| TERE1 (Transitional epithelial response gene 1) localizes to chromosome 1p36, encodes a protein of 338 amino acids which expressing in various human tissues including urothelium, and the molcecular weight is 36.8KD. It is also called UBIAD1(UbiA prenyltransferase containing 1)because of containing an prenyltransferase domaim., The expression of TERE1/UBIAD1 is decreased in bladder and prostate carcinomas, and it also found that the cellular proliferation of bladder and prostate carcinomas cell lines was decreasing when the above two cell lines overexpresed with TERE1/UBIAD1. But the molecular mechanism of TERE1/UBIAD1 in suppressing cellular proliferation was still unclear. We found that the expression of TERE1/UBIAD1 decreased in bladder carcinomas cell line (T24), and the Ras-MAPK singal pathway was activated. When knocked down TERE1/UBIAD1 in human Embryonic liver cell line L02, we also found Ras-MAPK singal pathway was activated. So it can concluded that TERE1/UBIAD1 controls cellular proliferation though Ras-MAPK singal pathway. TERE1/UBIAD1 is a prenyltransferase, and the post-translational modifications of Ras contain prenylcysteine. We found that TERE1/UBIAD1 and HRas had interaction when we used immunoprecipitation (IP) experiment. When knocked down the expression of TERE1/UBIAD1 in human Embryonic kidney cell line HEK293, it can found that the localization of BFP-HRas in Golgi was decreased, and the farnesyl HRas was increased when used LC-MS /MS analyses. This data suggested that TERE1/UBIAD1 can exchange the farnesyl group of HRas, so HRas detents in the Golgi, can not traffic to the plasma membrane to activate Ras-MAPK singal pathway and promote cellular proliferation. |
