beta-Adrenergic receptor regulation of N-linked protein glycosylation in rat parotid acinar cells.

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Abstract
The relationship between .beta.-adrenergic receptor stimulation and protein glycosylation and secretion was studied in rat parotid gland cells in vitro. The potent .beta.-adrenergic agonist (-)-isoproterenol increases [3H]mannose incorporation into newly synthesized glycoproteins. This effect is enhanced if cells are first preincubated with dolichyl phosphate and is not observed after muscarinic-cholinergic or .alpha.-adrenergic stimulation of cells. The increase in [3H]mannose incorporation is abolished by incubation of cells with tunicamycin, suggesting that the glycosylation events being studied involved asparagine-linked oligosaccharides. The extent of increase in glycosylation is dependent on the concentration of (-)-isoproterenol to which cells are exposed. (.+-.)-Propanolol totally abolishes the (-)-isoproterenol-induced increase in [3H]mannose incorporation, in a manner similar to its effects on exocrine secretion. Evidently, .beta.-adrenergic receptor activation has a profound influence on N-linked protein glycosylation in rat parotid cells in addition to eliciting exocrine protein release.