scholarly journals Exogenous substrate stimulates autodephosphorylation of cyclic-AMP-dependent protein kinase II

1993 ◽  
Vol 294 (2) ◽  
pp. 497-503 ◽  
Author(s):  
B T Gjertsen ◽  
B Fauske ◽  
S O Døskeland
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Intact Cell ◽  
Regulatory Subunit ◽  
Free Form ◽  
Dependent Protein Kinase ◽  
Exogenous Substrate ◽  
Protein Kinase Ii ◽  
C Subunit ◽  
Dependent Protein

The autophosphorylated regulatory subunit (32P-RII) of cyclic-AMP-dependent protein kinase II was efficiently dephosphorylated by its C subunit in the absence of added ADP, provided that Mg/ATP and a standard protein kinase peptide substrate were present. This raises the possibility that autodephosphorylation could be significant in the intact cell. Only the cyclic-AMP-complexed free form of 32P-RII was efficiently dephosphorylated, indicating that the autodephosphorylation was intermolecular. Autodephosphorylation of 32P-RII in the presence of MgATP and kemptide occurred with formation of [gamma-32P]ATP, suggesting transfer of 32P of phospho-RII to a transient C*(MgADP) complex formed during the forward kinase reaction with peptide as substrate. Autodephosphorylation promoted by phosphorylation of exogenous substrates could operate also for other kinases conforming to a mechanism where MgADP remains bound to the active site after the other product (phosphorylated substrate) has left the catalytic complex.

scholarly journals The amino acid sequence of a hinge region in the regulatory subunit of bovine cardiac muscle cyclic AMP-dependent protein kinase II

FEBS Letters ◽  
1980 ◽  
Vol 114 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Koji Takio ◽  
Kenneth A. Walsh ◽  
Hans Neurath ◽  
Stephen B. Smith ◽  
Edwin G. Krebs ◽  
...  
Keyword(s):  
Amino Acid ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Amino Acid Sequence ◽  
Cardiac Muscle ◽  
Hinge Region ◽  
Regulatory Subunit ◽  
Dependent Protein Kinase ◽  
Protein Kinase Ii ◽  
Dependent Protein

scholarly journals cAMP signaling in neurons: patterns of neuronal expression and intracellular localization for a novel protein, AKAP 150, that anchors the regulatory subunit of cAMP-dependent protein kinase II beta.

1992 ◽  
Vol 3 (11) ◽  
pp. 1215-1228 ◽  
Author(s):  
S B Glantz ◽  
J A Amat ◽  
C S Rubin
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Regulatory Subunit ◽  
Mammalian Brain ◽  
Dependent Protein Kinase ◽  
Intracellular Location ◽  
Anchor Protein ◽  
Camp Dependent Protein Kinase ◽  
Protein Kinase Ii ◽  
Dependent Protein

In mammalian brain, physiological signals carried by cyclic AMP (cAMP) seem to be targeted to effector sites via the tethering of cAMP-dependent protein kinase II beta (PKAII beta) to intracellular structures. Recently characterized A kinase anchor proteins (AKAPs) are probable mediators of the sequestration of PKAII beta because they contain a high-affinity binding site for the regulatory subunit (RII beta) of the kinase and a distinct intracellular targeting domain. To establish a cellular basis for this targeting mechanism, we have employed immunocytochemistry to 1) identify the types of neurons that are enriched in AKAPs, 2) determine the primary intracellular location of the anchor protein, and 3) demonstrate that an AKAP and RII beta are coenriched and colocalized in neurons that utilize the adenylate cyclase-cyclic AMP-dependent protein kinase (PKA) signaling pathway. Antibodies directed against rat brain AKAP 150 were used to elucidate the regional, cellular and intracellular distribution of a prototypic anchor protein in the CNS. AKAP 150 is abundant in Purkinje cells and in neurons of the olfactory bulb, basal ganglia, cerebral cortex, and other forebrain regions. In contrast, little AKAP 150 is detected in neurons of the thalamus, hypothalamus, midbrain, and hindbrain. A high proportion of total AKAP 150 is concentrated in primary branches of dendrites, where it is associated with microtubules. We also discovered that the patterns of accumulation and localization of RII beta (and PKAII beta) in brain are similar to those of AKAP 150. The results suggest that bifunctional AKAP 150 tethers PKAII beta to the dendritic cytoskeleton, thereby creating a discrete target site for the reception and propagation of signals carried by cAMP.

scholarly journals Modulation of nuclear cyclic AMP-dependent protein kinase in dibutyryl cyclic AMP-treated rat H4IIE hepatoma cells

1989 ◽  
Vol 260 (3) ◽  
pp. 673-682 ◽  
Author(s):  
S P Squinto ◽  
R A Jungmann
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Nuclear Protein ◽  
Fold Increase ◽  
Hepatoma Cells ◽  
Regulatory Subunit ◽  
Dibutyryl Cyclic Amp ◽  
Dependent Protein Kinase ◽  
C Subunit ◽  
Dependent Protein

Biochemical and immunochemical studies were undertaken to quantify the effects of cyclic AMP on cyclic AMP-dependent protein kinase subunit levels in nuclei of H4IIE hepatoma cells. Dibutyryl cyclic AMP (10 microM) caused a significant biphasic (10 and 120 min after stimulation) increase in total nuclear protein kinase activity. The increase observed 10 min after dibutyryl cyclic AMP stimulation was primarily due to an approx. 3-fold increase of catalytic (C) subunit activity, whereas the change observed 120 min after stimulation consisted of an increase in both C subunit and cyclic AMP-independent protein kinase activities. Analysis of nuclear protein extracts by photoaffinity labelling with 8-azido cyclic [32P]AMP identified only the type II regulatory subunit (RII), but not the type I regulatory subunit (RI). Analysis of nuclear RII variants by two-dimensional gel electrophoresis demonstrated that dibutyryl cyclic AMP caused the appearance of two RII variant forms which were not present in the nuclei of unstimulated cells. Using affinity-purified polyclonal antibodies and immunoblotting procedures, we identified an approx. 2-fold increase in the RII and C subunits in nuclear extracts of dibutyryl cyclic AMP-treated hepatoma cells. Finally, the RI, RII and C subunits were quantified by an e.l.i.s.a. which indicated that dibutyryl cyclic AMP increased nuclear RII and C subunits levels biphasically, reaching peak values 10 and 120 min after the initial stimulation. Nuclear RI subunit levels were not affected. These results provide qualitative as well as quantitative evidence for a modulation by cyclic AMP of the nuclear RII and C subunit levels in rat H4IIE hepatoma cells, and indicate a relatively rapid but temporarily limited dibutyryl cyclic AMP-induced translocation of the RII and C subunits to nuclear sites.

scholarly journals Cloning and characterization of BCY1, a locus encoding a regulatory subunit of the cyclic AMP-dependent protein kinase in Saccharomyces cerevisiae.

1987 ◽  
Vol 7 (4) ◽  
pp. 1371-1377 ◽  
Author(s):  
T Toda ◽  
S Cameron ◽  
P Sass ◽  
M Zoller ◽  
J D Scott ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Carbon Sources ◽  
Regulatory Subunit ◽  
Dependent Protein Kinase ◽  
Yeast Saccharomyces Cerevisiae ◽  
Regulatory Subunits ◽  
Dependent Protein

We have cloned a gene (BCY1) from the yeast Saccharomyces cerevisiae that encodes a regulatory subunit of the cyclic AMP-dependent protein kinase. The encoded protein has a structural organization similar to that of the RI and RII regulatory subunits of the mammalian cyclic AMP-dependent protein kinase. Strains of S. cerevisiae with disrupted BCY1 genes do not display a cyclic AMP-dependent protein kinase in vitro, fail to grow on many carbon sources, and are exquisitely sensitive to heat shock and starvation.

Cyclic AMP-dependent protein kinase regulates sensitivity of cells to multiple drugs

1987 ◽  
Vol 7 (9) ◽  
pp. 3098-3106
Author(s):  
I Abraham ◽  
R J Hunter ◽  
K E Sampson ◽  
S Smith ◽  
M M Gottesman ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Mammalian Cells ◽  
Multiple Drug Resistance ◽  
Regulatory Subunit ◽  
Parent Cell ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Antimitotic Drug ◽  
Multiple Drugs

The isolation of mutant cell lines affecting the activity of cyclic AMP (cAMP)-dependent protein kinase (PK-A) has made it possible to determine the function of this kinase in mammalian cells. We found that both a CHO cell mutant with a defective regulatory subunit (RI) for PK-A and a transfectant cell line expressing the same mutant kinase were sensitive to multiple drugs, including puromycin, adriamycin, actinomycin D, and some antimitotic drugs. The mutant and transfectant cells, after treatment with a concentration of the antimitotic drug colcemid that had no marked effect on the wild-type parent cell, had a severely disrupted microtubule network. The phenotype of hypersensitivity to the antimitotic drug colcemid was used to select revertants of the transfectant and the original mutant. These revertants simultaneously regained normal multiple drug resistance and cAMP sensitivity, thus establishing that the characteristics of colcemid sensitivity and cAMP resistance are linked. Four revertants of the transfectant reverted because of loss or rearrangement of the transfected mutant RI gene. These revertants, as well as one revertant selected from the original mutant, had PK-A activities equal to or higher than that of the parent. In these genetic studies, in which linkage of expression of a PK-A mutation with drug sensitivity is demonstrated, it was established that the PK-A system is involved in regulating resistance of mammalian cells to multiple drugs.

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