Expression of recombinant human choriogonadotropin in chinese hamster ovary glycosylation mutants

Jeffery L. Keene, Martin M. Matzuk, Irving Boime

Research output: Contribution to journalArticlepeer-review

30 Scopus citations

Abstract

Human CG, a member of the glycoprotein hormone family that includes LH, FSH, and TSH, is composed of two nonidentical subunits each containing two asparagine linked (N-linked) oligosaccharides. The role of the oligosaccharides in the action of these hormones is unclear. To examine the structure-activity relationships of the glycoprotein hormone oligosaccharides using nonenzymatic and nonchemical methods, we transfected CG subunit genes into mutant cell lines derived from Chinese hamster ovary cells. Two mutant cell lines that synthesize truncated oligosaccharides were used. Cell line 15B, lacking N-acetylglucosaminyltransferase I, synthesizes N-linked carbohydrates containing Mans oli-gomannosyl structures, and 1021, defective in transporting CMP-sialic acid into the Golgi, results in sialic-acid deficient glycoproteins. The binding of these derivatives to the LH/CG receptor did not differ significantly from purified CG (CR119), but the ability of the mutant hormones to stimulate cAMP biosynthesis in vitro is reduced compared to wild-type CG or CR119. Since the amino acid sequence of CG from the mutant and wild-type cells is identical, these data indicate that oligosaccharide structures, while not influencing receptor binding, directly affect signal transduction.

Original languageEnglish
Pages (from-to)2011-2017
Number of pages7
JournalMolecular Endocrinology
Volume3
Issue number12
DOIs
StatePublished - Dec 1989

Fingerprint

Dive into the research topics of 'Expression of recombinant human choriogonadotropin in chinese hamster ovary glycosylation mutants'. Together they form a unique fingerprint.

Cite this