DISTRIBUTION OF THE MESSENGER-RNA FOR PROTEIN PHOSPHATASE-T IN RAT-BRAIN

We have recently cloned a novel protein serine/threonine phosphatase ( PPT) from rat mRNA which is predominantly expressed in the brain (Beck er et al., J. Biol. Chem., 269 (1994) 22586-22592). In the present stu dy, the regional distribution of PPT mRNA in the brain of adult rats w as characterized by in situ hybridization histochemistry. PPT mRNA was found to be differentially expressed throughout the rat brain. Highes t transcript levels were found in specific neuronal populations (hippo campus, piriform cortex, taenia tecta, medial habenula, granular cell layer of the cerebellum) as well as in the choroid plexus of the third and lateral ventricles. In contrast, expression levels in some brain areas, e.g., caudate putamen and white matter, were beyond the detecti on limit of in situ hybridization. The pattern of expression of PPT in rat brain differs from that of other protein serine/threonine phospha tases and may reflect specific functions of this phosphatase.