Host specificity of Aceria centaureae (Nalepa), a candidate for biological control of Centaurea dίffusa De Lamarck

Κατά τη διάρκεια των ετών 1985 και 1986 έγιναν πειράματα υπαίθρου με το άκαρι Acerea centaureae το οποίο προκαλεί κηκίδες (στα φύλλα κυρίως) του φυτού Centaurea diffusa.Προσβεβλημένα από το άκαρι τμήματα του φυτού C. diffusa τέθηκαν σε επαφή με πειραματικά φυτά ορισμένων ειδών που βρίσκονταν σε κατάλληλο στάδιο ανάπτυξης. Ακολούθησαν περιοδικοί έλεγχοι για τη διαπίστωση ύπαρξης προσβολής από το άκαρι στα πειραματικά φυτά. Παρατηρήθηκε δημιουργία κηκίδων σε όλα τα πειραματικά φυτάίΓ. diffusa είτε αυτά ήταν ελληνικής είτε βορειοαμερικανικής προέλευσης, καθώς και σε μερικά από τα πειραματικά φυτά του είδους Centaurea solstitialis L. Καμία κηκίδα ή άλλο σύμπτωμα προσβολής από το άκαρι δεν παρατηρήθηκε στα άλλα πειραματικά είδη φυτών τα οποία ήταν τα ακόλουθα: Carthamus tinctorius L., Circium creticum (De Lamarck) D'Urvilleελληνικής προέλευσης και έξι (6) είδη του γένους Cirsium βορειοαμερικανικήςπροέλευσης (Η.Π.Α.), τα: cymosum (Greene) Howell, occidentale (Nutt) Jeps,pastrris Howell, andersonii (Gray) Petrak, brevistylum Crong, και undulatum (Nutt.) Spreng.Τα αποτελέσματα αυτά υποδηλώνουν ότι πιθανότατα το άκαρι Aceria centaureae είναι μάλλον ολιγοφάγο είδος το οποίο προσβάλλει μόνον ορισμένα ζιζάνια του είδους Centaurea και επομένως μπορεί να θεωρηθεί ως υποψήφιο είδος για τη βιολογική καταπολέμηση του C. diffusa στις Η.Π.Α. και στον Καναδά.Filed collected rosettes or twigs of Centaurea diffusa De Lamarck, infested by the gall mite Aceria centaureae, were fixed onto appropriately grown and planted test plants of ten different species in the area of Thessaloniki, Greece, in 1985 and 1986. The test plants were inspected for presence of galls and mites a few to several days after their contact with the infested twigs. Gall formation occurred on all of the Centaurea diffusa test plants, either of Greek or U.S. origin, and on some of the Centaurea solstitialis, L. test plants. No galls or other mite damage could be found on the other test plants, which were Carthamus tinctorius L. (safflower), Cirsiton creticion (De Lamarck) D’Urville, of local origin and six Cirsium species of U.S. origin, i.e. cymosum (Greene) J. T. Howell, occidentals (Nutt) Jeps., pastoris Howell, andersonii (Gray) Petrak, brevistylum Crong; and undulation (Nutt.) Spreng. These results suggest that A. centaureae most probably has a very restricted host plant range, feeding only on weedy Centaurea spp. Thus the mite should be considered as a possible candidate for biological control of diffuse knapweed in the U.S.A. and Canada

HIV-1 Tat complexes reveal subunit composition of active P-TEFb and stable association with 7SKsnRNP

International audiencen.

RAP80 Targets BRCA1 to Specific Ubiquitin Structures at DNA Damage Sites

Mutations affecting the BRCT domains of the breast cancer–associated tumor suppressor BRCA1 disrupt the recruitment of this protein to DNA double-strand breaks (DSBs). The molecular structures at DSBs recognized by BRCA1 are presently unknown. We report the interaction of the BRCA1 BRCT domain with RAP80, a ubiquitin-binding protein. RAP80 targets a complex containing the BRCA1-BARD1 (BRCA1-associated ring domain protein 1) E3 ligase and the deubiquitinating enzyme (DUB) BRCC36 to MDC1-γH2AX–dependent lysine6 - and lysine63-linked ubiquitin polymers at DSBs. These events are required for cell cycle checkpoint and repair responses to ionizing radiation, implicating ubiquitin chain recognition and turnover in the BRCA1-mediated repair of DSBs

BRCA1 is an essential regulator of heart function and survival following myocardial infarction

The tumour suppressor BRCA1 is mutated in familial breast and ovarian cancer but its role in protecting other tissues from DNA damage has not been explored. Here we show a new role for BRCA1 as a gatekeeper of cardiac function and survival. In mice, loss of BRCA1 in cardiomyocytes results in adverse cardiac remodelling, poor ventricular function and higher mortality in response to ischaemic or genotoxic stress. Mechanistically, loss of cardiomyocyte BRCA1 results in impaired DNA double-strand break repair and activated p53-mediated pro-apoptotic signalling culminating in increased cardiomyocyte apoptosis, whereas deletion of the p53 gene rescues BRCA1-deficient mice from cardiac failure. In human adult and fetal cardiac tissues, ischaemia induces double-strand breaks and upregulates BRCA1 expression. These data reveal BRCA1 as a novel and essential adaptive response molecule shielding cardiomyocytes from DNA damage, apoptosis and heart dysfunction. BRCA1 mutation carriers, in addition to risk of breast and ovarian cancer, may be at a previously unrecognized risk of cardiac failure

Tumor BRCA1, RRM1 and RRM2 mRNA Expression Levels and Clinical Response to First-Line Gemcitabine plus Docetaxel in Non-Small-Cell Lung Cancer Patients

Overexpression of RRM1 and RRM2 has been associated with gemcitabine resistance. BRCA1 overexpression increases sensitivity to paclitaxel and docetaxel. We have retrospectively examined the effect of RRM1, RRM2 and BRCA1 expression on outcome to gemcitabine plus docetaxel in advanced non-small-cell lung cancer (NSCLC) patients. = 0.001). Low BRCA1 expression was the only factor significantly associated with longer time to progression in 31 patients receiving cisplatin-based second-line therapy.The mRNA expression of BRCA1, RRM1 and RRM2 is potentially a useful tool for selecting NSCLC patients for individualized chemotherapy and warrants further investigation in prospective studies

The Translation Initiation Factor 3f (eIF3f) Exhibits a Deubiquitinase Activity Regulating Notch Activation

The translation initiation factor complex eIF3f has an intrinsic deubiquitinase activity and regulates the Notch signaling pathway

Thiolutin is a zinc chelator that inhibits the Rpn11 and other JAMM metalloproteases

Thiolutin is a disulfide-containing antibiotic and anti-angiogenic compound produced by Streptomyces. Its biological targets are not known. We show that reduced thiolutin is a zinc chelator that inhibits the JAB1/MPN/Mov34 (JAMM) domain–containing metalloprotease Rpn11, a deubiquitinating enzyme of the 19S proteasome. Thiolutin also inhibits the JAMM metalloproteases Csn5, the deneddylase of the COP9 signalosome; AMSH, which regulates ubiquitin-dependent sorting of cell-surface receptors; and BRCC36, a K63-specific deubiquitinase of the BRCC36-containing isopeptidase complex and the BRCA1–BRCA2-containing complex. We provide evidence that other dithiolopyrrolones also function as inhibitors of JAMM metalloproteases