beta 1,4-Galactosyltransferase II (beta 4GalT-II) is one of the enzymes transferring galactose to the terminal N-acetylglucosamine of complex-type N-glycans and its expression is significantly altered during oncogenesis with unknown functions. Here, we reported for the first time the pro-apoptotic role of beta 4GalT-II in tumor cells. The level of beta 4GalT-II mRNA expression was obviously decreased during HeLa cell apoptosis induced by cisplatin. Interestingly, the ectopic expression of beta 4GAlT-II in HeLa cells markedly increased apoptosis and cleavage of PARP induced by cisplatin as well as the expression of pro-apoptotic protein Bax. Furthermore, deletion of Golgi localization domain abolished the apoptotic role of beta 4GalT-II in HeLa cells. Collectively, these results suggest that beta 4GalT-II increases HeLa cell apoptosis induced by cisplatin depending on its Golgi localization, which indicates that beta 4GalT-II might contribute to the therapeutic efficiency of cisplatin for cervix cancer. (c) 2007 Elsevier Inc. All rights reserved.