Transcription factor that binds GC and GT boxes in the D1A, D2 and D3 dopamine receptor promoters and displaces Sp1 and Sp3 from these sequences. It modulates dopaminergic transmission in the brain by repressing or activating transcription from several different promoters depending on cellular context. High expression in brain; olfactory tubercle, olfactory bulb, nucleus accumbens, striatum, hippocampal CA1 region, amygdala, dentate gyrus and frontal cortex. Moderate expression in hippocampal CA2-3 regions, piriform cortex, septum, and distinct thalamic nuclei. Low expression in the cerebellum. The Ala/Pro-rich domain may contain discrete activation and repression subdomains and also can mediate protein-protein interactions. Belongs to the Sp1 C2H2-type zinc-finger protein family.