Search results for "cop"
showing 10 items of 25502 documents
Human Papillomavirus Types 16, 18, and 31 Share Similar Endocytic Requirements for Entry
2013
ABSTRACT Human papillomavirus type 18 (HPV18), one of the HPVs with malignant potential, enters cells by an unknown endocytic mechanism. The key cellular requirements for HPV18 endocytosis were tested in comparison to those for HPV16 and -31 endocytoses. HPV18 (like HPV16 and -31) entry was independent of clathrin, caveolin, dynamin, and lipid rafts but required actin polymerization and tetraspanin CD151, and the viruses were routed to the same LAMP-1-positive compartment. Hence, the viruses shared similar cellular requirements for endocytic entry.
Baculovirus-mediated immediate-early gene expression and nuclear reorganization in human cells
2007
Baculovirus, Autographa californica multiple nucleopolyhedrovirus (AcMNPV), has the ability to transduce mammalian cell lines without replication. The general objective of this study was to detect the transcription and expression of viral immediate-early genes in human cells and to examine the interactions between viral components and subnuclear structures. Viral capsids were seen in large, discrete foci in nuclei of both dividing and non-dividing human cells. Concurrently, the transcription of viral immediate-early transregulator genes (ie-1, ie-2) and translation of IE-2 protein were detected. Quantitative microscopy imaging and analysis showed that virus transduction altered the size of …
Lipid Binding Controls Dimerization of the Coat Protein p24 Transmembrane Helix
2019
Abstract Coat protein (COP) I and COP II complexes are involved in the transport of proteins between the endoplasmic reticulum and the Golgi apparatus in eukaryotic cells. The formation of COP I/II complexes at membrane surfaces is an early step in vesicle formation and is mastered by p24, a type I transmembrane protein. Oligomerization of p24 monomers was suggested to be mediated and/or stabilized via interactions within the transmembrane domain, and the p24 transmembrane helix appears to selectively bind a single sphingomyelin C18:0 molecule. Furthermore, a potential cholesterol-binding sequence has also been predicted in the p24 transmembrane domain. Thus, sphingomyelin and/or cholestero…
SV40 transformed fibroblasts recognize the same 140 kD fibronectin chemotactic fragment as non-transformed cells
1985
SV40-virus-transformed human embryonal fibroblasts show an enhanced chemotactic response to the glycoprotein fibronectin. However, they recognize the same chemotactic active region as non-transformed fibroblasts. The result suggests that an enhancement of chemotaxis by fibroblasts which have been transformed with Simian Virus 40 is due not to the utilization of further chemotactic domains in the molecule, but to an increased sensitivity of the cells to the chemoattractant.
PTC124-mediated translational readthrough of a nonsense mutation causing Usher syndrome type 1C.
2011
We investigated the therapeutic potential of the premature termination codon (PTC) readthrough-inducing drug PTC124 in treating the retinal phenotype of Usher syndrome, caused by a nonsense mutation in the USH1C gene. Applications in cell culture, organotypic retina cultures, and mice in vivo revealed significant readthrough and the recovery of protein function. In comparison with other readthrough drugs, namely the clinically approved readthrough-inducing aminoglycoside gentamicin, PTC124 exhibits significant better retinal biocompatibility. Its high readthrough efficiency in combination with excellent biocompatibility makes PTC124 a promising therapeutic agent for PTCs in USH1C, as well a…
STAT1 and Its Crucial Role in the Control of Viral Infections
2022
The signal transducer and activator of transcription (STAT) 1 protein plays a key role in the immune response against viruses and other pathogens by transducing, in the nucleus, the signal from type I, type II and type III IFNs. STAT1 activates the transcription of hundreds of genes, some of which have been well characterized for their antiviral properties. STAT1 gene deletion in mice and complete STAT1 deficiency in humans both cause rapid death from severe infections. STAT1 plays a key role in the immunoglobulin class-switch recombination through the upregulation of T-bet; it also plays a key role in the production of T-bet+ memory B cells that contribute to tissue-resident humoral memory…
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…
Tumor targeting of baculovirus displaying a lymphatic homing peptide.
2008
Background Tumor-associated cells and vasculature express attractive molecular markers for site-specific vector targeting. To attain tumor-selective tropism, we recently developed a baculovirus vector displaying the lymphatic homing peptide LyP-1, originally identified by ex vivo/in vivo screening of phage display libraries, on the viral envelope by fusion to the transmembrane anchor of vesicular stomatitis virus G-protein. Methods In the present study, we explored the specificity and kinetics of viral binding and internalization as well as in vivo tumor homing of the LyP-1 displaying virus to elucidate the applicability of baculovirus for targeted therapies. Results We demonstrated that th…
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…