title: S-nitrosylation of proteins at the leading edge of migrating trophoblasts by inducible nitric oxide synthase promotes trophoblast invasion.
abstract: Nitric oxide regulates many important cellular processes including motility and invasion. Many of its effects are mediated through the modification of specific cysteine residues in target proteins, a process called S-nitrosylation. Here we show that S-nitrosylation of proteins occurs at the leading edge of migrating trophoblasts and can be attributed to the specific enrichment of inducible nitric oxide synthase (iNOS/NOS2) in this region. Localisation of iNOS to the leading edge is co-incidental with a site of extensive actin polymerisation and is only observed in actively migrating cells. In contrast endothelial nitric oxide synthase (eNOS/NOS3) shows distribution that is distinct and non-colocalised with iNOS, suggesting that the protein S-nitrosylation observed at the leading edge is caused only by iNOS and not eNOS. We have identified MMP-9 as a potential target for S-nitrosylation in these cells and demonstrate that it co-localises with iNOS at the leading edge of migrating cells. We further demonstrate that iNOS plays an important role in promoting trophoblast invasion, which is an essential process in the establishment of a successful pregnancy.
authors.affiliation: Maternal and Fetal Health Research Centre, Division of Human Development, University of Manchester, St. Mary's Hospital, Manchester, UK.
authors.forename: Lynda K
authors.initials: LK
authors.lastname: Harris
authors.forename: James
authors.initials: J
authors.lastname: McCormick
authors.forename: Judith E
authors.initials: JE
authors.lastname: Cartwright
authors.forename: Guy St J
authors.initials: GS
authors.lastname: Whitley
authors.forename: Philip R
authors.initials: PR
authors.lastname: Dash
mesh_terms: D008841:Actin Cytoskeleton / Q000201:enzymology; D002460:Cell Line; D002465:Cell Movement; D003545:Cysteine / Q000378:metabolism; D003593:Cytoplasm / Q000201:enzymology; D006801:Humans; D020780:Matrix Metalloproteinase 9 / Q000032:analysis; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000032:analysis / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000032:analysis; D011499:Protein Processing, Post-Translational; D014327:Trophoblasts / Q000201:enzymology* / Q000502:physiology
chemical_list: D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D020780:Matrix Metalloproteinase 9; D003545:Cysteine