Role of protein kinase A in tax transactivation of the human T-cell leukemia virus type I long terminal repeat.
The human T-cell leukemia virus type I (HTLV-I) long terminal repeat (LTR) is inducible both by the retroviral tax gene product and by cyclic AMP in the murine thymoma S49 cell line. The cis-acting sequences that control transcriptional induction by tax and by cyclic AMP are in close proximity within the HTLV-I promoter. By using a protein kinase A (PKA)-deficient S49 mutant cell line, the response of the viral promoter to cyclic AMP was shown to depend on PKA, whereas the response to tax did not require the activity of this enzyme. Transactivation of the HTLV-I LTR by tax, however, decreased in PKA-deficient and adenylate cyclase-deficient cells. The evidence presented supports largely independent mechanisms of promoter induction by cyclic AMP and tax but also suggests a role for PKA-mediated phosphorylation in the regulation of HTLV-I LTR-driven gene expression by tax.
Kadison
P
P
Division of Pediatric Oncology, Dana Farber Cancer Institute, Boston, Massachusetts.
Poteat
H T
HT
Klein
K M
KM
Faller
D V
DV
D000262:Adenylyl Cyclases / Q000172:deficiency / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D003994:Bucladesine / Q000494:pharmacology; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D002872:Chromosome Deletion; D000242:Cyclic AMP / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D005814:Genes, Viral; D015368:Human T-lymphotropic virus 1 / Q000187:drug effects / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000172:deficiency / Q000378:metabolism*; D012367:RNA, Viral / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D015534:Trans-Activators / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection
D012367:RNA, Viral; D015534:Trans-Activators; D003994:Bucladesine; D000242:Cyclic AMP; D015500:Chloramphenicol O-Acetyltransferase; D011494:Protein Kinases; D000262:Adenylyl Cyclases