About: Pyruvate kinase is a(n) research topic. Over the lifetime, 5683 publication(s) have been published within this topic receiving 180020 citation(s). The topic is also known as: ATP:pyruvate 2-O-phosphotransferase & phosphoenolpyruvate kinase.
Papers published on a yearly basis
TL;DR: It is demonstrated that M2 expression is necessary for aerobic glycolysis and that this metabolic phenotype provides a selective growth advantage for tumour cells in vivo.
Abstract: Many tumour cells express the M2 form of pyruvate kinase rather than the usual M1 form. PKM2 is now shown to promote tumorigenesis and switch the cellular metabolism to increased lactate production and reduced oxygen consumption, recapitulating key aspects of the Warburg effect.
TL;DR: In this article, the role of HIF-1 as a mediator of adaptive responses to hypoxia that underlie cellular and systemic oxygen homeostasis was investigated in Hep3B cells.
Abstract: Hypoxia-inducible factor 1 (HIF-1) activates erythropoietin gene transcription in Hep3B cells subjected to hypoxia. HIF-1 activity is also induced by hypoxia in non-erythropoietin-producing cells, suggesting a more general regulatory role. We now report that RNAs encoding the glycolytic enzymes aldolase A (ALDA), phosphoglycerate kinase 1 (PGK1), and pyruvate kinase M were induced by exposure of Hep3B or HeLa cells to inducers of HIF-1 (1% O2, cobalt chloride, or desferrioxamine), whereas cycloheximide blocked induction of glycolytic RNAs and HIF-1 activity. Oligonucleotides from the ALDA, PGK1, enolase 1, lactate dehydrogenase A, and phosphofructokinase L (PFKL) genes, containing sequences similar to the HIF-1 binding site in the erythropoietin enhancer, specifically bound HIF-1 present in crude nuclear extracts or affinity-purified preparations. Sequences from the ALDA, PFKL, and PGK1 genes containing HIF-1 binding sites mediated hypoxia-inducible transcription in transient expression assays. These results support the role of HIF-1 as a mediator of adaptive responses to hypoxia that underlie cellular and systemic oxygen homeostasis.
TL;DR: In this article, the pyruvate kinase isoforms PKM1 and PKM2 are alternatively spliced products of the PKM 2 gene, and they are activated by hypoxia-inducible factor 1 (HIF-1).
Abstract: The pyruvate kinase isoforms PKM1 and PKM2 are alternatively spliced products of the PKM2 gene. PKM2, but not PKM1, alters glucose metabolism in cancer cells and contributes to tumorigenesis by mechanisms that are not explained by its known biochemical activity. We show that PKM2 gene transcription is activated by hypoxia-inducible factor 1 (HIF-1). PKM2 interacts directly with the HIF-1α subunit and promotes transactivation of HIF-1 target genes by enhancing HIF-1 binding and p300 recruitment to hypoxia response elements, whereas PKM1 fails to regulate HIF-1 activity. Interaction of PKM2 with prolyl hydroxylase 3 (PHD3) enhances PKM2 binding to HIF-1α and PKM2 coactivator function. Mass spectrometry and anti-hydroxyproline antibody assays demonstrate PKM2 hydroxylation on proline-403/408. PHD3 knockdown inhibits PKM2 coactivator function, reduces glucose uptake and lactate production, and increases O2 consumption in cancer cells. Thus, PKM2 participates in a positive feedback loop that promotes HIF-1 transactivation and reprograms glucose metabolism in cancer cells.
TL;DR: The results indicate that expression of this phosphotyrosine-binding form of pyruvate kinase is critical for rapid growth in cancer cells and Diverts glucose metabolites from energy production to anabolic processes when cells are stimulated by certain growth factors.
Abstract: Growth factors stimulate cells to take up excess nutrients and to use them for anabolic processes. The biochemical mechanism by which this is accomplished is not fully understood but it is initiated by phosphorylation of signalling proteins on tyrosine residues. Using a novel proteomic screen for phosphotyrosine-binding proteins, we have made the observation that an enzyme involved in glycolysis, the human M2 (fetal) isoform of pyruvate kinase (PKM2), binds directly and selectively to tyrosine-phosphorylated peptides. We show that binding of phosphotyrosine peptides to PKM2 results in release of the allosteric activator fructose-1,6-bisphosphate, leading to inhibition of PKM2 enzymatic activity. We also provide evidence that this regulation of PKM2 by phosphotyrosine signalling diverts glucose metabolites from energy production to anabolic processes when cells are stimulated by certain growth factors. Collectively, our results indicate that expression of this phosphotyrosine-binding form of pyruvate kinase is critical for rapid growth in cancer cells.
TL;DR: A pathway that regulates an alternative splicing event required for tumour cell proliferation is defined, establishing a relevance to cancer, and it is demonstrated that human gliomas overexpress c-Myc, PTB, hnRNPA1 and hn RNPA2 in a manner that correlates with PKM2 expression.
Abstract: When oxygen is abundant, quiescent cells efficiently extract energy from glucose primarily by oxidative phosphorylation, whereas under the same conditions tumour cells consume glucose more avidly, converting it to lactate. This long-observed phenomenon is known as aerobic glycolysis, and is important for cell growth. Because aerobic glycolysis is only useful to growing cells, it is tightly regulated in a proliferation-linked manner. In mammals, this is partly achieved through control of pyruvate kinase isoform expression. The embryonic pyruvate kinase isoform, PKM2, is almost universally re-expressed in cancer, and promotes aerobic glycolysis, whereas the adult isoform, PKM1, promotes oxidative phosphorylation. These two isoforms result from mutually exclusive alternative splicing of the PKM pre-mRNA, reflecting inclusion of either exon 9 (PKM1) or exon 10 (PKM2). Here we show that three heterogeneous nuclear ribonucleoprotein (hnRNP) proteins, polypyrimidine tract binding protein (PTB, also known as hnRNPI), hnRNPA1 and hnRNPA2, bind repressively to sequences flanking exon 9, resulting in exon 10 inclusion. We also demonstrate that the oncogenic transcription factor c-Myc upregulates transcription of PTB, hnRNPA1 and hnRNPA2, ensuring a high PKM2/PKM1 ratio. Establishing a relevance to cancer, we show that human gliomas overexpress c-Myc, PTB, hnRNPA1 and hnRNPA2 in a manner that correlates with PKM2 expression. Our results thus define a pathway that regulates an alternative splicing event required for tumour cell proliferation.
Related Topics (5)
Protein kinase A
68.4K papers, 3.9M citations
113.3K papers, 5.5M citations
124.9K papers, 4M citations
84.1K papers, 4.3M citations
122.6K papers, 8.2M citations