Glutathione S-transferase P1-1 (GSTP1-1) inhibits c-Jun N-terminal kinase (JNK1) signaling through interaction with the C terminus.
c-Jun N-terminal kinase (JNK)-mediated cell signaling pathways are regulated endogenously in part by protein-protein interactions with glutathione S-transferase P1-1 (GSTP1-1) (). Using purified recombinant proteins, combined with fluorescence resonance energy transfer technology, we have found that the C terminus of JNK is critical to the interaction with GSTP1-1. The apparent K(d) for full-length JNK was 188 nm and for a C-terminal fragment (residues 200-424) 217 nm. An N-terminal fragment (residues 1-206) did not bind to GSTP1-1. Increased expression of the C-terminal JNK fragment in a tetracycline-inducible transfected NIH3T3 cell line produced a concentration-dependent increase in the kinase activity of JNK under normal, unstressed growth conditions indicating a dominant-negative effect. This suggests that the fragment can compete with endogenous full-length functional JNK resulting in dissociation of the GSTP1-1-JNK interaction and concomitant JNK enzyme activation. By using an antibody to hemagglutinin-tagged C-JNK, a concentration-dependent co-immunoprecipitation of GSTP1-1 was achieved. These data provide evidence for direct interactions between the C-terminal of JNK and GSTP1-1 and a rationale for considering GSTP1-1 as a critical ligand-binding protein with a role in regulating kinase pathways.
Wang
T
T
Department of Pharmacology, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA.
Arifoglu
P
P
Ronai
Z
Z
Tew
K D
KD
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D004735:Energy Transfer; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase / Q000737:chemistry* / Q000378:metabolism*; D007527:Isoenzymes / Q000737:chemistry* / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases; D007700:Kinetics; D020935:MAP Kinase Signaling System / Q000502:physiology*; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013050:Spectrometry, Fluorescence; D014162:Transfection
D007527:Isoenzymes; D011994:Recombinant Proteins; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase; C496557:Gstp1 protein, mouse; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases