Lack of Evidence for PKM2 Protein Kinase Activity
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 activi...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
Elsevier
2016
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| Online Access: | http://hdl.handle.net/1721.1/105827 https://orcid.org/0000-0002-7702-5877 https://orcid.org/0000-0003-0130-3428 https://orcid.org/0000-0002-6702-4192 |
| Summary: | 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 [32P]-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 [32P]-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. |
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