized proteins involved in prokaryotic oxidative stress response are rare, we sought to learn more about the DUF328 family. Using comparative genomics, we found a robust association between the DUF328 family and genes involved in DNA recombination and the oxidative stress response. In some proteins, DUF328 domains are fused to other domains involved in DNA binding, recombination, and repair. Cofitness analysis indicates that DUF328 family genes associate with recombination-mediated DNA repair pathways, particularly the RecFOR pathway. Purified recombinant YaaA binds to dsDNA, duplex DNA containing bubbles of unpaired nucleotides, and Holliday junction constructs in vitro with dissociation equilibrium constants of 200–300 nm. YaaA binds DNA with positive cooperativity, forming multiple shifted species in electrophoretic mobility shift assays. The 1.65-Å resolution X-ray crystal structure of YaaA reveals that the protein possesses a new fold that we name the cantaloupe fold. YaaA has a positively charged cleft and a helix-hairpin-helix DNA-binding motif found in other DNA repair enzymes. Our results demonstrate that YaaA is a new type of DNA-binding protein associated with the oxidative stress response and that this molecular function is likely conserved in other DUF328 family members.


2012 ◽  
Vol 303 (11) ◽  
pp. C1198-C1205 ◽  
Author(s):  
José Ponce-Coria ◽  
Kenneth B. Gagnon ◽  
Eric Delpire

X-ray crystallography of the catalytic domain of oxidative stress response 1 (OSR1) has provided evidence for dimerization and domain swapping. However, the functional significance of dimer formation or domain swapping has yet to be addressed. In this study, we used nine glutamine residues to link the carboxyl end of one SPAK (related Ste20 kinase) monomer to the amino end of another SPAK monomer to assess the role of kinase monomers versus dimers in Na-K-2Cl cotransporter 1 (NKCC1) activation. Transport studies in Xenopus laevis oocytes show that forcing dimerization of two wild-type SPAK molecules results in cotransporter activation when calcium-binding protein 39 (Cab39) is coexpressed, indicating that the presence of Cab39 can bypass the upstream phosphorylation requirement of SPAK normally associated with kinase activation. We determined that monomers are the functional units of the kinase as concatamers consisting of an active and various inactive monomers were still functional. Furthermore, we found that two different nonfunctional SPAK mutants could be linked together in a concatamer and activated, presumably by domain swapping, indicating that dimerization and domain swapping are both important components of kinase activation. Finally, we demonstrate rescue of a nonfunctional SPAK mutant by domain swapping with wild-type OSR1, indicating that heterodimers of the two Ste20-related kinases are possible and therefore potentially relevant to the regulation of NKCC1 activity.


2021 ◽  
Vol 9 (6) ◽  
pp. 1116
Author(s):  
Laurens Maertens ◽  
Pauline Cherry ◽  
Françoise Tilquin ◽  
Rob Van Houdt ◽  
Jean-Yves Matroule

Bacteria encounter elevated copper (Cu) concentrations in multiple environments, varying from mining wastes to antimicrobial applications of copper. As the role of the environment in the bacterial response to Cu ion exposure remains elusive, we used a tagRNA-seq approach to elucidate the disparate responses of two morphotypes of Caulobacter crescentus NA1000 to moderate Cu stress in a complex rich (PYE) medium and a defined poor (M2G) medium. The transcriptome was more responsive in M2G, where we observed an extensive oxidative stress response and reconfiguration of the proteome, as well as the induction of metal resistance clusters. In PYE, little evidence was found for an oxidative stress response, but several transport systems were differentially expressed, and an increased need for histidine was apparent. These results show that the Cu stress response is strongly dependent on the cellular environment. In addition, induction of the extracytoplasmic function sigma factor SigF and its regulon was shared by the Cu stress responses in both media, and its central role was confirmed by the phenotypic screening of a sigF::Tn5 mutant. In both media, stalked cells were more responsive to Cu stress than swarmer cells, and a stronger basal expression of several cell protection systems was noted, indicating that the swarmer cell is inherently more Cu resistant. Our approach also allowed for detecting several new transcription start sites, putatively indicating small regulatory RNAs, and additional levels of Cu-responsive regulation.


Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 345
Author(s):  
Hidemasa Bono

Data accumulation in public databases has resulted in extensive use of meta-analysis, a statistical analysis that combines the results of multiple studies. Oxidative stress occurs when there is an imbalance between free radical activity and antioxidant activity, which can be studied in insects by transcriptome analysis. This study aimed to apply a meta-analysis approach to evaluate insect oxidative transcriptomes using publicly available data. We collected oxidative stress response-related RNA sequencing (RNA-seq) data for a wide variety of insect species, mainly from public gene expression databases, by manual curation. Only RNA-seq data of Drosophila melanogaster were found and were systematically analyzed using a newly developed RNA-seq analysis workflow for species without a reference genome sequence. The results were evaluated by two metric methods to construct a reference dataset for oxidative stress response studies. Many genes were found to be downregulated under oxidative stress and related to organ system process (GO:0003008) and adherens junction organization (GO:0034332) by gene enrichment analysis. A cross-species analysis was also performed. RNA-seq data of Caenorhabditis elegans were curated, since no RNA-seq data of insect species are currently available in public databases. This method, including the workflow developed, represents a powerful tool for deciphering conserved networks in oxidative stress response.


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