ARS | Publication request: ANALYSIS OF INTERFERON TAU GENE ENHANCER/SILENCER ELEMENTS

Submitted to: Biology of Reproduction Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: April 23, 1999
Publication Date: December 19, 1999
Citation: Yamaguchi, H., Katsumura, M., Imakawa, K., Sakai, S., Christenson, R.K. 1999. Analysis of interferon tau gene enhancer/silencer elements [abstract]. Biology of Reproduction. 60 (Supplement 1):235. (Abstract # 457)

Technical Abstract: To examine regulatory mechanisms of ovine interferon tau (oIFNtau) gene expression, potential enhancer/silencer elements of the IFNtau gene were examined using a transient transfection system with oIFNtau gene- chloramphenicol acetyltransferase reporter (oIFNtau-CAT) constructs in human choriocarcinoma cells, JEG3. The experiments with 5'-deletion constructs or a heterologous transcriptional system in which the upstream regions of oIFNtau were inserted in front of the SV40 promoter revealed that the upstream regions from -654 to -555 bases was the enhancer region required for oIFNtau transactivation. The oIFNtau-CAT constructs with site-specific mutagenesis revealed that multiple enhancer elements existed between -654 and -555 bases. A subsequent study with oIFNtau-CAT constructs designed for detailed analysis of silencer elements revealed that the sequences from -700 to -655 bases and from -502 to -453 bases seemed to act as silencer regions. Gel mobility shift assays revealed tha AP-1, GATA and GATA related protein could bind to enhancer elements and that several nuclear factors could bind to the silencer regions if extracted from trophoblasts on day 20 of pregnancy, but not day 14. In co-transfection studies, AP-1 expression enhanced oIFNtau-CAT transactivation, however, GATA-1, -2, or -3 expression did not. Taken together, these results suggest that the upstream region between -654 and -555 bases could be considered as the enhancer region and regions between -700 and -655, -502 and -453 as the silencer for oIFNtau gene transactivation.