Deletion of eIF2β lysine stretches creates a dominant negative that affects the translation and proliferation in human cell line: A tool for arresting the cell growth.

Background: Eukaryote initiation factor 2 subunit β (eIF2β) plays a crucial role in regulation protein synthesis, which mediates the interaction of eIF2 with mRNA. eIF2β contains evolutionarily conserved polylysine stretches in amino-terminal region and a zinc finger motif in the carboxy-terminus.

Methods: The gene eIF2β was cloned under tetracycline transcription control and the polylysine stretches were deleted by site-directed mutagenesis (eIF2βΔ3K).

Sak1 kinase interacts with Pso2 nuclease in response to DNA damage induced by interstrand crosslink-inducing agents in Saccharomyces cerevisiae.

By isolating putative binding partners through the two-hybrid system (THS) we further extended the characterization of the specific interstrand cross-link (ICL) repair gene PSO2 of Saccharomyces cerevisiae. Nine fusion protein products were isolated for Pso2p using THS, among them the Sak1 kinase, which interacted with the C-terminal β-CASP domain of Pso2p. Comparison of mutagen-sensitivity phenotypes of pso2Δ, sak1Δ and pso2Δsak1Δ disruptants revealed that SAK1 is necessary for complete WT-like repair.

Hepatitis B virus genotypes from European origin explains the high endemicity found in some areas from southern Brazil.

Southern Brazil is considered an area of low Hepatitis B endemicity, but some areas of higher endemicity have been described in the Southwest of Paraná and Santa Catarina states. The aim of this study was to evaluate viral genotypes circulating throughout Paraná state. PCR amplification and partial sequencing of the S gene was carried out in 228 samples from HBsAg positive candidate blood donors.

Cloning and purification of recombinant proteins of Mycoplasma hyopneumoniae expressed in Escherichia coli.

Mycoplasma hyopneumoniae, the etiological agent of swine enzootic pneumonia, is an important pathogen in the swine industry worldwide. Vaccination is the most cost-effective strategy for controlling and prevention of this disease. However, investigations on pathogenicity mechanisms as well as current serological detection methods and the development of new recombinant subunit vaccines are hampered by the lack of known and well characterized species-specific M.

Increased growth hormone (GH), growth hormone receptor (GHR), and insulin-like growth factor I (IGF-I) gene transcription after hyperosmotic stress in the Brazilian flounder Paralichthys orbignyanus.

Growth hormone (GH) action is the result of an intracellular cascade initiated just after its interaction with the growth hormone receptor (GHR) located on the surface of target cells. This cascade culminates with the transcription of target genes, such as the insulin-like growth factors (IGFs), which are responsible for most GH biological effects. In addition to its central role in growth, fish GH is also involved with osmoregulatory control.

cDNA cloning and expression analysis of the catalytic subunit of glutamate cysteine ligase gene in an annelid polychaete after cadmium exposure: a potential tool for pollution biomonitoring.

The enzyme glutamate cysteine ligase (GCL) is the rate-limiting enzyme in glutathione (GSH) synthesis and is formed by a catalytic (GCLC) and a modulatory subunit (GCLM). Some studies have demonstrated that environmental pollutants can regulate the expression of these subunits. Despite the importance of these genes in toxicological responses, no sequences are available for the GCL subunits in annelids.

Short-term responses to cadmium exposure in the estuarine polychaete Laeonereis acuta (polychaeta, Nereididae): subcellular distribution and oxidative stress generation.

Some effects of cadmium exposure (100 microg/L for 4, 8, 12, and 24 h) on the estuarine polychaete Laeonereis acuta (Nereididae) were evaluated. This polychaete was able to accumulate cadmium in the body, with the metal stored mainly in the cytosolic fraction (>10 kDa). Activity of the antioxidant enzymes superoxide dismutase, glutathione S-transferase, and glutathione reductase (GR) as well as the total oxyradical scavenger capacity, the glutamate cysteine ligase catalytic subunit gene expression, and the metallothionein-like proteins content were not affected by cadmium at any exposure time tested.

Molecular evidence of HTLV-II subtype B among an urban population living in South Brazil.

Human T cell lymphotropic virus type II (HTLV-II) is a deltaretrovirus endemic in Indian populations living in Central and South America, among Pygmies tribes from Central Africa, and epidemic among injecting drug users (IDUs) in the United States, Europe, Southeast Asia, and South America. To date only the HTLV-IIa subtype has been demonstrated among Brazilians (Amazon basin Indians, blood donors, and IDUs). We analyzed HTLV-II isolates from 12 individuals living in the urban area of Porto Alegre, Southern Brazil, identified as seropositive for HTLVI/II in a blood donation.

Swine and poultry pathogens: the complete genome sequences of two strains of Mycoplasma hyopneumoniae and a strain of Mycoplasma synoviae.

This work reports the results of analyses of three complete mycoplasma genomes, a pathogenic (7448) and a nonpathogenic (J) strain of the swine pathogen Mycoplasma hyopneumoniae and a strain of the avian pathogen Mycoplasma synoviae; the genome sizes of the three strains were 920,079 bp, 897,405 bp, and 799,476 bp, respectively. These genomes were compared with other sequenced mycoplasma genomes reported in the literature to examine several aspects of mycoplasma evolution. Strain-specific regions, including integrative and conjugal elements, and genome rearrangements and alterations in adhesin sequences were observed in the M.