| First Author | Hynes NE | Year | 1981 |
| Journal | Proc Natl Acad Sci U S A | Volume | 78 |
| Issue | 4 | Pages | 2038-42 |
| PubMed ID | 6264458 | Mgi Jnum | J:6521 |
| Mgi Id | MGI:54997 | Doi | 10.1073/pnas.78.4.2038 |
| Citation | Hynes NE, et al. (1981) Hormone-responsive expression of an endogenous proviral gene of mouse mammary tumor virus after molecular cloning and gene transfer into cultured cells. Proc Natl Acad Sci U S A 78(4):2038-42 |
| abstractText | A recombinant lambda phage containing mouse mammary tumor virus (MMTV) proviral DNA was isolated from a gene library constructed from GR mouse liver DNA. Restriction enzyme analyses reveal that the cloned molecule contains a copy of one of the GR endogenous MMTV proviruses flanked on both sides by 2--3 kb of mouse genomic DNA. In this report we have examined the expression of the cloned MMTV provirus after cotransfection with the herpes thymidine kinase (TK; ATP:thymidine 5'-phosphotransferase,, EC 2.7.1.21) gene and integration into mouse LTK- cells. Nine individual TK+ transformants were selected, and all were found to contain MMTV-transfected DNA. One of the TK+ transformants was chosen for further study. Total poly(A)-containing RNA was isolated from the cells, and liquid hybridization analyses with MMTV cDNA showed that it contained 0.02% MMTV-specific RNA. The sizes of the MMTV-specific species were determined and found to correspond to the 35S and 24S mRNAs synthesized in MMTV-infected cells. Glucocorticoid hormones have been shown to increase the concentration of MMTV RNA in virus-infected cultured cells. Therefore, we tested the effect of dexamethasone on the concentration of MMTV-specific RNA in cells transfected with the MMTV proviral DNA. The amount of MMTV-specific poly(A)-containing RNA found in the cells grown in the presence of hormone was 0.17%. Therefore, dexamethasone causes an 8-fold increase in the amount of MMTV-specific RNA in mouse cells containing several copies of a cloned and transfected MMTV proviral gene. |
