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c‐JUN N‐terminal kinase (JNK α1 ) binds and phosphorylates endothelial nitric oxide synthase at S116, differentiating it from p38 and ERK‐mediated regulation
Author(s) -
Caldara Amber,
Chrestensen Carol,
Salerno John,
McMurry Jonathan
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.724.21
Subject(s) - mapk/erk pathway , enos , phosphorylation , p38 mitogen activated protein kinases , kinase , chemistry , protein kinase a , microbiology and biotechnology , mitogen activated protein kinase , nitric oxide , nitric oxide synthase , biochemistry , biology , organic chemistry
Recent studies identified direct submicromolar affinity interactions of mitogen activated protein kinases (MAPK) p38 and ERK with endothelial nitric oxide synthase (eNOS) via a pentabasic sequence in the autoinhibitory insertion of eNOS that resembles a MAPK binding motif. The neuronal isoform, which lacks the pentabasic motif, did not bind MAPK. In the present study, eNOS binding by another MAPK, c‐Jun N‐terminal kinase (JNKα1), was examined using optical biosensing. Similar to p38 and ERK, high affinity binding was measured with a 31 nM KD as determined by fit to a one‐state global model. Rate constants were determined. kon was 4125 M‐1s‐1 and koff was 1.3 x 10‐4 s‐1. Immunoblotting identified phosphorylation at S116, contrasting with ERK, which phosphorylated S602, and p38, which phosphorylated both. Phosphorylation did not inhibit NO production nor alter the conformational manifold. The results underscore the importance the newly discovered noncanonical MAPK binding site on eNOS as a regulatory element bound by an array of MAPK. Further, they contribute to the emerging paradigm of eNOS as a junction of multiple signaling pathways