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Clustered distribution of cAMP‐dependent protein kinase regulatory isoform RIα during the development of the rat brain
Author(s) -
MucignatCaretta Carla,
Caretta Antonio
Publication year - 2002
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.10352
Subject(s) - olfactory bulb , biology , hippocampus , gene isoform , neuroscience , brainstem , kinase , protein subunit , protein kinase a , hypothalamus , cerebral cortex , microbiology and biotechnology , central nervous system , gene , genetics
cAMP is a ubiquitous second messenger, which acts mainly through specific protein kinases that consist of two regulatory and two catalytic subunits. An unsolved problem in cAMP physiology is how it can regulate so many cellular functions through this simple enzymatic cascade. A tentative explanation is related to the different biochemical properties of the four regulatory subunit isoforms (RIα and RIβ, RIIα and RIIβ) and to their differential cell and tissue distribution. For example, detergent insoluble aggregates of RIα are present in some cholinergic neurons of the adult rat brain. Rat brains, from the embryonic stage to old age, were examined for the presence of highly concentrated clusters of RIα. They are present only in some neurons of restricted brain areas, for a limited time span. During development, labeled neurons appear in different brain areas after neuron migration, at a stage of advanced functional maturation. They have their greatest expression after birth but before sexual maturation, and then they slowly decline, persisting only in a few brain areas throughout life. The first appearance, time course, and eventual disappearance is different in the different brain areas: RIα clusters appear in brainstem, hypothalamus, and accessory olfactory bulb at a late embryonic stage; in the main olfactory bulb, hippocampus, and medial thalamic nuclei shortly after birth; and in the cortex as late as in the third and fourth postnatal week. During the rat's lifespan, the distribution of these peculiar RIα clusters undergo changes that may contribute to shape neuronal responses differentially to agents modifying cAMP levels. J. Comp. Neurol. 451:324–333, 2002. © 2002 Wiley‐Liss, Inc.