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751.
Degot S Le Hir H Alpy F Kedinger V Stoll I Wendling C Seraphin B Rio MC Tomasetto C 《The Journal of biological chemistry》2004,279(32):33702-33715
MLN51 is a nucleocytoplasmic shuttling protein that is overexpressed in breast cancer. The function of MLN51 in mammals remains elusive. Its fly homolog, named barentsz, as well as the proteins mago nashi and tsunagi have been shown to be required for proper oskar mRNA localization to the posterior pole of the oocyte. Magoh and Y14, the human homologs of mago nashi and tsunagi, are core components of the exon junction complex (EJC). The EJC is assembled on spliced mRNAs and plays important roles in post-splicing events including mRNA export, nonsense-mediated mRNA decay, and translation. In the present study, we show that human MLN51 is an RNA-binding protein present in ribonucleo-protein complexes. By co-immunoprecipitation assays, endogenous MLN51 protein is found to be associated with EJC components, including Magoh, Y14, and NFX1/TAP, and subcellular localization studies indicate that MLN51 transiently co-localizes with Magoh in nuclear speckles. Moreover, we demonstrate that MLN51 specifically associates with spliced mRNAs in co-precipitation experiments, both in the nucleus and in the cytoplasm, at the position where the EJC is deposited. Most interesting, we have identified a region within MLN51 sufficient to bind RNA, to interact with Magoh and spliced mRNA, and to address the protein to nuclear speckles. This conserved region of MLN51 was therefore named SELOR for speckle localizer and RNA binding module. Altogether our data demonstrate that MLN51 associates with EJC in the nucleus and remains stably associated with mRNA in the cytoplasm, suggesting that its overexpression might alter mRNA metabolism in cancer. 相似文献
752.
Kedinger V Alpy F Tomasetto C Thisse C Thisse B Rio MC 《Gene expression patterns : GEP》2005,5(4):545-552
The tumor necrosis factor-associated factor 4 (TRAF4) is a particular member of the TRAF protein family since it is not involved in the Tumor Necrosis Factor (TNF) and Interleukin-1 (IL-1) signaling pathways. In the present study, we cloned two zebrafish orthologs of the human traf4, traf4a and traf4b, which are the first TRAFs described in zebrafish. During embryogenesis, traf4b expression is present in a weak ubiquitous manner. In contrast, traf4a exhibits a highly specific expression pattern in the sensorial and neural cells, and the somites of embryos. This gene is tightly regulated during embryogenesis. Together, our data show that traf4 is conserved during evolution, and traf4a is the zebrafish ortholog of traf4. 相似文献
753.
Simian immunodeficiency virus promoter exchange results in a highly attenuated strain that protects against uncloned challenge virus 总被引:1,自引:0,他引:1 下载免费PDF全文
Blancou P Chenciner N Ho Tsong Fang R Monceaux V Cumont MC Guétard D Hurtrel B Wain-Hobson S 《Journal of virology》2004,78(3):1080-1092
Among the many simian immunodeficiency virus (SIV) immunogens, only live attenuated viral vaccines have afforded strong protection to a natural pathogenic isolate. Since the promoter is crucial to the tempo of viral replication in general, it was reasoned that promoter exchange might confer a novel means of attenuating SIV. The core enhancer and promoter sequences of the SIV macaque 239nefstop strain (NF-κB/Sp1 region from −114 bp to mRNA start) have been exchanged for those of the human cytomegalovirus immediate-early promoter (CMV-IE; from −525 bp to mRNA start). During culture of the resulting virus, referred to as SIVmegalo, on CEMx174 or rhesus macaque peripheral blood mononuclear cells, deletions arose in distal regions of the CMV-IE sequences that stabilized after 1 or 2 months of culture. However, when the undeleted form of SIVmegalo was inoculated into rhesus macaques, animals showed highly controlled viremia during primary and persistent infection. Compared to parental virus infection in macaques, primary viremia was reduced by >1,000-fold to undetectable levels, with little sign of an increase of cycling cells in lymph nodes, CD4+ depletion, or altered T-cell activation markers in peripheral blood. Moreover, in contrast to wild-type infection in most infected animals, the nef stop mutation did not revert to the wild-type codon, indicating yet again that replication was dramatically curtailed. Despite such drastic attenuation, antibody titers and enzyme-linked immunospot reactivity to SIV peptides, although slower to appear, were comparable to those seen in a parental virus infection. When animals were challenged intravenously at 4 or 6 months with the uncloned pathogenic SIVmac251 strain, viremia was curtailed by ~1,000-fold at peak height without any sign of hyperactivation in CD4+- or CD8+-T-cell compartment or increase in lymph node cell cycling. To date, there has been a general inverse correlation between attenuation and protection; however, these findings show that promoter exchange constitutes a novel means to highly attenuate SIV while retaining the capacity to protect against challenge virus. 相似文献
754.
755.
Clough KB Thomas SS Fitoussi AD Couturaud B Reyal F Falcou MC 《Plastic and reconstructive surgery》2004,114(7):1743-1753
Patients with suboptimal results following breast conservative therapy are presenting more frequently to plastic surgeons as a difficult management problem. A three-type "cosmetic sequelae classification" is proposed to evaluate and manage these patients. From February of 1991 to November of 2001, 85 patients were treated for cosmetic sequelae of breast conservative therapy at the Institut Curie. The patients were followed up prospectively for 6 to 132 months (median, 33 months). They were assessed with regard to age, site and stage of tumor, type of initial breast conservative therapy undertaken, corrective operative procedures performed, complications, and cosmetic results. Forty-eight patients (56.5 percent) had type 1 cosmetic sequelae, 33 patients (38.8 percent) had type 2, and four patients (4.7 percent) had type 3. Type 1 was managed by contralateral symmetrizing procedures. Type 2 was the most difficult to manage by means of various procedures. Type 3 required mastectomy and immediate breast reconstruction. Type 1 had 97.6 percent good results compared with 82.7 percent for type 2. Three of the four type 3 patients had good results. This article reaffirms the validity of the cosmetic sequelae classification as a simple, practical guide for breast reconstructive surgeons. It discusses the various choices of reconstructive procedures available, the importance of preventing these cosmetic sequelae, and the role of the plastic surgeon in the planning of conservative treatment of breast cancers. 相似文献
756.
Isolation from sugar beet cell walls of arabinan oligosaccharides esterified by two ferulic acid monomers 下载免费PDF全文
Levigne SV Ralet MC Quéméner BC Pollet BN Lapierre C Thibault JF 《Plant physiology》2004,134(3):1173-1180
Side chains of sugar beet (Beta vulgaris) pectins, which are mainly composed of arabinose (Ara) and galactose (Gal) residues, are esterified by ferulic acid units. Enzymatic hydrolysis of beet cell walls yielded several feruloylated oligosaccharides, which were separated by hydrophobic interaction chromatography. Two new oligomers were isolated in the fraction eluted by 25:75 (v/v) ethanol:water. An arabinotriose and an arabinotetraose esterified by two ferulic acid residues were obtained, and their structure was elucidated by mass spectrometry. It is shown that feruloyl groups are linked to O-5 of Ara residues, in addition to the known O-2 position. This work establishes for the first time, to our knowledge, that two neighboring Ara units may be esterified by two ferulic acid units. This close proximity may have important biochemical implications. 相似文献
757.
Ral JP Derelle E Ferraz C Wattebled F Farinas B Corellou F Buléon A Slomianny MC Delvalle D d'Hulst C Rombauts S Moreau H Ball S 《Plant physiology》2004,136(2):3333-3340
Whereas Glc is stored in small-sized hydrosoluble glycogen particles in archaea, eubacteria, fungi, and animal cells, photosynthetic eukaryotes have resorted to building starch, which is composed of several distinct polysaccharide fractions packed into a highly organized semicrystalline granule. In plants, both the initiation of polysaccharide synthesis and the nucleation mechanism leading to formation of new starch granules are currently not understood. Ostreococcus tauri, a unicellular green alga of the Prasinophyceae family, defines the tiniest eukaryote with one of the smallest genomes. We show that it accumulates a single starch granule at the chloroplast center by using the same pathway as higher plants. At the time of plastid division, we observe elongation of the starch and division into two daughter structures that are partitioned in each newly formed chloroplast. These observations suggest that in this system the information required to initiate crystalline polysaccharide growth of a new granule is contained within the preexisting polysaccharide structure and the design of the plastid division machinery. 相似文献
758.
759.
Anastasia A. Abaeva Matthias Canault Yana N. Kotova Sergey I. Obydennyy Alena O. Yakimenko Nadezhda A. Podoplelova Vladimir N. Kolyadko Herve Chambost Aleksei V. Mazurov Fazoil I. Ataullakhanov Alan T. Nurden Marie-Christine Alessi Mikhail A. Panteleev 《The Journal of biological chemistry》2013,288(41):29621-29632
Strongly activated “coated” platelets are characterized by increased phosphatidylserine (PS) surface expression, α-granule protein retention, and lack of active integrin αIIbβ3. To study how they are incorporated into thrombi despite a lack of free activated integrin, we investigated the structure, function, and formation of the α-granule protein “coat.” Confocal microscopy revealed that fibrin(ogen) and thrombospondin colocalized as “cap,” a single patch on the PS-positive platelet surface. In aggregates, the cap was located at the point of attachment of the PS-positive platelets. Without fibrin(ogen) retention, their ability to be incorporated in aggregates was drastically reduced. The surface fibrin(ogen) was strongly decreased in the presence of a fibrin polymerization inhibitor GPRP and also in platelets from a patient with dysfibrinogenemia and a fibrinogen polymerization defect. In contrast, a fibrinogen-clotting protease ancistron increased the amount of fibrin(ogen) and thrombospondin on the surface of the PS-positive platelets stimulated with collagen-related peptide. Transglutaminases are also involved in fibrin(ogen) retention. However, platelets from patients with factor XIII deficiency had normal retention, and a pan-transglutaminase inhibitor T101 had only a modest inhibitory effect. Fibrin(ogen) retention was normal in Bernard-Soulier syndrome and kindlin-3 deficiency, but not in Glanzmann thrombasthenia lacking the platelet pool of fibrinogen and αIIbβ3. These data show that the fibrin(ogen)-covered cap, predominantly formed as a result of fibrin polymerization, is a critical mechanism that allows coated (or rather “capped”) platelets to become incorporated into thrombi despite their lack of active integrins. 相似文献
760.
Mathilde Causse Nelly Desplat Laura Pascual Marie-Christine Le Paslier Christopher Sauvage Guillaume Bauchet Aurélie Bérard Rémi Bounon Maria Tchoumakov Dominique Brunel Jean-Paul Bouchet 《BMC genomics》2013,14(1)