Mumps Virus Replication in Chick Embryo Lung Cells: Properties of Ribonucleic Acids in Virions and Infected Cells

Abstract

Ribonucleic acid (RNA) species in mumps virions and in infected cells were compared. The predominant RNA species in virions labeled with 3 H-uridine sedimented at 50 S ; RNA species sedimenting at 28, 18, and about 10 S were also present. The virion-associated RNA species sedimenting slower than 50 S contained some nucleotide sequences similar to 50 S virion RNA. Although mumps virus replication was severely inhibited by high concentrations of actinomycin D, some virus was made, and virus-specific RNA species accumulated in infected cells. Mumps virus resembled other paramyxoviruses in inducing, in infected cells, synthesis not only of 50 S RNA but also of slower sedimenting RNA species with a peak distribution at about 18 S , complementary in base sequences to 50 S virion RNA. In addition, base sequences of the parental type were relatively abundant in the RNA species sedimenting slower than 50 S ; these may represent precursors of the slowly sedimenting RNA species associated with virions. Ribonuclease-resistant RNA was detected in infected cells; this may represent replicative or transcriptive intermediates. Inhibition of protein synthesis with cycloheximide severely depressed accumulation of labeled 50 S RNA in infected cells but did not interfere with accumulation of RNA species sedimenting slower than 50 S . Actinomycin D treatment had a similar effect. Annealing of genomes and virus-induced complementary RNA species of Newcastle disease virus, Sendai virus, and mumps virus did not reveal any base sequence homologies.

Persistent Infection of Cells in Culture by Measles Virus III. Comparison of Virus-Specific RNA Synthesized in Primary and Persistent Infection in HeLa Cells

“…However, quantitative differences have been observed. In addition, we have found that, as reported by Schluederberg (23), measles virions like those of other paramyxoviruses possess high-molecular-weight RNA (2,5,9,11), and that the sedimentation constant of this RNA is identical to that of NDV.…”

“…5C), whereas K11-VF1 shows pattems which are undistinguishable from those of uninfected HeLa cells. DISCUSSION In measles virus infection, as in NDV (5), Sendai (2), and mumps (11) infection, the majority of the RNA synthesized in actinomycin D-treated infected cells sediments more slowly than the 50S RNA of the virus. The major peak of this RNA is at 18S, and, in addition, the usual 28 to 35S RNA is found.…”

Replication of Measles Virus: Continued Synthesis of Nucleocapsid RNA and Increased Synthesis of mRNA in the Presence of Cycloheximide

“…Our observation that cycloheximide did not decrease the amount of labeled measles nucleocapsid RNA is in apparent contrast with previous reports that protein synthesis is required for synthesis of virion RNA of paramyxoviruses (1,2,4,11,14) and of vesicular stomatitis virus (13). More specifically, Robinson (11) found that cycloheximide markedly suppressed synthesis of Sendai virus nucleocapsid-associated RNA which was complementary to Sendai viral mRNA.…”

Measles virus and its associated diseases.

“…It is not known whether the enzyme that is necessary for genomic RNA replication (replicase) represents an alternate function of the transcriptase or whether a separate enzyme or enzyme subunit is required (188). The synthesis of Sendai (293,311) and mumps (82) 50S RNA is inhibited by cycloheximide, suggesting that genomic RNA replication requires continued protein synthesis. However, there are conflicting reports on whether the synthesis of measles 52S RNA is inhibited by cycloheximide (124,184).…”