Type D retrovirus specific sequences in lymphocytes of the children with Burkitt-type lymphoma and their parents.

Type D retroviruses cause immunodeficiency in monkey. Earlier we have revealed genetical and serological markers of type D retroviruses in children with Burkitt-type lymphoma. Using PCR/Southern blotting assay we have found sequences related to MPMV in PBMC's DNA from children with Burkitt-type lymphoma and from their parents.

Human spontaneous laryngeal carcinoma HEp-2 cells are chronically infected with SRV-1 virus, a variant of simian type D retrovirus.

A type D retrovirus chronically persisting in HEp-2 cells from human laryngeal carcinoma was analyzed by PCR and sequenced. This virus is most similar to SRV-1 and probably represents one of its subtypes.

The role of phosphorylation of DNA-binding proteins in regulation of transcription of the human c-myc gene.

The goal of the present study was to identify transcriptional factors, to determine their specificity toward nucleotide sequences of binding sites, and to elucidate their regulatory effects on transcription of the human c-myc oncogene. Three novel phosphorylated proteins (transcriptional factors) participating in the regulation of transcription of the c-myc gene have been identified, and the following data have been obtained. A) The binding of the regulatory phosphoproteins activates in vitro transcription of the human c-myc gene.

Enhancement of in vitro transcription of human c-myc correlates with the binding of phosphorylated protein factors from HeLa cell extract.

Hela cell extract overphosphorylated with endogenous protein kinases was used for in vitro transcription of human c-myc DNA. The activation of transcription initiated from P1, P1a and P2 cap-sites was observed. Three phosphoproteins of 70, 35 and 23 kDa are found, whose binding to DNA correlates with activation of c-myc transcription.