Top Highlights

• ne still occurred even after GA function was disrupted with brefeldin A (BFA), indicating that a significant fraction of cargo enters the RE network in a GA-independent manner. Accordingly, disrupting RE function impaired surface delivery of GluA1 released from the ER. Combined, these data support a novel GA-independent mode of local trafficking in...
• To determine whether a GA-independent trafficking pathway is generally utilized by all membrane proteins, we tested whether NL1 or a generic trafficking cargo, vesicular stomatitis viral glycoprotein (VSV-G), could also reach the cell surface in the presence of BFA. In contrast to GluA1, we observed that both NL1 and VSV-G surface expression was fu...
• A recent report demonstrated that a significant fraction of select neuronal surface proteins, including AMPA, NMDA and GABA receptors display immature (high mannose) glycosylation profiles, consistent with a GA-independent trafficking route (Hanus et al., 2016). High mannose glycans generated in the ER are
• we purified surface proteins by surface biotinylation and subjected them to either endoH or peptide-N-glycosidase (PNGase, a glycolytic enzyme which removes both mature and immature N-linked carbohydrates)
• However, based on the BFA sensitivity of NL1 and VSV-G surface expression, their trafficking itineraries must diverge from GluA1 following ERGIC accumulation.

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