Cell Signaling Technology

Product Pathways - Ca / cAMP / Lipid Signaling

PKA RI-α (D54D9) Rabbit mAb #5675

Applications Reactivity Sensitivity MW (kDa) Isotype
W IP H M R Hm Mk Endogenous 48 Rabbit IgG

Applications Key:  W=Western Blotting  IP=Immunoprecipitation
Reactivity Key:  H=Human  M=Mouse  R=Rat  Hm=Hamster  Mk=Monkey
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

PKA RI-α (D54D9) Rabbit mAb recognizes endogenous levels of total PKA RI-α protein. This antibody may also detect PKA RI-β and detects a background band of unknown origin at 32 kDa.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to residues surrounding Gln371 of human PKA RI-α protein.

Western Blotting

Western Blotting

Western blot analysis of extracts from MEF wild-type, MEF PKA RI-α (-/-) and HeLa cells using PKA RI-α (D54D9) Rabbit mAb. MEF wild-type and PKA RI-α (-/-) cells were kindly provided by Dr. Lawrence Kirschner, The Ohio State University, Columbus, OH.

Western Blotting

Western Blotting

Western blot analysis of extracts from SH-SY5Y and NIH/3T3 cells using PKA RI-α (D54D9) Rabbit mAb.

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. 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. The two R families exist in two isoforms, α and β (RI-α, RI-β, RII-α, and RII-β). 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 are 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 -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).

  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

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Companion Products

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

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