Validity of pHluorin-tagged GluA2 as a reporter for AMPA receptor surface expression and endocytosis

Abstract

The recent paper by Rathje et al. (1) questions the interpretation of previous studies using super ecliptic pHluorin-GluA2 (SEP-GluA2) to monitor AMPA receptor surface expression and particularly its use as a reporter of endocytosis following NMDA or AMPA receptor stimulation. The concerns raised are based on two main observations: ( i ) that application of the agonists NMDA or AMPA leads to intracellular acidification and ( ii ) that the acid (pH 6) wash, which is routinely used in these experiments to identify surface receptors, can also cause intracellular acidification, leading to misidentification of surface and intracellular receptors. [↵][1]1To whom correspondence should be addressed. E-mail: j.m.henley{at}bris.ac.uk. [1]: #xref-corresp-1-1