Site specificity of the chorionic gonadotropin N-linked oligosaccharides in signal transduction.

摘要: Abstract The role of the human chorionic gonadotropin (hCG) N-linked oligosaccharides in receptor binding and signal transduction was analyzed using site-directed mutagenesis transfection studies. hCG derivatives with alterations at individual glycosylation sites were expressed Chinese hamster ovary cells. Receptor studies showed that absence any or all had only a minor effect on affinity derivatives. Similarly, from beta subunit single oligosaccharide Asn-78 alpha no production cAMP steroidogenesis. However, carbohydrate Asn-52 decreases both steroidogenic responses. Furthermore, this critical unit unmasks differences two beta; Asn-13 but not Asn-30 plays more important Dimers containing deglycosylated an lacking either fail to stimulate steroid formation. Moreover, these bind behave as competitive antagonists. use uncovering site-specific functions reveals importance process.