Publications by authors named "Pablo D T Valenzuela"

The family of non-coding mitochondrial RNAs (ncmtRNA) is differentially expressed according to proliferative status. Normal proliferating cells express sense (SncmtRNA) and antisense ncmtRNAs (ASncmtRNAs), whereas tumor cells express SncmtRNA and downregulate ASncmtRNAs. Knockdown of ASncmtRNAs with oligonucleotides induces apoptotic cell death of tumor cells, leaving normal cells unaffected, suggesting a potential application for developing a novel cancer therapy.

View Article and Find Full Text PDF

Recent studies have examined gene transfer from bacteria to humans that would result in vertical inheritance. Bacterial DNA appears to integrate into the human somatic genome through an RNA intermediate, and such integrations are detected more frequently in tumors than normal samples and in RNA than DNA samples. Also, vertebrate viruses encode products that interfere with the RNA silencing machinery, suggesting that RNA silencing may indeed be important for antiviral responses in vertebrates.

View Article and Find Full Text PDF

To gain insights into coordinated lineage-specification and morphogenetic processes during early embryogenesis, here we report a systematic identification of transcriptional programs mediated by a key developmental regulator--Brachyury. High-resolution chromosomal localization mapping of Brachyury by ChIP sequencing and ChIP-exonuclease revealed distinct sequence signatures enriched in Brachyury-bound enhancers. A combination of genome-wide in vitro and in vivo perturbation analysis and cross-species evolutionary comparison unveiled a detailed Brachyury-dependent gene-regulatory network that directly links the function of Brachyury to diverse developmental pathways and cellular housekeeping programs.

View Article and Find Full Text PDF

Botrytis cinerea causes gray mold on a great number of host plants. Infection is initiated by airborne conidia that invade the host tissue, often by penetration of intact epidermal cells. To mimic the surface properties of natural plant surfaces, conidia were incubated on apple wax-coated surfaces, resulting in rapid germination and appressorium formation.

View Article and Find Full Text PDF
Article Synopsis
  • Deformed wing virus (DWV) is a prevalent virus impacting honey bees, with a lack of data on its status in Chile.
  • This report confirms the presence of DWV in honey bee colonies from two locations in central Chile.
  • Additionally, the complete genome of a DWV isolate from Chile was sequenced, marking the first documentation of a honey bee virus in the country.
View Article and Find Full Text PDF

The study of RNA and DNA oncogenic viruses has proved invaluable in the discovery of key cellular pathways that are rendered dysfunctional during cancer progression. An example is high risk human papillomavirus (HPV), the etiological agent of cervical cancer. The role of HPV oncogenes in cellular immortalization and transformation has been extensively investigated.

View Article and Find Full Text PDF

Chilean strawberry (Fragaria chiloensis), the maternal progenitor of Fragaria×ananassa, has emerged as a new berry fruit with excellent organoleptic characteristics. The fast softening of strawberries is a limiting step for their commercialization. Fruit softening has been shown to be related to cell wall degradation.

View Article and Find Full Text PDF
Article Synopsis
  • Hantaviruses enter human cells by attaching to them and fusing their viral membranes at low pH, primarily facilitated by the Gn and Gc glycoproteins.
  • Research involved modifying specific residues in the Gc protein of the Andes virus to study their role in fusion and infection processes, confirming that certain conserved residues were crucial for membrane fusion.
  • The study's findings align with previous predictions about Gc residues acting as an internal fusion peptide, highlighting the significance of both aromatic and polar residues in the fusion mechanism of hantaviruses.
View Article and Find Full Text PDF

At least 58 viruses have been reported to infect grapevines causing economic damage globally. Conventional detection strategies based on serological assays, biological indexing and RT-PCR targeting one or few viruses in each assay are widely used. Grapevines are prone to contain mixed infections of several viruses, making the use of these techniques time-consuming.

View Article and Find Full Text PDF

Acidithiobacillus caldus is an extremely acidophilic, moderately thermophilic, chemolithoautotrophic gammaproteobacterium that derives energy from the oxidation of sulfur and reduced inorganic sulfur compounds. Here we present the draft genome sequence of Acidithiobacillus caldus ATCC 51756 (the type strain of the species), which has permitted the prediction of genes for survival in extremely acidic environments, including genes for sulfur oxidation and nutrient assimilation.

View Article and Find Full Text PDF

Hantavirus cardiopulmonary syndrome (HCPS) is a highly pathogenic emerging disease (40% case fatality rate) caused by New World hantaviruses. Hantavirus infections are transmitted to humans mainly by inhalation of virus-contaminated aerosol particles of rodent excreta and secretions. At present, there are no antiviral drugs or immunotherapeutic agents available for the treatment of hantaviral infection, and the survival rates for infected patients hinge largely on early virus recognition and hospital admission and aggressive pulmonary and hemodynamic support.

View Article and Find Full Text PDF

The equine influenza virus is the causal agent of influenza in horses. In July 2006, horses from various regions of Chile presented fever, serious nasal discharge, dry cough, anorexia and depression. Here we describe the isolation and characterization of the virus responsible for this outbreak.

View Article and Find Full Text PDF

The infectious salmon anemia virus (ISAV), which belongs to the new genus Isavirus of the Orthomyxoviridae family, is an important pathogen of the salmon farming industry. Indirect immunofluorescence assays carried out with monoclonal antibodies specific for the nucleoprotein (NP) reveal differential staining of sub-cellular compartments in infected cells. Particularly interesting was the staining of the nucleolus, which showed co-localization with nucleolin in CHSE-214, EPC and SHK-1 cells infected with ISAV.

View Article and Find Full Text PDF

The complete genome of the Chilean isolate Cl-766 of Grapevine leafroll-associated virus-3 (GLRaV-3) has been sequenced. This is the first genome sequence obtained from a GLRaV-3 isolate of the Southern hemisphere. The genomic RNA of 17,919 nucleotides contains 13 open reading frames (ORFs) with 5' and 3' untranslated regions (UTR) of 158 and 277 nucleotides, respectively.

View Article and Find Full Text PDF

Dinoflagellates of the genus Alexandrium are photosynthetic microalgae that have an extreme importance due to the impact of some toxic species on shellfish aquaculture industry. Alexandrium catenella is the species responsible for the production of paralytic shellfish poisoning in Chile and other geographical areas. We have constructed a cDNA library from midexponential cells of A.

View Article and Find Full Text PDF

The hantavirus nucleocapsid (N) protein fulfills several key roles in virus replication and assembly and is the major antigen in humoral immune responses in humans and mice. Here we report on epitopes involved in serotype-specific and cross-reactive recognition of the N proteins of hantaviruses using monoclonal antibodies (mAbs) against the N proteins of Andes virus (ANDV) and Sin Nombre virus (SNV). The mAbs define at least twelve different epitopic patterns which span eight sequences, including amino acids 17-59, 66-78, 79-91, 157-169, 222-234, 244-263, 274-286 and 326-338 on the SNV and ANDV N proteins.

View Article and Find Full Text PDF

The transcription factors CBF/DREB play an important role during low temperature, drought and high-salt stress in higher plants. In this work, we isolated one full-length CBF cDNA clone from the angiosperm Eucalyptus globulus. The derived peptide sequence reveals that it encodes a transcriptional activator that has all the characteristic motifs present in CBF proteins previously described in Arabidopsis and tomato.

View Article and Find Full Text PDF

Botrytis cinerea is a filamentous plant pathogen of a wide range of plant species, and its infection may cause enormous damage both during plant growth and in the post-harvest phase. We have constructed a cDNA library from an isolate of B. cinerea and have sequenced 11,482 expressed sequence tags that were assembled into 1,003 contigs sequences and 3,032 singletons.

View Article and Find Full Text PDF

We report here the protective effect against piscirickettsiosis elicited in fish by a mixture of recombinant proteins. A comparative genomics strategy was used on a genomic library of Piscirickettsia salmonis in order to select optimal candidates for a recombinant subunit vaccine to protect fish from rickettsial septicaemia (SRS). Based on this information, 15 P.

View Article and Find Full Text PDF

Hantavirus cell entry is promoted by its envelope glycoproteins, Gn and Gc, through cell attachment and by fusion between viral and endosomal membranes at low pH. However, the role of Gn and Gc in receptor binding and cell fusion has not yet been defined. In this work, a sequence presenting characteristics similar to those of class II fusion peptides (FPs) of alphavirus E1 and flavivirus E proteins is identified within the hantavirus Gc glycoprotein.

View Article and Find Full Text PDF

We have isolated and sequenced the genes encoding the heat shock proteins 60 (Hsp60) and 70 (Hsp70) of the salmon pathogen Piscirickettsia salmonis. The sequence analysis revealed the expected two open reading frames that encode proteins with calculated molecular weights of 60,060 and 70,400. The proteins exhibit a 70-80% homology with other known prokaryotic Hsp60 and Hsp70 sequences.

View Article and Find Full Text PDF

We report here on the isolation and sequencing of the hemagglutinin, neuraminidase and nucleoprotein genes of the Chilean equine influenza virus subtypes H7N7 (A/equi-1/Santiago/77, Sa77) and H3N8 (A/equi-2/Santiago/85, Sa85). The sequences obtained allowed a variability analysis, which indicated significant differences when compared with other isolates. We found that Chilean isolates are more similar to the North American variety than to European isolates.

View Article and Find Full Text PDF

In the present work we identified B-cell epitopes recognized by sera of humans and rodents naturally infected with Andes virus, a hantavirus present in Chile and Argentina. Analysis of patient and rodent sera with overlapping peptides revealed 21 human and rodent epitopes on the three structural proteins. Whereas in the nucleoprotein the region comprising aa 248-260 was shown to be the key determinant of human sera, the major antigenic site of rodent antibody reactivity is located at aa 326-338.

View Article and Find Full Text PDF

We have isolated and sequenced the genes encoding the membrane bound transglycosylase B (MltB) and the transferring binding protein B (TbpB) of the salmon pathogen Piscirickettsia salmonis. The results of the sequence revealed two open reading frames that encode proteins with calculated molecular weights of 38,830 and 85,140. The deduced aminoacid sequences of both proteins show a significant homology to the respective protein from phylogenetically related microorganisms.

View Article and Find Full Text PDF

An enzyme-linked immunosorbent assay (ELISA) for the detection of Piscirickettsia salmonis in fish tissue samples was developed. The test uses a combination of different monoclonal antibodies specific against P. salmonis in the capture step of the assay.

View Article and Find Full Text PDF