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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
24
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pubmed:dateCreated |
1992-9-25
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pubmed:abstractText |
The addition of phorbol esters to U937 leukemic cells stimulates the phosphorylation of c-Jun on serines 63 and 73. To isolate the protein kinase which stimulates this phosphorylation, we have used heparin-Sepharose chromatography followed by affinity chromatography over glutathione-Sepharose beads bound with a fusion protein of glutathione S-transferase and amino acids 5-89 of c-Jun (GST-c-Jun). Using this procedure we purify a 67-kDa protein which is capable of phosphorylating GST-c-Jun as well as the complete c-Jun protein. By making mutations in serines 63 and 73 and then creating a fusion protein with GST (GST-c-Jun mut), we demonstrate that this protein kinase specifically phosphorylates these sites in the c-Jun amino terminus. Treatment of purified c-Jun amino-terminal protein kinase (cJAT-PK) with phosphatase 2A inhibits its ability to phosphorylate GST-c-Jun. This inactivated enzyme can be reactivated by phosphorylation with protein kinase C (PKC), although PKC is not capable of phosphorylating the GST-c-Jun substrate. Because v-Jun cannot be phosphorylated in vivo, we compared the ability of cJAT-PK to bind to GST-v-Jun or GST-c-Jun mut. The cJAT-PK bound 50-fold better to GST-c-Jun mut than GST-v-Jun suggesting that the delta domain which is missing in v-Jun plays a role in binding the cJAT-PK. These results suggest that there is a protein kinase cascade mediated by protein phosphatases and PKC which regulates c-Jun phosphorylation.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Glutathione Transferase,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphoprotein Phosphatases,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinases,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Phosphatase 2,
http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins c-jun,
http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Serine,
http://linkedlifedata.com/resource/pubmed/chemical/Tetradecanoylphorbol Acetate,
http://linkedlifedata.com/resource/pubmed/chemical/Threonine
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pubmed:status |
MEDLINE
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pubmed:month |
Aug
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
25
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pubmed:volume |
267
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
17001-5
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pubmed:dateRevised |
2009-11-19
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pubmed:meshHeading |
pubmed-meshheading:1324919-Cell Line,
pubmed-meshheading:1324919-Chromatography, Affinity,
pubmed-meshheading:1324919-Glutathione Transferase,
pubmed-meshheading:1324919-Humans,
pubmed-meshheading:1324919-Kinetics,
pubmed-meshheading:1324919-Leukemia,
pubmed-meshheading:1324919-Phosphoprotein Phosphatases,
pubmed-meshheading:1324919-Phosphorylation,
pubmed-meshheading:1324919-Protein Kinases,
pubmed-meshheading:1324919-Protein Phosphatase 2,
pubmed-meshheading:1324919-Proto-Oncogene Proteins c-jun,
pubmed-meshheading:1324919-Recombinant Fusion Proteins,
pubmed-meshheading:1324919-Serine,
pubmed-meshheading:1324919-Substrate Specificity,
pubmed-meshheading:1324919-Tetradecanoylphorbol Acetate,
pubmed-meshheading:1324919-Threonine
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pubmed:year |
1992
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pubmed:articleTitle |
Affinity-purified c-Jun amino-terminal protein kinase requires serine/threonine phosphorylation for activity.
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pubmed:affiliation |
Division of Hematology/Oncology, University of Alabama, Birmingham 35294.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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