Nucleocapsid Protein Subunits of Simian Virus 5, Newcastle Disease Virus, and Sendai Virus
TL;DR: There is suggestive evidence that conversion of the larger subunit to the smaller by proteolytic cleavage may occur intracellularly and the possibility that such a mechanism could be involved in the accumulation of nucleocapsid in cells persistently infected with paramyxoviruses is discussed.
Abstract: Helical nucleocapsids of each of the paramyxoviruses simian virus 5 (SV5), Newcastle disease virus (NDV), and Sendai virus have been isolated in two different forms. One form contains larger protein subunits and is obtained from mature virions or infected cells dispersed by ethylenediaminetetraacetic acid. The other form possesses smaller subunits and is obtained from infected cells dispersed by trypsin. The estimated molecular weights of the larger subunits in the three viruses are similar: SV5, 61,000; Sendai virus, 60,000; NDV, 56,000. The smaller nucleocapsid subunits are also very similar: SV5, 43,000; Sendai virus, 46,000; NDV, 47,000. The helical nucleocapsid composed of the smaller subunit appears to be less flexible and more stable than that formed by the larger subunit. There is suggestive evidence that conversion of the larger subunit to the smaller by proteolytic cleavage may occur intracellularly. The possibility that such a mechanism could be involved in the accumulation of nucleocapsid in cells persistently infected with paramyxoviruses is discussed.
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TL;DR: The results indicate that the small glycoprotein of paramyxoviruses is biologically active and is involved in virus-induced hemolysis, cell fusion, and the initiation of infection, and provides a biochemical basis for previously observed host-dependent variation in infectivity, and in hemolyzing and cell-fusion induced by paramyxviruses.
945 citations
TL;DR: Polypeptides of egg-borne Sendai virus (egg Sendai), which is biologically active on the basis of criteria of the infectivity for L cells and of hemolytic and cell fusion activities, were compared by polyacrylamide gel electrophoresis with those of L cell-borne (L Sendai) and HeLa cell- transmitted viruses, which are judged biologically inactive.
Abstract: Polypeptides of egg-borne Sendai virus (egg Sendai), which is biologically active on the basis of criteria of the infectivity for L cells and of hemolytic and cell fusion activities, were compared by polyacrylamide gel electrophoresis with those of L cell-borne (L Sendai) and HeLa cell-borne Sendai (HeLa Sendai) viruses, which are judged biologically inactive by the above criteria. Densitometer profiles on the stained gels of egg Sendai resolved six polypeptides (virion protein [VP] 1 to VP6), in which VP2 and VP4 were identified as glycoproteins by PAS stain. Comparative electropherograms of both L Sendai and HeLa Sendai revealed that there were significantly larger amounts in the VP2 region of these viruses but VP4 was present only in greatly reduced amounts as compared to egg Sendai. It was also found that VP2 of L Sendai and HeLa Sendai consisted of two components, VP2a and VP2b, but the one of egg Sendai consisted of only VP2a. A mild trypsin treatment which converts both L Sendai and HeLa Sendai to a biologically active form selectively removed VP2b from these viruses and increased concomitantly the amounts of materials in the VP4 region. The same treatment of egg Sendai affected neither its biological activities nor its electropherogram. Consequently, gross polypeptide profiles on the stained gels of L Sendai and HeLa Sendai after trypsin treatment became favorably comparable to that of egg Sendai. Electrophoresis of labeled L Sendai and HeLa Sendai with a (3)H-amino acids mixture and (14)C-glucosamine resolved at least three glycoproteins, GP1, GP2, and GP3, each corresponding to VP2a, VP2b, and VP4, respectively. The trypsin treatment of these viruses removed almost all the radioactivity of GP2 and simultaneously increased the radioactive counts of GP3 and raised small amounts of rapidly moving heterogeneous glycoprotein, GP4. A possible relationship between the biological modification and the above characteristic polypeptide patterns of Sendai virus was discussed.
514 citations
TL;DR: Findings suggest that the association of hemagglutinating and neuraminidase activities with one glycoprotein is a general property of the paramyxovirus group.
Abstract: A procedure has been developed for the isolation of Newcastle disease virus (NDV) envelope proteins The two surface glycoproteins and the non-glycosylated membrane protein were solubilized with 2% Triton X-100 and 1 m KCl Removal of the KCl by dialysis yielded by precipitation a pure preparation of the non-glycosylated membrane protein, which is insoluble in solutions of low ionic strength The soluble fraction consisting of the two glycoproteins possessed full neuraminidase and hemagglutinating activities The two glycoproteins could be separated by rate zonal sedimentation in a sucrose gradient containing 1% Triton X-100 and 1 m KCl Under these conditions, the sedimentation coefficient of the larger glycoprotein, virus protein 1, was 93s, and that of the smaller, virus protein 2, was 61s Both hemagglutinating and neuraminidase activities were associated with virus protein 1; virus protein 2 had neither activity The results suggest that both activities reside on a single NDV glycoprotein Similar results were obtained previously with another paramyxovirus, simian virus 5 These findings suggest that the association of hemagglutinating and neuraminidase activities with one glycoprotein is a general property of the paramyxovirus group
291 citations
TL;DR: The results of pulse and pulse-chase experiments suggest that large, polyprotein precursors are not involved in Sendai virus replication, and that polypeptides are synthesized from monocistronic messenger RNA species.
285 citations
01 Jan 1975
TL;DR: Measles, canine distemper, and rinderpest viruses form a distinct subgroup on the basis of antigenicity, hemagglutinating characteristics, and lack of evidence for a virion-associated neuraminidase or neuraminic acid-containing cellular receptors, but it is now generally accepted that these viruses should be included in the paramyxovirus group because of their similar structural properties.
Abstract: The paramyxovirus group is a large one which includes the parainfluenza viruses types 1–5, Newcastle disease, and mumps viruses. Measles, canine distemper, and rinderpest viruses form a distinct subgroup on the basis of antigenicity, hemagglutinating characteristics, and lack of evidence for a virion-associated neuraminidase or neuraminic acid-containing cellular receptors. However, it is now generally accepted that these viruses should also be included in the paramyxovirus group because of their similar structural properties. Other more recently isolated viruses which have been classified as paramyxoviruses on the basis of morphological and biological properties are Yucaipa (Dinter et al., 1964) and Nariva (Walder, 1971) viruses. Table 1 lists paramyxoviruses and their primary hosts.
253 citations
References
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TL;DR: Pure virus lines were established by isolating the virus population produced in single plaques, which had the same morphological, serological, and pathogenic properties as the parent strain.
Abstract: Plaques have been produced with the three types of poliomyelitis viruses on monolayer tissue cultures of monkey kidney and monkey testis. The number of plaques was proportional to the concentration of the virus. Each plaque originates, therefore, from a single virus particle, defined as the virus unit that is unseparable by dilution. The plaques are due to the specific action of the virus since they are suppressed by type-specific antiserum. Pure virus lines were established by isolating the virus population produced in single plaques. These derived virus lines had the same morphological, serological, and pathogenic properties as the parent strain. High titer virus stocks, with titers up to 7 x 10(8) plaque-forming particles per ml., were obtained.
3,394 citations
TL;DR: In vitro propagation of a patient with subacute sclerosing panencephalitis and cocultivation of the brain cells with a line of green-monkey-kidney cells offers direct evidence that measles virus has a a role in the etiology of the disease.
Abstract: Isolation of measles virus from the brain of a patient with subacute sclerosing panencephalitis was accomplished by in vitro propagation of the patient's brain cells and cocultivation of the brain cells with a line of green-monkey-kidney cells. This observation offers direct evidence that measles virus has a a role in the etiology of the disease. Before the production of detectable, mature virus by the cell cultures, there was a prolonged period when they produced syncytia containing measles antigen, but they failed to hemadsorb.
326 citations
"Nucleocapsid Protein Subunits of Si..." refers background in this paper
...It is possible that such a mechanism might play a role in persistent infections not only in cell culture but also in such disease states as subacute sclerosing panencephalitis, a disease of the human central nervous system associated with chronic infection with measles virus and characterized by large intracellular inclusions of nucleocapsid (22, 23, 25)....
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TL;DR: Infection with the attenuated strain of poliovirus type 2 depressed cellular RNA and protein synthesis in parallel both in human embryonic lung cells (diploid) and in ERK cells and the eventual degeneration of guanidine-treated infected cells may indeed be due to the virus-induced inhibitions in cellular metabolism.
279 citations
216 citations
"Nucleocapsid Protein Subunits of Si..." refers methods in this paper
...Monolayer cultures of a variant of the MDBK line of bovine kidney cells were grown on plastic surfaces in reinforced Eagle's medium (REM) (1) with 10% fetal calf serum as described previously (7)....
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