me1 inhibitor  (MedChemExpress)

Journal: PLOS ONE

Article Title: Real-time resolution studies of the regulation of lactate production by hexokinases binding to mitochondria in single cells

doi: 10.1371/journal.pone.0300150

Figure Lengend Snippet: Left panel. As we recently reported during low energy production by the glycolysis (hexokinase knock down) ME1 may transform pyruvate into malate and then OAA to activate the TCA cycle and may, as a result, transform lactate into pyruvate in the intermembrane space . Right panel. However, under most conditions the ME1 transforms malate, which exits the mitochondria, into pyruvate. In this case ME1 is part of what is known as the pyruvate/malate cycle . When the TCA cycle is inhibited the pyruvate that is generated in this process is no longer taken up by the mitochondria and will be transformed into lactate in the cytosol.

Article Snippet: The inhibitor of ME1 (ME1*) was purchased from (ProbeChem Biochemicals, Shanghai, China).

Techniques: Knockdown, Generated, Transformation Assay

Journal: PLOS ONE

Article Title: Real-time resolution studies of the regulation of lactate production by hexokinases binding to mitochondria in single cells

doi: 10.1371/journal.pone.0300150

Figure Lengend Snippet: Elevation of cytosolic pyruvate activates the TCA cycle, which then activates MAS to facilitate the transformation of lactate into pyruvate in the intermembrane space “phase 2”. This transformation of lactate into pyruvate is mediated by LDH and the production of NAD by MAS. Pyruvate is then transported into the matrix to further supply the TCA cycle. Inhibition of MAS due to inhibition of the electron transport chain by NaCN stops the transformation of lactate into pyruvate in the intermembrane space, resulting in a fast phase of lactate elevation (phase 4). As shown in Figs and this fast phase (phase 4), which is the reversal of phase 2, is followed, in the continued presence of NaCN, by a slower phase of lactate accumulation (phase 5). Two hypotheses may explain this slower phase 5. In one pyruvate may be directly transformed into lactate as the metabolism of pyruvate by mitochondria is blocked. Alternatively, it may involve first the reduction of OAA into malate as the TCA cycle is inhibited and then the transformation of malate into pyruvate, via ME1 in the cytoplasm (phase 5). Lastly pyruvate may be transformed into lactate in the cytoplasm. This schematic also illustrates the effect of the inhibitor of ME1 (ME1*). In this case the experiment was carried out in the absence of HKI, which allows for NaCN-evoked lactate production as a result of ME1 activity. Incubation with the inhibitor ME1* blocks this effect of HKI, thus preventing the development of phase 5. The activity of ME1 in the cytosol is one of the sources of NADPH production. Another source is G6PD the enzyme that mediates the first step of the PPP. The production of NADPH by G6PD may feed back onto ME1 to block the transformation of malate into pyruvate . As a corollary inhibition of G6PD by 6-AN, which prevents the formation of NADPH by PPP would relieve the inhibition of ME1.

Article Snippet: The inhibitor of ME1 (ME1*) was purchased from (ProbeChem Biochemicals, Shanghai, China).

Techniques: Transformation Assay, Inhibition, Activity Assay, Incubation, Blocking Assay

Journal: PLOS ONE

Article Title: Real-time resolution studies of the regulation of lactate production by hexokinases binding to mitochondria in single cells

doi: 10.1371/journal.pone.0300150

Figure Lengend Snippet: The upper panels A1 to A3 illustrate the effects of HEK cells incubation with the inhibitor of ME1 (ME1*). Panel A1 shows the changes in lactate levels in response to addition of NaCN in the presence of pyruvate, characterized by pronounced phases 4 and 5. In this experiment as in most other experiments, recordings were started in the presence of 5mM glucose. After reaching a steady state YFP/CFP ratio, which usually occurred after a couple of minutes, 2mM pyruvate was added to the perfusion solution. Then NaCN was added once the YFP/CFP ratio had reached a new steady state. This usually occurred within approximately 1min30s. For instance, in panel A1 NaCN was added after 1min34s in the presence of pyruvate + Glucose. In panel A2 NaCN was added after 1min15s in the presence of pyruvate + Glucose. These were typical time intervals needed to reach steady state before the addition of NaCN and lactate. Panel A2 shows the results of a similar addition of NaCN in the presence of pyruvate after incubation of the cells with ME1*. As previously shown the amplitude of phases 2 and 4 decreases by 40% on average . Similarly, the amplitude of phase 5 decreases almost by half, suggesting that inhibiting ME1 with ME1*, which blocks the transformation of malate into pyruvate, prevents the production of lactate evoked by NaCN-induced inhibition of the TCA cycle. Panel A3 shows a quantification of the inhibitory effects of ME1*on the amplitude of phase 5 with a mean phase 5 amplitude of 75.22 ±2.85 (n = 26) without ME1* and a mean amplitude of 35.99±2.32 (n = 38) after incubation with ME1*. The P value in this case was <0.0005. Panels B1 to B3 illustrate how inhibition of G6PD by 6-AN reverses the blocking effect of HKI overexpression (OE). Panel B1 illustrates how overexpression of HKI blocks both phase 2 and 4, which become only transient. There is no longer a phase 5 in this case (compare panels A1 and B1). Panel B2 shows how incubation with 6-AN reverses the inhibitory effect of HKI overexpression with strong recovery of phases 2, 4 and 5. Panel B3 shows a quantification of the effects of 6-AN on the amplitude of phase 5 with a mean amplitude of 22.25±2.80 (n = 37) in the absence of 6AN and 44.43±2.07 (n = 54) after incubation with 6AN. The P value was <0.0005 in this case.

Article Snippet: The inhibitor of ME1 (ME1*) was purchased from (ProbeChem Biochemicals, Shanghai, China).

Techniques: Incubation, Transformation Assay, Inhibition, Blocking Assay, Over Expression

Journal: Cell reports

Article Title: EGFR-phosphorylated GDH1 harmonizes with RSK2 to drive CREB activation and tumor metastasis in EGFR-activated lung cancer

doi: 10.1016/j.celrep.2022.111827

Figure Lengend Snippet:

Article Snippet: Malic enzyme inhibitor, ME1 , MedChemExpress , Cat#HY-124861; CAS: 522649-59-8.

Techniques: Microarray, Recombinant, Purification, Membrane, SYBR Green Assay, Viability Assay, Kinase Assay, Reverse Transcription, Transcription Factor Assay, Enzyme-linked Immunosorbent Assay, Multiplex Assay, Extraction, Isolation, shRNA, Sequencing, Plasmid Preparation, Software