The Sodium-dependent serotonin transporter, also known as SERT, is a protein that transports serotonin, a neurotransmitter, across the cell membrane. It plays a crucial role in the regulation of mood, anxiety, and other brain functions. SERT is the target for selective serotonin reuptake inhibitors (SSRIs), which are commonly prescribed antidepressant medications. SERT is part of the neurotransmitter sodium symporter (NSS) family and functions by binding to serotonin and sodium ions to facilitate the transport of serotonin from the synaptic cleft back into the presynaptic neuron, terminating the signal. The transporter undergoes a series of conformational changes that allow it to bind to serotonin and sodium ions and then release them on the other side of the cell membrane.