Juana Pérez

Juana Pérez
University of Granada | UGR · Department of Microbiology

Professor

About

72
Publications
11,519
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,382
Citations
Citations since 2016
16 Research Items
1490 Citations
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
Additional affiliations
January 1985 - January 2014
University of Granada
Position
  • Professor (Full)

Publications

Publications (72)
Article
Full-text available
Myxococcus xanthus is a multicellular bacterium with a complex lifecycle. It is a soil-dwelling predator that preys on a wide variety of microorganisms by using a group and collaborative epibiotic strategy. In the absence of nutrients this myxobacterium enters in a unique developmental program by using sophisticated and complex regulatory systems w...
Article
Full-text available
Extracytoplasmic function (ECF) sigma factors are subunits of the RNA polymerase specialized in activating the transcription of a subset of genes responding to a specific environmental condition. The signal-transduction pathways where they participate can be activated by diverse mechanisms. The most common mechanism involves the action of a membran...
Article
Full-text available
Discovery of antimicrobials in the past century represented one of the most important advances in public health. Unfortunately, the massive use of these compounds in medicine and other human activities has promoted the selection of pathogens that are resistant to one or several antibiotics. The current antibiotic crisis is creating an urgent need f...
Article
Full-text available
Myxococcus xanthus is a soil myxobacterium that exhibits a complex lifecycle with two multicellular stages: cooperative predation and development. During predation, myxobacterial cells produce a wide variety of secondary metabolites and hydrolytic enzymes to kill and consume the prey. It is known that eukaryotic predators, such as ameba and macroph...
Article
Full-text available
The bacterium Myxococcus xanthus exhibits a complex multicellular life cycle. In the presence of nutrients, cells prey cooperatively. Upon starvation, they enter a developmental cycle wherein cells aggregate to produce macroscopic fruiting bodies filled with resistant myxospores. We used RNA-Seq technology to examine the transcriptome of the 96 hr...
Article
Full-text available
In order to survive, bacteria must adapt to multiple fluctuations in their environment, including coping with changes in metal concentrations. Many metals are essential for viability, since they act as cofactors of indispensable enzymes. But on the other hand, they are potentially toxic because they generate reactive oxygen species or displace othe...
Preprint
Full-text available
The bacteria Myxococcus xanthus exhibit a complex multicellular life cycle. In the presence of nutrients, cells prey cooperatively. Upon starvation, they enter a developmental cycle wherein cells aggregate to produce macroscopic fruiting bodies filled with resistant myxospores. We used RNA-Seq technology to examine the global transcriptome of the 9...
Article
Full-text available
The complex copper response of the multicellular proteobacterium M. xanthus includes structural genes similar to those described in other bacteria, such as P1B-type ATPases, multicopper oxidases, and heavy metal efflux systems. However, the two time-dependent expression profiles of the different copper systems are unique. There are a number of gene...
Article
Full-text available
Myxococcus xanthus, like other myxobacteria, is a social bacterium that moves and feeds cooperatively in predatory groups. On surfaces, rod-shaped vegetative cells move in search of the prey in a coordinated manner, forming dynamic multicellular groups referred to as swarms. Within the swarms, cells interact with one another and use two separate lo...
Article
Full-text available
Extracytoplasmic function sigma factors represent the third pillar of signal-transduction mechanisms in bacteria. The variety of stimuli they recognize and mechanisms of action they use have allowed their classification into more than 50 groups. We have characterized CorE2 from Myxococcus xanthus, which belongs to group ECF44 and upregulates the ex...
Article
Full-text available
Myxococcus xanthus CorSR is a two-component system responsible for maintaining the response of this bacterium to copper. In the presence of this metal it up-regulates, among others, the genes encoding the multicopper oxidase CuoA and the P1B -ATPase CopA. Dissection of the periplasmic sensor domain of the histidine kinase CorS by the analysis of a...
Article
Summary The first documented study on bacterial predation was carried out using myxobacteria three quarters of a century ago (Beebe, 1941). Since then, many predatory strains, diverse hunting strategies, environmental consequences, and potential applications have been reported by groups all over the world. Now we know that predatory bacteria are d...
Article
Full-text available
Myxococcus xanthus is a social bacterium that preys on prokaryotic and eukaryotic microorganisms. Co-culture of M. xanthus with reference laboratory strains and field isolates of the legume symbiont Sinorhizobium meliloti revealed two different predatory patterns that resemble frontal and wolfpack attacks. Use of mutants impaired in the two types o...
Article
Full-text available
Myxococcus xanthus is a soil-dwelling member of the δ-Proteobacteria that exhibits a complex developmental cycle upon starvation. Development comprises aggregation and differentiation into environmentally resistant myxospores in an environment that includes fluctuations in metal ion concentrations. While copper is essential for M. xanthus cells bec...
Data
Full-text available
Microsynteny conservation in several bacteria in the genomic environment of genes coding for proteins with PF13442 domains (red arrows). The other colored arrows represent genes with predicted function associated to copper response. Dark pink, Cu2+-exporting ATPase (PF00122, PF00702); light green, multicopper oxidase (PF07732, PF07731 and PF00394);...
Article
Full-text available
One of the mechanisms widely used by bacteria to adapt to their environment is mediated by alternative σ factors. Here we discuss the mechanism of action of a novel metal-dependent ECF σ factor, whose ability to bind DNA depends on the redox state of copper.
Article
Full-text available
Myxococcus xanthus is widely used as a model system for studying gliding motility, multicellular development, and cellular differentiation. Moreover, M. xanthus is a rich source of novel secondary metabolites. The analysis of these processes has been hampered by the limited set of tools for inducible gene expression. Here we report the construction...
Article
Full-text available
Lignocellulosic materials as industrial, agricultural, and forest residues account for the majority of the total renewable biomass present on Earth. Some fungi are equipped with potent enzymatic systems involved in the hydrolysis or oxidation of these biopolymers. Herein, we provide an update of lignocellulose biodegradation processes and the main...
Data
Expression of the systems involved in M. xanthus copper and other metal homeostasis in the WT strain (blue line) and the ΔcorE mutant (red line). The systems or genes analyzed are indicated in each panel. Cells were incubated on CTT agar plates containing the metal that yields highest induction for each system [7]–[9]: 0.3 mM copper (panels A, B, E...
Data
Genotype of the M. xanthus strains harboring cuoB-lacZ fusions used in this report. (A) cuoB-lacZ fusion in the WT background. (B) cuoB-lacZ fusion in the ΔcorE in-frame mutant. (C) cuoB-lacZ fusion in the ΔcorECRD in-frame mutant. (D) Genotype of the strain harboring the cuoB-lacZ fusion, and corE cloned under the strong constitutive oar promoter....
Data
In silico identification of the CorE-binding site and determination of the genes of the CorE regulon. (A) Comparison of the upstream regions of the four genes regulated by CorE. (B) Sequence logo constructed at WebLogo (http://weblogo.berkeley.edu/) [41] using the −35 and −10 regions of the four CorE-regulated genes. (C) Consensus sequence of the −...
Data
Qualitative analysis of cuoB up-regulation by different metals and oxidants. The WT strain harboring the cuoB-lacZ fusion was spotted onto CTT agar plates containing metals or oxidants at the concentrations indicated above each picture. Plates also contained 5-bromo-4-chloro-3-indolyl-β-D-galacto-pyranoside to monitor β-gal activity (blue color dev...
Data
Expression of cuoB in the presence (continuous lines) and the absence (dashed lines) of copper when hcorE was cloned under control of its own promoter (blue lines) or of oar promoter (red lines). Error bars indicate standard deviations. (TIF)
Data
Effect of different chelators on cuoB expression. The expression was qualitatively analyzed on CTT media containing 5-bromo-4-chloro-3-indolyl-β-D-galacto-pyranoside (to determine the accumulation of the chromogenic blue product resulting of the activity of β-galactosidase) and the indicated concentrations of BCS, BCA, or TTM (controls contain no c...
Data
Expression of cuoB in strains harboring point mutations in the CRD region of CorE in media supplemented with only copper, copper plus Ag+, or copper plus BCS. The mutated Cys is indicated in each panel. Cells were incubated on CTT agar plates containing only 0.15 mM copper (blue lines), 0.15 mM copper plus 0.05 mM BCS (red lines), or 0.15 mM copper...
Article
Full-text available
The dual toxicity/essentiality of copper forces cells to maintain a tightly regulated homeostasis for this metal in all living organisms, from bacteria to humans. Consequently, many genes have previously been reported to participate in copper detoxification in bacteria. Myxococcus xanthus, a prokaryote, encodes many proteins involved in copper home...
Article
Interaction of the predatory myxobacterium Myxococcus xanthus with the non-motile, antibiotic producer Streptomyces coelicolor was examined using a variety of experimental approaches. Myxococcus xanthus cells prey on S. coelicolor, forming streams of ordered cells that lyse the S. coelicolor hyphae in the contact area between the two colonies. The...
Data
Interaction between M. xanthus (left) and S. coelicolor (right) on solid CTT medium. The pictures were taken every 5 minutes and compiled with Quicktime Pro (Apple).
Article
Full-text available
Myxococcus xanthus has to cope with changes in its environment during growth and development. Among these factors, the concentration of copper is crucial due to the essential toxic effect of this metal, which forces the cells to maintain a tight homeostasis. The M. xanthus copper response is more complex than that in other bacteria, which is reflec...
Article
Full-text available
Myxococcus xanthus is a soil-dwelling bacterium that exhibits a complex life cycle comprising social behavior, morphogenesis, and differentiation. In order to successfully complete this life cycle, cells have to cope with changes in their environment, among which the presence of copper is remarkable. Copper is an essential transition metal for life...
Article
Full-text available
The multicellular behavior of the myxobacterium Myxococcus xanthus requires the participation of an elevated number of signal-transduction mechanisms to coordinate the cell movements and the sequential changes in gene expression patterns that lead to the morphogenetic and differentiation events. These signal-transduction mechanisms are mainly based...
Article
Full-text available
A newly identified extracellular laccase produced by Streptomyces ipomoea CECT 3341 (SilA) was cloned and overexpressed, and its physicochemical characteristics assessed together with its capability to decolorize and detoxify an azotype dye. Molecular analysis of the deduced sequence revealed that SilA contains a TAT-type signal peptide at the N-te...
Article
Full-text available
Ser/Thr/Tyr kinases, which together comprise a major class of regulatory proteins in eukaryotes, were not believed to play an important role in prokaryotes until recently. However, our analysis of 626 prokaryotic genomes reveals that eukaryotic-like protein kinases (ELKs) are found in nearly two-thirds of the sequenced strains. We have identified 2...
Article
n-Propanol was the most effective solvent for extracting antibacterial substances from olive oil mill waste water (‘alpechines’). Several phenolics were detected in propanol extracts that had bactericidal effects on Bacillus megaterium ATCC 33085, inhibiting sporulation and germination at 5.6 mmol/l total phenolics (expressed as syringic acid). The...
Article
Thirty-eight bacterial strains were isolated from waste water of olive oil mills, olives and soil in chemically defined media containing the pigment of these wastes as sole carbon source. Most of the organisms were Pseudomonas spp. Four of the six phenolic acids associated with polymeric pigments in olive oil waste degradation were used by three st...
Article
Full-text available
The genus Sorangium synthesizes approximately half of the secondary metabolites isolated from myxobacteria, including the anti-cancer metabolite epothilone. We report the complete genome sequence of the model Sorangium strain S. cellulosum So ce56, which produces several natural products and has morphological and physiological properties typical of...
Article
Full-text available
Myxococcus xanthus is a soil bacterium that undergoes a unique life cycle among the prokaryotes upon starvation, which includes the formation of macroscopic structures, the fruiting bodies, and the differentiation of vegetative rods into coccoid myxospores. This peculiarity offers the opportunity to study the copper response in this bacterium in tw...
Article
Full-text available
The pair PhoR1-PhoP1 is the third two-component system of the family PhoRP reported in M. xanthus. PhoR1 is a histidine kinase anchored to the membrane through a transmembrane domain located in the amino-terminal portion of the protein. As a result, 93% of the protein is located in the cytoplasm. This topology is unusual in the PhoR-type histidine...
Article
Copper induces a red pigmentation in cells of the bacterium Myxococcus xanthus when they are incubated in the dark, at suboptimal growth conditions. The colouration results from the accumulation of carotenoids, as demonstrated by chemical analysis, and by the lack of a copper effect on M. xanthus mutants affected in known structural genes for carot...
Article
Full-text available
We have cloned a two-component regulatory system (phoR2-phoP2) of Myxococcus xanthus while searching for genes that encode proteins with phosphatase activity, where phoR2 encodes the histidine kinase and phoP2 encodes the response regulator. A second system, phoR3-phoP3, was identified and isolated by using phoP2 as a probe. These two systems are q...
Article
Full-text available
Phanerochaete flavido-alba is able to remove simple and polymeric phenols from the recalcitrant wastes of the olive oil industry, in a process in which a laccase is involved. This report describes the characterization of a laccase produced by P. flavido-alba and induced by vanillin. Although the amino acid composition of the purified enzyme is typi...
Article
Phanerochaete flavido-alba is able to decolorize and detoxify olive oil wastewater (OMW) in a process in which simple and polymeric phenols are removed. An unusual acidic MnP is accumulated during the degradation course. This microorganism produces two families of MnPs. MnP1 has an apparent molecular weight of 45 kDa and is secreted as a mixture of...
Article
We report the cloning and kinetic characterization of Trypanosoma cruzi deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) whose coding sequence was isolated by genetic complementation in Escherichia coli. The deduced amino acid sequence was similar to Leishmania major dUTPase although it exhibits an amino acid insertion which is sensitive...
Article
Full-text available
In nature, cellulose, lignocellulose and lignin are major sources of plant biomass; therefore, their recycling is indispensable for the carbon cycle. Each polymer is degraded by a variety of microorganisms which produce a battery of enzymes that work synergically. In the near future, processes that use lignocellulolytic enzymes or are based on micr...
Article
Our previous results have demonstrated that Phanerochaete flavido-alba decoloration, dephenolization and detoxification of olive oil mill wastewater (OMW) were associated with changes in the ligninolytic major exoenzymes accumulated in the cultures. This paper describes the effect of the two main OMW components (monomeric aromatic compounds and a m...
Article
Full-text available
Apurinic/apyrimidinic (AP) sites in DNA are considered to be highly mutagenic and must be corrected to preserve genetic integrity. We have isolated cDNAs from the Trypanosomatidae Leishmania major and Trypanosoma cruzi capable of complementing the deficiency of exonuclease III and dUTPase in the Escherichia coli mutant BW286. This double mutant is...
Article
Full-text available
Lignin-degrading enzymes were partially purified from supernatant solutions obtained from Phanerochaete flavido-alba-decolorized olive oil mill wastewaters (OMW). The dominant enzymes, manganese peroxidases, exhibited different isoform patterns in decolorized OMW-containing cultures than in residue-free samples. Laccase induction was also detected...
Article
Among 12 basidiomycetaceous fungal strains, Phanerochaete chrysosporium SC26 and K3 and Phanerochaete flavido-alba FPL 106507 were the most efficient in decolorizing paper mill wastes. Enzymatic activities attributable to both families of extracellular ligninases, lignin peroxidase (LiP) and manganese peroxidase (MnP), have been detected in P. flav...
Article
Full-text available
In addition to excreting lignin-degrading peroxidases, the white rot fungus Phanerochaete flavido-alba also excretes a laccase. This protein was purified to homogeneity and found to have a molecular weight of 94,000 and an isoelectric point lower than 3.55. Its UV-visible spectrum is typical of copper-containing proteins.
Article
Full-text available
Nitrogen, carbon, and manganese are potent regulators of lignin degradation, but although nitrogen and carbon elicit a generalizated response when cells are starved, manganese is a relatively specific regulator of lignin and manganese peroxidase (LiP and MnP, respectively). At high manganese levels, MnP is induced, and LiP is repressed. At low Mn l...