scholarly journals Purification and characterization of the catalytic subunit of adenosine 3':5'-cyclic monophosphate-dependent protein kinase from bovine liver

1976 ◽  
Vol 159 (2) ◽  
pp. 409-422 ◽  
Author(s):  
P H Sugden ◽  
L A Holladay ◽  
E M Reimann ◽  
J D Corbin
Keyword(s):  
Protein Kinase ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Bovine Liver ◽  
Polyacrylamide Gel ◽  
Catalytic Subunit ◽  
Type Ii ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Gel Isoelectric Focusing

1. The catalytic subunit of bovine liver cyclic AMP-dependent protein kinase (EC2.7.1.37) was purified essentially by the method of Reimann & Corbin [(1976) Fed. Proc. Fed. Am. Soc. Exp. Biol. 35, 1384]. 2. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, sedimentation-velocity centrifugation and sedimentation-equilibrium centrifugation showed that the catalytic subunit was monodisperse. Polyacrylamide-gel isoelectric-focusing electrophoresis revealed the presence of at least three isoenzyme forms of catalytic subunit activity with slightly different pI values (6.72, 7.04 and 7.35). 3. Physical properties of the catalytic subunit were determined by several different methods. It had mol.wt. 39000-42000, Stokes radium 2.73-3.08 nm, so20.w 3.14S, f/fo 1.19-1.23 and, assuming a prolate ellipsoid, axial ration 4-5. 4. Amino acid analysis was performed on the catalytic subunit. It had one cysteine residue/molecule which was essential for activity. Inhibition by thiol-specific reagents was partially prevented by the presence of ATP-Mg2+. 5. The circular-dichroic spectrum showed the catalytic subunit contained 29% α-helical form, 18% β-form and 53% aperiodic form. Near-u.v. circular dichroism showed the presence of aromatic residues whose equivalent molar ellipticity was greatly altered by the addition of ATP-Mg2+. 6. Kinetic experiments showed that the catalytic subunit had an apparent Km for ATP of 7 muM. 5'-Adenylyl imidodiphosphate inhibitied competitively with ATP with a Ki of 60 muM. The kinetic plot for histone (Sigma, type II-A) was biphasic showing ‘high’-and ‘low’-Km segments. Under assay conditions the specific activity of the catalytic subunit was 3 × 10(6) units/mg of protein. Of various metal ions tested, the catalytic subunit was most active with Mg2+.7. When assayed with histone (Sigma, type II-A) as substrate, the activity of the catalytic subunit was increased by non-ionic detergents or urea. No such activation was observed with casein as substrate.

scholarly journals Ca2+ and phospholipid-dependent protein kinase (protein kinase C) activity is not necessarily required for secretion by human neutrophils

Blood ◽  
1986 ◽  
Vol 68 (4) ◽  
pp. 810-817
Author(s):  
KJ Balazovich ◽  
JE Smolen ◽  
LA Boxer
Keyword(s):  
Protein Kinase ◽  
Phorbol Esters ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Soluble Form ◽  
Human Neutrophils ◽  
Dependent Manner ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Dose Dependent

Ca2+-dependent and phospholipid-dependent protein kinase (PKC) is a receptor for and is activated by phorbol esters. This enzyme is reportedly involved in the mechanism of superoxide anion (O2-) production and the release of intracellular granule contents from human neutrophils. As previously reported by others, we found that greater than 75% of the total cellular PKC activity existed in a soluble form in untreated neutrophils and that this activity was enhanced in a dose- dependent manner by phorbol 12-myristate 13-acetate (PMA) and by phorbol 12,13-dibutyrate (PDBu). Furthermore, mezerein, an analogue of PMA that is thought to be a competitive inhibitor, did not activate PKC, and on the contrary, inhibited PMA-stimulated activity in a dose- dependent manner. Pretreatment of intact neutrophils with PMA or PDBu caused the “translocation” of PKC activity to the insoluble cell fraction; PKC translocation was not detected after mezerein stimulation at any of the tested concentrations. Neither did mezerein cause an increase in intracellular Ca2+, as monitored by Quin 2 fluorescence. Both phorbol esters and mezerein stimulated intact neutrophils to generate O2- and release lysosomal enzymes into the extracellular medium. Finally sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis demonstrated key differences in the patterns of endogenous phosphoproteins of neutrophils stimulated with phorbol as compared with mezerein. We therefore suggest that PKC activation may not be the only pathway required to elicit neutrophil responses.

Amino acid sequence of the catalytic subunit of bovine type II adenosine cyclic 3',5'-phosphate-dependent protein kinase

Biochemistry ◽  
1983 ◽  
Vol 22 (15) ◽  
pp. 3702-3709 ◽  
Author(s):  
Shozo Shoji ◽  
Lowell H. Ericsson ◽  
Kenneth A. Walsh ◽  
Edmond H. Fischer ◽  
Koiti Titani
Keyword(s):  
Amino Acid ◽  
Protein Kinase ◽  
Amino Acid Sequence ◽  
Catalytic Subunit ◽  
Type Ii ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Bovine Type

scholarly journals Antiserum against the catalytic subunit of adenosine 3′:5′-cyclic monophosphate-dependent protein kinase. Reactivity towards various protein kinases

1980 ◽  
Vol 192 (1) ◽  
pp. 223-230 ◽  
Author(s):  
G Schwoch ◽  
A Hamann ◽  
H Hilz
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Kinases ◽  
Rat Liver ◽  
Catalytic Subunit ◽  
Type Ii ◽  
Dependent Protein Kinase ◽  
Subunit C ◽  
Bovine Heart ◽  
Dependent Protein

An antiserum against the catalytic subunit C of cyclic AMP-dependent protein kinase, isolated from bovine heart type II protein kinase, was produced in rabbits. Reaction of the catalytic subunit with antiserum and separation of the immunoglobulin G fraction by Protein A-Sepharose quantitatively removed the enzyme from solutions. Comparative immunotitration of protein kinases showed that the amount of antiserum required to eliminate 50% of the enzymic activity was identical for pure catalytic subunit, and for holoenzymes type I and type II. The reactivity of the holoenzymes with the antiserum was identical in the absence or the presence of dissociating concentrations of cyclic AMP. Most of the holoenzyme (type II) remains intact when bound to the antibodies as shown by quantification of the regulatory subunit in the supernatant of the immunoprecipitate. Titration with the antibodies also revealed the presence of a cyclic AMP-independent histone kinase in bovine heart protein kinase I preparations obtained by DEAE-cellulose chromatography. Cyclic AMP-dependent protein kinase purified from the particulate fraction of bovine heart reacted with the antiserum to the same degree as the soluble enzyme, whereas two cyclic AMP-independent kinases separated from the particle fraction neither reacted with the antiserum nor influenced the reaction of the antibodies with the cyclic AMP-dependent protein kinase. Immunotitration of the protein kinase catalytic subunit C from rat liver revealed that the antibodies had rather similar reactivities towards the rat liver and the bovine heart enzyme. This points to a relatively high degree of homology of the catalytic subunit in mammalian tissues and species. Broad applicability of the antiserum to problems related to cyclic AMP-dependent protein kinases is thus indicated.

scholarly journals Substrates for cyclic AMP-dependent protein kinase in islets of Langerhans. Studies with forskolin and catalytic subunit

1985 ◽  
Vol 227 (3) ◽  
pp. 727-736 ◽  
Author(s):  
M R Christie ◽  
S J Ashcroft
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Insulin Release ◽  
Islets Of Langerhans ◽  
Plasma Membranes ◽  
Sodium Dodecyl ◽  
Catalytic Subunit ◽  
Subcellular Fractions ◽  
Dependent Protein Kinase ◽  
Dependent Protein

To investigate substrates for cyclic AMP-dependent protein kinase in intact islets of Langerhans, batches of islets were incubated with [32P]Pi for 1 h in the presence of 10 mM-glucose; the adenylate cyclase activator forskolin, which in parallel experiments was shown to increase islet cyclic AMP content and insulin release, was then added. Islets were homogenized and subcellular fractions prepared by differential centrifugation. Phosphopeptides were electrophoresed on sodium dodecyl sulphate/polyacrylamide gels and quantified by autoradiography and densitometry. Within 5 min forskolin caused increased labelling of Mr-25 000 and −30 000 cytosolic and Mr-23 000 and −32 000 particulate peptides; a rapid decrease in phosphorylation of Mr-18 000 and −34 000 cytosolic peptides was also observed. In addition, rather slower phosphorylation occurred of the Mr-15 000 peptide previously identified as histone H3 [Christie & Ashcroft (1984) Biochem. J. 218, 87-99]. When similar subcellular fractions were incubated with [gamma-32P]ATP and purified catalytic subunit of cyclic AMP-dependent protein kinase, peptides phosphorylated included cytosolic species of Mr 25 000 and 30 000 and particulate species of Mr 23 000 and 32 000. The distribution of RNA in the subcellular fractions suggested that the Mr-32 000 species could be a ribosomal protein. The 24 000 g pellet was heterogeneous, as judged by marker assays, and was therefore fractionated further by Percoll-density-gradient centrifugation. The peak containing the Mr-23 000 peptide was resolved from marker enzymes for plasma membranes, mitochondria and endoplasmic reticulum and coincided with a peak for insulin: hence the Mr-23 000 peptide is likely to be a secretory-granule component. The study demonstrates that the potentiation of insulin release that occurs when islet cyclic AMP is increased is accompanied by rapid phosphorylation of specific islet substrates for cyclic AMP-dependent protein kinase. The data are consistent with the hypothesis that protein phosphorylation is involved in the regulation of insulin secretion.

scholarly journals Adenosine 3':5'-cyclic monophosphate-binding proteins in bovine and rat tissues

1976 ◽  
Vol 159 (2) ◽  
pp. 423-427 ◽  
Author(s):  
P H Sugden ◽  
J D Corbin
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Binding Proteins ◽  
Binding Protein ◽  
Bovine Liver ◽  
Catalytic Subunit ◽  
Regulatory Subunit ◽  
Trypsin Treatment ◽  
Dependent Protein Kinase ◽  
Dependent Protein

1. At least two classes of high-affinity cyclic AMP-binding proteins have been identified: those derived from cyclic AMP-dependent protein kinases (regulatory subunits) and those that bind a wide range of adenine analogues (adenine analogue-binding proteins). 2. In fresh-tissue extracts, regulatory subunits could be further subdivided into ‘type I’ or ‘type II’ depending on whether they were derived from ‘type I’ or ‘type II’ protein kinase [see Corbin et al. (1975) J. Biol. Chem. 250, 218-225]. 3. The adenine analogue-binding protein was detected in crude tissue supernatant fractions of bovine and rat liver. It differed from the regulatory subunit of cyclic AMP-dependent protein kinase in many of its properties. Under the conditions of assay used, the protein accounted for about 45% of the binding of cyclic AMP to bovine liver supernatants. 4. The adenine analogue-binding protein from bovine liver was partially purified by DEAE-cellulose and Sepharose 6B chromatography. It had mol.wt. 185000 and was trypsin-sensitive. As shown by competition and direct binding experiments, it bound adenosine and AMP in addition to cyclic AMP. At intracellular concentrations of adenine nucleotides, binding of cyclic AMP was essentially completely inhibited in vitro. Adenosine binding was inhibited by only 30% under similar conditions. 5. Rat tissues were examined for the presence of the adenine analogue-binding protein, and, of those examined (adipose tissue, heart, brain, testis, kidney and liver), significant amounts were only found in the liver. The possible physiological role of the adenine analogue-binding protein is discussed. 6. Because the adenine analogue-binding protein or other cyclic AMP-binding proteins in tissues may be products of partial proteolysis of the regulatory subunit of cyclic AMP-dependent protein kinase, the effects of trypsin and aging on partially purified protein kinase and its regulatory subunit from bovine liver were investigated. In all studies, the effects of trypsin and aging were similar. 7. In fresh preparations, the cyclic AMP-dependent protein kinase had mol.wt. 150000. Trypsin treatment converted it into a form of mol.wt 79500. 8. The regulatory subunit of the protein kinase had mol.wt. 87000. It would reassociate with and inhibit the catalytic subunit of the enzyme. Trypsin treatment of the regulatory subunit produced a species of mol.wt. 35500 which bound cyclic AMP but did not reassociate with the catalytic subunit. Trypsin treatment of the protein kinase and dissociation of the product by cyclic AMP produced a regulatory subunit of mol.wt. 46500 which reassociated with the catalytic subunit. 9. These results may be explained by at least two trypsin-sensitive sites on the regulatory subunit. A model for the effects of trypsin is described.

scholarly journals Comparison of Ca2+-dependent phosphorylation in viable dispersed brain cells with calmodulin-dependent protein kinase activity in cell-free preparations of rat brain

1985 ◽  
Vol 232 (3) ◽  
pp. 629-635 ◽  
Author(s):  
L L Norling ◽  
M Landt
Keyword(s):  
Protein Kinase ◽  
Gel Electrophoresis ◽  
Kinase Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Brain Cells ◽  
Synapsin I ◽  
Protein Kinase Activity ◽  
Dependent Protein Kinase ◽  
Dependent Protein

Using two depolarizing agents, veratrine and high concentrations of extracellular KCl, we studied depolarization-stimulated phosphorylations in 32P-labelled dispersed brain tissue in order to identify phosphoprotein substrates for Ca2+ - and calmodulin-dependent protein kinase activity at the cellular level, for comparison with findings in cell-free preparations. In intact brain cells, the only prominent depolarization-stimulated phosphorylation was a 77 kDa protein separated on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. This phosphorylation was dependent on external Ca2+, since chelation of Ca2+ in media with 6 mM-EGTA or the presence of verapamil (a Ca2+ -channel blocker) in the incubation media inhibited depolarization-stimulated phosphorylation of the 77 kDa protein. Phosphorylation of the 77 kDa protein also appeared to be dependent on calmodulin, because depolarization-stimulated phosphorylation was significantly decreased (P less than 0.05) when 100 microM-trifluoperazine was present in the incubation media. Polymyxin B, an inhibitor of Ca2+- and phospholipid-dependent phosphorylation, and 12-O-tetradecanoylphorbol 13-acetate, the phorbol ester enhancing Ca2+- and phospholipid-dependent phosphorylation, had no effect on the phosphorylation of the 77 kDa protein. The 77 kDa phosphoprotein was identified as a protein previously named synapsin I [Ueda, Maeno & Greengard (1973) J. Biol. Chem 248, 8295-8305] on the basis of similar migration of native and proteolytic fragments of the 77 kDa protein with those of authentic synapsin I on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Whereas several studies with cell-free preparations showed that 57 kDa and 54 kDa endogenous phosphoproteins were the most prominent species phosphorylated in a Ca2+ and calmodulin-dependent manner, these results indicate that synapsin is the most prominent Ca2+-and calmodulin-dependent phosphorylation in intact cells. The phosphorylations of 54 kDa and 57 kDa proteins may not be as important in vivo, but instead occur as a result of the disruption of cellular integrity inherent in preparation of cell-free subfractions of brain tissue.

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