SNAT1 is a system N/A type amino acid transporter that primarily expresses in neurons and mediates the transport of L-Glutamine. Glutamine (Gln) is an important amino acid involved in multiple cellular functions and also is a precursor for neurotransmitters, glutamate and GABA. In this study, we demonstrated that SNAT1 is an N-glycoprotein expressed in neurons. We identified three glycosylation sites at asparagine residues 251, 257 and 310 in SNAT1 protein, and that the first two are the primary sites. The biotinylation and confocal immunofluorescence analysis showed that the glycosylation-impaired mutants as well as deglycosylated SNAT1 were equally capable of expressing on the cell surface. However, L-Gln and MeAIB transport was significantly compromised in N-glycosylation impaired mutants and deglycosylated SNAT1 as compared to the wild-type control. Together, these results suggest that SNAT1 is an N-glycosylated protein with three de novo glycosylation sites and N-glycosylation of SNAT1 may play an important role in transport of substrates across the cell membrane.
- amino acid transporter
- ©2016 The Author(s)
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