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Biomedical subjects

A Roman

Publications and source records attributed to A Roman.

At least 91 records · Page 5Linked to original sources
PubMed1982

Alteration in the simian virus 40 maturation pathway after butyrate-induced hyperacetylation of histones.

The role of histone acetylation in the replication and maturation pathways of simian virus 40 was assessed. Histones were hyperacetylated by briefly exposing infected cells to sodium butyrate. Viral DNA in cells exposed to butyrate was found to reenter replication to a greater extent and mature to the previrion form to a lesser extent than viral DNA in control cells. Previrions formed in the presence of butyrate had altered sedimentation properties. These data suggest that increased acetylation of histones is not the signal for removal of DNA from the pool of molecules available for replication. It appears, in fact, that hyperacetylation retards entry into and progression along the maturation pathway.

Acetylation↗
PubMed1981

Cessation of reentry of simian virus 40 DNA into replication and its simultaneous appearance in nucleoprotein complexes of the maturation pathway.

Newly synthesized SV40 DNA is used as a template for further DNA synthesis (reenters replication) or as a substrate in the assembly of virions (maturation pathway). The time courses of reentry into replication and progression along the maturation pathway were both determined on identical samples. DNA, synthesized during a 20-min pulse, reentered replication over a period of several hours and then was removed from the pool of molecules available for replication. The cessation of reentry coincided with the maturation of this DNA from the chromatin form to previrion and virion forms. More reentry and less maturation was observed at 24 h postinfection than at 42 h postinfection. The data are consistent with the hypothesis that the factor(s) responsible for cessation of reentry is also responsible for initiation of the maturation pathway.

Animals↗
PubMed1981

Ultraviolet irradiation inhibits encapsidation of simian virus 40 chromatin.

During normal maturation and majority of pulse-labeled simian virus 40 DNA progresses from chromatin to previrions and virions within 5 h. UV light inhibits this progression. In heavily irradiated cultures (108 J m-2) most of the simian virus 40 DNA synthesized immediately before irradiation remains as chromatin for at least 5 h. This inhibition of maturation seems to be a result of the inhibition of protein synthesis. The data suggest that the pool of proteins required for maturation is sufficient to convert one-third of the simian virus 40 DNA molecules labeled in a 10-min pulse (at 33 h postinfection) from chromatin to previrions and virions and is exhausted within 1 h.

Capsid↗
PubMed1980

Identification of permissive and nonpermissive murine cells for polyoma virus.

The interaction of polyoma virus with primary cell cultures derived from mouse heart, brain, and kidney was characterized to identify the organ(s) best suited for isolation of permissive and nonpermissive cells within a species. The outcome of infection was determined by measurement of the extent of cellular destruction, virus amplification, and viral gene expression. While the majority of cells in the kidney cultures were permissive, the heart cell cultures contained a significant population of nonpermissive cells.

Animals↗
PubMed1975

Fate of polyoma form IDNA during replication.

The fate of polyoma form IDNA generated during replication was investigated in resting BALB-3T3 cells. The experiments showed that there was extensive re-entry of such molecules into replication. This process took place over a period of several hours and appeared to be random. Progeny form I molecules must, therefore, spend some time in a nonreplicating pool before reinitiating replication. We propose that two factors affect the fate of progeny form IDNA. (i) The rate of reinitiation of progeny molecules is determined by the capacity of the initiation machinery. (ii) The extent of re-entry is determined by the availability of maturation proteins which divert form I from replication.

Animals↗