Cell Signaling Technology
XP Monoclonal Antibody

Product Pathways - Metabolism

PKM2 (D78A4) XP® Rabbit mAb #4053

Applications Reactivity Sensitivity MW (kDa) Isotype
W IP IHC-P IF-IC H M R Mk Endogenous 60 Rabbit IgG

Applications Key:  W=Western Blotting  IP=Immunoprecipitation  IHC-P=Immunohistochemistry (Paraffin)  IF-IC=Immunofluorescence (Immunocytochemistry)
Reactivity Key:  H=Human  M=Mouse  R=Rat  Mk=Monkey
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

PKM2 (D78A4) XP® Rabbit mAb detects endogenous levels of total PKM2 protein.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to the sequence of human PKM2.

Western Blotting

Western Blotting

Western blot analysis of extracts from various cell lines and mouse skeletal muscle using PKM2 (D78A4) XP® Rabbit mAb (upper) or GAPDH (14C10) Rabbit mAb #2118.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human lung carcinoma using PKM2 (D78A4) XP® Rabbit mAb.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human lymphoma using PKM2 (D78A4) XP® Rabbit mAb.


IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human skeletal muscle using PKM2 (D78A4) XP® Rabbit mAb. Note the lack of staining in the skeletal muscle cells which do not express PKM2 while vessels within the tissue stain positively.

IF-IC

IF-IC

Confocal immunofluorescent analysis of A204 cells using PKM2 (D78A4) XP® Rabbit mAb (green). Blue pseudocolor = DRAQ5® #4084 (fluorescent DNA dye).

Background

Pyruvate kinase, a glycolytic enzyme, catalyses the conversion of phosphoenolpyruvate to pyruvate. In mammals, the M1 isoform (PKM1) is expressed in most adult tissues (1). The M2 isoform (PKM2), an alternatively-spliced variant of M1, is expressed during embryonic development (1). Studies found that cancer cells exclusively express PKM2 (1-3). PKM2 is shown to be essential for aerobic glycolysis in tumors (Warburg effect) (1). When the M2 isoform is switched to the M1 isoform, aerobic glycolysis is reduced and oxidative phosphorylation is increased in cancer cells (1). These cells also show decreased tumorigenicity in mouse xenografts (1). Recent studies show that the oncogenic forms of FGFR1 directly phosphorylate Tyr105 of PKM2 and thereby inhibit the formation of active tetrameric PKM2 (4). A PKM2 mutant found in cancer cells, in which Tyr105 is replaced by phenylalanine, leads to reduced cell proliferation in hypoxia and tumor growth in xenografts in nude mice (4). These findings suggest that the phosphorylation at Tyr105 is a critical switch for the metabolism in cancer cells that promotes tumor growth (4).

  1. Christofk, H.R. et al. (2008) Nature 452, 230-3.
  2. Mazurek, S. et al. (2005) Semin Cancer Biol 15, 300-8.
  3. Dombrauckas, J.D. et al. (2005) Biochemistry 44, 9417-29.
  4. Hitosugi, T. et al. (2009) Sci Signal 2, ra73.

Application References

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For Research Use Only. Not For Use In Diagnostic Procedures.

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