Publicaciones 2011-2020

@article{RN382,
title = {The Developmental Regulator Pcz1 Affects the Production of Secondary Metabolites in the Filamentous Fungus Penicillium Roqueforti},
author = { J.F. Rojas-Aedo and C. Gil-Duran and A. Goity and I. Vaca and G. Levican and L.F. Larrondo and R. Chavez},
url = {/brokenurl#<Go to ISI>://WOS:000438320100007},
doi = {10.1016/j.micres.2018.05.005},
issn = {0944-5013},
year = {2018},
date = {2018-01-01},
journal = {Microbiological Research},
volume = {212},
pages = {67-74},
abstract = {Penicillium roqueforti is used in the production of several kinds of ripened blue-veined cheeses. In addition, this fungus produces interesting secondary metabolites such as roquefortine C, andrastin A and mycophenolic acid. To date, there is scarce information concerning the regulation of the production of these secondary metabolites. Recently, the gene named pcz1 (Penicillium C6 zinc domain protein 1) was described in P. roqueforti, which encodes for a Zn(II)(2)Cys(6) protein that controls growth and developmental processes in this fungus. However, its effect on secondary metabolism is currently unknown. In this work, we have analyzed how the overexpression and down-regulation of pcz1 affect the production of roquefortine C, andrastin A and mycophenolic acid in P. roqueforti. The three metabolites were drastically reduced in the pcz1 down-regulated strains. However, when pcz1 was overexpressed, only mycophenolic acid was overproduced while, on the contrary, levels of roquefortine C and andrastin A were diminished. Importantly, these results match the expression pattern of keywords genes involved in the biosynthesis of these metabolites. Taken together, our results suggest that Pcz1 plays a keywords role in regulating secondary metabolism in the fungus Penicillium roqueforti.},
keywords = {biosynthesis, chrysogenum complex, cross-talk, discovery, expression, gene-cluster, laea, metabolism, mycophenolic-acid, pathway pcz1, penicillium protein, roqueforti, secondary subunit},
pubstate = {published},
tppubtype = {article}
}

@article{RN338,
title = {Role of Sfk1 Gene in the Filamentous Fungus Penicillium Roqueforti},
author = { C. Torrent and C. Gil-Duran and J.F. Rojas-Aedo and E. Medina and I. Vaca and P. Castro and R.O. Garcia-Rico and M. Cotoras and L. Mendoza and G. Levican and R. Chavez},
url = {/brokenurl#<Go to ISI>://WOS:000417142700001},
doi = {10.3389/fmicb.2017.02424},
issn = {1664-302x},
year = {2017},
date = {2017-01-01},
journal = {Frontiers in Microbiology},
volume = {8},
abstract = {The sfk1 (suppressor of four kinase) gene has been mainly studied in Saccharomyces cerevisiae, where it was shown to be involved in growth and thermal stress resistance. This gene is widely conserved within the phylum Ascomycota. Despite this, to date sfk1 has not been studied in any filamentous fungus. Previously, we found that the orthologous of sfk1 was differentially expressed in a strain of Penicillium roqueforti with an altered phenotype. In this work, we have performed a functional characterization of this gene by using RNAi-silencing technology. The silencing of sfk1 in P. roqueforti resulted in decreased apical growth and the promotion of conidial germination, but interesting, it had no effect on conidiation. In addition, the attenuation of the sfk1 expression sensitized the fungus to osmotic stress, but not to thermal stress. RNA-mediated gene-silencing of sfk1 also affected cell wall integrity in the fungus. Finally, the silencing of sfk1 depleted the production of the main secondary metabolites of P. roqueforti, namely roquefortine C, andrastin A, and mycophenolic acid. To the best of our knowledge this is the first study of the sfk1 gene in filamentous fungi.},
keywords = {alpha-subunit, biosynthesis, botrytis-cinerea, changes, chrysogenum, expression, four gene germination, growth kinase, metabolites, of pathways, penicillium phenotypic protein rna-mediated roqueforti, saccharomyces-cerevisiae, secondary signaling silencing, stress, suppressor},
pubstate = {published},
tppubtype = {article}
}

@article{RN339,
title = {Heterotrimeric G Protein Alpha Subunit Controls Growth, Stress Response, Extracellular Protease Activity, and Cyclopiazonic Acid Production in Penicillium Camemberti},
author = { R.O. Garcia-Rico and C. Gil-Duran and J.F. Rojas-Aedo and I. Vaca and L. Figueroa and G. Levican and R. Chavez},
url = {/brokenurl#<Go to ISI>://WOS:000419930600002},
doi = {10.1016/j.funbio.2017.05.007},
issn = {1878-6146},
year = {2017},
date = {2017-01-01},
journal = {Fungal Biology},
volume = {121},
number = {9},
pages = {754-762},
publisher = {2017 British Mycological Society. Published by Elsevier Ltd.},
abstract = {The fungus Penicillium camemberti is widely used in the ripening of various bloomy-rind cheeses. Several properties of P. camemberti are important in cheese ripening, including conidiation, growth and enzyme production, among others. However, the production of mycotoxins such as cyclopiazonic acid during the ripening process by P. camemberti has raised concerns among consumers that demand food with minimal contamination. Here we show that overexpressing an alpha-subunit from the subgroup I of the heterotrimeric G protein (G alpha i) influences several of these processes: it negatively affects growth in a media dependent manner, triggers conidial germination, reduces the rate of sporulation, affects thermal and osmotic stress resistance, and also extracellular protease and cyclopiazonic acid production. Our results contribute to understanding the biological determinants underlying these biological processes in the economically important fungus P. camemberti.},
keywords = {alpha-subunit, aspergillus-nidulans, expression, filamentous fungus, g-beta, gene, geotrichum-candidum, growth, metabolism, micotoxin, mycotoxin pathogenicity, pcr, production, proteases, real-time reproduction resistance, secondary stress vegetative},
pubstate = {published},
tppubtype = {article}
}

@article{RN290,
title = {Identification and Functional Analysis of the Mycophenolic Acid Gene Cluster of Penicillium Roqueforti},
author = { A. Del-Cid and C. Gil-Duran and I. Vaca and J.F. Rojas-Aedo and R.O. Garcia-Rico and G. Levican and R. Chavez},
url = {/brokenurl#<Go to ISI>://WOS:000367888100190},
doi = {10.1371/journal.pone.0147047},
issn = {1932-6203},
year = {2016},
date = {2016-01-01},
journal = {Plos One},
volume = {11},
number = {1},
abstract = {The filamentous fungus Penicillium roqueforti is widely known as the ripening agent of blue-veined cheeses. Additionally, this fungus is able to produce several secondary metabolites, including the meroterpenoid compound mycophenolic acid (MPA). Cheeses ripened with P. roqueforti are usually contaminated with MPA. On the other hand, MPA is a commercially valuable immunosuppressant. However, to date the molecular basis of the production of MPA by P. roqueforti is still unknown. Using a bioinformatic approach, we have identified a genomic region of approximately 24.4 kbp containing a seven-gene cluster that may be involved in the MPA biosynthesis in P. roqueforti. Gene silencing of each of these seven genes (named mpaA, mpaB, mpaC, mpaDE, mpaF, mpaG and mpaH) resulted in dramatic reductions in MPA production, confirming that all of these genes are involved in the biosynthesis of the compound. Interestingly, the mpaF gene, originally described in P. brevicompactum as a MPA self-resistance gene, also exerts the same function in P. roqueforti, suggesting that this gene has a dual function in MPA metabolism. The knowledge of the biosynthetic pathway of MPA in P. roqueforti will be important for the future control of MPA contamination in cheeses and the improvement of MPA production for commercial purposes.},
keywords = {biosynthesis, cheese, chrysogenum, dehydrogenase, expression, fungi, immunosuppressant, imp liquid-chromatography, mycotoxins, strains},
pubstate = {published},
tppubtype = {article}
}

@article{RN242,
title = {Iron Chelators and Antioxidants Regenerate Neuritic Tree and Nigrostriatal Fibers of Mpp Plus /Mptp-Lesioned Dopaminergic Neurons},
author = { P. Aguirre and N.P. Mena and C.M. Carrasco and Y. Munoz and P. Perez-Henriquez and R.A. Morales and B.K. Cassels and C. Mendez-Galvez and O. Garcia-Beltran and C. Gonz\'{a}lez-Billault and M. Nunez},
url = {/brokenurl#<Go to ISI>://WOS:000366715900118},
doi = {10.1371/journal.pone.0144848},
issn = {1932-6203},
year = {2015},
date = {2015-01-01},
journal = {Plos One},
volume = {10},
number = {12},
abstract = {Neuronal death in Parkinson's disease (PD) is often preceded by axodendritic tree retraction and loss of neuronal functionality. The presence of non-functional but live neurons opens therapeutic possibilities to recover functionality before clinical symptoms develop. Considering that iron accumulation and oxidative damage are conditions commonly found in PD, we tested the possible neuritogenic effects of iron chelators and antioxidant agents. We used three commercial chelators: DFO, deferiprone and 2.2'-dypyridyl, and three 8-hydroxyquinoline-based iron chelators: M30, 7MH and 7DH, and we evaluated their effects in vitro using a mesencephalic cell culture treated with the Parkinsonian toxin MPP+ and in vivo using the MPTP mouse model. All chelators tested promoted the emergence of new tyrosine hydroxylase (TH)-positive processes, increased axodendritic tree length and protected cells against lipoperoxidation. Chelator treatment resulted in the generation of processes containing the presynaptic marker synaptophysin. The antioxidants N-acetylcysteine and dymetylthiourea also enhanced axodendritic tree recovery in vitro, an indication that reducing oxidative tone fosters neuritogenesis in MPP+-damaged neurons. Oral administration to mice of the M30 chelator for 14 days after MPTP treatment resulted in increased TH- and GIRK2-positive nigra cells and nigrostriatal fibers. Our results support a role for oral iron chelators as good candidates for the early treatment of PD, at stages of the disease where there is axodendritic tree retraction without neuronal death.},
keywords = {apoptosis, degeneration, dendritic disease, expression, induced models, neurodegeneration, protein, restoration substantia-nigra, tree},
pubstate = {published},
tppubtype = {article}
}

@article{RN241,
title = {Filamentous Fungi from Extreme Environments as a Promising Source of Novel Bioactive Secondary Metabolites},
author = { R. Chavez and F. Fierro and R.O. Garcia-Rico and I. Vaca},
url = {/brokenurl#<Go to ISI>://WOS:000361157000001},
doi = {10.3389/fmicb.2015.00903},
issn = {1664-302x},
year = {2015},
date = {2015-01-01},
journal = {Frontiers in Microbiology},
volume = {6},
abstract = {Natural product search is undergoing resurgence upon the discovery of a huge previously unknown potential for secondary metabolite (SM) production hidden in microbial genomes. This is also the case for filamentous fungi, since their genomes contain a high number of "orphan" SM gene clusters. Recent estimates indicate that only 5% of existing fungal species have been described, thus the potential for the discovery of novel metabolites in fungi is huge. In this context, fungi thriving in harsh environments are of particular interest since they are outstanding producers of unusual chemical structures. At present, there are around 16 genomes from extreme environment-isolated fungi in databases. In a preliminary analysis of three of these genomes we found that several of the predicted SM gene clusters are probably involved in the biosynthesis of compounds not yet described. Genome mining strategies allow the exploitation of the information in genome sequences for the discovery of new natural compounds. The synergy between genome mining strategies and the expected abundance of SMs in fungi from extreme environments is a promising path to discover new natural compounds as a source of medically useful drugs.},
keywords = {aspergillus-nidulans, biosynthetic clusters, discovery, drug environments, expression, extreme filamentous fungi, gene genome heterologous metabolites, metagenome, metagenomics, mining, natural natural-products, polyketide, products, resource, secondary sequence, strategy},
pubstate = {published},
tppubtype = {article}
}

@article{RN132,
title = {Increase in the Astaxanthin Synthase Gene (Crts) Dose by in Vivo DNA Fragment Assembly in Xanthophyllomyces Dendrorhous},
author = { G. Contreras and S. Barahona and M.C. Rojas and M. Baeza and V. Cifuentes and J. Alcaino},
url = {/brokenurl#<Go to ISI>://WOS:000327426600001},
doi = {Unsp 84, 10.1186/1472-6750-13-84},
issn = {1472-6750},
year = {2013},
date = {2013-01-01},
journal = {Bmc Biotechnology},
volume = {13},
abstract = {Background: Xanthophyllomyces dendrorhous is a basidiomycetous yeast that is relevant to biotechnology, as it can synthesize the carotenoid astaxanthin. However, the astaxanthin levels produced by wild-type strains are low. Although different approaches for promoting increased astaxanthin production have been attempted, no commercially competitive results have been obtained thus far. A promising alternative to facilitate the production of carotenoids in this yeast involves the use of genetic modification. However, a major limitation is the few available molecular tools to manipulate X. dendrorhous., Results: In this work, the DNA assembler methodology that was previously described in Saccharomyces cerevisiae was successfully applied to assemble DNA fragments in vivo and integrate these fragments into the genome of X. dendrorhous by homologous recombination in only one transformation event. Using this method, the gene encoding astaxanthin synthase (crtS) was overexpressed in X. dendrorhous and a higher level of astaxanthin was produced., Conclusions: This methodology could be used to easily and rapidly overexpress individual genes or combinations of genes simultaneously in X. dendrorhous, eliminating numerous steps involved in conventional cloning methods.},
keywords = {astaxanthin beta-carotene, biosynthetic-pathway, carotenoid cloning, dendrorhous, DNA assembler, expression, growth mutants, overproducing oxygen, phaffia-rhodozyma, selection, strains, synthase, xanthophyllomyces},
pubstate = {published},
tppubtype = {article}
}

@article{RN37c,
title = {Production of a Heterologous Recombinant Protein Using Fragments of the Glyceraldehyde-3-Phosphate Dehydrogenase Promoter from Penicillium Camemberti},
author = { Y. Espinosa and J. Trebotich and F. Sepulveda and J. Cadena and M.J. Vargas-Straube and I. Vaca and P. Bull and G. Levican and R. Chavez},
url = {/brokenurl#<Go to ISI>://WOS:000297594400033},
doi = {10.1007/s11274-011-0782-7},
issn = {0959-3993},
year = {2011},
date = {2011-01-01},
journal = {World Journal of Microbiology & Biotechnology},
volume = {27},
number = {12},
pages = {3019-3023},
abstract = {The biotechnological applications of cheese-ripening fungi have been limited by a lack of genetics tools, in particular the identification and characterization of suitable promoters for protein expression. In this study, the suitability of the glyceraldehyde-3-phosphate dehydrogenase (gpdP) promoter from Penicillium camemberti to drive the production of a recombinant protein was evaluated. The gpdP gene and its promoter were isolated using PCR and Genome Walker. The promoter of gpdP has two regions with high identity to the regulatory elements gpd-box and ct-box previously described in Aspergillus nidulans. Two fragments of the promoter containing the gpd- and ct-box or the ct-box alone were used to drive the in vivo production of recombinant beta-galactosidase using A. nidulans as host. Our results indicate that larger fragment containing gpd-box enhances the production of beta-galactosidase activity levels respect to ct-box alone, and that both boxes are necessary to obtain maximal enzymatic activity production. The smaller fragment (187 nt) containing the ct-box alone was able to trigger up to 27% of beta-galactosidase activity, and to our knowledge this is the smallest fragment from a gpd gene used to produce a recombinant protein. Differences were not observed when glycerol, galactose or glucose were used as carbon sources, suggesting that the promoter activity is carbohydrate-independent. This is the first report in which a Penicillium gpd promoter is used for recombinant protein production. Our results open the way for the future development of a system for recombinant proteins expression in the biotechnologically important cheese-ripening fungus P. camemberti.},
keywords = {aspergillus-nidulans, beta-galactosidase, camemberti, cloning, dehydrogenase elements, expression, functional gene, glyceraldehyde-3-phosphate gpda heterologous nidulans penicillium promoter, protein region sequence-analysis, transformation, yeast},
pubstate = {published},
tppubtype = {article}
}