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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
24
|
| pubmed:dateCreated |
1985-11-29
|
| pubmed:abstractText |
Rat liver L-type pyruvate kinase was phosphorylated in vitro by a Ca2+/calmodulin-dependent protein kinase purified from rabbit liver. The calmodulin (CaM)-dependent kinase catalyzed incorporation of up to 1.7 mol of 32P/mol of pyruvate kinase subunit; maximum phosphorylation was associated with a 3.0-fold increase in the K0.5 for P-enolpyruvate. This compares to incorporation of 0.7 to 1.0 mol of 32P/mol catalyzed by the cAMP-dependent protein kinase with a 2-fold increase in K0.5 for P-enolpyruvate. When [32P]pyruvate kinase, phosphorylated by the CaM-dependent protein kinase, was subsequently incubated with 5 mM ADP and cAMP-dependent protein kinase (kinase reversal conditions), 50-60% of the 32PO4 was removed from pyruvate kinase, but the K0.5 for P-enolpyruvate decreased only 20-30%. Identification of 32P-amino acids after partial acid hydrolysis showed that the CaM-dependent protein kinase phosphorylated both threonyl and seryl residues (ratio of 1:2, respectively) whereas the cAMP-dependent protein kinase phosphorylated only seryl groups. The two phosphorylation sites were present in the same 3-4-kDa CNBr fragment located near the amino terminus of the enzyme subunit. These results indicate that the CaM-dependent protein kinase catalyzed phosphorylation of L-type pyruvate kinase at two discrete sites. One site is apparently the same serine which is phosphorylated by the cAMP-dependent protein kinase. The second site is a unique threonine residue whose phosphorylation also inactivates pyruvate kinase by elevating the K0.5 for P-enolpyruvate. These results may account for the Ca2+-dependent phosphorylation of pyruvate kinase observed in isolated hepatocytes.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Diphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Calmodulin,
http://linkedlifedata.com/resource/pubmed/chemical/Cyanogen Bromide,
http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP,
http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphates,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphoenolpyruvate,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphoproteins,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphoserine,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinases,
http://linkedlifedata.com/resource/pubmed/chemical/Pyruvate Kinase
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Oct
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
25
|
| pubmed:volume |
260
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
13018-22
|
| pubmed:dateRevised |
2009-11-19
|
| pubmed:meshHeading |
pubmed-meshheading:2997154-Adenosine Diphosphate,
pubmed-meshheading:2997154-Animals,
pubmed-meshheading:2997154-Calcium,
pubmed-meshheading:2997154-Calmodulin,
pubmed-meshheading:2997154-Cyanogen Bromide,
pubmed-meshheading:2997154-Cyclic AMP,
pubmed-meshheading:2997154-Kinetics,
pubmed-meshheading:2997154-Liver,
pubmed-meshheading:2997154-Peptide Fragments,
pubmed-meshheading:2997154-Phosphates,
pubmed-meshheading:2997154-Phosphoenolpyruvate,
pubmed-meshheading:2997154-Phosphoproteins,
pubmed-meshheading:2997154-Phosphorylation,
pubmed-meshheading:2997154-Phosphoserine,
pubmed-meshheading:2997154-Protein Kinases,
pubmed-meshheading:2997154-Pyruvate Kinase,
pubmed-meshheading:2997154-Rabbits,
pubmed-meshheading:2997154-Rats
|
| pubmed:year |
1985
|
| pubmed:articleTitle |
Phosphorylation of L-type pyruvate kinase by a Ca2+/calmodulin-dependent protein kinase.
|
| pubmed:publicationType |
Journal Article,
Comparative Study
|