A regulatory subunit of the cAMP-dependent protein kinase down-regulated in aplysia sensory neurons during long-term sensitization.
Binding of cAMP by the five neuronal isoforms (N1-5) of the regulatory (R) subunit of the Aplysia cAMP-dependent protein kinase is diminished in sensory neurons stimulated to produce long-term presynaptic facilitation. To determine how the cAMP-binding activity of the R subunits is lost, we isolated cDNAs encoding N4, which is a homolog of mammalian RI. Immunoblots with antisera raised against the R protein overexpressed in E. coli show that the diminished binding activity, which occurs in long-term facilitation, results from coordinate loss of R protein isoforms. No change was detected in the amount of transcripts for R subunits, suggesting that the down-regulation results from enhanced proteolytic turnover.
Bergold
P J
PJ
Howard Hughes Medical Institute, Columbia University, New York, New York 10032.
Beushausen
S A
SA
Sacktor
T C
TC
Cheley
S
S
Bayley
H
H
Schwartz
J H
JH
D000595:Amino Acid Sequence; D000818:Animals; D001048:Aplysia / Q000502:physiology*; D001483:Base Sequence; D003001:Cloning, Molecular; D000242:Cyclic AMP / Q000502:physiology*; D004247:DNA / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics / Q000502:physiology*; D007106:Immune Sera; D015151:Immunoblotting; D007527:Isoenzymes / Q000032:analysis / Q000235:genetics / Q000502:physiology; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009475:Neurons, Afferent / Q000737:chemistry / Q000201:enzymology* / Q000502:physiology; D009693:Nucleic Acid Hybridization; D011494:Protein Kinases / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D012689:Sequence Homology, Nucleic Acid; D013997:Time Factors; D014158:Transcription, Genetic / Q000235:genetics
D007106:Immune Sera; D007527:Isoenzymes; D046911:Macromolecular Substances; D004247:DNA; D000242:Cyclic AMP; D011494:Protein Kinases