bluuebunny/crossref_metadata_2025_split huggingface dataset:
N- and C-Terminal Cooperation in Rotavirus Enterotoxin: Novel Mechanism of Modulation of the Properties of a Multifunctional Protein by a Structurally and Functionally Overlapping Conformational Domain
Authors: Jagannath M. R. , Kesavulu M. M. , Deepa R. , Sastri P. Narayan , Kumar S. Senthil , Suguna K. , Rao C. Durga 
Published: December 2005

ABSTRACT

Rotavirus NSP4 is a multifunctional endoplasmic reticulum (ER)-resident nonstructural protein with the N terminus anchored in the ER and about 131 amino acids (aa) of the C-terminal tail (CT) oriented in the cytoplasm. Previous studies showed a peptide spanning aa 114 to 135 to induce diarrhea in newborn mouse pups with the 50% diarrheal dose approximately 100-fold higher than that for the full-length protein, suggesting a role for other regions in the protein in potentiating its diarrhea-inducing ability. In this report, employing a large number of methods and deletion and amino acid substitution mutants, we provide evidence for the cooperation between the extreme C terminus and a putative amphipathic α-helix located between aa 73 and 85 (AAH
73-85
) at the N terminus of ΔN72, a mutant that lacked the N-terminal 72 aa of nonstructural protein 4 (NSP4) from Hg18 and SA11. Cooperation between the two termini appears to generate a unique conformational state, specifically recognized by thioflavin T, that promoted efficient multimerization of the oligomer into high-molecular-mass soluble complexes and dramatically enhanced resistance against trypsin digestion, enterotoxin activity of the diarrhea-inducing region (DIR), and double-layered particle-binding activity of the protein. Mutations in either the C terminus, AAH
73-85
, or the DIR resulted in severely compromised biological functions, suggesting that the properties of NSP4 are subject to modulation by a single and/or overlapping highly sensitive conformational domain that appears to encompass the entire CT. Our results provide for the first time, in the absence of a three-dimensional structure, a unique conformation-dependent mechanism for understanding the NSP4-mediated pleiotropic properties including virus virulence and morphogenesis.
Mutations in the U5 Sequences Adjacent to the Primer Binding Site Do Not Affect tRNA Cleavage by Rous Sarcoma Virus RNase H but Do Cause Aberrant Integrations In Vivo
Authors: Oh Jangsuk , Chang Kevin W. , Hughes Stephen H. 
Published: December 2005

ABSTRACT
In most retroviruses, the first nucleotide added to the tRNA primer becomes the right end of the U5 region in the right long terminal repeat (LTR); the removal of this tRNA primer by RNase H defines the right end of the linear double-stranded DNA. Most retroviruses have two nucleotides between the 5′ end of the primer binding site (PBS) and the CA dinucleotide that will become the end of the integrated provirus. However, human immunodeficiency virus type 1 (HIV-1) has only one nucleotide at this position, and HIV-2 has three nucleotides. We changed the two nucleotides (TT) between the PBS and the CA dinucleotide of the Rous sarcoma virus (RSV)-derived vector RSVP(A)Z to match the HIV-1 sequence (G) and the HIV-2 sequence (GGT), and we changed the CA dinucleotide to TC. In all three mutants, RNase H removes the entire tRNA primer. Sequence analysis of RSVP(HIV2) proviruses suggests that RSV integrase can remove three nucleotides from the U5 LTR terminus of the linear viral DNA during integration, although this mutation significantly reduced virus titer, suggesting that removing three nucleotides is inefficient. However, the results obtained with RSVP(HIV1) and RSVP(CATC) show that RSV integrase can process and integrate the normal U3 LTR terminus of a linear DNA independently of an aberrant U5 LTR terminus. The aberrant end can then be joined to the host DNA by unusual processes that do not involve the conserved CA dinucleotide. These unusual events generate either large duplications or, less frequently, deletions in the host genomic DNA instead of the normal 5- to 6-base duplications.
Entry of Vaccinia Virus and Cell-Cell Fusion Require a Highly Conserved Cysteine-Rich Membrane Protein Encoded by the A16L Gene
Authors: Ojeda Suany , Senkevich Tatiana G. , Moss Bernard 
Published: December 2005

ABSTRACT

The vaccinia virus A16L open reading frame encodes a 378-amino-acid protein with a predicted C-terminal transmembrane domain and 20 invariant cysteine residues that is conserved in all sequenced members of the poxvirus family. The A16 protein was expressed late in infection and incorporated into intracellular virus particles with the N-terminal segment of the protein exposed on the surface. The cysteine residues were disulfide bonded via the poxvirus cytoplasmic redox system. Unsuccessful attempts to isolate a mutant virus with the A16L gene deleted suggested that the protein is essential for replication. To study the role of the A16 protein, we made a recombinant vaccinia virus that has the
Escherichia coli lac
operator system regulating transcription of the A16L gene. In the absence of inducer, A16 synthesis was repressed and plaque size and virus yield were greatly reduced. Nevertheless, virus morphogenesis occurred and normal-looking intracellular and extracellular virus particles formed. Purified virions made in the presence and absence of inducer were indistinguishable, though the latter had 60- to 100-fold-lower specific infectivity. A16-deficient virions bound to cells, but their cores did not penetrate into the cytoplasm. Furthermore, A16-deficient virions were unable to induce low-pH-triggered syncytium formation. The phenotype of the inducible A16L mutant was similar to those of mutants in which synthesis of the A21, A28, H2, or L5 membrane protein was repressed, indicating that at least five conserved viral proteins are required for entry of poxviruses into cells as well as for cell-cell fusion.
Simian Immunodeficiency Virus Vpx Is Imported into the Nucleus via Importin Alpha-Dependent and -Independent Pathways
Authors: Singhal Prabhat K. , Kumar P. Rajendra , Rao Malireddi R. K. Subba , Kyasani Mahesh , Mahalingam Sundarasamy 
Published: December 2005

ABSTRACT

Vpx protein of human immunodeficiency virus type 2/simian immunodeficiency virus (SIV) has been implicated in the transport of the viral genome into the nuclei of nondividing cells. The mechanism by which Vpx enters the nucleus remains unknown. Here we have identified two distinct noncanonical nuclear localization signals (NLSs) in Vpx of SIV
smPbj1.9
and defined the pathways for its nuclear import. Although nuclear targeting signals identified here are distinct from known nuclear import signals, translocation of Vpx into the nucleus involves the interaction of its N-terminal NLS (amino acids 20 to 40) or C-terminal NLS (amino acids 65 to 75) with importin alpha and, in the latter case, also with importin beta. Collectively, these results suggest that importins interact with Vpx and ensure the effective import of Vpx into the nucleus to support virus replication in nondividing cells.
Expression of m157, a Murine Cytomegalovirus-Encoded Putative Major Histocompatibility Class I (MHC-I)-Like Protein, Is Independent of Viral Regulation of Host MHC-I
Authors: Tripathy Sandeep K. , Smith Hamish R. C. , Holroyd Erika A. , Pingel Jeanette T. , Yokoyama Wayne M. 
Published: December 2005

ABSTRACTA murine cytomegalovirus (MCMV)-encoded protein, m157, has a putative major histocompatibility complex class I (MHC-I) structure and is recognized by the Ly49H NK cell activation receptor. Using a monoclonal antibody against m157, in this study we directly demonstrated that m157 is a cell surface-expressed glycophosphatidylinositol-anchored protein with early viral gene kinetics. Beta-2 microglobulin and TAP1 (transporter associated with antigen processing 1) were not required for its expression. MCMV-encoded proteins that down-regulate MHC-I did not affect the expression of m157. Thus, m157 is expressed on infected cells in a manner independent of viral regulation of host MHC-I.
Anti-CD45RO Suppresses Human Immunodeficiency Virus Type 1 Replication in Microglia: Role of Hck Tyrosine Kinase and Implications for AIDS Dementia
Authors: Kim Mee-Ohk , Suh Hyeon-Sook , Si Qiusheng , Terman Bruce I. , Lee Sunhee C. 
Published: December 2005

ABSTRACTMacrophages and microglia are productively infected by HIV-1 and play a pivotal role in the pathogenesis of AIDS dementia. Although macrophages and microglia express CD45, a transmembrane protein tyrosine phosphatase, whether modulation of its activity affects human immunodeficiency virus type 1 (HIV-1) replication is unknown. Here, we report that of the five human CD45 isoforms, microglia express CD45RB and CD45RO (RB > RO) and treatment of microglia with a CD45 agonist antibody αCD45RO (UCHL-1) inhibits HIV-1 replication. αCD45RO prevented HIV-1 negative factor (Nef)-induced autophosphorylation of hematopoietic cell kinase (Hck), a myeloid lineage-specific Src kinase. Recombinant CD45 protein also inhibited HIV-1-induced Hck phosphorylation in microglia. Antennapedia-mediated delivery of Hck Src homology domain 3 (SH3), a domain that binds to the Nef PxxP motif with high affinity, reduced HIV-1-induced Hck phosphorylation and HIV-1 production in microglia. HIV-1-induced LTR transactivation was observed in U38 cells stably overexpressing wild-type Hck but not kinase-inactive Hck. In microglia, αCD45RO reduced activation of transcription factors (NF-κB and CCAAT enhancer binding protein) necessary for LTR transactivation in macrophages. These results establish that in myeloid lineage cells, Nef interacts with the Hck SH3 domain, resulting in autophosphorylation of Hck and an increase in HIV-1 transcription. αCD45RO-mediated inhibition of HIV-1 replication in microglia identifies the CD45 protein tyrosine phosphatase as a potential therapeutic target for HIV-1 infection/AIDS dementia.
The Equine Herpesvirus 1 UL20 Product Interacts with Glycoprotein K and Promotes Egress of Mature Particles
Authors: Guggemoos Simone , Just Frank T. , Neubauer Antonie 
Published: December 2005

ABSTRACT

The aim of the present study was to identify and functionally characterize the equine herpesvirus 1 (EHV-1) UL20 protein (UL20p). Using a specific antiserum, UL20p was shown to be associated with membranes of infected cells, as well as with envelopes of purified virions. By Western blot analysis, UL20p was detected in two main forms exhibiting
M
r
s of 25,000 and 75,000. Both moieties did not enter the separating gel after heating of protein samples to 99°C. The slower-migrating form of UL20p contains N-linked carbohydrates, and its presence is dependent of that of other viral proteins. Infection of cells that either constitutively express UL20p or a gK-green fluorescent protein (GFP) fusion protein with various EHV-1 deletion mutants revealed a relatively stable hetero-oligomer containing gK and UL20p with an apparent
M
r
of 75,000. As demonstrated by confocal microscopy, UL20p distribution in Rk13 cells changed from a diffuse granular or netlike appearance to a pattern confined to the Golgi network when gK was coexpressed. Analysis of a UL20 deletion mutant of EHV-1 strain RacL11 indicated an involvement of UL20p in cell-to-cell spread, as well as in very late events in virus egress. Based on these and electron microscopic studies we suggest that the EHV-1 UL20 protein might be necessary to avoid fusion of mature virions with membranes of their transport vesicles.
Variation in conserved non-coding sequences on chromosome 5q and susceptibility to asthma and atopy
Authors: Donfack Joseph , Schneider Daniel H , Tan Zheng , Kurz Thorsten , Dubchak Inna , Frazer Kelly A , Ober Carole 
Published: December 2005

Abstract

Background
Evolutionarily conserved sequences likely have biological function.

Methods
To determine whether variation in conserved sequences in non-coding DNA contributes to risk for human disease, we studied six conserved non-coding elements in the Th2 cytokine cluster on human chromosome 5q31 in a large Hutterite pedigree and in samples of outbred European American and African American asthma cases and controls.

Results
Among six conserved non-coding elements (>100 bp, >70% identity; human-mouse comparison), we identified one single nucleotide polymorphism (SNP) in each of two conserved elements and six SNPs in the flanking regions of three conserved elements. We genotyped our samples for four of these SNPs and an additional three SNPs each in the IL13 and IL4 genes. While there was only modest evidence for association with single SNPs in the Hutterite and European American samples (P < 0.05), there were highly significant associations in European Americans between asthma and haplotypes comprised of SNPs in the IL4 gene (P < 0.001), including a SNP in a conserved non-coding element. Furthermore, variation in the IL13 gene was strongly associated with total IgE (P = 0.00022) and allergic sensitization to mold allergens (P = 0.00076) in the Hutterites, and more modestly associated with sensitization to molds in the European Americans and African Americans (P < 0.01).

Conclusion
These results indicate that there is overall little variation in the conserved non-coding elements on 5q31, but variation in IL4 and IL13, including possibly one SNP in a conserved element, influence asthma and atopic phenotypes in diverse populations.
Copine A, a calcium-dependent membrane-binding protein, transiently localizes to the plasma membrane and intracellular vacuoles in Dictyostelium
Authors: Damer Cynthia K , Bayeva Marina , Hahn Emily S , Rivera Javier , Socec Catherine I 
Published: December 2005

Abstract

Background
Copines are soluble, calcium-dependent membrane binding proteins found in a variety of organisms. Copines are characterized as having two C2 domains at the N-terminal region followed by an "A domain" at the C-terminal region. The "A domain" is similar in sequence to the von Willebrand A (VWA) domain found in integrins. The presence of C2 domains suggests that copines may be involved in cell signaling and/or membrane trafficking pathways.

Results
We have identified six copines genes in the Dictyostelium discoideum genome, cpnA-cpnF, and have focused our studies on cpnA. CpnA is expressed throughout development and was shown to be capable of binding to membranes in a calcium-dependent manner in vitro. A GFP-tagged CpnA was also capable of binding to membranes in a calcium-dependent manner in vitro. In live wildtype Dictyostelium cells expressing GFP-CpnA, GFP-CpnA was typically found in the cytoplasm without any specific localization to membranes. However, in a small subset of starved cells, GFP-CpnA was observed to bind transiently (typically ~1–10 s) to the plasma membrane and intracellular vacuoles. In some cells, the transient membrane localization of GFP-CpnA was observed to occur multiple times in an oscillatory manner over several minutes. In plasma membrane disrupted cells, GFP-CpnA was observed to associate with the plasma membrane and intracellular vacuoles in a calcium-dependent manner. In fixed cells, GFP-CpnA labeled the plasma membrane and intracellular vacuoles, including contractile vacuoles, organelles of the endolysosomal pathway, and phagosomes.

Conclusion
Our results show that Dictyostelium has multiple copine homologs and provides an excellent system in which to study copine function. The localization of a GFP-tagged CpnA to the plasma membrane, contractile vacuoles, organelles of the endolysosomal pathway, and phagosomes suggests that CpnA may have a role in the function of these organelles or the trafficking to and from them. In addition, we hypothesize that the observed transient oscillatory membrane localization of GFP-CpnA in a small subset of starved cells is caused by fast calcium waves and speculate that CpnA may have a role in development, particularly in the differentiation of stalk cells.
Flecainide overdose – support using an intra-aortic balloon pump
Authors: Timperley Jonathan , Mitchell Andrew RJ , Brown Peter D , West Nicholas EJ 
Published: December 2005

Abstract

Background
Flecainide is an antiarrhythmic agent which is being used increasingly for the management of super-ventricular arrhythmias. Overdose with flecainide is frequently fatal with mortality reported as high as 22% due to arrhythmias, myocardial depression and conduction defects leading to electro-mechanical dissociation and asytole. Supportive measures are often required during the case and previously have included inotropes, extracorporeal membrane oxygenation and cardiopulmonary bypass.

Case presentation
A 47 year old lady presented to the emergency department with a four hour history of severe central chest pain. Her ECG showed atrial fibrillation and broad QRS complexes with a sine wave appearance. She had a past history of paroxysmal atrial fibrillation and significant psychiatric history. Following thrombolysis for a presumed myocardial infarction she developed cardiogenic shock with severely impaired left ventricular function. An intra-aortic balloon pump was inserted and coronary angiography demonstrated normal coronary arteries. With inotropic support she improved over 48 hours, with both her QRS duration and left ventricular function returning to normal. Biochemical testing following her discharge demonstrated significantly elevated levels of flecainide.

Conclusion
The use of an intra-aortic balloon pump is a useful supportive measure during the acute phase of flecainide overdose associated with severe myocardial depression.
Socioeconomic status and non-fatal injuries among Canadian adolescents: variations across SES and injury measures
Authors: Potter Beth K , Speechley Kathy N , Koval John J , Gutmanis Iris A , Campbell M Karen , Manuel Douglas 
Published: December 2005

AbstractBackgroundWhile research to date has consistently demonstrated that socioeconomic status (SES) is inversely associated with injury mortality in both children and adults, findings have been less consistent for non-fatal injuries. The literature addressing SES and injury morbidity among adolescents has been particularly inconclusive. To explore potential explanations for these discrepant research findings, this study uniquely compared the relationship across different measures of SES and different causes of injury (recreation versus non-recreation injuries) within a sample of Canadian adolescents.MethodsThe sample included adolescent participants (aged 12 to 19 years) in the Canadian 1996–1997 cross-sectional National Population Health Survey (n = 6967). Five SES measures (household income, two neighbourhood-level proxy measures, two parental indicators) were examined in relation to three injury outcomes (total, recreation, and non-recreation injuries) using multivariable logistic regression.ResultsAmong males, a clear relationship with injury was observed only for a parental SES index, which was positively associated with total and recreation injuries (odds ratios for the highest versus lowest SES category of 1.9 for total and 2.5 for recreation injuries). Among females, there was some evidence of a positive relationship between SES and injuries, particularly for a neighbourhood-level education measure with total and recreation injuries (odds ratios of 1.7 for total and 2.0 for recreation injuries).ConclusionThe results suggest that differences related to the measures of SES chosen and the causes of injury under study may both contribute to discrepancies in past research on SES and non-fatal injuries among adolescents. To clarify the potential SES-injury relationship among youth, the findings emphasize a need for a greater understanding of the meaning and relevance of different SES measures for adolescents, and for an exploration of the pathways through which SES may be related to injury risk.
High Frequency of Submicroscopic Hemizygous Deletion Is a Major Mechanism of Loss of Expression ofPTENin Uveal Melanoma
Authors: Abdel-Rahman Mohamed H. , Yang Ying , Zhou Xiao-Ping , Craig Elson L. , Davidorf Frederick H. , Eng Charis 
Published: December 2005

PurposeAlthough cytogenetic aberrations at 10q have been reported in up to 27% of uveal melanomas, the role of PTEN in the pathogenesis of uveal melanoma is largely unknown. Our aim was to determine the frequency and clinical significance of PTEN alterations in uveal melanomas.Patients and MethodsWe examined PTEN expression using immunohistochemistry in 75 sporadic uveal melanomas, with an average follow-up of 89 months. Molecular cytogenetic alterations were studied using comparative genomic hybridization (CGH). Genotyping was carried out using an intragenic PTEN marker and two flanking markers. Mutational analysis of PTEN was also carried out.ResultsOf the 75 tumors, 12 (16%) showed no PTEN immunostaining, 32 (42.7%) showed weak to moderate staining and the remaining 31 (38.2%) showed staining similar to the normal internal controls. Using CGH, only two (15.4%) of 13 samples showed any loss of 10q. However, in the 38 tumors with informative genotyping, we found that 29 (76.3%) had loss of heterozygosity (LOH) of at least one PTEN marker, and 15 (39.5%) showed LOH of at least two markers. Mutations in the coding region of PTEN were identified in four (11.4%) of 35 tumors. Further, loss of cytoplasmic PTEN expression by immunohistochemistry was associated with shortened disease-free survival (P = .029).ConclusionThis is the first demonstration that PTEN is a tumor suppressor involved in uveal melanoma pathogenesis and may be associated with clinical outcome. Our data also suggest that submicroscopic deletion, but not large deletions, is the major mechanism of loss of PTEN expression in uveal melanomas.
Detection of Hidden Mercury in Cosmetic Products by Partially Cross-Linked Poly(4-vinylpyridine)/Screen-Printed Electrode
Authors: Shih Ying , Senthil Kumar Annamalai , Zen Jyh-Myng , Hsu Jaw-Cherng 
Published: December 2005

Abstract
Due to the severe toxic effects of mercury (Hg) and its derivatives, they are strictly prohibited to be used as cosmetics ingredients. Nevertheless, unknown quantities of Hg are formulated in consumer cosmetic products. We demonstrate a disposable screen-printed electrode modified with 1,5-dibromopentane partially (7%) cross-linked poly(4-vinylpyridine) (SPE/pcPVP) system for the detection of hidden concentrations of mercury, [Hg] within cosmetics goods by anodic stripping analysis in 0.01 M KCl + 0.02 M H2SO4 (1M = 1mol dm−3) solution. The Hg2+ ion in a chloride medium transforms to [HgCl4]2−, which then selectively preconcentrate and electro-deposite as metallic mercury, Hg0 on the cationic SPE/pcPVP (PVP exist as PVP+ in pH &lt; 5). Under optimal conditions, the calibration graph is linear in the window of 25–150 ppb, with a detection limit (S/N = 3) and regression coefficient of 3.21 ppb and 0.9909 respectively for the SPE/pcPVP. Real sample assay results for the three skin-lightening agents are evidence of the precise existence of prohibited Hg (compared with ICP-MS measurements) in the products. This article further cautions the public of Hg toxicity in cosmetics. Since the approach is low cost and disposable, it is highly suitable for unskilled electrochemists.
Chiral Distortion of Di(μ-sulfido)bis[oxomolybdenum(V)] Complexes of a Hexadentate Ligand N,N,N′,N′-Tetrakis(2-pyridylmethyl)-R-propylenediamine and Its Analogs
Authors: Jin Hai-Ying , Hazama Ryoichi , Yamasaki Mikio , Umakoshi Keisuke , Tsuge Kiyoshi , Sasaki Yoichi 
Published: December 2005

Abstract
Chiral distortion of the basal four pyridyl nitrogen donors of the titled complex [Mo2(O)2(μ-S)2{μ-N,N,N′,N′-tetrakis(2-pyridylmethyl)-R-propylenediamine}]2+ has been found to be the reverse to that of the corresponding di-μ-oxo complex, on the basis of the inverse pattern of the circular dichroism spectra. Asymmetric distortion of the dimolybdenum(III) dimer [Mo2(μ-OH)2(μ-CH3COO){μ-N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine}]3+ has also been discussed.