title: Mechanism of action of interferon-tau in the uterus during early pregnancy.
abstract: Early pregnancy is maintained in ruminants through the actions of conceptus-derived interferon (IFN)-tau on the endometrium. IFN-tau alters uterine release of PGF2 alpha' which results in rescue of the corpus luteum and continued release of progesterone. The mechanism of action of IFN-tau includes inhibition of oestradiol receptors, consequent reduction in oxytocin receptors, activation of a cyclooxygenase inhibitor, and a shift in the PGs to favour PGE2 over PGF2 alpha' IFN-tau also induces several endometrial proteins that may be critical for survival of the developing embryo. One endometrial protein induced by pregnancy and IFN-tau has been identified as bovine granulocyte chemotactic protein-2 (bGCP-2). This chemotactic cytokine (chemokine) has been used as a marker to delineate IFN-tau from IFN-alpha responses in the endometrium. A second protein, called ubiquitin cross-reactive protein (UCRP), resembles a tandem ubiquitin repeat. UCRP becomes conjugated to cytosolic endometrial proteins in response to IFN-tau and pregnancy. Proteins conjugated to UCRP are either modulated or targeted for processing through the proteasome. The action of IFN-tau is mediated by induction of signal transducer and activator of transcription 1 (STAT-1), STAT-2 and interferon regulatory factor 1 (IRF-1) transcription factors. Induction of these transcription factors, the alpha chemokines and UCRP is the prelude to maternal recognition of pregnancy in ruminants.
authors.affiliation: Department of Animal Science, University of Wyoming, Laramie 82071, USA.
authors.forename: T R
authors.initials: TR
authors.lastname: Hansen
authors.forename: K J
authors.initials: KJ
authors.lastname: Austin
authors.forename: D J
authors.initials: DJ
authors.lastname: Perry
authors.forename: J K
authors.initials: JK
authors.lastname: Pru
authors.forename: M G
authors.initials: MG
authors.lastname: Teixeira
authors.forename: G A
authors.initials: GA
authors.lastname: Johnson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle / Q000378:metabolism*; D054426:Chemokine CXCL2; D054427:Chemokine CXCL6; D018925:Chemokines / Q000235:genetics / Q000378:metabolism; D019743:Chemokines, CXC / Q000235:genetics / Q000378:metabolism; D003340:Corpus Luteum Maintenance / Q000502:physiology*; D015237:Dinoprost / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D004622:Embryo, Mammalian / Q000378:metabolism*; D005260:Female; D007370:Interferon Type I / Q000378:metabolism*; D008969:Molecular Sequence Data; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000378:metabolism*; D011270:Pregnancy, Animal / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism; D011485:Protein Binding; D011959:Receptors, Estradiol / Q000378:metabolism*; D017471:Receptors, Interferon / Q000378:metabolism; D014452:Ubiquitins / Q000378:metabolism
chemical_list: D054426:Chemokine CXCL2; D054427:Chemokine CXCL6; D018925:Chemokines; D019743:Chemokines, CXC; C404915:Cxcl2 protein, mouse; D007370:Interferon Type I; D011257:Pregnancy Proteins; D011959:Receptors, Estradiol; D017471:Receptors, Interferon; D014452:Ubiquitins; C020947:interferon tau; D011374:Progesterone; D015237:Dinoprost; D015232:Dinoprostone