Carbohydrate sulfotransferase 8 (CHST8) transfers sulfate (SO4(2-)) from the high energy donor 3'-phospho-5'-adenylyl sulfate (PAPS) to position 4 of non-reducing N-acetylgalactosamine (GalNAc) residues of N-glycosylated proteins terminating with the saccharide sequence SO(4)-4-GalNAc-beta1,4-GlcNAc-beta1,2-Man-alpha. This sequence is present on the pituitary hormones lutropin (LH), thyrotropin and pro-opiomelanocortin. The sulfated oligosaccharides on LH are essential for its biologic function (Xia et al. 2000, Hiraoka et al. 2001). LH is required for the production of the sex hormones estradiol, progesterone, and testosterone. The unique saccharide signature is used for clearing LH from blood. Ablation of Chst8 in mice exhibited increased levels of circulating LH resulting in precocious sexual maturation (Mi et al. 2008).