Cell Signaling Technology

Product Pathways - Translational Control

p70 S6 Kinase Blocking Peptide #1205

Description

This peptide is used to block p70 S6 Kinase (49D7) Rabbit mAb #2708 reactivity.

Quality Control

The quality of the peptide was evaluated by reversed-phase HPLC and by mass spectrometry. The peptide blocks p70 S6 Kinase (49D7) Rabbit mAb #2708 signal in immunohistochemistry.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human breast carcinoma, using p70 S6 Kinase (49D7) Rabbit mAb #2708 in the presence of control peptide (left) or p70 S6 Kinase Blocking Peptide (right).

Applications

Use as a blocking reagent to evaluate the specificity of antibody reactivity in immunohistochemistry protocols.

Directions for Use

For immunohistochemistry, add twice the volume of peptide as volume of antibody used in 100ul total volume. Incubate for a minimum of 30 minutes prior to adding the entire volume to the slide. Recommended antibody dilutions can be found on the product data sheet.

Background

p70 S6 kinase is a mitogen activated Ser/Thr protein kinase that is required for cell growth and G1 cell cycle progression (1,2). p70 S6 kinase phosphorylates the S6 protein of the 40S ribosomal subunit and is involved in translational control of 5' oligopyrimidine tract mRNAs (1). A second isoform, p85 S6 kinase, is derived from the same gene and is identical to p70 S6 kinase except for 23 extra residues at the amino terminus, which encode a nuclear localizing signal (1). Both isoforms lie on a mitogen activated signaling pathway downstream of phosphoinositide-3 kinase (PI-3K) and the target of rapamycin, FRAP/mTOR, a pathway distinct from the Ras/MAP kinase cascade (1). The activity of p70 S6 kinase is controlled by multiple phosphorylation events located within the catalytic, linker and pseudosubstrate domains (1). Phosphorylation of Thr229 in the catalytic domain and Thr389 in the linker domain are most critical for kinase function (1). Phosphorylation of Thr389, however, most closely correlates with p70 kinase activity in vivo (3). Prior phosphorylation of Thr389 is required for the action of phosphoinositide 3-dependent protein kinase 1 (PDK1) on Thr229 (4,5). Phosphorylation of this site is stimulated by growth factors such as insulin, EGF and FGF, as well as by serum and some G-protein-coupled receptor ligands, and is blocked by wortmannin, LY294002 (PI-3K inhibitor) and rapamycin (FRAP/mTOR inhibitor) (1,6,7). Ser411, Thr421 and Ser424 lie within a Ser-Pro-rich region located in the pseudosubstrate region (1). Phosphorylation at these sites is thought to activate p70 S6 kinase via relief of pseudosubstrate suppression (1,2). Another LY294002 and rapamycin sensitive phosphorylation site, Ser371, is an in vitro substrate for mTOR and correlates well with the activity of a partially rapamycin resistant mutant p70 S6 kinase (8).

No product specific background information is currently available for this product.

  1. Pullen, N. and Thomas, G. (1997) FEBS Lett. 410, 78-82.
  2. Dufner, A. and Thomas, G. (1999) Exp. Cell Res. 253, 100-109.
  3. Weng, Q.P. et al. (1998) J. Biol. Chem. 273, 16621-16629.
  4. Pullen, N. et al. (1998) Science 279, 707-710.
  5. Alessi, D.R. et al. (1998) Curr. Biol. 8, 69-81.
  6. Polakiewicz, R.D. et al. (1998) J. Biol. Chem. 273, 23534-23541.
  7. Fingar, D.C. et al. (2002) Genes Dev. 16, 1472-1487.
  8. Saitoh, M. et al. (2002) J. Biol. Chem. 277, 20104-20112.

Application References

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Companion Products

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

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