Hyperactive Mouse Serotonin Transporter Interacting Proteins LC-MSMS

The serotonin (5-HT) transporter (SERT) is a key determinant of the concentration of 5-HT available for synaptic signaling and is the target of the antidepressant-selective 5-HT reuptake inhibitors (SSRIs). In addition to the role of SERT in mediating the actions of antidepressant medications, multiple, rare gain of function coding variants in SERT have been identified in subjects with autism spectrum disorder (ASD). The Blakely lab has extensively characterized the structural and functional impact of one of these variants, SERT Ala56, in vitro and in vivo, revealing a constitutively-imposed, biased conformation that enhances transporter function and that perturbs transporter regulation. We hypothesize that SERT Ala56 disrupts the interactions of molecular networks that normally ensure proper transporter structure, localization and regulation, and whose elucidation may reveal new determinants of serotonergic dysfunction in ASD. Here, we pursue an unbiased proteomic analysis of changes in SERT interacting protein (SIPs) imposed by the SERT Ala56 variant, expressed in transgenic mice. Further investigation of the SIPs and associated networks nominated through our studies may provide new opportunities to detect and modulate brain networks that contribute to the underlying complexity of ASD.