Several signaling pathways activated in response to extracellular molecules regulate the expression of GLT-1 by activating transcription factors that interact with cis elements in the promoter. The pathways that increase or decrease GLT-1 transcription are depicted in different schematics (Panel A & B, respectively). For a detail description see the text. TX: tamoxifen, E2: estrogen, AC: adenylate cyclase, GR: glucocorticoid receptor, MR: mineralocorticoid receptor.