Disease relevance of J1R

• This late promoter activation block was overcome by cotransfecting either naked linear vaccinia virion DNA or three cloned viral genes encoding trans-activator polypeptides of 17, 26, and 30 kd [1].
• Polyadenylation of mRNAs in poxviruses, crucial for virion maturation, is carried out by a poly(A) polymerase heterodimer composed of a catalytic component, VP55, and a processivity factor, VP39 [2].
• Human immunodeficiency virus (HIV) envelope glycoprotein interactions with cell surface CD4 are involved in both virion infectivity and virally mediated cell fusion [3].
• More interestingly, however, we have also found that nucleocapsid protein (N), an internal virion protein, can be detected on infected cell surfaces using mAb, and serves as a major target antigen for VSV-specific CTL [4].
• In the presence or absence of other virion proteins, a mutated D13 with one amino acid substitution formed stacks of membrane-unassociated flat sheets that closely resembled the curved honeycombs of immature virions except for the absence of pentagonal facets [5].

High impact information on J1R

• D-mannose-specific lectins such as Con A specifically blocked virion infectivity and cell fusion [3].
• The cavity would be capable of shielding the myristate moiety, which is essential for virion assembly [6].
• The latter is a thioredoxin-like protein that directly oxidizes thiols of L1R, a structural component of the virion membrane with three stable disulfide bonds, and of the related protein F9L [7].
• In the majority of cases, however, one of the interacting proteins was known to be involved in DNA replication, transcription, virion structure, or host evasion, thereby providing a clue to the role of the other uncharacterized protein in a specific process [8].
• The virion-derived protein, as well as a recombinant form expressed in Escherichia coli, exhibited thioltransferase and dehydroascorbate reductase activities indicative of a functional GRX [9].

Chemical compound and disease context of J1R

• Sinefungin (A9145) and a related metabolite, A9145C, were found to be potent inhibitors of Newcastle disease virion and vaccinia virion mRNA(guanine-7-)-methyltransferase and vaccinia virion mRNA(nucleoside-2'-)-methyltransferase [10].
• An NH2-terminal peptide from the vaccinia virus L1R protein directs the myristylation and virion envelope localization of a heterologous fusion protein [11].
• IPTG-dependent vaccinia virus: identification of a virus protein enabling virion envelopment by Golgi membrane and egress [12].
• A 25-kDa vaccinia virus (VV) virion protein, designated M25, is modified in vivo by covalent addition of myristic acid [13].
• Methyl group analysis of virion-associated high-molecular-weight RNA synthesized in vitro by purified vaccinia virus [14].

Biological context of J1R

• Recently, four vaccinia virus membrane proteins, namely A21, A28, H2 and L5, were reported to be necessary for cell entry and virus-induced cell-cell fusion but not for virion morphogenesis or attachment of virus particles to cells [15].
• The gene encoding the repressor protein of the lac operon was integrated into the vaccinia virus genome so that it was expressed constitutively, and the lac operator was inserted next to the promoter of a gene that encodes an 11-kDa virion-associated protein of unknown function [16].
• Reovirus mRNAs synthesized by the virion-associated RNA polymerase contain a 5'-terminal cap that is added to nascent transcripts by polypeptide lambda 2, a structural component of virions encoded by double-stranded RNA genome segment L2 [17].
• Vaccinia virus early gene transcription termination requires the vaccinia termination factor (VTF), NPH I, a single stranded DNA-dependent ATPase, the virion form of RNA polymerase containing the Rap 94 subunit, and the signal UUUUUNU, which resides in the nascent mRNA, located 30 to 50 bases upstream from the poly(A) addition site [18].
• The envelope protein encoded by the vaccinia virus A17L open reading frame is essential for virion assembly [19].

Anatomical context of J1R

• Influenza virus stimulates a vigorous cytolytic T lymphocyte (CTL) response in the mouse that is directed to several virion polypeptides [20].
• Rhodamine-actin incorporation experiments show that the first stage of tail assembly involves a polarized recruitment of G-actin, and not pre-formed actin filaments, to the membrane surrounding the virion [21].
• Electron microscopic examination of cells infected with vH3Delta or vH3i in the absence of inducer revealed that virion assembly was impaired, resulting in a high ratio of immature to mature virus forms with an accumulation of crescent membranes adjacent to granular material and DNA crystalloids [22].
• The mechanism and direction of intracellular virion movement predicted that viral proteins directly or indirectly interact with the microtubule motor protein kinesin [23].
• In this study, transcription complementation assays were used to demonstrate that VLTF-X activity is also present in virion extracts and in the cytoplasm of uninfected HeLa cells [24].

Associations of J1R with chemical compounds

• Target cells sensitized with heat-treated virus were recognized by all 11 CTL clones that were specific for internal virion proteins (nucleoprotein and basic polymerase 1), and by one of six clones specific for the major viral glycoprotein (the hemagglutinin) [25].
• Sinefungin, a potent inhibitor of virion mRNA(guanine-7-)-methyltransferase, mRNA(nucleoside-2'-)-methyltransferase, and viral multiplication [10].
• This level of inhibition was not observed at incubation temperatures below 21 degrees C, suggesting that virion surface proteins undergo thermal transitions that expose cysteine residues to modification by the reagent [26].
• Virion movement approached 3 mum/s and was sensitive to the microtubule depolymerizing drug nocodazole [27].
• Virion-released 8 to 12S mRNA derived from virion-associated HMW RNA during a chase in the presence of ATP, GTP, and S-adenosylmethionine was also translated [28].

Other interactions of J1R

• The submolar amount of Rap94, relative to RNA polymerase, was confirmed by quantitative immunoblotting of total virion extracts [29].
• Characterization of the vaccinia virus L1R myristylprotein as a component of the intracellular virion envelope [30].

Analytical, diagnostic and therapeutic context of J1R

• To determine which viral proteins were responsible for this immune protection, virion proteins prepared by SDS-PAGE and electroelution were used to immunize mice [31].
• Outcomes included quantification of viral PFU, vaccinia viral gene expression by quantitative real-time RT-PCR, and changes in virion structure by transmission electron microscopy [32].
• In cells infected with VVindA10L in the absence of the inducer virion assembly is blocked, as defined by electron microscopy [33].
• Polyacrylamide gel electrophoresis and Western blot analysis of extracts and purified virions from cells infected with vA22-HA revealed that the resolvase was expressed after the onset of DNA replication and incorporated into virion cores. vA22i exhibited a conditional replication defect [34].
• Immunoelectron microscopy revealed that the A9L protein was associated with both immature and mature virus particles and was oriented in the membrane with its C terminus exposed on the virion surface [35].

References