Structural modeling and mutational analysis of yeast eukaryotic translation initiation factor 5A reveal new critical residues and reinforce its involvement in protein synthesis

Eukaryotic translation initiation factor 5A (eIF5A) is a protein that is highly conserved and essential for cell viability. This factor is the only protein known to contain the unique and essential amino acid residue hypusine. This work focused on the structural and functional characterization of Saccharomyces cerevisiae eIF5A. The tertiary structure of yeast eIF5A was modeled based on the structure of its Leishmania mexicana homologue and this model was used to predict the structural localization of new site-directed and randomly generated mutations. Most of the 40 new mutants exhibited phenotypes that resulted from eIF-5A protein-folding defects. Our data provided evidence that the C-terminal alpha-helix present in yeast eIF5A is an essential structural element, whereas the eIF5A N-terminal 10 amino acid extension not present in archaeal eIF5A homologs, is not. Moreover, the mutants containing substitutions at or in the vicinity of the hypusine modification site displayed nonviable or temperature-sensitive phenotypes and were defective in hypusine modification. Interestingly, two of the temperature-sensitive strains produced stable mutant eIF5A proteins - eIF5A(K56A) and eIF5A(Q22H,L93F)- and showed defects in protein synthesis at the restrictive temperature. Our data revealed important structural features of eIF5A that are required for its vital role in cell viability and underscored an essential function of eIF5A in the translation step of gene expression.

Genotypic characterization of Toxoplasma gondii in sheep from Brazilian slaughterhouses: New atypical genotypes and the clonal type II strain identified

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chromosomal data of two pholcids (Araneae, Haplogynae): A new diploid number and the first cytogenetical record for the New World Clade

Mesobolivar luteus (Keyserling 1891) and Micropholcus fauroli (Simon 1887) specimens were collected in Ubatuba and Rio Claro, both in the state of São Paulo, Brazil. Mesabolivar luteus showed 2n (male) = 15 = 14 + X and 2n (9) = 16 = 14 + XX in mitotic metaphases and 711 + X in diplotenic cells. During late prophage 1, all bivalents presented a ring shape, evidencing two chiasmata per bivalent. In this species, some diplotenic cells appear in pairs, maybe due to specific characteristics of the intercellular bridges. The metaphases 11 showed n = 7 or n = 8 = 7 + X chromosomes. Micropholcus fauroti evidenced 2n (male) = 17 = 16 + X in spermatogonial metaphases and 8II+X in diplotenic cells, with only one chiasma per bivalent, contrasting with M. luteus. In both species, all chromosomes were metacentrics. The sexual chromosome X was the largest element and appeared as a univalent during meiosis I. These are the first cytogenetical data for the genera Mesabolivar and Micropholcus. Additionally, M. luteus is the first chromosomally analyzed species of the New World clade and the observed diploid number for M. fauroti had not yet been recorded in Pholcidae.

Cytogenetic analyses of eight species in the genus Leptodactylus Fitzinger, 1843 (Amphibia, Anura, Leptodactylidae), including a new diploid number and a karyotype with multiple translocations

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Amphibia, Anura, Hylidae, Dendropsophus melanargyreus (Cope, 1887): distribution extension, new state record and geographic distribution map.

We present the first record of Dendropsophus melanargyreus for the state of São Paulo and a distribution map for this species. This new record represents the southeastern limit of distribution, which is 106 Km from the nearest locality previously recorded for this species and is the fourth new register of anuran to northwestern region of São Paulo in the last two years, increasing species list of the region from 33 to 36 species. This results evidence the importance of this region as priority area for inventory.

Investigation of (CH3OH)-C-13 methanol: new laser lines and assignments

We have reinvestigated (CH3OH)-C-13 as a source of far-infrared (FIR) laser emission using a CO2 laser as a pumping source. Thirty new FIR laser lines in the range 36.5 mum to 202.6 mum were observed and characterized. Five of them have wavelengths between 36.5 and 75 mum and have sufficient intensity to be used in LMR spectroscopy. Using Fourier-transform spectroscopic data in the infrared (IR) and FIR regions we have determined the assignment for 10 FIR laser transitions and predict nine frequencies for laser lines which have yet to be observed.

CH3OH optically pumped by a (CO2)-C-13 laser: new laser lines and assignments

We report 12 new THz (far-infrared) laser lines from methanol (CH3OH), ranging from 58.1 mu m (5.2 THz) to 624.6 mu m (0.5 THz). A(13) CO2 laser of wide tunability (110 MHz) has been used for optical pumping, allowing access to previously unexplored spectral regions. Optoacoustic absorption spectra were used as a guide to search for new THz laser lines, which have been characterized in wavelength, polarization, offset, relative intensity, and optimum operation pressure. For 20 laser lines previously observed, we have measured the absorption offset with respect to the (CO2)-C-13 laser line center.

Planifolin, a new naphthopyranone dimer and flavonoids from Paepalanthus planifolius

A new naphthopyranone dimer (I) named planifolin was isolated from a methylene chloride extract of the capitula of Paepalanthus planifolius. The structure of 1 has been determined by chemical and spectroscopic means. In addition, a known dihydronaphthopyranone glycoside and seven known flavonoids were isolated from an ethanolic extract of the leaves of P. planifolius.

A new synonym, a new male description and new geographical records for three Ceraeochrysa species (Neuroptera: Chrysopidae)

Ceraeochrysa Adams is the largest genus in Chrysopini with 62 valid species distributed in the New World. The taxonomy of this group is complex and largely based on male genitalic characters. There are still serious complications, especially with the species that have been described solely from female specimens. The male of C. montoyana (Navas, 1913), unknown previously, is herein described for the first time, and compared with its closest relative, C. claveri (Navas, 1911). Ceraeochrysa acutipuppis Adams & Penny, 1985 is designated as a junior synonym of C. fairchildi (Banks, 1946) based on the evidence that both species share external morphological features uncommon in other species of the genus. The species C. claveri, C. fairchildi and C. montoyana are recorded from Venezuela for the first time. External morphology and genitalia of these insects are described and illustrated.

A new imidazole alkaloid and other constituents from Pilocarpus grandiflorus and their antifungal activity

The stems of Pilocarpus grandiflorus have afforded the new imidazole alkaloid 4,6-dehydro-1,2,4,5-tetrahydro-2,5-dioxopilocarpine in addition to the 17 known compounds germanicol, β-amiryn, ocotillone, stigmast-4-en-3-one, 3β-hydroxy-stigmast-5-en-7-one, 6β-hydroxy-stigmast-4-en-3-one, β-sitosterol, scopoletin, 3-(1′,1′-dimethylallyl)-scopoletin, elisin, dictamine, 4-methoxy-2-quinolone, platydesmine, syringaresinol, syringaldehyde, syringic acid and vanillic acid. Their structures were elucidated on the basis of chemical and spectroscopic evidence. The phenolic compounds vanillic acid and syringaldehyde and the furoquinoline alkaloid platydesmine exhibited antifungal activity against Leucoagaricus gongylophorus, the symbiotic fungus of leaf-cutting ants (Atta sexdens rubropilosa). © 2005 Verlag der Zeitschrift für Naturforschung.

New integrated Zeta and Cuk inverters intended for standalone and grid-connected applications

This paper presents new inverter topologies based on the integration of a DC to DC Zeta or Cuk converter with a voltage source inverter (VSI). The proposed integration procedure aims to reduce the amount of components, meaning lower volume, weight and costs. In this context, new families of single-phase and three-phase integrated inverters are also presented. Therefore, considering the novelty for Zeta and Cuk integrated inverters structures, the proposed single-phase and three-phase inverters versions are analyzed for grid-tied and stand-alone applications. Furthermore, in order to demonstrate the feasibility of the proposal, the main simulation and experimental results are presented. © 2011 IEEE.

A new tropane alkaloid and other constituents of Erythroxylum rimosum (Erythroxylaceae)

A new tropane alkaloid, named the 7β-acetoxy-3β,6β- dibenzoyloxytropane (1), was isolated from a methanol extract of Erythroxylum rimosum O.E. Schulz leaves. Other known compounds were detected, including quercetin, kaempferol-3-O-α-l-arabinofuranoside, (+)-catechin, epicatechin, quercetin-3-O-α-arabinofuranoside, quercetin-3-O-α- arabinopyranoside, quercetin-3-O-β-arabinopyranoside, quercetin-3-β- glucopyranoside, kaempferol, quercetin-3-O-β-galactopyranoside, β-sitosterol, α-amyrin, β-amyrin, and the ester derivatives of these two amyrins. Compound 1 exhibited weak inhibition of acetylcholinesterase. Structural identification was performed using IR, ESIHRMS and one- and two-dimensional NMR data analyses and confirmed by comparison with literature data. © 2013 Phytochemical Society of Europe.

New karyologycal data and cytotaxonomic considerations on small mammals from Santa Virginia (Parque Estadual da Serra do Mar, Atlantic Forest, Brazil)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

New host records and a checklist of fishes infected with Austrodiplostomum compactum (Digenea: Diplostomidae) in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)