24] Biosynthesis, N-glycosylation, and surface trafficking of biogenic amine transporter proteins

Abstract

Publisher Summary This chapter describes biosynthesis, N-glycosylation, and surface trafficking of biogenic amine transporter proteins. Except for acetylcholine, whose actions are limited by extracellular enzymatic hydrolysis, neurotransmitters, including L-glutamate, γ-aminobutyric acid (GABA), dopamine (DA), nonrepinephrine (NE), and serotonin (5HT), are inactivated by synaptic transport systems that rapidly clear neurotransmitter after release. The chapter illustrates methods employed to characterize the synthesis, N-glycosylation, and surface expression of antidepressant-sensitive norepinephrine transporters (NETs) and serotonin transporters (SERTs) in mammalian cells. It presents the data in the context of recent studies of transporter posttranslational processing and trafficking. It determines whether mutations introduced into NET and SERT cDNAs disrupt protein synthesis or stability, whether NET and SERT utilize canonical N-glycosylation sites found in the TMD 3-4 loop, whether N-glycosylation plays an important role in transporter protein biosynthesis and surface trafficking, and whether kinase-mediated signal transduction pathways regulate transporter surface expression.