Search results for "SOM"
showing 10 items of 8346 documents
DNA-induced structural changes in the papillomavirus capsid.
2001
ABSTRACT Human papillomavirus capsid assembly requires intercapsomeric disulfide bonds between molecules of the major capsid protein L1. Virions isolated from naturally occurring lesions have a higher degree of cross-linking than virus-like particles (VLPs), which have been generated in eukaryotic expression systems. Here we show that DNA encapsidation into VLPs leads to increased cross-linking between L1 molecules comparable to that seen in virions. A higher trypsin resistance, indicating a tighter association of capsomeres through DNA interaction, accompanies this structural change.
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.
Papillomavirus assembly requires trimerization of the major capsid protein by disulfides between two highly conserved cysteines.
1998
ABSTRACT We have used viruslike particles (VLPs) of human papillomaviruses to study the structure and assembly of the viral capsid. We demonstrate that mutation of either of two highly conserved cysteines of the major capsid protein L1 to serine completely prevents the assembly of VLPs but not of capsomers, whereas mutation of all other cysteines leaves VLP assembly unaffected. These two cysteines form intercapsomeric disulfides yielding an L1 trimer. Trimerization comprises about half of the L1 molecules in VLPs but all L1 molecules in complete virions. We suggest that trimerization of L1 is indispensable for the stabilization of intercapsomeric contacts in papillomavirus capsids.
In vitro studies on the activation of the hepatitis C virus NS3 proteinase by the NS4A cofactor.
1996
AbstractProteolytic processing of the nonstructural proteins of the hepatitis C virus (HCV) is mediated by two viral proteinases: the NS2-3 proteinase cleaving at the NS2/3 junction and the NS3 serine-type proteinase responsible for processing at the NS3/4A, NS4A/B, NS4B/5A, and NS5A/B sites. Activity of the NS3 proteinase is modulated by NS4A. In the absence of this cofactor processing at the NS3-dependent sites does not occur or, in the case of the NS5A/B junction, is poor but increased when NS4A is present. Although recent studies demonstrated that proteinase activation requires direct interaction between NS3 and NS4A, the mechanism by which NS4A exerts the activation function is not kno…
Molecular Basis of SARS-CoV-2 Nsp1-Induced Immune Translational Shutdown as Revealed by All-Atom Simulations.
2021
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic represents the most severe global health crisis in modern human history. One of the major SARS-CoV-2 virulence factors is nonstructural protein 1 (Nsp1), which, outcompeting with the binding of host mRNA to the human ribosome, triggers a translation shutdown of the host immune system. Here, microsecond-long all-atom simulations of the C-terminal portion of the SARS-CoV-2/SARS-CoV Nsp1 in complex with the 40S ribosome disclose that SARS-CoV-2 Nsp1 has evolved from its SARS-CoV ortholog to more effectively hijack the ribosome by undergoing a critical switch of Q/E158 and E/Q159 residues that perfects Nsp1's interactions…
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…
Transnational responsibilities and multi-sited strategies : voluntary associations of Somali diaspora in Finland
2013
La tutela del lavoratore straniero irregolare dopo il decreto n. 130/2020
2022
Lo scritto si propone di indagare i profili di vulnerabilità legati alla posizione di clandestinità dei migranti irregolari ed il duplice ruolo dell’ordinamento giuridico, quale causa della loro stessa vulnerabilità e strumento di tutela. A tal fine, si propone un’analisi degli ultimi interventi in tema di immigrazione, a cui segue un dettagliato esame della più recente giurisprudenza in materia di protezione speciale. L’obiettivo è quello di definire l’ambito di applicazione della “nuova” protezione speciale come ultimo approdo legislativo in grado di fornire un meccanismo residuale di protezione delle vulnerabilità dei lavoratori migranti, laddove il permesso di soggiorno per motivi di la…
Zooleksēmu denotācija un konotācija somu sakāmvārdos
2015
Bakalaura darbā “Zooleksēmu denotācija un konotācija somu sakāmvādros” tiek apskatīta dzīvnieku atveide somu sakāmvārdos un tiem piemītošās denotatīvās un konotatīvās iezīmes. Darba mērķis ir izpētīt denotatīvo un konotatīvo nozīmi zooleksēmām, kas parādās apkopotajos somu sakāmvārdos. Darbs sastāv no trim daļām, no kurām pirmajā tiek konkretizēta kopsakarība starp semantiku un sakāmvārdiem. Šajā nodaļā atklājas kas ir semantika, konotācija un denotācija, kā arī kā tās ir saistāmas ar sakāmvārdu pētīšanu. Otrā bakalaura daļa pievēršās dzīvnieku tēla parādīšanās biežumam sakāmvārdos. Šeit tiek atklātas zīdītāju, putnu, zivju un kukaiņu parādīšanās biežums somu sakāmvārdos, kā arī tiek atrast…
Tērpu stilu un somas šūšanas apguve kompetenču izglītības aspektā mājturībā un tehnoloģijās 8.klasē
2017
Diplomdarba tēma: ,,Tērpu stilu un somas šūšanas apguve kompetenču izglītības aspektā mājturībā un tehnoloģijās 8. klasē’’, teorētiskajā pamatojumā ir pedagoģiskās atziņas par kompetenču pieeju izglītībā, mācību metodēm, vērtēšanu. Diplomdarba pētījuma mērķis: Izstrādāt mācību saturu tēmai „Tērpu stili un somas šūšana” kompetenču izglītības aspektā un aprobēt to praksē mājturības un tehnoloģijas mācību stundās 8.klasē. Diplomdarba pirmajā daļā tiek raksturots kompetenču jēdziens izglītības aspektā, mācību metodes un vērtēšana. Diplomdarba otrajā daļā tiek apskatīts mācību tēmas ,,Tērpu stili un somas šūšana” saturs. Diplomdarba trešajā daļā tika veikta mācību satura aprobācija un iegūto dat…