title: Protein Never in Mitosis Gene A Interacting-1 (PIN1) regulates degradation of inducible nitric oxide synthase in endothelial cells.
abstract: The peptidyl-proline isomerase Protein Never in Mitosis Gene A Interacting-1 (PIN1) increases the level or activity of several transcription factors that can induce the inducible nitric oxide (NO) synthase (iNOS). PIN1 can also regulate mRNA and protein turnover. Here, the effect of depletion of PIN1 on induction of iNOS by Escherichia coli endotoxin (LPS) and interferon-gamma (IFNgamma) in murine aortic endothelial cells (MAEC) was determined. Suppression of PIN1 by 85% with small hairpin RNA enhanced the induction of NO and iNOS protein by LPS-IFNgamma. There was no effect on induction of iNOS mRNA, suggesting a posttranscriptional effect. The enhanced levels of iNOS protein were functionally significant since LPS-IFNgamma was cytotoxic to MAEC lacking PIN1 but not MAEC harboring an inactive control construct, and because cytotoxicity was blocked by the NO synthase inhibitor N(omega)-nitro-L-arginine methyl ester. Consistent with posttranscriptional action, knockdown of PIN1 increased the stability of iNOS protein in cycloheximide-treated cells. Furthermore, loss of iNOS was blocked by the calpain inhibitor carbobenzoxy-valinyl-phenylalaninal but not by the selective proteasome inhibitor epoxomicin. Immunoprecipitation indicated that PIN1 can interact with iNOS. Pull down of iNOS with a wild-type glutathione-S-transferase-PIN1 fusion protein, but not with a mutant of the amino terminal phospho-(serine/threonine)-proline binding WW domain of PIN1, indicated that this domain mediates interaction. The results suggest that PIN1 associates with iNOS and can limit its induction by facilitating calpain-mediated degradation in MAEC.
authors.affiliation: Division of Pharmacology, The Ohio State University College of Pharmacy, 500 West Twelfth Ave., Columbus, OH 43210, USA.
authors.forename: Tongzheng
authors.initials: T
authors.lastname: Liu
authors.forename: Yongcheng
authors.initials: Y
authors.lastname: Huang
authors.forename: Rostislav I
authors.initials: RI
authors.lastname: Likhotvorik
authors.forename: Lakhu
authors.initials: L
authors.lastname: Keshvara
authors.forename: Dale G
authors.initials: DG
authors.lastname: Hoyt
mesh_terms: D000818:Animals; D002154:Calpain / Q000037:antagonists & inhibitors / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004151:Dipeptides / Q000494:pharmacology; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D029968:Escherichia coli Proteins; D007371:Interferon-gamma / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009842:Oligopeptides / Q000494:pharmacology; D019696:Peptidylprolyl Isomerase / Q000235:genetics / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors; D011485:Protein Binding; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013997:Time Factors
chemical_list: D004151:Dipeptides; D004791:Enzyme Inhibitors; D029968:Escherichia coli Proteins; D008070:Lipopolysaccharides; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D009842:Oligopeptides; D061988:Proteasome Inhibitors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; C440499:lipopolysaccharide, Escherichia coli O111 B4; D009569:Nitric Oxide; D007371:Interferon-gamma; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D002154:Calpain; D046988:Proteasome Endopeptidase Complex; D019696:Peptidylprolyl Isomerase; C000606850:Pin1 protein, mouse; C000606851:parvA protein, E coli; D019331:NG-Nitroarginine Methyl Ester; C058076:calpain inhibitor III; C078846:epoxomicin