Product Pathways - Ca / cAMP / Lipid Signaling

SignalSilence® PKA C-alpha siRNA #6406

• pathway
• more info
• application references
• datasheet PDF
• MSDS PDF
• protocols

Directions for Use

CST recommends transfection with 100 nM SignalSilence® PKA C-alpha siRNA 48 hours prior to cell lysis. See protocol for transfection procedure.

Background

The second messenger cyclic AMP (cAMP) activates cAMP-dependent protein kinase (PKA or cAPK) in mammalian cells and controls many cellular mechanisms such as gene transcription, ion transport and protein phosphorylation (1). Inactive PKA is a heterotetramer composed of a regulatory subunit (R) dimer and a catalytic subunit (C) dimer, and in this inactive state, the pseudosubstrate sequences on the R subunits block the active sites on the C subunits. Three C subunit isoforms (C-α, C-β and C-γ) and two families of regulatory subunits (RI and RII) with distinct cAMP binding properties have been identified. Within the two R families, two isoforms, α and β (RI-α, RI-β, RII-α and RII-β) exist. Upon binding of cAMP to the R subunits, the autoinhibitory contact is eased and active monomeric C subunits are released. PKA shares substrate specificity with Akt (PKB) and PKC, which is characterized by an arginine at position -3 relative to the phosphorylated serine or threonine residue (2). Substrates that present this consensus sequence and have been shown to be phosphorylated by PKA are Bad (Ser155), CREB (Ser133) and GSK-3 (GSK-3α Ser21 and GSK-3β Ser9) (3-5). In addition, combined knock-down of PKA C-α and C-β blocks cAMP-mediated phosphorylation of Raf (Ser43 and Ser259) (6). Autophosphorylation and phosphorylation by PDK-1 are two known mechanisms responsible for phosphorylation of the C subunit at Thr197 (7).

Small interfering RNA (siRNA) has been used to specifically silence PKA C-alpha in NIH/3T3 cells (6).

1. Montminy, M. (1997) Annu. Rev. Biochem. 66, 807-822.
2. Dell'Acqua, M.L. and Scott, J.D. (1997) J. Biol. Chem. 272, 12881-12884.
3. Tan, Y. et al. (2000) J. Biol. Chem. 275, 25865-25869.
4. Gonzalez, G.A. and Montminy, M.R. (1989) Cell 59, 675-680.
5. Fang, X. et al. (2000) Proc. Natl. Acad. Sci. USA 97, 11960-11965.
6. Dumaz, N. and Marais, R. (2003) J. Biol. Chem. 278, 29819 -29823.
7. Moore, M.J. et al. (2002) J. Biol. Chem. 277, 47878-47884.

Application References

Have you published research involving the use of our products? If so we'd love to hear about it. Please let us know!

Companion Products

• 4781 Phospho-PKA C (Thr197) Antibody
• 4782 PKA C-α Antibody
• 6405 SignalSilence® PKA C-alpha siRNA Kit
• 6201 SignalSilence® Control siRNA (Fluorescein Conjugate)
• 9272 Akt Antibody
• 7071 Phototope^®-HRP Western Blot Detection System, Anti-rabbit IgG, HRP-linked Antibody
• 7074 Anti-rabbit IgG, HRP-linked Antibody
• 7720 Prestained Protein Marker, Broad Range (Premixed Format)
• 7727 Biotinylated Protein Ladder Detection Pack
• 7003 20X LumiGLO^® Reagent and 20X Peroxide

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.

This product is for in vitro research use only and is not intended for use in humans or animals. This product is not intended for use as therapeutic or in diagnostic procedures.