RESEARCH ARTICLE Sorting nexin-27 regulates AMPA receptor trafficking through the synaptic adhesion protein LRFN2 Kirsty J McMillan1†*, Paul J Banks2†, Francesca LN Hellel1, Ruth E Carmichael1, Thomas Clairfeuille3, Ashley J Evans1, Kate J Heesom4, Philip Lewis4, Brett M Collins3, Zafar I Bashir2, Jeremy M Henley1, Kevin A Wilkinson1*, Peter J Cullen1* 1School of Biochemistry, University of Bristol, Bristol, United Kingdom; 2School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom; 3Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia; 4Proteomics facility, School of Biochemistry, University of Bristol, Bristol, United Kingdom Abstract The endosome-associated cargo adaptor sorting nexin-27 (SNX27) is linked to various neuropathologies through sorting of integral proteins to the synaptic surface, most notably AMPA receptors. To provide a broader view of SNX27-associated pathologies, we performed proteomics in rat primary neurons to identify SNX27-dependent cargoes, and identified proteins linked to excitotoxicity, epilepsy, intellectual disabilities, and working memory deficits. Focusing on the *For correspondence: synaptic adhesion molecule LRFN2, we established that SNX27 binds to LRFN2 and regulates its
[email protected] endosomal sorting. Furthermore, LRFN2 associates with AMPA receptors and knockdown of (KJMM); LRFN2 results in decreased surface AMPA receptor expression, reduced synaptic activity, and
[email protected] attenuated hippocampal long-term potentiation. Overall, our study provides an additional (KAW); mechanism by which SNX27 can control AMPA receptor-mediated synaptic transmission and
[email protected] (PJC) plasticity indirectly through the sorting of LRFN2 and offers molecular insight into the perturbed †These authors contributed function of SNX27 and LRFN2 in a range of neurological conditions.