Chapter 13 DARPP-32, a dopamine-regulated phosphoprotein

Publisher Summary A dopamine-regulated phosphoprotein (DARPP-32) is a phosphoprotein specifically enriched in dopaminoceptive neurons possessing D-1 dopamine receptors. The chapter summarizes some studies in which DARPP-32 has provided useful information or holds promise for future research. Biochemical studies have shown that DARPP-32 functions as a potent inhibitor of protein phosphatase-1 in vitro and that it may be involved in mediating some of the physiological effects of dopamine by inhibiting this enzyme in vivo . The regulation of the state of phosphorylation of DARPP-32 may also mediate specific interactions between the dopamine acting through cyclic adenosine monophosphate and other first messengers acting through calcium ion. The chapter shows the regional distribution of DARPP-32 in the rat central nervous system determined by radioimmunoassay. The highest concentrations of immunoreactive DARPP-32 are found in the substantia nigra, caudatoputamen, and globus pallidus, while slightly lower concentrations are found in the olfactory tubercle and nucleus accumbens.