Search results for "ASES"
showing 10 items of 26804 documents
SARS-CoV-2 envelope protein topology in eukaryotic membranes
2020
Coronavirus E protein is a small membrane protein found in the virus envelope. Different coronavirus E proteins share striking biochemical and functional similarities, but sequence conservation is limited. In this report, we studied the E protein topology from the new SARS-CoV-2 virus both in microsomal membranes and in mammalian cells. Experimental data reveal that E protein is a single-spanning membrane protein with the N-terminus being translocated across the membrane, while the C-terminus is exposed to the cytoplasmic side (Nt lum /Ct cyt ). The defined membrane protein topology of SARS-CoV-2 E protein may provide a useful framework to understand its interaction with other viral and ho…
Characterization of the autoantigen La (SS-B) as a dsRNA unwinding enzyme
1997
During the analysis of the La (SS-B) autoantigen for catalytic activities an ATP-dependent double-stranded RNA unwinding activity was detected. Both native and recombinant La proteins from different species displayed this activity, which could be inhibited by monospecific anti-La antibodies. La protein was able to melt dsRNA substrates with either two 3'-overhangs or a single 3'- and a 5'-overhang. Double-stranded RNAs with two 5'-overhangs were not unwound, indicating that at least one 3'-overhang is required for unwinding. Sequence elements of the La protein that might be involved in dsRNA unwinding, such as an evolutionarily conserved putative ATP-binding motif and an element that is hom…
Clathrin- and Caveolin-Independent Entry of Human Papillomavirus Type 16—Involvement of Tetraspanin-Enriched Microdomains (TEMs)
2008
BACKGROUND: Infectious entry of human papillomaviruses into their host cells is an important step in the viral life cycle. For cell binding these viruses use proteoglycans as initial attachment sites. Subsequent transfer to a secondary receptor molecule seems to be involved in virus uptake. Depending on the papillomavirus subtype, it has been reported that entry occurs by clathrin- or caveolin-mediated mechanisms. Regarding human papillomavirus type 16 (HPV16), the primary etiologic agent for development of cervical cancer, clathrin-mediated endocytosis was described as infectious entry pathway. METHODOLOGY/PRINCIPAL FINDINGS: Using immunofluorescence and infection studies we show in contra…
Quantitative microscopy reveals stepwise alteration of chromatin structure during herpesvirus infection
2019
During lytic herpes simplex virus 1 (HSV-1) infection, the expansion of the viral replication compartments leads to an enrichment of the host chromatin in the peripheral nucleoplasm. We have shown previously that HSV-1 infection induces the formation of channels through the compacted peripheral chromatin. Here, we used three-dimensional confocal and expansion microscopy, soft X-ray tomography, electron microscopy, and random walk simulations to analyze the kinetics of host chromatin redistribution and capsid localization relative to their egress site at the nuclear envelope. Our data demonstrated a gradual increase in chromatin marginalization, and the kinetics of chromatin smoothening arou…
Parvovirus B19 Nonstructural Protein-Induced Damage of Cellular DNA and Resultant Apoptosis
2011
Parvovirus B19 is a widespread virus with diverse clinical presentations. The viral nonstructural protein, NS1, binds to and cleaves the viral genome, and induces apoptosis when transfected into nonpermissive cells, such as hepatocytes. We hypothesized that the cytotoxicity of NS1 in such cells results from chromosomal DNA damage caused by the DNA-nicking and DNA-attaching activities of NS1. Upon testing this hypothesis, we found that NS1 covalently binds to cellular DNA and is modified by PARP, an enzyme involved in repairing single-stranded DNA nicks. We furthermore discovered that the DNA nick repair pathway initiated by poly(ADPribose)polymerase and the DNA repair pathways initiated by …
Antiviral prophylaxis in patients with haematological malignancies and solid tumours: Guidelines of the Infectious Diseases Working Party (AGIHO) of …
2006
Morbidity and mortality in patients with malignancies are increased by viral infections. These mostly are reactivations of asymptomatic latent infections. They primarily concern clinical entities associated with the reactivation of herpes viruses, such as varicella zoster virus (VZV) and cytomegalovirus (CMV). Respiratory tract infections caused by influenza, parainfluenza or respiratory syncytial virus (RSV) are less common. Since reactivation of latent infections has major clinical impact, antiviral prophylaxis is an attractive approach for patients expecting immunosuppression. The main risk factor for clinically relevant reactivation is profound disruption of cellular immune response. Du…
Truncated forms of viral VP2 proteins fused to EGFP assemble into fluorescent parvovirus-like particles
2006
Fluorescence correlation spectroscopy (FCS) monitors random movements of fluorescent molecules in solution, giving information about the number and the size of for example nano-particles. The canine parvovirus VP2 structural protein as well as N-terminal deletion mutants of VP2 (-14, -23, and -40 amino acids) were fused to the C-terminus of the enhanced green fluorescent protein (EGFP). The proteins were produced in insect cells, purified, and analyzed by western blotting, confocal and electron microscopy as well as FCS. The non-truncated form, EGFP-VP2, diffused with a hydrodynamic radius of 17 nm, whereas the fluorescent mutants truncated by 14, 23 and 40 amino acids showed hydrodynamic r…
A single tube PCR assay for detecting viruses and their recombinants that cause tomato yellow leaf curl disease in Mediterranean basin
2007
Tomato yellow leaf curl disease (TYLCD) is well known in Mediterranean countries, where it has been causing severe losses in tomato crops for decades. Until recently, two viruses (with several isolates) in the genus Begomovirus, family Geminiviridae, have been associated with the epidemics: Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl Sardinia virus (TYLCSV). However, recombinants between these, such as Tomato yellow leaf curl Malaga virus (TYLCMalV), are spreading, and new methods for detecting all viruses present in the region are needed. By considering all DNA sequences available of viruses causing TYLCD in the Mediterranean basin, a PCR/RFLP protocol was developed t…
Additional file 2 of COVID-19: viral–host interactome analyzed by network based-approach model to study pathogenesis of SARS-CoV-2 infection
2020
Additional file 2: Figure S1. Pairwise distances along 259 full length CoV genomes. In the bottom of picture, indicative gene positioning along CoVs genomes is reported. The list of all considered genomes is reported in Additional file 1: Table S1. Figure S2. 3D structure of S-glycoprotein of SARS-CoV-2 and comparison with the ortholog from HCoV-229E, SARS-CoV, and MERS-CoV. Lateral (a) and superior (b) representation of SARS-CoV-2 S-glycoprotein, deducted for the sequence of patient INMI1 (MT066156.1). Each subunit chain has a different color. Structure comparison of S-glycoprotein subunit between: HCoV-229E and SARS-CoV-2, in purple and blue respectively (c); SARS-CoV and SARS-CoV-2, in r…
Estrabismo y visión binocular tras cirugía refractiva
2018
ANTECEDENTES: La cirugía refractiva ha demostrado ser segura y efectiva para la corrección de errores de refracción y estrabismos puramente acomodativos. Sin embargo, alteraciones sensoriomotoras como descompensación de estrabismos, aparición de diplopía y supresión son complicaciones también descritas tras la cirugía refractiva. OBJETIVOS: El objetivo principal fue evaluar los efectos en la alineación ocular y en la visión binocular, en términos de fusión y estereopsis, en pacientes sometidos a cirugía refractiva mediante técnicas tanto ablativas corneales como intraoculares. Los objetivos secundarios fueron determinar la prevalencia de alteraciones en la visión binocular y el alineamiento…