174 research outputs found
In vitro exposure of Ulva lactuca Linnaeus (Chlorophyta) to gasoline: biochemical and morphological alterations
Refined fuels have considerable share of pollution of marine ecosystems. Gasoline is one of the most consumed fuel worldwide, but its effects on marine benthic primary producers are poorly investigated. In this study, Ulva lactuca was chosen as a biological model due to its cosmopolitan nature and tolerance to high levels and wide range of xenobiotics and our goal was to evaluate the effects of gasoline on ultrastructure and metabolism of that seaweed. The experimental design consisted of in vitro exposure of U. lactuca to four concentrations of gasoline (0.001%, 0.01%, 0.1%, and 1.0%, v/v) over 30 min, 1 h, 12 h, and 24 h, followed by cytochemical, SEM, and biochemical analysis. Increase in the number of cytoplasmic granules, loss of cell turgor, cytoplasmic shrinkage, and alterations in the mucilage were some of the ultrastructural alterations observed in thalli exposed to gasoline. Decrease in carotenoid and polyphenol contents, as well as increase of soluble sugars and starch contents were associated with the time of exposure to the xenobiotic. In combination, the results revealed important morphological and biochemical alterations in the phenotype of U. lactuca upon acute exposure to gasoline. This seaweed contain certain metabolites assigned as candidates to biomarkers of the environmental stress investigated and it is thought to be a promise species for usage in coastal ecosystems perturbation monitoring system. In addition, the findings suggest that U. lactuca is able to metabolize gasoline hydrocarbons and use them as energy source, acting as bioremediator of marine waters contaminated by petroleum derivatives.To Coordination for the Improvement of Higher Education Personnel (CAPES) for financial support. Authors are thankful to the Central Laboratory of Electron Microscopy (LCME) and Multi-User Laboratory for Studies in Biology (LAMEB) at Federal University of Santa Catarina. The research fellowships granted to M. Maraschin (Proc. 307099/2015-6) and Fernanda Ramlov (Proc. 473408/2013-9) by National Council of Technological and Scientific Development (CNPq) are also acknowledged. This work was partially funded by CNPq and FCT agreement through the PropMine (Proc. 490383/2013-0) and PVE (Proc. 407323/2013-9, Dr. Miguel Rocha) grants
Extensions of superalgebras of Krichever-Novikov type
An explicit construction of central extensions of Lie superalgebras of
Krichever-Novikov type is given. In the case of Jordan superalgebras related to
the superalgebras of Krichever-Novikov type we calculate a 1-cocycle with
coefficients in the dual space
Structural History of Human SRGAP2 Proteins
This is the author accepted manuscript. The final version is available from Oxford University Press via the DOI in this record.We thank Adam Frost and Eckart Gundelfinger for valuable advice on the manuscript, Michaela Vogel, Lada Gevorkyan-Airapetov, Rinat Vasserman and Tomer Orevi for technical assistance, and Hadar Amartely and Mario Lebendiker for help with SEC-MALS experiments and analysis. Thanks to the staff of beamlines ID14, ID23, and ID29 of ESRF, and the staff of BESSY II BL14.1. This work was supported by funds from the ISF (Grants no. 182/10 and 1425/15 to Y.O.) and BSF (Grant no. 2013310, to Y.O. and Adam Frost) as well as by the DFG grants QU116/6-2 to B.Q. and KE685/4-2 to M.M.K
A probable case of tick-borne encephalitis (TBE) acquired in England, July 2019
The United Kingdom (UK) has thus far been considered to be free from tick-borne encephalitis (TBE), yet in July 2019, a German infant developed serologically diagnosed TBE following a tick bite in southern England. This first report of a probable human case together with recent findings of TBE virus in ticks in foci in England suggest that TBE may be acquired in parts of England and should be considered in patients with aetiologically-unexplained neurological manifestations.Peer Reviewe
Extending the allelic spectrum at noncoding risk loci of orofacial clefting
Genome-wide association studies (GWAS) have generated unprecedented insights into the genetic etiology of orofacial clefting (OFC). The moderate effect sizes of associated noncoding risk variants and limited access to disease-relevant tissue represent considerable challenges for biological interpretation of genetic findings. As rare variants with stronger effect sizes are likely to also contribute to OFC, an alternative approach to delineate pathogenic mechanisms is to identify private mutations and/or an increased burden of rare variants in associated regions. This report describes a framework for targeted resequencing at selected noncoding risk loci contributing to nonsyndromic cleft lip with/without cleft palate (nsCL/P), the most frequent OFC subtype. Based on GWAS data, we selected three risk loci and identified candidate regulatory regions (CRRs) through the integration of credible SNP information, epigenetic data from relevant cells/tissues, and conservation scores. The CRRs (total 57 kb) were resequenced in a multiethnic study population (1061 patients; 1591 controls), using single-molecule molecular inversion probe technology. Combining evidence from in silico variant annotation, pedigree- and burden analyses, we identified 16 likely deleterious rare variants that represent new candidates for functional studies in nsCL/P. Our framework is scalable and represents a promising approach to the investigation of additional congenital malformations with multifactorial etiology
Regulatory Elements within the Prodomain of Falcipain-2, a Cysteine Protease of the Malaria Parasite Plasmodium falciparum
Falcipain-2, a papain family cysteine protease of the malaria parasite Plasmodium falciparum, plays a key role in parasite hydrolysis of hemoglobin and is a potential chemotherapeutic target. As with many proteases, falcipain-2 is synthesized as a zymogen, and the prodomain inhibits activity of the mature enzyme. To investigate the mechanism of regulation of falcipain-2 by its prodomain, we expressed constructs encoding different portions of the prodomain and tested their ability to inhibit recombinant mature falcipain-2. We identified a C-terminal segment (Leu155–Asp243) of the prodomain, including two motifs (ERFNIN and GNFD) that are conserved in cathepsin L sub-family papain family proteases, as the mediator of prodomain inhibitory activity. Circular dichroism analysis showed that the prodomain including the C-terminal segment, but not constructs lacking this segment, was rich in secondary structure, suggesting that the segment plays a crucial role in protein folding. The falcipain-2 prodomain also efficiently inhibited other papain family proteases, including cathepsin K, cathepsin L, cathepsin B, and cruzain, but it did not inhibit cathepsin C or tested proteases of other classes. A structural model of pro-falcipain-2 was constructed by homology modeling based on crystallographic structures of mature falcipain-2, procathepsin K, procathepsin L, and procaricain, offering insights into the nature of the interaction between the prodomain and mature domain of falcipain-2 as well as into the broad specificity of inhibitory activity of the falcipain-2 prodomain
Is (poly-) substance use associated with impaired inhibitory control? A mega-analysis controlling for confounders
The Role of Extramembranous Cytoplasmic Termini in Assembly and Stability of the Tetrameric K+-Channel KcsA
Membrane-active alcohol 2,2,2-trifluoroethanol has been proven to be an attractive tool in the investigation of the intrinsic stability of integral membrane protein complexes by taking K+-channel KcsA as a suitable and representative ion channel. In the present study, the roles of both cytoplasmic N and C termini in channel assembly and stability of KcsA were determined. The N terminus (1–18 residues) slightly increased tetramer stability via electrostatic interactions in the presence of 30 mol.% acidic phosphatidylglycerol (PG) in phosphatidylcholine lipid bilayer. Furthermore, the N terminus was found to be potentially required for efficient channel (re)assembly. In contrast, truncation of the C terminus (125–160 residues) greatly facilitated channel reversibility from either a partially or a completely unfolded state, and this domain was substantially involved in stabilizing the tetramer in either the presence or absence of PG in lipid bilayer. These studies provide new insights into how extramembranous parts play their crucial roles in the assembly and stability of integral membrane protein complexes
Dermoscopic evaluation of nodular melanoma
Importance: Nodular melanoma (NM) is a rapidly progressing potentially lethal skin tumor for which early diagnosis is critical
A Pro-Cathepsin L Mutant Is a Luminal Substrate for Endoplasmic-Reticulum-Associated Degradation in C. elegans
Endoplasmic-reticulum associated degradation (ERAD) is a major cellular misfolded protein disposal pathway that is well conserved from yeast to mammals. In yeast, a mutant of carboxypeptidase Y (CPY*) was found to be a luminal ER substrate and has served as a useful marker to help identify modifiers of the ERAD pathway. Due to its ease of genetic manipulation and the ability to conduct a genome wide screen for modifiers of molecular pathways, C. elegans has become one of the preferred metazoans for studying cell biological processes, such as ERAD. However, a marker of ERAD activity comparable to CPY* has not been developed for this model system. We describe a mutant of pro-cathepsin L fused to YFP that no longer targets to the lysosome, but is efficiently eliminated by the ERAD pathway. Using this mutant pro-cathepsin L, we found that components of the mammalian ERAD system that participate in the degradation of ER luminal substrates were conserved in C. elegans. This transgenic line will facilitate high-throughput genetic or pharmacological screens for ERAD modifiers using widefield epifluorescence microscopy
- …