Effect of trans-acting factor on rat glutathione S-transferase P1 gene transcription regulation in tumor cells.
OBJECTIVE
To investigate the effect of trans-acting factor(s) on rat glutathione S-transferase P1 gene (rGSTP1) transcription regulation in tumor cells.


METHODS
The binding of trans-acting factor(s) to two enhancers of the rGSTP1 gene, glutathione S-transferase P enhancer I (GPEI) and glutathione S-transferase P enhancer II-1 (GPE II-1), was identified by an electrophoretic mobility shift assay (EMSA). The molecular weight of trans-acting factor was measured in a UV cross-linking experiment.


RESULTS
Trans-acting factor interacting with the core sequence of GPEI (cGPEI) were found in human cervical adenocarcinoma cell line (HeLa) and rat hepatoma cell line (CBRH7919). These proteins were not expressed in normal rat liver. Although specific binding proteins that bound to GPE II-1 were detected in all three cell types, a 64 kDa binding protein that exists in HeLa and CBRH7919 cells was absent in normal rat liver.


CONCLUSIONS
cGPEI, GPEII specific binding proteins expressed in HeLa and CBRH7919 cells may play an important role in the high transcriptional level of the rGSTP1 gene in tumor cells.
Liu
Dongyuan
D
National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China.
Liao
Mingxiang
M
Zuo
Jin
J
Fang
Fude
F
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase / Q000235:genetics*; D007527:Isoenzymes / Q000235:genetics*; D009687:Nuclear Proteins / Q000378:metabolism; D051381:Rats; D014158:Transcription, Genetic
D002352:Carrier Proteins; D007527:Isoenzymes; D009687:Nuclear Proteins; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase; C496558:Gstp1 protein, rat