Arrestin-3 binds the MAP kinase JNK3?2 via multiple sites on both domains.

ABSTRACT: Although arrestins bind dozens of non-receptor partners, the interaction sites for most signaling proteins remain unknown. Here we report the identification of arrestin-3 elements involved in binding MAP kinase JNK3?2. Using purified JNK3?2 and MBP fusions containing separated arrestin-3 domains and peptides exposed on the non-receptor-binding surface of arrestin-3 we showed that both domains bind JNK3?2 and identified one element on the N-domain and two on the C-domain that directly interact with JNK3?2. Using in vitro competition we confirmed that JNK3?2 engages identified N-domain element and one of the C-domain peptides in the full-length arrestin-3. The 25-amino acid N-domain element has the highest affinity for JNK3?2, suggesting that it is the key site for JNK3?2 docking. The identification of elements involved in protein-protein interactions paves the way to targeted redesign of signaling proteins to modulate cell signaling in desired ways. The tools and methods developed here to elucidate the molecular mechanism of arrestin-3 interactions with JNK3?2 are suitable for mapping of arrestin-3 sites involved in interactions with other partners.

SUBMITTER: Zhan X 

PROVIDER: S-EPMC3936466 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature