Details

Autor(en) / Beteiligte

• Wang, Tieli
• Arifoglu, Pinar
• Ronai, Ze'ev
• Tew, Kenneth D.

Titel

Glutathione S-transferase P1–1 (GSTP1–1) Inhibits c-Jun N-terminal Kinase (JNK1) Signaling through Interaction with the C Terminus

Ist Teil von

• The Journal of biological chemistry, 2001-06, Vol.276 (24), p.20999-21003

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2001

Quelle

MEDLINE

Beschreibungen/Notizen

• 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) (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 Kd 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.