Transcending hybridity: recovering difference

Roland Hagenbüchle widmet sich in seinem einleitenden Essay der allgemeinen Kulturtheorie. Er zeichnet die Erfolgsgeschichte aber auch die Grenzen des Konzepts der Hybridität nach und argumentiert für eine neue Beschäftigung mit dem Ansatz der Differenz als Grundlage für die Notwendigkeit, trotz der Erkenntnis kultureller Relativität Entscheidungen treffen zu müssen

Short-lived AUF1 p42-binding mRNAs of RANKL and BCL6 have two distinct instability elements each.

Regulation of mRNA stability by RNA-protein interactions contributes significantly to quantitative aspects of gene expression. We have identified potential mRNA targets of the AU-rich element binding protein AUF1. Myc-tagged AUF1 p42 was induced in mouse NIH/3T3 cells and RNA-protein complexes isolated using anti-myc tag antibody beads. Bound mRNAs were analyzed with Affymetrix microarrays. We have identified 508 potential target mRNAs that were at least 3-fold enriched compared to control cells without myc-AUF1. 22.3% of the enriched mRNAs had an AU-rich cluster in the ARED Organism database, against 16.3% of non-enriched control mRNAs. The enrichment towards AU-rich elements was also visible by AREScore with an average value of 5.2 in the enriched mRNAs versus 4.2 in the control group. Yet, numerous mRNAs were enriched without a high ARE score. The enrichment of tetrameric and pentameric sequences suggests a broad AUF1 p42-binding spectrum at short U-rich sequences flanked by A or G. Still, some enriched mRNAs were highly unstable, as those of TNFSF11 (known as RANKL), KLF10, HES1, CCNT2, SMAD6, and BCL6. We have mapped some of the instability determinants. HES1 mRNA appeared to have a coding region determinant. Detailed analysis of the RANKL and BCL6 3'UTR revealed for both that full instability required two elements, which are conserved in evolution. In RANKL mRNA both elements are AU-rich and separated by 30 bases, while in BCL6 mRNA one is AU-rich and 60 bases from a non AU-rich element that potentially forms a stem-loop structure

A mitochondrial rRNA dimethyladenosine methyltransferase in Arabidopsis

S-adenosyl-l-methionine-dependent rRNA dimethylases mediate the methylation of two conserved adenosines near the 3′ end of the rRNA in the small ribosomal subunits of bacteria, archaea and eukaryotes. Proteins related to this family of dimethylases play an essential role as transcription factors (mtTFBs) in fungal and animal mitochondria. Human mitochondrial rRNA is methylated and human mitochondria contain two related mtTFBs, one proposed to act as rRNA dimethylase, the other as transcription factor. The nuclear genome of Arabidopsis thaliana encodes three dimethylase/mtTFB-like proteins, one of which, Dim1B, is shown here to be imported into mitochondria. Transcription initiation by mitochondrial RNA polymerases appears not to be stimulated by Dim1B in vitro. In line with this finding, phylogenetic analyses revealed Dim1B to be more closely related to a group of eukaryotic non-mitochondrial rRNA dimethylases (Dim1s) than to fungal and animal mtTFBs. We found that Dim1B was capable of substituting the E. coli rRNA dimethylase activity of KsgA. Moreover, we observed methylation of the conserved adenines in the 18S rRNA of Arabidopsis mitochondria; this modification was not detectable in a mutant lacking Dim1B. These data provide evidence: (i) for rRNA methylation in Arabidopsis mitochondria; and (ii) that Dim1B is the enzyme catalyzing this process

Living Together as an Intercultural Task

In his article, Living Together as an Intercultural Task, Roland Hagenbüchle explores the multi-faceted challenges we face in a multicultural world. At the same time, he refers the reader to a survey of recent studies indispensable to an informed investigation of this topic. After analyzing the various options for coming to terms with life in multicultural societies and paying special attention to John Rawls\u27 global model of justice as fairness and Martha C. Nussbaum\u27s concept of a good life (based on the capability model), Hagenbüchle advances the transcultural concept of personhood as a non-hegemonic starting point for a dialogic intercultural exchange. Surprisingly enough, the correspondences of values among otherwise widely differing cultures tend to converge in the form of a common human ethos, thus strengthening our trust in a peaceful coexistence of peoples and (hopefully) laying to rest the ghosts of an inevitable and close-to-apocalyptic clash of civilizations (Huntington)