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PRMT1 directly methylates eNOS and thereby prevents Akt‐dependent serine1177 phosphorylation leading to decreased NO production
Author(s) -
Chicoine Louis G,
Pope Arthur J,
Han Zhaosheng,
Druhan Lawrence J,
Nelin Leif D,
Cardounel Arturo J
Publication year - 2013
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.27.1_supplement.724.13
Subject(s) - enos , phosphorylation , protein kinase b , nitric oxide , methylation , microbiology and biotechnology , endogeny , chemistry , endothelial nos , medicine , biology , biochemistry , nitric oxide synthase , endocrinology , gene
Diminished nitric oxide (NO) biosynthesis is implicated in the pathogenesis of cardiopulmonary disease. Much attention has focused on the production of endogenous eNOS inhibitors by protein‐arginine methyl transferase's (PRMT's). Our recent studies demonstrate that in addition to generating free methylarginines, PRMT's can directly methylate eNOS protein. We hypothesized that direct methylation of eNOS would decrease NO production by altering serine1177 phosphorylation. Silencing of PRMT1 in bovine pulmonary arterial endothelial cells (bPAEC) resulted in greater nitrite production than with scramble siRNA treatment. The levels of methylated eNOS by western blotting were substantially lower than in the control cells. Treatment of bPAEC with the PRMT1 siRNA resulted in greater levels of serine1177 phosphorylation and lower levels of Threonine495 phosphorylation of eNOS compared with scramble siRNA treatment. In studies using purified human eNOS addition of PRMT1 decreased NO production while addition of a biologically active Akt increased NO production compared to control. The addition of both PRMT1 and biologically active Akt resulted in NO production that was not different from control. Results from these studies implicate PRMT‐dependent methylation of eNOS as a novel post‐translational modification regulating eNOS activity through Akt‐dependent phosphorylation of serine1177.