[Functional analysis of the CPS I upstream sequences with a CAT assay].
Expression plasmids (pKCPSx-CAT) containing carbamyl phosphate synthetase I (CPS I) upstream sequences of different lengths were constructed, and the function and characteristics of the sequences were studied with the CAT assay. The results showed that the CPS I upstream sequences exerted highly tissue-specific control on CPS I gene expression, and the -142- -38bp region relative to the cap site was found to be indispensable for CPS I gene transcription. The -1700- -161bp region contains sequences which confer an enhancing effect on CPS I gene transcription. Dexamethasone and thioproline (a differentiation inducer) showed enhancing effects on CPS I gene transcription in hepatoma cells. These results would have significance in studies on the gene regulation of CPS I associated with the mechanism of hepatocyte differentiation and carcinogenesis.
Niu
B
B
Institute of basic Medical Sciences, CAMS and PUMC, Beijing.
Wang
Z
Z
Yu
Y
Y
Wang
M
M
Zeng
S
S
D016475:3T3 Cells; D000818:Animals; D016466:CHO Cells; D002222:Carbamoyl-Phosphate Synthase (Ammonia) / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D006528:Carcinoma, Hepatocellular / Q000201:enzymology; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D006224:Cricetinae; D003907:Dexamethasone / Q000494:pharmacology; D015870:Gene Expression; D005809:Genes, Regulator; D006801:Humans; D008113:Liver Neoplasms / Q000201:enzymology; D051379:Mice; D010957:Plasmids; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic / Q000187:drug effects*; D014162:Transfection / Q000187:drug effects; D014407:Tumor Cells, Cultured / Q000378:metabolism
D003907:Dexamethasone; D015500:Chloramphenicol O-Acetyltransferase; D002222:Carbamoyl-Phosphate Synthase (Ammonia)