Cell Signaling Technology

Product Pathways - Protein Stability

SignalSilence® Skp1 siRNA I #12514

Applications Reactivity
Transfection H (M) (R) (Mk)

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.

Western Blotting

Western Blotting

Western blot analysis of extracts from 293T cells, transfected with 100 nM SignalSilence® Control siRNA (Unconjugated) #6568 (-) or SignalSilence® Skp1 siRNA I (+), using Skp1 (D3J4N) Rabbit mAb #12248 (upper) or GAPDH (D16H11) XP® Rabbit mAb #5174 (lower). The Skp1 (D3J4N) Rabbit mAb confirms silencing of Skp1 expression, while the GAPDH (D16H11) XP® Rabbit mAb is used as a loading control.

Description

SignalSilence® Skp1 siRNA I from Cell Signaling Technology (CST) allows the researcher to specifically inhibit Skp1 expression using RNA interference, a method whereby gene expression can be selectively silenced through the delivery of double stranded RNA molecules into the cell. All SignalSilence® siRNA products from CST are rigorously tested in-house and have been shown to reduce target protein expression by western analysis.

Quality Control

Oligonucleotide synthesis is monitored base by base through trityl analysis to ensure appropriate coupling efficiency. The oligo is subsequently purified by affinity-solid phase extraction. The annealed RNA duplex is further analyzed by mass spectrometry to verify the exact composition of the duplex. Each lot is compared to the previous lot by mass spectrometry to ensure maximum lot-to-lot consistency.

Directions for Use

CST recommends transfection with 100 nM SignalSilence® Skp1 siRNA I 48 to 72 hours prior to cell lysis. For transfection procedure, follow protocol provided by the transfection reagent manufacturer. Please feel free to contact CST with any questions on use.

Each vial contains the equivalent of 100 transfections, which corresponds to a final siRNA concentration of 100 nM per transfection in a 24-well plate with a total volume of 300 μl per well.

Background

Ubiquitin can be covalently linked to many cellular proteins by the ubiquitination process, which targets proteins for degradation by the 26S proteasome. Three components are involved in the target protein-ubiquitin conjugation process. Ubiquitin is first activated by forming a thiolester complex with the activation component E1; the activated ubiquitin is subsequently transferred to the ubiquitin-carrier protein E2 and then from E2 to ubiquitin ligase E3 for final delivery to the epsilon-NH2 of the target protein lysine residue (1-3). Combinatorial interactions of different E2 and E3 proteins result in substrate specificity (4). Recent data suggests that activated E2 associates transiently with E3, and the dissociation is a critical step for ubiquitination (5). S phase kinase-associated protein 1 (Skp1) is a critical scaffold protein of the Skp1/CUL1/F-box (SCF) E3 ubiquitin ligase protein complex. Various F-box proteins (e.g., β-TrCP, Skp2) mediate an interaction with Skp1, via their defining and conserved domain of 40 amino acids, and with substrates to be ubiquitinated (e.g., β-catenin, p27) (4).

  1. Ciechanover, A. (1998) EMBO J. 17, 7151-60.
  2. Hochstrasser, M. (2000) Nat. Cell Biol. 2, E153-7.
  3. Hochstrasser, M. (2000) Science 289, 563-4.
  4. DeSalle, L.M. and Pagano, M. (2001) FEBS Lett. 490, 179-89.
  5. Deffenbaugh, A.E. et al. (2003) Cell 114, 611-22.

Application References

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Companion Products

Limited Use Label License, RNA interference: This product is licensed under European Patent 1144623 and foreign equivalents from Ribopharma AG, Kulmbach, Germany and is provided only for use in non-commercial research specifically excluding use (a) in drug discovery or drug development, including target identification or target validation, by or on behalf of a commercial entity, (b) for contract research or commercial screening services, (c) for the production or manufacture of siRNA-related products for sale, or (d) for the generation of commercial databases for sale to Third Parties. Information about licenses for these and other commercial uses is available from Ribopharma AG, Fritz-Hornschuch-Str. 9, D-95326 Kulmbach, Germany.

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

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