Cell Signaling Technology

Product Pathways - MAPK Signaling

p44/42 MAP Kinase (L34F12) Mouse mAb #4696

Applications Reactivity MW (kDa) Source Isotype
W IHC-P IF-IC F H M R Mk Mi Pg Z 42, 44 Mouse IgG1

Applications Key:  W=Western Blotting  IHC-P=Immunohistochemistry (Paraffin)  IF-IC=Immunofluorescence (Immunocytochemistry)  F=Flow Cytometry
Reactivity Key:  H=Human  M=Mouse  R=Rat  Mk=Monkey  Mi=Mink  Pg=Pig  Z=Zebra Fish
Species enclosed in parentheses are predicted to react based on 100% sequence homology. Species cross-reactivity is determined by Western blot.

Specificity / Sensitivity

p44/42 MAP Kinase (L34F12) Mouse mAb detects endogenous levels of total p44/42 MAP kinase (Erk1/Erk2) protein. In some systems this antibody may recognize p42/Erk2 more readily than p44/Erk1. The antibody does not cross-react with JNK/SAPK or p38 MAP kinase.

Source / Purification

Monoclonal antibodies are produced by immunizing mice with a synthetic peptide (KLH-coupled) derived from the sequence of p42 MAP Kinase.

Western Blotting

Western Blotting

Western blot analysis of extracts from NIH/3T3, PC12 and COS cells, using p44/42 MAP Kinase (L34F12) Mouse mAb.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human breast carcinoma, using p44/42 MAP Kinase (L34F12) Mouse mAb in the presence of control peptide (left) or p44/42 MAP Kinase Blocking Peptide (#4696 Specific) #1245 (right).

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human colon carcinoma, showing cytoplasmic and nuclear localization, using p44/42 MAP Kinase (L34F12) Mouse mAb.


Flow Cytometry

Flow Cytometry

Flow cytometric analysis of Jurkat cells, U0126-treated (blue) or PMA-treated (green), using p44/42 MAP Kinase (L34F12) Mouse mAb compared to a nonspecific negative control antibody (red).

IF-IC

IF-IC

Confocal immunofluorescent analysis of NIH/3T3 cells, either U0126-treated (#9903, 10 μM, 2 hour, left) or PDGF-treated (#9909, 100 ng/ml, 20 min, right), using p44/42 MAP Kinase (L34F12) Mouse mAb (green). Actin filaments have been labeled with DY-554 phalloidin (red).

Background

Mitogen-activated protein kinases (MAPKs) are a widely conserved family of serine/threonine protein kinases involved in many cellular programs such as cell proliferation, differentiation, motility, and death. The p44/42 MAPK (ERK1/2) signaling pathway can be activated in response to a diverse range of extracellular stimuli including mitogens, growth factors, and cytokines (1-3) and is an important target in the diagnosis and treatment of cancer (4). Upon stimulation, a sequential three-part protein kinase cascade is initiated, consisting of a MAP kinase kinase kinase (MAPKKK), a MAP kinase kinase (MAPKK), and a MAP kinase. While multiple ERK1/2 MAP3Ks have been identified, including the Raf family, Mos, and Tpl2/Cot, MEK1 and MEK2 are the primary MAPKKs in this pathway (5,6). MEK1 and MEK2 activate ERK1/p44 and ERK2/p42 through phosphorylation of activation loop residues Thr202/Tyr204 and Thr185/Tyr187, respectively. Several downstream targets of ERK1/2 have been identified, including p90RSK (7) and the transcription factor Elk-1 (8,9). ERK1/2 are negatively regulated by a family of dual-specificity (Thr/Tyr) MAPK phosphatases, known as DUSPs or MKPs (10), along with MEK inhibitors such as U0126 and PD98059.

  1. Roux, P.P. and Blenis, J. (2004) Microbiol Mol Biol Rev 68, 320-44.
  2. Baccarini, M. (2005) FEBS Lett 579, 3271-7.
  3. Meloche, S. and Pouyssegur, J. (2007) Oncogene 26, 3227-39.
  4. Roberts, P.J. and Der, C.J. (2007) Oncogene 26, 3291-310.
  5. Rubinfeld, H. and Seger, R. (2005) Mol Biotechnol 31, 151-74.
  6. Murphy, L.O. and Blenis, J. (2006) Trends Biochem Sci 31, 268-75.
  7. Dalby, K.N. et al. (1998) J Biol Chem 273, 1496-505.
  8. Marais, R. et al. (1993) Cell 73, 381-93.
  9. Kortenjann, M. et al. (1994) Mol Cell Biol 14, 4815-24.
  10. Owens, D.M. and Keyse, S.M. (2007) Oncogene 26, 3203-13.

Application References

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