Conjugative transposition of transposon Tn916 has been shown to proceed by excision of the transposon in the donor strain and insertion of this element in the recipient. This process requires the product of the transposon int gene. We report here the surprising finding that the int gene is required only in the donor during conjugative transposition. We find that Tn916 int-1, whose int gene has been inactivated by an insertion mutation, transposes when a complementing wild-type int gene is present only in the donor during mating. When the int+ gene is present in a plasmid and is expressed from the spac promoter, conjugative transposition is very inefficient. However, when the Int+ function is supplied from a coresident distantly linked Tn916 tra-641 mutant, which is defective in a function required for conjugation, efficient conjugative transposition of Tn916 int-1 occurs. This suggests either that Int is not required for integration of Tn916 in gram-positive bacteria or that the protein is transferred from the donor to the transconjugant during the mating event. When the nonconjugative plasmid pAT145 was present in the donor, it was rarely cotransferred with Tn916. This suggests that complete fusion of mating cells is not common during conjugative transposition.
The int gene of bacteriophage P2 is the only viral gene necessary for the integration of P2 into the Escherichia coli host chromosome. This gene is situated between the phage attachment site, attP, and the repressor C gene, and is cotranscribed with C from the Pc promoter, towards attP. The Pc promoter is negatively controlled by the cox gene, which is the first gene of the early operon. In vitro recombination assays have indicated that in P2 an overproduction of Int is deleterious to the integrative process. We report here that the level of int expression is affected by several different mechanisms after transcriptional initiation. First, a partial transcription termination signal located between the int and C genes reduces the the transcriptional readthrough by about 30%. Second, the ribosome binding site and AUG codon of the int gene are located in a putative stem-loop structure, which may inhibit the initiation of translation. The nip1 mutation (a G to A substitution at the 22nd coding nucleotide of int which results in an increased efficiency of excision) is shown to relieve this inhibition, possible through the formation of an alternative mRNA secondary structure. However, the third and probably most important control of int expression in P2 seems to be that of posttranscriptional autoregulation. The binding site of the Int protein on int gene mRNA is shown to extend into the ribosome binding site of int...
The frequency with which int-1 and int-2 are rearranged in mouse mammary tumors by mouse mammary tumor virus (MMTV)-induced insertional mutagenesis is a consequence of the host genetic background. In 75% of C3H mammary tumors, int-1 is rearranged by MMTV insertion, whereas only 30% of BALB/cfC3H tumors contain a virus-induced rearrangement of int-1. This difference is significant (P less than 0.005) and could not be accounted for by the potentially additive effect of the genetically transmitted Mtv-1-encoded virus in C3H mice. Similarly, MMTV-induced rearrangement of the int-2 gene in mammary tumors of the R111 mouse strain (59%) occurred at a significantly (P less than 0.025) higher frequency than in BALB/cfR111 (25%) mammary tumors. Moreover, in BALB/cfR111 mammary tumors, there is evidence that rearrangement of int-1 and int-2 does not occur independently (P less than 0.025). These results suggest that the long history of inbreeding for high tumor incidence of C3H and R111 mouse strains has selected for the fixation of host mutations which either complement the action of the particular int gene or affect the sensitivity of specific subpopulations of mammary epithelium to infection by particular strains of MMTV.
Mouse mammary tumor virus (MMTV)-induced mammary adenocarcinomas can develop from several different premalignant precursors common in GR mice. Insertion mutagenesis of the mammary protooncogenes int-1 and int-2 was studied in this multistep system by analyzing samples from various stages of neoplastic development for novel int-1 and int-2 restriction fragments generated by MMTV provirus integration. int-1 and int-2 insertion mutations were observed in both premalignant lesions and malignant tumors. Some of the tumors with insertion mutations were experimentally derived from insertion mutation-free premalignant precursors. Each class of neoplasm examined had a characteristic frequency of int-1 and int-2 insertion mutations; however, no correspondence was observed between neoplasm morphology and mutation of either gene. These results indicate that insertion mutation of the int-1 and int-2 loci by MMTV provirus can be involved in the earliest identifiable stages of neoplastic development as well as during progression of premalignant lesions to tumors. Insertion mutation of int-1 and int-2 is therefore not stage specific in this system.
Mammary tumors in the GR mouse strain are caused by the expression of an endogenous provirus of the mouse mammary tumor virus (MMTV). The tumors progress from a hormone-dependent growth phase to autonomous, hormone-independent growth. We studied proviral insertion of MMTV at the int-1 and int-2 mammary oncogenes and the transcription of these genes during progression of a series of transplanted mammary tumors. During the hormone-dependent phase, 6 of 15 transplanted tumors were positive for proviral insertion at int-1 or int-2 or both. These tumors were oligoclonal with respect to the fraction of tumor cells with novel int-1 and int-2 restriction fragments and, apparently, consisted of different tumor cells with proviruses integrated at different oncogenes, including genes that are not yet known. In 10 tumors we detected expression of the int genes, indicating that most tumors contain minor populations of cells with int-1 or int-2 activations. On transplantation the tumors remained oligoclonal during the hormone-dependent phase. The hormone-independent variants of the tumors emerged as clonal outgrowths of cells with MMTV proviruses that could be traced back in the hormone-dependent tumors, but not always those of cells that were positive for insertions near int-1 or int-2. The maintenance of oligoclonality during the hormone-dependent phase suggests a growth-controlling effect of different populations of cells on each other. The clonal...
Bacteriophage lambda regulates the integration--excision reaction as a crucial aspect of the choice of pathway during lysogenic or lytic viral development. This control involves differential expression of the tightly linked, partially overlapping int and xis genes from two promoter sites: pI, positively regulated by cII/cIII proteins, and pL, positively regulated by N protein. After lambda infection, Int is synthesized from the pI transcript under cII regulation; however, very little Int is produced from the pL RNA because of the existence of a cis-acting regulatory element, sib, on the opposite side of the int gene from the pL promoter. Presumably sib serves to prevent unwanted synthesis of Int protein during the lytic response; the Int protein necessary for excisive recombination from a prophage can be supplied by pL transcription because sib is separated from int by prophage insertion. We have studied the effect of sib on nearby lambda genes by means of gel electrophoresis of labeled proteins from infected cells. Deletion of the sib region greatly enhances production of Int protein without substantial effect on Xis production; thus, sib regulation normally is highly specific for Int. When the sib region is moved past int and xis by deletion...
Site-specific recombination in bacteriophage λ is mediated by two phage-encoded proteins, Int and Xis. The structural genes encoding these proteins are located immediately to the right of their site of action, the phage att site. The DNA sequence for both the structural and regulatory regions of these genes has been determined. The location and reading frame of the xis gene were ascertained by sequence comparisons with the b538 deletion (that ends within xis) and with the xis6 amber mutation. From the DNA sequence Xis has a molecular weight of 8630; it is rich in basic amino acids with lysine and arginine comprising 25% of the 72 amino acids. Identification of the int reading frame was also unambiguous. From the DNA sequence, Int has a molecular weight of 40,330; of the 356 amino acids, 69 are basic and 46 are acidic. In the NH2-terminal portion of Int, 35% of the first 20 amino acids are basic. The site-specific recombination functions form a very tight cluster (att-int-xis) on the λ chromosome. The combined protein-encoding sequences of xis and int start 1347 base pairs, and terminate 84 base pairs, from the center of the phage att site. The two genes overlap one another by 20 base pairs (xis is upstream of int) and a possible means of controlling the relative synthesis rates of Int and Xis at the level of translation is proposed. Control at the level of transcription is also considered. The mutation intc226 leads to constitutive production of Int...
The murine int-1 proto-oncogene has been implicated in neural development and, when transcriptionally activated by mouse mammary tumor virus, contributes to the genesis of mammary tumors. To understand the function of the int-1 gene product in these processes, we have characterized the biochemical properties of int-1 protein expressed in a neuroendocrine cell line transfected with int-1 cDNA. Here we provide evidence that int-1 protein is secreted and associates with the cell surface. int-1 protein was very efficiently processed and secreted through the constitutive secretory pathway, although no int-1 protein could be immunoprecipitated from the culture medium. Treatment with suramin effectively released mature int-1 proteins into the culture fluid, which suggests that secreted int-1 protein associates with the cell surface or extracellular matrix. We have also shown directly, by radioiodination of intact cells and by surface antibody adsorption, that secreted int-1 proteins can be detected on the cell surface. These data support a model in which int-1 protein is secreted and functions locally in cell-to-cell signaling.
The int-1 proto-oncogene is a target for insertional activation of transcription by mouse mammary tumor virus in many murine mammary tumors. Whereas no expression of int-1 is seen in normal mammary tissue, int-1 RNA can be detected in normal mice in the neural tubes of midgestation embryos and in postmeiotic spermatocytes from adult testes. I report here the results of a study in which several different antibodies against synthetic peptides were produced and used to characterize the processing and secretion of int-1 protein. CHO cells were transfected with an inducible int-1 expression vector that was subsequently amplified to generate cell lines expressing very high levels of int-1 protein. Immunoprecipitation of [35S]cysteine-labeled cell lysates from these CHO cells yielded large amounts of four immature forms of int-1 glycoprotein (molecular weights of 36,000, 38,000, 40,000, and 42,000). A significant fraction of these int-1 species formed disulfide-linked multimers. Pulse-chase and glycosidase digestion studies demonstrated that some of the immature species of int-1 protein move through the secretory pathway and are processed to a mature heterogeneous glycoprotein with a molecular weight of about 44,000. Suramin treatment of the CHO cells during pulse-chase experiments increased the amount of 44...
Integrative recombination of bacteriophage lambda requires the action of the protein Int, the product of the phage int gene. In this paper we show that highly purified Int relaxes supercoiled DNA. The association of this nicking-closing activity with Int is shown by: (i) the cosedimentation of nicking-closing and recombination activities of purified Int, (ii) the parallel inactivation of the two activities in purified Int by both heat and a specific antiserum, and (iii) the alteration of both activities in crude extracts of a strain expressing a mutant int gene. The nicking-closing activity of Int functions in the absence of divalent cations and in the absence of an apparent source of chemical energy. The activity displays no obvious sequence specificity and is inhibited by Mg2+, spermidine, and single-stranded DNA. Int relaxes positive as well as negative supercoils. We present a model for the mechanism of strand exchange that describes how the nicking-closing activity of Int might be used during recombination.
The site-specific recombination at the attachment site for prophage integration might proceed by two general mechanisms: (1) a concerted reaction without a free intermediate; (2) a sequential mechanism differing from typical general recombination only by an inability of the cross-strand intermediate structure to migrate into the region of nonhomology adjacent to the attachment site. The blocked-migration, sequential model predicts frequent genetic exchange in the int xis region near the attachment site if Int-mediated recombination occurs between λ phage with homologous attachment sites. We find such additional int xis exchanges, but only at very low frequency (1% of the Int-mediated recombination). We conclude that the resolution point only rarely moves away from the initial crossover point specified by Int and, therefore, that the Int reaction is mainly concerted. We interpret the rare additional int xis recombinants as indicative of occasional branch migration from an initial Int-mediated crossover. The frequency of the rare int xis recombinants is not simply related to distance from the attachment site to an int- or xis- mutation, suggesting that the heteroduplex distance is often at least a gene in length. The frequency of these additional exchanges is also not a strong function of distance between two mutations; from this we conclude that the resolution to the observed recombinant structure in the sequential cases occurs often by mismatch repair. We have found no marked effect of mutations in the bacterial recA...
We have studied the interaction of highly purified Int protein with DNA restriction fragments from the lambda phage attachment site (attP) region. Two different DNA sequences are protected by bound Int protein against partial digestion by either pancreatic DNAase or neocarzinostatin. One Int binding site includes the 15 bp common core sequence (the crossover region for site-specific recombination) plus several bases of sequence adjoining the core in both the P and P′ arms. The second Int-protected site occurs 70 bp to the right of the common core in the P′ arm, just at the distal end of the sequence encoding Int protein. The two Int binding sites are of comparable size, 30–35 bp, but do not share any extensive sequence homology. The interaction of Int with the two sites is distinctly different, as defined by the observation that only the site in the P′ arm and not the site at the common core region is protected by Int in the face of challenge by the polyanion heparin. Restriction fragments containing DNA from the bacterial attachment site (attB) region exhibit a different pattern of interaction with Int. In the absence of heparin, a smaller (15 bp) sequence, which includes the left half of the common core region and the common core-B arm juncture...
The notions of int-soft filters, int-soft G-filters, regular int-soft filters, and MV-int-soft filters in residuated lattices are introduced, and their relations, properties, and characterizations are investigated. Conditions for an int-soft filter to be an int-soft G-filter, a regular int-soft filter, or an MV-int-soft filter are provided. The extension property for an int-soft G-filter is discussed. Finally, it is shown that the notion of an MV-int-soft filter coincides with the notion of a regular int-soft filter in BL-algebras.
La base de datos sobre la que se ha realizado este trabajo esta disponible en: http://hdl.handle.net/10481/24251; Tras realizar una b??squeda en la red, localizamos 287 fotograf??as de int??rpretes tomadas entre 1839 y 1914 en diecisiete fuentes en las que se identifica claramente al int??rprete, por su nombre o su oficio, en el t??tulo, en la ficha documental del archivo digital, en leyendas al pie o en inscripciones en el dorso de las fotograf??as. Para poder analizar y estudiar estas fotograf??as creamos una base de datos para clasificarlas por atributos biogr??ficos y t??cnicos. En esta comunicaci??n presentamos los resultados preliminares de un an??lisis iconogr??fico y contextual de las fotograf??as. Para ello nos fundamentaremos en la metodolog??a de la antropolog??a visual y situaremos las fotograf??as en su contexto hist??rico, social y geogr??fico investigando a los autores, a los propios int??rpretes retratados o cualquier otro dato significativo de la ficha documental.; As a result of a search on internet, we locate 287 photographs of interpreters taken between 1839 and 1914 in seventeen digital collections. These pictures clearly identify the interpreter by their name or their occupation, in the title, in legends in footnote...
Esta base de datos ha servido de apoyo para la comunicaci??n presentada en el 6?? Congreso Internacional AIETI (Asociaci??n Ib??rica de Estudios de Traducci??n e Interpretaci??n): traducimos desde el sur. Universidad de Las Palmas de Gran Canaria, 23-25 enero, 2013. [http://hdl.handle.net/10481/24236]; Base de datos que recoge cerca de 300 fotograf??as digitalizadas de int??rpretes tomadas entre 1839 y 1914. En la base de datos se recogen los siguientes datos: fot??grafo, fecha de la fotograf??a, tipo de foto y el archivo digital de donde se ha obtenido.
Comunicaci??n presentada el 19.04.2001 en el ???I Congreso Internacional sobre evaluaci??n de la calidad en interpretaci??n de conferencias???, celebrado en la Casa de la Cultura de Almu????car (Granada), del 19-21 de abril de 2001.; Cualquier int??rprete profesional conoce la importancia que tienen para nuestro trabajo aspectos como la preparaci??n del tema, la atenci??n y la concentraci??n. En determinadas situaciones la concentraci??n y la atenci??n, por ejemplo, pueden verse mermadas debido a factores externos y, por lo tanto, ajenos al int??rprete. En estas circunstancias, ser??a injusto atribuir al int??rprete en exclusiva la calidad o falta de calidad del resultado de su trabajo, la interpretaci??n.
Los equipos de int??rpretes para eventos de cierta relevancia suelen contratarse (al menos en Espa??a) a trav??s de Organizadores Profesionales de Congresos (OPC) o de empresas de traducci??n e interpretaci??n.
Al evaluar las expectativas de calidad y la calidad de la interpretaci??n, los te??ricos se han centrado fundamentalmente en las relaciones int??rprete/orador, int??rprete/discurso e int??rprete/receptor. Sin embargo, la relaci??n int??rprete/intermediario tambi??n proporciona una valiosa informaci??n en este sentido. Por eso...
Congresso ABIPTI, 2008: Os desafios regionais e a inovação no Brasil:os desafios para as instituições de pesquisa tecnológica.; Apresenta os resultados de um levantamento preliminar das relações do INT com o setor produtivo, identificando os principais setores industriais que interagem com a instituição.
Congresso ABIPTI, 2008: Os desafios regionais e a inovação no Brasil: os desafios para as instituições de pesquisa tecnológicas.; O presente trabalho apresenta o modelo de gestão de propriedade intelectual do INT, quanto a proteção patentária e mostra os impactos da Lei de Inovação na instituição utilizando como indicador depósito de patentes.
O int??rprete educacional difere de outros int??rpretes pela intencionalidade e pelo uso de recursos para favorecer a aprendizagem do seu p??blico alvo. Este atua em sala de aula na interpreta????o e tradu????o do conte??do ministrado pelo professor regente para a L??ngua Brasileira de Sinais (LIBRAS), e tamb??m na sala de recursos em turno contr??rio. O objetivo desse trabalho ?? relatar e discutir o papel pedag??gico do int??rprete no desempenho dos alunos surdos observado durante a realiza????o de um projeto de inicia????o cient??fica (PIC) em uma escola p??blica de Ensino M??dio em Sobradinho. Esse trabalho se trata de uma an??lise de caso idealizada durante a realiza????o de um projeto que visa estimular a elabora????o de sinais em LIBRAS para termos espec??ficos das Ci??ncias Biol??gicas por um grupo formado por alunos surdos e int??rprete. Durante cinco encontros o int??rprete pesquisou e trouxe conceitos sobre os termos biol??gicos sugeridos, consultou os pesquisadores sobre a veracidade e a qualidade das informa????es que seriam explicadas aos alunos surdos e estimulou os alunos a criarem novos sinais em LIBRAS pelo uso de recursos expositivos com desenhos, esquemas e v??deos. A atua????o do int??rprete possibilitou a elabora????o de sinais para dez termos espec??ficos em Biologia. A partir das observa????es...
O int??rprete educacional difere de outros int??rpretes pela intencionalidade e
pelo uso de recursos para favorecer a aprendizagem do seu p??blico alvo. Este atua
em sala de aula na interpreta????o e tradu????o do conte??do ministrado pelo professor
regente para a L??ngua Brasileira de Sinais (LIBRAS), e tamb??m na sala de recursos
em turno contr??rio. O objetivo desse trabalho ?? relatar e discutir o papel pedag??gico
do int??rprete no desempenho dos alunos surdos observado durante a realiza????o de
um projeto de inicia????o cient??fica (PIC) em uma escola p??blica de Ensino M??dio em
Sobradinho. Esse trabalho se trata de uma an??lise de caso idealizada durante a
realiza????o de um projeto que visa estimular a elabora????o de sinais em LIBRAS para
termos espec??ficos das Ci??ncias Biol??gicas por um grupo formado por alunos surdos
e int??rprete. Durante cinco encontros o int??rprete pesquisou e trouxe conceitos
sobre os termos biol??gicos sugeridos, consultou os pesquisadores sobre a
veracidade e a qualidade das informa????es que seriam explicadas aos alunos surdos
e estimulou os alunos a criarem novos sinais em LIBRAS pelo uso de recursos
expositivos com desenhos, esquemas e v??deos. A atua????o do int??rprete possibilitou
a elabora????o de sinais para dez termos espec??ficos em Biologia. A partir das