An intronic silencer element is responsible for specific zonal expression of glutamine synthetase in the rat liver
Frank Gaunitz, Danilo Deichsel, Kerstin Heise, Max Werth, Ulf Anderegg, Rolf Gebhardt – 23 May 2005 – The most striking phenomenon of glutamine synthetase (GS) expression in the liver is its unique restriction to cells surrounding the terminal hepatic venules. Expression is positively regulated by elements located in the 5′‐upstream region and in the first intron of the gene. It was long believed that transcription factors present in GS‐positive cells and absent in GS‐negative cells are responsible for the phenomenon of zonal expression.