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Distribution of Protein Phosphatase Inhibitor‐1 in Brain and Peripheral Tissues of Various Species: Comparison with DARPP‐32
Author(s) -
Hemmings Hugh C.,
Girault JeanAntoine,
Nairn Angus C.,
Bertuzzi Gloria,
Greengard Paul
Publication year - 1992
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1992.tb08347.x
Subject(s) - biology , striatum , immunolabeling , inhibitor protein , acid phosphatase , microbiology and biotechnology , biochemistry , medicine , endocrinology , enzyme , immunohistochemistry , dopamine , immunology
The distribution of inhibitor‐1, a cyclic AMP‐regulated inhibitor of protein phosphatase‐1, was analyzed in various brain regions and peripheral tissues of various species by immunolabeling of sodium dodecyl sulfate‐polyacrylamide gel transfers using specific antibodies. The distribution of inhibitor‐1 was directly compared to that of DARPP‐32, a structurally related cyclic AMP‐regulated inhibitor of protein phosphatase‐1. In rat CNS, a single immunoreactive protein of M r 30,000, identified as inhibitor‐1, was widely distributed. In contrast, DARPP‐32 was highly concentrated in the basal ganglia. Inhibitor‐1 was detected in brain tissue from frog (M r 27,000), turtle (M r 29,000/33,000), canary (M r 26,000), pigeon (M r 28,000), mouse (M r 30,500), rabbit (M r 26,500), cow (M r 27,000), and monkey (M r 27,500), but not from goldfish. Inhibitor‐1 was detected at various levels in most peripheral tissues of the species studied; however, it was not detectable in certain tissues of particular species (e.g., rat and cow liver). DARPP‐32 was detected in brain tissue of all the species tested except frog and goldfish, but was not detectable in most peripheral tissues. Both inhibitor‐1 and DARPP‐32 were concentrated in the cytosol and synaptosomal cytosol of rat striatum. The developmental expressions of inhibitor‐1 and DARPP‐32 in rat striatum differed: the level of inhibitor‐1 peaked in the first postnatal week and then declined by the third postnatal week, whereas the level of DARPP‐32 increased to a peak level by the third postnatal week and remained elevated thereafter. Because inhibitor‐1 and DARPP‐32 have distinct but partially overlapping regional distributions and developmental expression in rat CNS and have distinct tissue distributions in a number of species, it appears that their functions are not fully interchangeable.