Cell Signaling Technology
XP Monoclonal Antibody

Product Pathways - Neuroscience

Non-phospho-STEP (Ser221) (D74H3) XP® Rabbit mAb #5659

Applications Reactivity Sensitivity MW (kDa) Isotype
W IP IF-F H M R Endogenous 46, 61 Rabbit IgG

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

Protocols

Specificity / Sensitivity

Non-phospho-STEP (Ser221) (D74H3) XP® Rabbit mAb detects endogenous levels of STEP61 protein only when dephosphorylated at Ser221 and of STEP46 protein when dephosphorylated at Ser49.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic nonphosphopeptide corresponding to residues surrounding Ser221 of human STEP61 protein.

Western Blotting

Western Blotting

Western blot analysis of extracts from rat brain and mouse brain using Non-phospho-STEP (Ser221) (D74H3) XP® Rabbit mAb. The nonphospho-specificity of the antibody was verified by preincubating the antibody without peptide, with STEP61 (Ser221) non-phosphopeptide, or with STEP61 (Ser221) phosphopeptide prior to incubation with the membrane.

IF-F

IF-F

Confocal immunofluorescent analysis of rat hippocampus (left) and striatum (right) using Non-phospho-STEP (Ser221) (D74H3) XP® Rabbit mAb (green) and α/β-Synuclein (Syn205) Mouse mAb #2644 (red). Blue pseudocolor = DRAQ5® #4084 (fluorescent DNA dye).

Background

Striatal enriched phosphatase (STEP, also known as PTPN5), is a protein tyrosine phosphatase expressed in dopaminoceptive neurons of the central nervous system (1). Alternative splicing produces the cytosolic STEP46 and the membrane-associated STEP61 isoforms of STEP. Dopamine activates D1 receptors and PKA, which in turn phosphorylate both isoforms of STEP. Phosphorylation of STEP61 occurs at Ser160 and Ser221, while STEP46 is phosphorylated at Ser49 (equivalent to Ser221 of STEP61) (2). NMDA-mediated activation of STEP is an important mechanism for regulation of Erk activity in neurons (3). Furthermore, STEP is involved in the regulation of both NMDAR and AMPAR trafficking (4,5). Due to its importance in cognitive function, STEP may play a role in Alzheimer's disease (1).

Activity of STEP61 is reduced upon phosphorylation of Ser221 (Ser49 of STEP46) due to lower affinity for its substrates (2).

  1. Braithwaite, S.P. et al. (2006) Trends Neurosci 29, 452-8.
  2. Paul, S. et al. (2000) J Neurosci 20, 5630-8.
  3. Paul, S. et al. (2003) Nat Neurosci 6, 34-42.
  4. Braithwaite, S.P. et al. (2006) Eur J Neurosci 23, 2847-56.
  5. Zhang, Y. et al. (2008) J Neurosci 28, 10561-6.

Application References

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Companion Products

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

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