Constitutive oligomer formation appears to be the rule for the neurotransmitter: sodium
symporter (NSS) family of proteins. The propensity to form oligomers is a prerequisite for
NSS proteins to pass the rigid mechanisms of quality control in the endoplasmic reticulum.
Moreover, recent findings suggest that correct trafficking to the plasma membrane appears
to rely on the interaction of NSS homo-oligomers with components of the COPII-vesicle
machinery. The transporters present at the plasma membrane are most likely organized in a …