Abstract
The role of pyruvate kinase M2 (PKM2) in cell proliferation is controversial. A unique function of PKM2 proposed to be important for the proliferation of some cancer cells involves the direct activity of this enzyme as a protein kinase; however, a detailed biochemical characterization of this activity is lacking. Using [(32)P]-phosphoenolpyruvate (PEP) we examine the direct substrates of PKM2 using recombinant enzyme and in vitro systems where PKM2 is genetically deleted. Labeling of some protein species from [(32)P]-PEP can be observed; however, most were dependent on the presence of ADP, and none were dependent on the presence of PKM2. In addition, we also failed to observe PKM2-dependent transfer of phosphate from ATP directly to protein. These findings argue against a role for PKM2 as a protein kinase.
Copyright © 2015 Elsevier Inc. All rights reserved.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenosine Triphosphate / metabolism
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Animals
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Carrier Proteins / genetics
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Carrier Proteins / metabolism*
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Cell Line, Tumor
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Cell Proliferation / physiology
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Cells, Cultured
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Gene Deletion
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Glycolysis
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Humans
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Membrane Proteins / deficiency
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Membrane Proteins / genetics
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Membrane Proteins / metabolism*
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Mice
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Phosphoenolpyruvate / metabolism
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Phosphorylation
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Protein Kinases / deficiency
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Protein Kinases / genetics
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Protein Kinases / metabolism*
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Pyruvate Kinase / deficiency
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Pyruvate Kinase / genetics
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Pyruvate Kinase / metabolism*
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Recombinant Proteins / genetics
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Recombinant Proteins / metabolism
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Substrate Specificity
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Thyroid Hormone-Binding Proteins
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Thyroid Hormones / deficiency
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Thyroid Hormones / genetics
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Thyroid Hormones / metabolism*
Substances
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Carrier Proteins
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Membrane Proteins
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Recombinant Proteins
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Thyroid Hormones
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Phosphoenolpyruvate
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Adenosine Triphosphate
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Protein Kinases
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Pyruvate Kinase