Modulation of protein kinase C by adenosine: Involvement of adenosine A1 receptor-pertussis toxin sensitive nucleotide binding protein system

1995 ◽  
pp. 51-58 ◽  
Author(s):  
Ravi B. Marala ◽  
S. Jamal Mustafa
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Pertussis Toxin ◽  
Binding Protein ◽  
Nucleotide Binding ◽  
Adenosine A1 Receptor ◽  
Kinase C ◽  
Adenosine A1 ◽  
A1 Receptor ◽  
Nucleotide Binding Protein

scholarly journals Isolation, cloning and characterization of a low-molecular-mass purine nucleoside- and nucleotide-binding protein

1997 ◽  
Vol 326 (2) ◽  
pp. 471-477 ◽  
Author(s):  
Jeffrey GILMOUR ◽  
Nianci LIANG ◽  
John M. LOWENSTEIN
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Binding Protein ◽  
Gel Filtration ◽  
Nucleotide Binding ◽  
Adenosine Kinase ◽  
Purine Nucleoside ◽  
Affinity Column ◽  
Kinase C ◽  
Nucleotide Binding Protein

A purine nucleoside- and nucleotide-binding protein has been isolated from extracts of rat and rabbit heart, calf aortic smooth muscle and rat liver using an affinity column containing adenosine bound through the N6-position. The protein, which was eluted by adenosine, was cloned and expressed in Escherichia coli. The deduced amino acid sequence has a calculated Mr of 13693 (p13.7). The expressed protein has properties identical with the protein isolated from heart and liver, including an anomalous, apparent Mr of 15300, observed on gel electrophoresis. Gel filtration shows it to be a dimer. p13.7 differs by only three amino acids out of 125 from protein kinase C inhibitor 1 [Pearson, DeWald, Mathews, Mozier, Zürcher-Neely, Heinrikson, Morris, McCubbin, McDonald, Fraser et al. (1990) J. Biol. Chem. 265, 4583–4591]. However, we have not been able to demonstrate inhibition of protein kinase C by physiological concentrations of p13.7, regardless of whether it was isolated from tissue extracts or expressed in E. coli. p13.7 is a member of the histidine triad motif family of proteins [Séraphin (1992) J. DNA Sequencing Mapping 3, 177–179]. The affinity of p13.7 for a number of different purine nucleosides and nucleotides, as measured by fluorescence titration and gel filtration, falls within the range 5–50 μM. On the basis of these properties and its crystal structure [Brenner, Garrison, Gilmour, Peisach, Ringe, Petsko and Lowenstein (1997) Nature Struct. Biol. 4, 231–238], we have coined the acronym HINT (histidine triad nucleotide-binding motif) to describe the family of proteins of which p13.7 is a member. Other proteins that bind to the affinity column have been identified as malate and lactate dehydrogenases, cAMP-binding proteins, adenosine kinase and S-adenosylhomocysteine hydrolase.

Adenosine A1 receptor-induced upregulation of protein kinase C: role of pertussis toxin-sensitive G protein(s)

1995 ◽  
Vol 269 (5) ◽  
pp. H1619-H1624 ◽  
Author(s):  
R. B. Marala ◽  
S. J. Mustafa
Keyword(s):  
Protein Kinase C ◽  
Coronary Artery ◽  
Protein Kinase ◽  
G Protein ◽  
Pertussis Toxin ◽  
Protein S ◽  
Porcine Coronary Artery ◽  
Kinase C ◽  
Adenosine A1 ◽  
A1 Receptor

Biochemical and pharmacological studies have established that adenosine modulates protein kinase C (PKC), which plays an important role in the maintenance of vascular tone. Our earlier studies [Marala and Mustafa. Am. J. Physiol. 268 (Heart Circ. Physiol. 37): H271-H277, 1995. Marala, R. B., K. Ways, and S. J. Mustafa. Am. J. Physiol. 264 (Heart Circ. Physiol. 33): H1465-H1471, 1993] have shown the involvement of adenosine A1 receptors and not the A2 receptors in the upregulation of PKC in porcine coronary artery. The mechanism(s) by which adenosine upregulates PKC is not yet clearly understood. We now report the increased expression of PKC by adenosine A1 receptor through an upstream activation of pertussis toxin-sensitive G protein(s). Incubation of porcine coronary artery for 24 h with a relatively specific A1-receptor agonist (2S)-N6-(2-endo-norbornyl)adenosine (ENBA) elevated the contractile responses to endothelin-1 by about twofold, probably due to an increased expression of PKC. Incubation of porcine coronary artery with ENBA also protected against the phorbol 12,13-dibutyrate (PDBu)-induced depletion of PKC. Inclusion of pertussis toxin in the incubation medium completely blocked both the upregulatory and the protective effects of ENBA. Incubation with pertussis toxin did not alter the PKC activity as judged by the contractile responses to PDBu. On the contrary, incubation of porcine coronary artery with cholera toxin for 24 h did not alter any of the ENBA responses (upregulation of PKC and the protection against PDBu-induced PKC depletion). Incubation conditions of coronary arteries with toxins are sufficient to cause ADP ribosylation of respective G proteins as judged by back ADP ribosylation studies.(ABSTRACT TRUNCATED AT 250 WORDS)

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