RGS2, a Regulators of G-protein Signaling family member, regulates signaling activities of G-proteins, and RGS2 itself is controlled in part by regulation of its expression. This investigation extended previous studies of the regulation of RGS2 expression by examining the effects of stress, differentiation, and signaling activities on RGS2 mRNA level in human neuroblastoma SH-SY5Y cells. Cell stress induced by heat shock rapidly and transiently increased RGS2 mRNA levels, whereas differentiation to a neuronal phenotype reduced basal RGS2 mRNA levels by 50%. RGS2 mRNA levels were increased in differentiated cells by heat shock, carbachol, and activation of protein kinase C. After transient transfection of GFP-tagged RGS2, a predominant nuclear localization was observed by confocal microscopy. Thus, RGS2 expression is regulated by stress and differentiation, as well as by second messenger signaling, and transfected GFP-RGS2 is predominantly nuclear. © 2001 Academic Press.