The newt ribozyme is part of a riboprotein complex

Strand-specific transcripts of a satellite DNA of the newts, Notophthalmus and Triturus, are present in cells in monomeric and multimeric sizes. These transcripts undergo self-catalyzed, site-specific cleavage in vitro: the reaction requires Mg2+ and is mediated by a “hammerhead” domain. Transcription of the newt ribozyme appears to be performed by RNA polymerase II under the control of a proximal sequence element and a distal sequence element. In vitro, the newt ribozyme can cleave in trans an RNA substrate, suggesting that in vivo it might be involved in RNA processing events, perhaps as a riboprotein complex. Here we show that the newt ribozyme is in fact present as a riboprotein particle of about 12 S in the oocytes of Triturus. In addition, reconstitution experiments and gel-shift analyses show that a complex is assembled in vitro on the monomeric ribozyme molecules. UV cross-linking studies identify a few polypeptide species, ranging from 31 to 65 kDa, associated to the newt ribozyme with different affinities. Finally, we find that an appropriate oligoribonucleotide substrate is specifically cleaved by the riboproteic activity in S-100 ovary extracts.

Human AML1/MDS1/EVI1 fusion protein induces an acute myelogenous leukemia (AML) in mice: A model for human AML

The human t(3;21)(q26;q22) translocation is found as a secondary mutation in some cases of chronic myelogenous leukemia during the blast phase and in therapy-related myelodysplasia and acute myelogenous leukemia. One result of this translocation is a fusion between the AML1, MDS1, and EVI1 genes, which encodes a transcription factor of approximately 200 kDa. The role of the AML1/MDS1/EVI1 (AME) fusion gene in leukemogenesis is largely unknown. In this study, we analyzed the effect of the AME fusion gene in vivo by expressing it in mouse bone marrow cells via retroviral transduction. We found that mice transplanted with AME-transduced bone marrow cells suffered from an acute myelogenous leukemia (AML) 5–13 mo after transplantation. The disease could be readily transferred into secondary recipients with a much shorter latency. Morphological analysis of peripheral blood and bone marrow smears demonstrated the presence of myeloid blast cells and differentiated but immature cells of both myelocytic and monocytic lineages. Cytochemical and flow cytometric analysis confirmed that these mice had a disease similar to the human acute myelomonocytic leukemia. This murine model for AME-induced AML will help dissect the molecular mechanism of AML and the molecular biology of the AML1, MDS1, and EVI1 genes.

Posttranslational modification of TEL and TEL/AML1 by SUMO-1 and cell-cycle-dependent assembly into nuclear bodies

The E-26 transforming specific (ETS)-related gene, TEL, also known as ETV6, encodes a strong transcription repressor that is rearranged in several recurring chromosomal rearrangements associated with leukemia and congenital fibrosarcoma. TEL is a nuclear phosphoprotein that is widely expressed in all normal tissues. TEL contains a DNA-binding domain at the C terminus and a helix–loop–helix domain (also called a pointed domain) at the N terminus. The pointed domain is necessary for homotypic dimerization and for interaction with the ubiquitin-conjugating enzyme UBC9. Here we show that the interaction with UBC9 leads to modification of TEL by conjugating it to SUMO-1. The SUMO-1-modified TEL localizes to cell-cycle-specific nuclear speckles that we named TEL bodies. We also show that the leukemia-associated fusion protein TEL/AML1 is modified by SUMO-1 and found in the TEL bodies, in a pattern quite different from what we observe and report for AML1. Therefore, SUMO-1 modification of TEL could be a critical signal necessary for normal functioning of the protein. In addition, the modification by SUMO-1 of TEL/AML1 could lead to abnormal localization of the fusion protein, which could have consequences that include contribution to neoplastic transformation.

Il racconto breve nella letteratura bulgara moderna: Dejan Enev

Il progetto di tesi consiste in una proposta di traduzione di tre racconti brevi dello scrittore bulgaro Dejan Enev, introdotti da un excursus sulla short story nel panorama letterario in Bulgaria. Le proposte di traduzione sono accompagnate dal relativo commento, che si incentra soprattutto sulla difficoltà del traduttore nel decidere tra i vari approcci da adottare. Si fa un costante riferimento al concetto di perdita delle sfumature di significato delle parole e alla scelta di quale aspetto di esse preservare a discapito di altri.

(Table 1) Helium concentration in sediments

Two decades ago, Merrihue (1964) reported 3He/4He ratios of >10**-4 in ferromagnetic separates from a Pacific deep ocean red clay and concluded that the high ratio is due to extraterrestrial debris amounting to ~1% of the sediment. A decade later Krylov et al. (1973) compiled 3He/4He isotopic data on ocean sediments measured in the Soviet Union and observed that the 3He/4He ratio is generally higher in pelagic sediments where the sedimentation rate is lower. They suggested that the high 3He/4He ratio was attributable to extraterrestrial materials which were concentrated in slowly accumulating ocean floor. However, these important discoveries were almost completely neglected until we re-examined the problem. We have measured 39 sediments from 12 different sites, 10 sites from the western to central Pacific and two sites from the Atlantic Ocean. We find 3He/4He ratios >5 * 10**-5 for six sites, well above the values generally observed in common terrestrial materials. The very high 3He/4He ratio in the sediments is probably due to input of extraterrestrial materials. Input of stratospheric dust of <1 p.p.m., which corresponds to a fallout rate of ~2,000 tons per year, can explain the observation.

Additiones seu annotationes aureae, nouissimae ad decisiones S.R.C. Neap. Thomae Grammatici Regij Consiliarij /

Mode of access: Internet.

Decisiones sacri Consilii Neapolitani, a d. Matthaeo de Afflictis, iurisconsulto aetatis suae clarissimo, summa diligentia, parique iudicio collecta, nunc denuo maiore, quam hactenus unquam, cura studioque emendatae. Quibus nunc primum accesserunt d. Thomae Grammatici, eiusdem Neapolitani consilij senatoris dignissimi, noue, & hactenus nunquam conspectae annotationes, & toti operi plurimum loci, & studiosorum rationibus non parum commoditatis allaturae.

"Index verborum, rerum, ac sententiarum maximae insignium, in decisiones Neapolitanas d. Matthaei de Afflict. Parthenopaei, viri utriusque iuris citra controuersiam peritissimi ..." con port. y sign. propias.

Scritti di storia e critica; commenorazioni e programmi ...

Reprints form various publications.

Decisiones Sacri Consilii Neapolitani /

Index verborum, rerum ac sententiarum maxime insignium in Decisiones Neapolitanas D. Matthaei... uiri utriusque iuris citra controuersiarum peritissimi: tanta iam demum fide, studio, [et] industria collectus, ut uel ad copiam, uel uenustate[m] à quoquam nihil omnino iure possit desiderari, [136] p., con port. y sign. propias.

Un periodo delle istorie siciliane del secolo XIII /

Includes bibliographical references.

Liber maiolichinus de gestis Pisanorum illustribus;

Mode of access: Internet.

La guerra del vespro siciliano,

Mode of access: Internet.