The asparagine-linked oligosaccharides of bovine pituitary hormones are unique due to the presence of N-acetyl galactosamine (GalNAc) and sulfate. Sulfate is covalently linked to GlcNAc and GalNAc at the non-reducing termini of oligosaccharides on both the Alpha and Beta subunits of lutropin (LH) and thyrotropin (TSH). In contrast the human placental hormone, chorionic gonadotropin (hCG), which shares nearly identical Alpha subunit with the pituitary hormones, lacks sulfate and GalNAc. Instead it contains the terminal sialic acid on its asparagine-linked oligosaccharides. Although these comparative studies involved peptide hormones derived from different species, they suggest that some step(s) leading to the synthesis of sulfated rather than sialylated oligosaccharide on similar Alpha subunits is tissue specific. The basis of this specificity represents an important focus for this proposal. We propose to deal with the following issues: 1) Structures of sulfated and non-sulfated oligosaccharides on the intracellular and secreted hormone species synthesized in pituitary. These studies will encompass both bovine and human hormones, LH and FSH. 2) The structural and/or tissue determinants that are responsible for sulfation of these hormones. 3) Characterization of the glycosyl transferase responsible for addition of GalNAc to bLH. Experiments will be directed at determining if addition of GalNAc is tissue or protein specific and if GalNAc addition is required for sulfation. 4) Identification and isolation of the sulfotransferases. For example, are there tissue and/or substrate-specific sulfotransferases? 5) The role of sulfation in the packaging and secretion of LH. 6) The effect of sulfate on biologic function of LH including half-life in the circulation, targeting, and receptor stimulation. The model we propose will be useful for determining why particular proteins undergo certain post-translational modifications.

National Institute of Health (NIH)
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
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Physiological Chemistry Study Section (PC)
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Washington University
Schools of Medicine
Saint Louis
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Galway, A B; Hsueh, A J; Keene, J L et al. (1990) In vitro and in vivo bioactivity of recombinant human follicle-stimulating hormone and partially deglycosylated variants secreted by transfected eukaryotic cell lines. Endocrinology 127:93-100
Smith, P L; Kaetzel, D; Nilson, J et al. (1990) The sialylated oligosaccharides of recombinant bovine lutropin modulate hormone bioactivity. J Biol Chem 265:874-81
Keene, J L; Matzuk, M M; Boime, I (1989) Expression of recombinant human choriogonadotropin in Chinese hamster ovary glycosylation mutants. Mol Endocrinol 3:2011-7
Matzuk, M M; Spangler, M M; Camel, M et al. (1989) Mutagenesis and chimeric genes define determinants in the beta subunits of human chorionic gonadotropin and lutropin for secretion and assembly. J Cell Biol 109:1429-38
Bielinska, M; Matzuk, M M; Boime, I (1989) Site-specific processing of the N-linked oligosaccharides of the human chorionic gonadotropin alpha subunit. J Biol Chem 264:17113-8
Keene, J L; Matzuk, M M; Otani, T et al. (1989) Expression of biologically active human follitropin in Chinese hamster ovary cells. J Biol Chem 264:4769-75
Matzuk, M M; Boime, I (1988) Site-specific mutagenesis defines the intracellular role of the asparagine-linked oligosaccharides of chorionic gonadotropin beta subunit. J Biol Chem 263:17106-11
Green, E D; Baenziger, J U (1988) Asparagine-linked oligosaccharides on lutropin, follitropin, and thyrotropin. II. Distributions of sulfated and sialylated oligosaccharides on bovine, ovine, and human pituitary glycoprotein hormones. J Biol Chem 263:36-44
Smith, P L; Baenziger, J U (1988) A pituitary N-acetylgalactosamine transferase that specifically recognizes glycoprotein hormones. Science 242:930-3
Baenziger, J U; Green, E D (1988) Pituitary glycoprotein hormone oligosaccharides: structure, synthesis and function of the asparagine-linked oligosaccharides on lutropin, follitropin and thyrotropin. Biochim Biophys Acta 947:287-306

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