Tumor pyruvate kinase M2:A promising molecular target of gastrointestinal cancer

Gastrointestinal(GI) cancer is one of the most common causes of cancer-related deaths worldwide.Tumor markers are valuable in detecting post-surgical recurrence or in monitoring response to chemotherapy.Pyruvate kinase isoform M2(PKM2),a glycolytic enzyme catalyzing conversion of phosphoenolpyruvate(PEP) to pyruvate,confers a growth advantage to the tumor cells and enables them to adapt to the tumor microenvironment.In this review,we have summarized current research on the expression and regulation of PKM2 in tumor cells,and its potential role in GI carcinogenesis and progression.Furthermore,we have also discussed the potential of PKM2 as a diagnostic and screening marker,and a therapeutic target in GI cancer.

Allogeneic hematopoietic stem cell transplantation in a 3-year-old boy with congenital pyruvate kinase deficiency: A case report

BACKGROUND The understanding regarding genetic variation,pathophysiology,and complications associated with pyruvate kinase deficiency(PKD)in red blood cells has been explained largely,and supportive treatment is currently the main management strategy.Etiotropic managements,including transplantation and genome editing,supplying for substitute dugs of the pyruvate kinase,are all under research.CASE SUMMARY We herein report a 3-year-old boy with severe transfusion-dependent PKD cured by unrelated identical peripheral blood stem cell transplantation(PBSCT).Hemoglobin was corrected to a normal level by gene correction after PBSCT,with no complication related to the transplantation.CONCLUSION Hematopoietic stem cell transplantation could be a substitute for transfusiondependent PKD.

Perioperative Changes of Erythrocyte Pyruvate Kinase Activity in Patients Undergoing Upper Abdominal Surgery

The purpose of this study is to investigate the perioperative changes of erythrocyte kinase (PK) activity. Thirty patients undergoing upper abdominal surgery were dirided into epidural blockade(EB) group or intra venous procaine balanced anesthesia(IPBA) group. The blood level of glucose increased significantly at 60 min after the beginning of operations in both groups. Blood glucose levels on the first postoperative day were significantly higher than the baselines in both groups [(8. 29±1. 5)vs (4. 8±0.18) mmol/L (P< 0.01) in EB, (6.36±0.33) vs (4. 55±0.18 ) mmol/L (P<0. 01 ) in IPBA]. The concentrations of 2, 3-DPG in RBC were not significantly changed in both groups. The PK activity in RBC decreased signficantly at 60 min after the end of operation in both groups. The PK activity levels on the first postoperative day were significantly lower than the baselines in both groups [(7. 59±1. 01) vs (11. 62±1. 06) IU/gHb (P<0. 05) in EB; (7. 75±0. 94) vs (11. 84 ±1.12) IU/gHb (P<0. 05 ) in IPBA]. The results suggest that the PK activity is decreased and the concentration of 2, 3-DPG remians unchanged under the hyperglycemic response to surgical stress, which may be related to an inhibition of glycolysis in RBC.

THE VALUE OF M_2-TYPE PYRUVATE KINASE IMMUNOASSAY IN THE DIAGNOSIS OF HEPATOCARCINOMA

By using Fab'-enzyme labelled immuno absorbent assay (ELISA) with sensitivity of picogram (10-12 g or pg) level, the M-type pyruvate kinase (M-PyK) in plasma was determined in 47 cases of normal healthy adult and 26 cases of hepatocellular carcinoma (HCC) patient. It was found that the upper limits of normal male and female were 1.1 and 1.4 ng/ml (expressed as M2-PyK) respectively. The plasma M-PyK in HCC patients was significant increased to above 5 times of average normal level, the positive rate was about 95%. In 6 cases of subclinical small hepatocarcinoma and 7 cases of HCC patient with normal serum alpha-fetal protein level, the mean plasma M-PyK value was also increased. Whereas the plasma M-PyK level in acute or chronic hepatitis and other benign diseases were normal. After the HCC being resected, the plasma M-PyK returned to normal, but increased again in the cases of recurrent hepatocarcinoma, suggesting that the increased M-PyK in the plasma of HCC patient was criginated from M2-type PyK in HCC tissue. Therefore, plasma M-PyK may become a new micro-level index of hepatocarcinoma.

Pyruvate kinase M in germ cells is essential for sperm motility and male fertility but not spermatogenesis

Male germ cells employ specific metabolic pathways throughout their developmental stages.In a previous study,we discovered heightened expression of pyruvate kinase M(PKM),a pivotal glycolytic enzyme,in spermatogonia and spermatids.To gain deeper insights into PKM's roles in spermatogenesis,sperm function,and male fertility,we engineered a conditional-knockout mouse model(Pkm-vkO mice)to selectively disrupt the Pkm gene within germ cells.Despite maintaining regular testicular histology and sperm morphology,the male Pkm-vko mice were infertility,characterized by significant impairments in sperm motility and adenosine triphosphate(ATP)generation.In addition,Pkm-null spermatozoa exhibited similar deficits in protein tyrosine phosphorylation linked to capacitation,as well as compromised performance in in vitro fertilization experiments.To conclude,PKM's presence is not obligatory for the entirety of spermatogenesis in male germ cells;however,it emerges as a critical factor influencing sperm motility and overall male fertility.

Bactericidal bissulfone B7 targets bacterial pyruvate kinase to impair bacterial biology and pathogenicity in plants

The prevention and control of rice bacterial leaf blight(BLB)disease has not yet been achieved due to the lack of effective agrochemicals and available targets.Herein,we develop a series of novel bissulfones and a novel target with a unique mechanism to address this challenge.The developed bissulfones can control Xanthomonas oryzae pv.oryzae(Xoo),and 2-(bis(methylsulfonyl)methylene)-N-(4-chlorophenyl)hydrazine-1-carboxamide(B_(7))is more effective than the commercial drugs thiodiazole copper(TC)and bismerthiazol(BT).Pyruvate kinase(PYK)in Xoo has been identified for the first time as the target protein of our bissulfone B_(7).PYK modulates bacterial virulence via a CRP-like protein(Clp)/two-component system regulatory protein(reg R)axis.The elucidation of this pathway facilitates the use of B_(7)to reduce PYK expression at the transcriptional level,block PYK activity at the protein level,and impair the interaction within the PYK-Clp-reg R complex via competitive inhibition,thereby attenuating bacterial biology and pathogenicity.This study offers insights into the molecular and mechanistic aspects underlying anti-Xoo strategies that target PYK.We believe that these valuable discoveries will be used for bacterial disease control in the future.

M2 pyruvate kinase enhances HIV-1 transcription from its long terminal repeat

Both thymocytes and tumor cells express M2 type isoenzyme of pyruvate kinase(M2PK),which is different from R type isoenzyme of pyruvate kinase(RPK)that is expressed in erythrocytes.In this report,the effect of RPK and M2PK on the transcription of human immunodeficiency virus type 1(HIV-1)was tested.The results indicated that M2PK could enhance HIV-1 transcription from its long terminal repeat(LTR)promoter,while RPK did not have such an effect.Specific down-regulation of M2PK could inhibit HIV-1 transcription from its LTR region.Furthermore,it was found that the C terminal region of M2PK is responsible for this effect.Collectively,the cellular factor M2PK that is expressed in thymocytes could facilitate the transcription of HIV-1.

External use of Ruyanneixiao cream efficiently blocks precancerous mammary lesions by interfering with glycolysis induced by inhibition of hypoxia inducible factor-1α, hexokinase 2, phosphofructokinase, and pyruvate kinase M2 expression

OBJECTIVE:To investigate the effect of Ruyanneixiao cream(RYNX) on the expression of hypoxia inducible factor-1α(HIF-1α), hexokinase 2(HK2),phosphofructokinase(PFK), and pyruvate kinase M2(PKM2) mRNA and protein in MCF-10 AT cells and in an animal model of precancerous mammary lesions.METHODS:Following treatment of MCF-10 AT cells with RYNX, tamoxifen(TAM) and YC-1 for 48 h,HIF-1α, HK2, PFK, PKM2 mRNA and protein expression was analyzed.Fifty female SD rats were randomly divided into control, model, TAM, and highand low-dose RYNX groups, with 10 rats in each group.A precancerous mammary lesion model was established for all groups except the control group.High-and low-dose RYNX cream containing TAM was coated on the breasts of animals in the corresponding groups.The rat mammary tissue was removed in the 10 th week and HIF-1α, HK2, PFK,PKM2 mRNA and protein was analyzed.RESULTS:In vitro analyses demonstrated that, compared with the matrix group, HIF-1α, HK2, PFK,PKM2 mRNA and protein expression was significantly decreased in the RYNX group(P < 0.05).Compared with the YC-1 + RYNX group, HK2, PFK,and PKM2 protein expression was significantly reduced in the RYNX group.HIF-1α, HK2, PFK, and PKM2 protein expression was increased significantly in the model group(P < 0.05) compared with the control group, while HIF-1α, HK2, PFK, and PKM2 mRNA and protein expression was significantly decreased in both the high-and low-dose RYNX groups(P < 0.05), with the effect being greater in the high-dose group.CONCLUSION:RYNX can block precancerous breast lesions by decreasing the expression of HK2,PFK, and PKM2 mRNA and protein via inhibition of HIF-1α mRNA and protein overexpression in a dose-dependent manner.

Exon-centric regulation of pyruvate kinase M alternative splicing via mutually exclusive exons

Alternative splicing of the pyruvate kinase M gene(PK-M)can generate the M2 isoform and promote aerobic glycolysis and tumor growth.However,the cancer-specific alternative splicing regulation of PK-M is not completely understood.Here,we demonstrate that PK-M is regulated by reciprocal effects on the mutually exclusive exons 9 and 10,such that exon 9 is repressed and exon 10 is activated in cancer cells.Strikingly,exonic,rather than intronic,cis-elements are key determinants of PK-M splicing isoform ratios.Using a systematic sub-exonic duplication approach,we identify a potent exonic splicing enhancer in exon 10,which differs from its homologous counterpart in exon 9 by only two nucleotides.We identify SRSF3 as one of the cognate factors,and show that this serine/arginine-rich protein activates exon 10 and mediates changes in glucose metabolism.These findings provide mechanistic insights into the complex regulation of alternative splicing of a key regulator of the Warburg effect,and also have implications for other genes with a similar pattern of alternative splicing.

OsPKpa_1 encodes a plastidic pyruvate kinase that affects starch biosynthesis in the rice endosperm

Pyruvate kinase （PK） is a key enzyme in glycolysis and carbon metabolism. Here, we isolated a rice （Oryza sativa） mutant, w59, with a white-core floury endosperm. Map-based cloning of w59 identified a mutation in OsPKpα1, which encodes a plastidic isoform of PK （PKp）. OsPKpα1 localizes to the amyloplast stroma in the developing endosperm, and the mutation of OsPKpα1 in w59 decreases the plastidic PK activity, resulting in dramatic changes to the lipid biosynthesis in seeds. The w59 grains were also characterized by a marked decrease in starch content. Consistent with a decrease in number and size of the w59 amyloplasts, large empty spaces were observed in the central region of the w59 endosperm, at the early grain-filling stage. Moreover, a phylogenetic analysis revealed four potential rice isoforms of OsPKp. We validated the in vitro PK activity of these OsPKps through reconstituting active PKp complexes derived from inactive individual OsPKps, revealing the heteromeric structure of rice PKps, which was further confirmed using a protein- protein interaction analysis. These findings suggest a functional connection between lipid and starch synthesis in rice endosperm amyloplasts.

Nanoscale metal organic frameworks inhibition of pyruvate kinase of M2

Tumor cells usually show abnormally high glycolysis rate to maintain the dynamic balance of energy.The growth of tumor cells can be affected by inhibiting the activity of pyruvate kinase(especially M2-type isozyme,PKM2),the rate limiting enzyme of glycolysis.This is helpful to the treatment of tumor.Herein,metal organic frameworks(MOFs) were found to inhibit the activity of PKM2.Nanoscale ZIF-8 was synthesized by standing and ultrasonic method,respectively.The ZIF-8 has the performance of inhibiting PKM2.Further research showed that the inhibition ability was attributed to zinc ion in ZIF-8.Interestingly,the IC_(50) of ZIF-8 on PKM2 was one percent of that of zinc ion.This novel enzyme inhibitor is expected to be used in cancer therapy.

Celastrol mitigates inflammation in sepsis by inhibiting the PKM2-dependent Warburg effect

Background: Sepsis involves life-threatening organ dysfunction and is caused by a dysregulated host response to infection. No specific therapies against sepsis have been reported. Celastrol(Cel) is a natural anti-inflammatory compound that shows potential against systemic inflammatory diseases. This study aimed to investigate the pharmacological activity and molecular mechanism of Cel in models of endotoxemia and sepsis.Methods: We evaluated the anti-inflammatory efficacy of Cel against endotoxemia and sepsis in mice and macrophage cultures treated with lipopolysaccharide(LPS). We screened for potential protein targets of Cel using activity-based protein profiling(ABPP). Potential targets were validated using biophysical methods such as cellular thermal shift assays(CETSA) and surface plasmon resonance(SPR). Residues involved in Cel binding to target proteins were identified through point mutagenesis, and the functional effects of such binding were explored through gene knockdown.Results: Cel protected mice from lethal endotoxemia and improved their survival with sepsis, and it significantly decreased the levels of pro-inflammatory cytokines in mice and macrophages treated with LPS(P <0.05). Cel bound to Cys424 of pyruvate kinase M2(PKM2), inhibiting the enzyme and thereby suppressing aerobic glycolysis(Warburg effect). Cel also bound to Cys106 in high mobility group box 1(HMGB1) protein, reducing the secretion of inflammatory cytokine interleukin(IL)-1β. Cel bound to the Cys residues in lactate dehydrogenase A(LDHA).Conclusions: Cel inhibits inflammation and the Warburg effect in sepsis via targeting PKM2 and HMGB1 protein.

Overexpressed PKM2 promotes macrophage phagocytosis and atherosclerosis

Background:The expression of pyruvate kinase muscle 2(PKM2)is augmented in macrophages of patients with atherosclerotic coronary artery disease.The role of PKM2 in atherosclerosis is to be determined.Methods:Global and myeloid cell-specific PKM2 knock-in mice with ApoE^(-/-)background(ApoE^(-/-),PKM2^(KI/KI)and Lyz2-cre,ApoE^(-/-),and PKM2^(flox/flox))were produced to evaluate the clinical significance of PKM2 in atherosclerosis development.Wild-type and PKM2 knock-in macrophages were isolated to assess the function of PKM2 in macrophage phagocytosis.Atherosclerotic mice were treated with PKM2 inhibitor shikonin(SKN)to evaluate the therapeutic potential of PKM2 suppression in atherosclerosis.Results:Oxidized low-density lipoprotein(oxLDL)upregulated PKM2 in macrophages.PKM2 in return promoted the uptake of oxLDL by macrophages.Overexpressed PKM2 accelerated atherosclerosis in mice.SKN blocked the progress of mouse atherosclerosis.Conclusions:PKM2 accelerates macrophage phagocytosis and atherosclerosis.Targeting PKM2 is a potential therapy for atherosclerosis.

Regulatory effects of evodiamine on glucose metabolism-related factors in CT26 colorectal carcinoma-bearing mice

Objective:To investigate the therapeutic effect of evodiamine(EVO)on the expression of hexokinase(HK),lactate dehydrogenase A(LDHA),and pyruvate kinase M(PKM),key enzymes of glycolysis,in the tumor-bearing mice after modeling mouse colon cancer cells(CT26).Methods:A tumor-bearing mouse model was generated by administering axillary injection of CT26 and intraperitoneally injecting different doses of EVO.The therapeutic effects of EVO on CT26 tumor-bearing mice were evaluated by measuring the thymus and spleen indices,tumor volume,tumor suppression rate,and other related indicators in the tumor tissues of mice in each group after the administration of EVO,in addition,histopathological changes in the tumor tissues of the mice in the groups were studied by hematoxylin and eosin staining.The expression levels of HK,LDHA,and PKM in the tumor tissues of each group of mice were measured by performing Western blot to investigate the mechanism of EVO treatment in CT26 tumor-bearing mice.Results:EVO inhibited the growth of tumors in CT26-bearing mice and enhanced their splenic and thymic indices.Western blot results showed that EVO reduced the expression levels of HK,LDHA,and PKM proteins in the tumor tissues of CT26 tumor-bearing mice.Conclusion:EVO has a therapeutic effect on CT26 tumor-bearing mice,and its mechanism of action may be related to the low expression of key enzymes HK,LDHA and PKM of glycolysis in tumor tissues.

Screening and Analysis of Proteins Interacting with TaPDK from Physiological Male Sterility Induced by CHA in Wheat

To further research the regulatory network of pyruvate dehydrogenase kinase （designated as TaPDK） in physiological male-sterility （PHYMS） of wheat induced by chemical hybridizing agent （CHA） SQ-1, an anther cDNA library was constructed, and the proteins interacting with TaPDK were screened via yeast two-hybrid technique. Subsequently, a few candidate proteins in nucleotide expression levels were detected by real-time quantitative PCR. Yeast-two hybrid screening was performed by mating yeast strain Y2HGold containing BD-TaPDK bait plasmid with yeast strain Y187 including anther cDNA library plasmid. Diploid yeast cells were plated on synthetic dropout nutrient medium （SD/-Ade/-His/-Leu/-Trp） （QDO）, and further were incubated on QDO medium containing AbA and X-α-Gal. The interactions between TaPDK and the proteins obtained from positive colonies were further confirmed by co-transformation validation. After plasmids DNA were extracted from blue colonies and sequenced, the sequences results were analyzed by bioinformatic methods. Finally, 24 colonies were obtained, including eight genes, namely non-specific lipid-transfer protein precursor （TanLTP）, polyubiquitin （TaPUbi）, glyceraldehyde-3-phosphate dehydrogenase, proliferating cell nuclear antigen （TaPCNA）, CBS domain containing protein （TaCBS）, actin, guanine nucleotide-binding protein beta subunit, chalcone synthase, and three new genes with unknown function. The results of quantitative RT-PCR showed that the expression levels of TanLTP, TaPUbi, and TaPCNA were obviously up-regulated in PHYMS anther, and TaCBS expression was only increased at the tricellular stage in PHYMS anther compared with in fertile lines. Whereas, the expression of TaPDK was obviously down-regulated in PHYMS lines. Collectively, these datas indicated that the majority of candidate proteins might be related to pollen abortion in PHYMS lines, which further suggested that TaPDK plays multiple roles in pollen development, besides participating in regulating pyruvate dehydrogenase complex activity.

Pyruvate dehydrogenase kinase is a negative regulator of interleukin-10 production in macrophages

Interleukin-10(IL-10)is the most potent anti-inflammatory cytokine in the body and plays an essential role in determining outcomes of many inflammatory diseases.Cellular metabolism is a critical determinant of immune cell function;however,it is currently unclear whether metabolic processes are specifically involved in IL-10 production.In this study,we aimed to find the central metabolic molecule regulating IL-10 production of macrophages,which are the main producers of IL-10.Transcriptomic analysis identified that metabolic changes were predominantly enriched in Kupffer cells at the early inflammatory phase of a mouse endotoxemia model.Among them,pyruvate dehydrogenase kinase(PDK)-dependent acute glycolysis was negatively involved in IL-10 production.Inhibition or knockdown of PDK selectively increased macrophage IL-10 expression.Mechanistically,PDK inhibition increased IL-10 production via profound phosphorylation of adenosine monophosphate(AMP)-activated protein kinase alpha 1(AMPKα1)by restricting glucose uptake in lipopolysaccharide-stimulated macrophages.AMPKα1 consequently activated p38 mitogen-activated protein kinase,c-Jun N-terminal kinase,and cyclic AMP-responsive element-binding protein to regulate IL-10 production.Our study uncovers a previously unknown regulatory mechanism of IL-10 in activated macrophages involving an immunometabolic function of PDK.

Deficiency of pyruvate dehydrogenase kinase 4 sensitizes mouse liver to diethylnitrosamine and arsenic toxicity through inducing apoptosis

Background and Aim:Pyruvate dehydrogenase kinase 4(PDK4)is a metabolism switch that regulates glucose oxidation and the tricarboxylic acid cycle(TCA cycle)in the mitochondria.Liver detoxifies xenobiotics and is constantly challenged by various injuries.This study aims at understanding how the loss of the metabolism regulator PDK4 contributes to liver injuries.Methods:Wild-type(WT)and Pdk4 knockout(Pdk4-/-)mice of different ages were examined for spontaneous hepatic apoptosis.Juvenile or adult mice of two genotypes were insulted by diethylnitrosamine(DEN),arsenic,galactosamine(GalN)/lipopolysaccharide(LPS),anti-CD95(Jo2)antibody or carbon tetrachloride(CCl4).Liver injury was monitored by blood biochemistry test.Apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)staining,poly(ADP-ribose)polymerase(PARP)cleavage,and caspase activity assay.Inflammatory response was determined by nuclear factor(NF)-kB activation and the activation of NF-kB target genes.Primary hepatocytes were isolated and cell viability was evaluated by MTS assay.Results:We showed that systematic Pdk4-/-in mice resulted in age-dependent spontaneous hepatic apoptosis.PDK4-deficiency increased the toxicity of DEN in juvenile mice,which correlated with a lethal consequence and massive hepatic apoptosis.Similarly,chronic arsenic administration induced more severe hepatic apoptosis in Pdk4-/-mice compared to WT control mice.An aggravated hepatic NF-kB mediated-inflammatory response was observed in Pdk4-/-mice livers.In vitro,Pdk4-deficient primary hepatocytes were more vulnerable to DEN and arsenic challenges and displayed higher caspase activity than wild type cells.Notably,hepatic PDK4 mRNA level was remarkably reduced during acute liver failure induced by GalN/LPS or Jo2 antibody.The diminished PDK4 expression was also observed in CCl4-induced acute liver injury.Conclusions:PDK4 may contribute to the protection from apoptotic injury in mouse liver.

The pyruvate dehydrogenase kinase 2(PDK2)is associated with conidiation,mycelial growth,and pathogenicity in Fusarium graminearum

Pyruvate dehydrogenase kinase(PDK)is a mitochondrial enzyme in a variety of eukaryotes,including the plant pathogen Fusarium graminearum.This enzyme can reduce the oxidation of glucose to acetyl-coA by phosphorylation and selectively inhibits the activity of pyruvate dehydrogenase(PDH),which is a kind of pyruvate dehydrogenase complex(PDC).In this study,we investigated the F.graminearum pyruvate dehydrogenase kinase encoded by FgPDK2,which is a homologue of Neurospora crassa PDK2.The disruption of the FgPDK2 gene led to several phenotypic defects including effects on mycelial growth,conidiation,pigmentation,and pathogenicity.The mutants also showed decreased resistance to osmotic stress and cell membrane/wall-damaging agents.The FgPDK2 deletion mutant exhibited reduced virulence.All of these defects were restored by genetic complementation of the mutant with the complete FgPDK2 gene.Overall,the results demonstrated that FgPDK2 is crucial for the growth of F.graminearum and can be exploited as a potential molecular target for novel fungicides to control Fusarium head blight caused by F.graminearum.

AAZ2 induces mitochondrial-dependent apoptosis by targeting PDK1 in gastric cancer

Drastic surges in intracellular reactive oxygen species(ROS)induce cell apoptosis,while most chemotherapy drugs lead to the accumulation of ROS.Here,we constructed an organic compound,arsenical N-(4-(1,3,2-dithiarsinan-2-yl)phenyl)acrylamide(AAZ2),which could prompt the ROS to trigger mitochondrial-dependent apoptosis in gastric cancer(GC).Mechanistically,by targeting pyruvate dehydrogenase kinase 1(PDK1),AAZ2 caused metabolism alteration and the imbalance of redox homeostasis,followed by the inhibition of phosphoinositide-3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)pathway and leading to the activation of B-cell lymphoma 2(Bcl2)/Bcl2-associated X(Bax)/caspase-9(Cas9)/Cas3 cascades.Importantly,our in vivo data demonstrated that AAZ2 could inhibit the growth of GC xenograft.Overall,our data suggested that AAZ2 could contribute to metabolic abnormalities,leading to mitochondrial-dependent apoptosis by targeting PDK1 in GC.

Structural insight into mechanisms for dynamic regulation of PKM2

Pyruvate kinase isoform M2 （PKM2） converts phospho- enolpyruvate （PEP） to pyruvate and plays an important role in cancer metabolism. Here, we show that post- translational modifications and a patient-derived muta- tion regulate pyruvate kinase activity of PKM2 through modulating the conformation of the PKM2 tetramer. We determined crystal structures of human PKM2 mutants and proposed a ＂seesaw＂ model to illustrate confor- mational changes between an inactive T-state and an active R-state tetramers of PKM2. Biochemical and structural analyses demonstrate that PKM2^Y105E （phos- phorylation mimic of Y105） decreases pyruvate kinase activity by inhibiting FBP （fructose 1,6-bisphosphate）- induced R-state formation, and PKM2K^3305Q （acetylation mimic of K305） abolishes the activity by hindering tet- ramer formation. K422R, a patient-derived mutation of PKM2, favors a stable, inactive T-state tetramer because of strong intermolecular interactions. Our study reveals the mechanism for dynamic regulation of PKM2 by post- translational modifications and a patient-derived muta- tion and provides a structural basis for further investi- gation of other modifications and mutations of PKM2 yet to be discovered.