title: Characterization of virus-like particles released from the hamster cell line CHO-K1 after treatment with 5-bromodeoxyuridine.
abstract: Simple biochemical measurements have been shown to seriously overestimate the production of C-type particles by Chinese hamster ovary (CHO) cells treated with 5-bromodeoxyuridine. First, most particle-bound DNA polymerase activity released by induced cells was associated with particles which had a different density from C-type particles. Second, when labelled with radioactive uridine, induced CHO cells released small amounts of particle-bound radioactivity. Most of the radioactivity, however, was in DNA and did not sediment with the particle-bound polymerase. Thus, few particles which had RNA, an associated DNA polymerase, and the density typical of RNA tumour viruses were released by BrdUrd-induced CHO cells. In spite of this, some immature C-type forms were observed by electron microscopy in partially purified preparations of DNA polymerase-containing particles from induced CHO cells.
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology*; D002460:Cell Line; D006224:Cricetinae; D000242:Cyclic AMP / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D012190:Retroviridae / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development*; D013698:Templates, Genetic; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000242:Cyclic AMP; D012194:RNA-Directed DNA Polymerase; D001973:Bromodeoxyuridine