cAMP-dependent protein kinase type RI is found in clusters in the rat detergent-insoluble neuronal fraction.
Different types of cAMP dependent regulatory subunits have been characterized in the mammalian brain: RI alpha and beta, RII alpha and beta. The subcellular distribution of RI subunits has been examined in the rat brain. Partial amino acid sequencing of tryptic fragments from the Triton insoluble pellet of the rat brain shows that cAMP dependent regulatory subunits type RI alpha are found in this fraction. Immunohistochemistry shows that Triton-insoluble RI subunits are concentrated to form clusters and this distribution is distinct from RII subunits. Immunohistochemistry and fluorescent cAMP labeling show that the clusters bind fluorescent cAMP analogues. These results suggest that the high local concentration of RI subunits can modulate cAMP distribution among different cellular compartments.
Mucignat-Caretta
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Dipartimento di Anatomia e Fisiologia Umana, Universita di Padova, Italy. mucignat@ux1.unipd.it
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Caretta
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D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D001921:Brain / Q000166:cytology / Q000201:enzymology*; D001923:Brain Chemistry; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D053938:DNA Fragmentation; D003902:Detergents; D005455:Fluorescent Antibody Technique; D005456:Fluorescent Dyes; D008969:Molecular Sequence Data; D009474:Neurons / Q000737:chemistry / Q000201:enzymology*; D010446:Peptide Fragments / Q000737:chemistry; D051381:Rats; D012995:Solubility; D013347:Subcellular Fractions / Q000737:chemistry / Q000201:enzymology*; D014357:Trypsin / Q000737:chemistry
D003902:Detergents; D005456:Fluorescent Dyes; D010446:Peptide Fragments; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D014357:Trypsin