Different human TFIIIB activities direct RNA polymerase III transcription from TATA-containing and TATA-less promoters

Transcription initiation at RNA polymerase III promoters requires transcription factor IIIB (TFIIIB), an activity that binds to RNA polymerase III promoters, generally through protein-protein contacts with DNA binding factors, and directly recruits RNA polymerase III. Saccharomyces cerevisiae TFIIIB is a complex of three subunits, TBP, the TFIIB-related factor BRF, and the more loosely associated polypeptide beta ". Although human homologs for two of the TFIIIB subunits; the TATA box-binding protein TBP and the TFIIB-related factor BRF, have been characterized, a human homolog of yeast B " has not been described. Moreover, human BRF, unlike yeast BRF, is not universally required for RNA polymerase III transcription. In particular, it is not involved in transcription from the small nuclear RNA (snRNA)-type, TATA-containing, RNA polymerase III promoters. Here, we characterize two novel activities, a human homolog of yeast B ", which is required for transcription of both TATA-less and snRNA-type RNA polymerase III promoters, and a factor equally related to human BRF and TFIIB, designated BRFU, which is specifically required for transcription of snRNA-type RNA polymerase III promoters. Together, these results contribute to the definition of the basal RNA polymerase III transcription machinery and show that two types of TFIIIB activities, with specificities for different classes of RNA polymerase III promoters, have evolved in human cells

RNA aptamer delivery through intact human skin

It is generally recognised that only relatively small molecular weight (typically 100,000-fold) and aptamer integrity was confirmed using an oligonucleotide precipitation assay. A Th17 response was stimulated in freshly excised human skin resulting in significantly upregulated IL-17f, and 22; topical application of the IL-23 aptamer decreased both IL-17f and IL-22 by approximately 45% but did not result in significant changes to IL-23 mRNA levels, confirming that the aptamer did not globally suppress mRNA levels. This study demonstrates that very large molecular weight RNA aptamers can permeate across the intact human skin barrier to therapeutically relevant levels into both the epidermis and dermis and that the skin penetrating aptamer retains its biologically active conformational structure capable of binding to endogenous IL-23

The 'PUCE CAFE' Project: the First 15K Coffee Microarray, a New Tool for Discovering Candidate Genes correlated to Agronomic and Quality Traits

Background: Understanding the genetic elements that contribute to key aspects of coffee biology will have an impact on future agronomical improvements for this economically important tree. During the past years, EST collections were generated in Coffee, opening the possibility to create new tools for functional genomics. Results: The "PUCE CAFE" Project, organized by the scientific consortium NESTLE/IRD/CIRAD, has developed an oligo-based microarray using 15,721 unigenes derived from published coffee EST sequences mostly obtained from different stages of fruit development and leaves in Coffea Canephora (Robusta). Hybridizations for two independent experiments served to compare global gene expression profiles in three types of tissue matter (mature beans, leaves and flowers) in C. canephora as well as in the leaves of three different coffee species (C. canephora, C. eugenoides and C. arabica). Microarray construction, statistical analyses and validation by Q-PCR analysis are presented in this study. Conclusion: We have generated the first 15 K coffee array during this PUCE CAFE project, granted by Genoplante (the French consortium for plant genomics). This new tool will help study functional genomics in a wide range of experiments on various plant tissues, such as analyzing bean maturation or resistance to pathogens or drought. Furthermore, the use of this array has proven to be valid in different coffee species (diploid or tetraploid), drastically enlarging its impact for high-throughput gene expression in the community of coffee research

Research strategies for organizational history:a dialogue between historical theory and organization theory

If history matters for organization theory, then we need greater reflexivity regarding the epistemological problem of representing the past; otherwise, history might be seen as merely a repository of ready-made data. To facilitate this reflexivity, we set out three epistemological dualisms derived from historical theory to explain the relationship between history and organization theory: (1) in the dualism of explanation, historians are preoccupied with narrative construction, whereas organization theorists subordinate narrative to analysis; (2) in the dualism of evidence, historians use verifiable documentary sources, whereas organization theorists prefer constructed data; and (3) in the dualism of temporality, historians construct their own periodization, whereas organization theorists treat time as constant for chronology. These three dualisms underpin our explication of four alternative research strategies for organizational history: corporate history, consisting of a holistic, objectivist narrative of a corporate entity; analytically structured history, narrating theoretically conceptualized structures and events; serial history, using replicable techniques to analyze repeatable facts; and ethnographic history, reading documentary sources "against the grain." Ultimately, we argue that our epistemological dualisms will enable organization theorists to justify their theoretical stance in relation to a range of strategies in organizational history, including narratives constructed from documentary sources found in organizational archives. Copyright of the Academy of Management, all rights reserved

From Pabst to Pepsi: The Deinstitutionalization of Social Practices and the Creation of Entrepreneurial Opportunities

In this paper, we examine the dual role that social movement organizations can play in altering organizational landscapes by undermining existing organizations and creating opportunities for the growth of new types of organizations. Empirically, we investigate the impact of a variety of tactics employed by the Woman’s Christian Temperance Union (WCTU), the leading organizational representative of the American temperance movement, on two sets of organizations: breweries and soft drink producers. By delegitimating alcohol consumption, altering attitudes and beliefs about drinking, and promoting temperance legislation, the WCTU contributed to brewery failures. These social changes, in turn, created opportunities for entrepreneurs to found organizations producing new kinds of beverages by creating demand for alternative beverages, providing rationales for entrepreneurial action, and increasing the availability of necessary resources.Tolbert13_From_Pabst_to_Pepsi.pdf: 3878 downloads, before Oct. 1, 2020

RNA-targeted activators, but not DNA-targeted activators, repress the synthesis of short transcripts at the human immunodeficiency virus type 1 long terminal repeat.

The human immunodeficiency virus type 1 (HIV-1) promoter directs the synthesis of two types of RNA molecules: full-length transcripts, whose synthesis is activated by the viral activator Tat, and short transcripts, whose synthesis is dependent on the inducer of short transcripts (IST), a bipartite DNA element located in large part downstream of the HIV-1 transcriptional start site. In the absence of Tat, short transcripts constitute the large majority of the RNA molecules synthesized from the HIV-1 promoter. In the presence of Tat, synthesis of the short transcripts is repressed and synthesis of the full-length transcripts is activated. Tat is unique among transcriptional activators in acting through an RNA target, the TAR element. However, Tat has been shown to activate transcription from a DNA target when fused to the appropriate DNA binding domain, raising the question of why Tat has been directed to the RNA. Here we have compared the abilities of Tat and other RNA- and DNA-bound activators to stimulate transcription from the HIV-1 promoter. We show that DNA-targeted activators, including DNA-targeted Tat, activate the synthesis of both short and long transcripts, while RNA-targeted Tat and another RNA-targeted activator activate the synthesis of full-length transcripts but specifically repress that of short transcripts. The unique ability of RNA-targeted activators to down-regulate short transcript synthesis suggests that Tat is directed to the RNA specifically for the purpose of repressing short transcripts

Purification and characterization of FBI-1, a cellular factor that binds to the human immunodeficiency virus type 1 inducer of short transcripts.

The human immunodeficiency virus (HIV-1) promoter directs the synthesis of two classes of RNA molecules, short transcripts and full-length transcripts. The synthesis of short transcripts depends on a bipartite DNA element, the inducer of short transcripts (IST), located in large part downstream of the HIV-1 start site of transcription. IST does not require any viral product for function and is thought to direct the assembly of transcription complexes that are incapable of efficient elongation. Nothing is known, however, about the biochemical mechanisms that mediate IST function. Here, we report the identification and purification of a factor that binds specifically to the IST. This factor, FBI-1, recognizes a large bipartite binding site that coincides with the bipartite IST element. It is constituted at least in part by an 86-kDa polypeptide that can be specifically cross-linked to IST. FBI-1 also binds to promoter and attenuation regions of a number of cellular and viral transcription units that are regulated by a transcription elongation block. This observation, together with the observation that the binding of FBI-1 to IST mutants correlates with the ability of these mutants to direct IST function, suggests that FBI-1 may be involved in the establishment of abortive transcription complexes