What is the difference between PKM1 and PKM2?
PKM1 and PKM2 differ by 22 amino acids and have distinct regulatory properties (Mazurek, 2011). While PKM1 forms a stable, constitutively active tetramer, PKM2 activity is controlled by numerous allosteric effectors and post-translational modifications that affect its tetramer stability.
What does PKM1 do?
Taken together, our data indicate that the stromal expression of PKM1 and PKM2 both drive tumor growth by different mechanisms. Stromal PKM1 feeds tumor cells by increasing L-lactate secretion, and triggers a tumor inflammatory response.
What is the reaction catalyzed by pyruvate kinase?
Pyruvate kinase catalyzes the direct transfer of phosphate from phosphoenolpyruvate (PEP) to ADP to produce ATP and pyruvate. This reaction is favorable due to the high energy of hydrolysis of PEP [31].
What are the consequences of PKM2 expression?
PKM2 can phosphorylate and activate certain transcription factors, thereby inducing fusion of Est variant 6 and neurotrophic tyrosine kinase receptor. The result may lead to malignant transformation of some neurogenic tumors. PKM2 in the cytoplasmic dimer form promotes the formation of the Warburg effect [134].
Is pyruvate kinase A transferase?
Pyruvate kinase is the enzyme involved in the last step of glycolysis. It catalyzes the transfer of a phosphate group from phosphoenolpyruvate (PEP) to adenosine diphosphate (ADP), yielding one molecule of pyruvate and one molecule of ATP….
| Pyruvate kinase | |
|---|---|
| EC no. | 2.7.1.40 |
| CAS no. | 9001-59-6 |
| Databases | |
| IntEnz | IntEnz view |
How is ATP formed by pyruvate kinase?
There are two steps in the pyruvate kinase reaction in glycolysis. First, PEP transfers a phosphate group to ADP, producing ATP and the enolate of pyruvate. Secondly, a proton must be added to the enolate of pyruvate to produce the functional form of pyruvate that the cell requires.
What type of glucose metabolism is likely to be driven when cells express PKM1 when cells express PKM2?
Future studies should clarify whether metabolic phenotypes of PkmM1/M1 and PkmM2/M2 cells observed in vitro reflect those in vivo. We observed that PKM1-expressing cells exhibit more active autophagy than PKM2-expressing cells, suggesting that PKM1 drives active glucose metabolism and autophagy in tumor cells.
How is PKM2 different to PK?
PKM1 and PKM2 are derived from a single PKM gene by alternative splicing of a primary mRNA transcript that contains exon 9 and exon 10, respectively (10). PKM2 is exclusively expressed by the embryonic cells, and as the embryogenesis proceeds, the PKM2 is replaced by tissue-specific PKM1, PKL, or PKR (6).