Jugendliche Konsummuster in Deutschland, Südkorea, Polen - Wie rational konsumieren Jugendliche?

Lange E. Jugendliche Konsummuster in Deutschland, Südkorea, Polen - Wie rational konsumieren Jugendliche? In: Villanyi D, Witte MD, Sander U, eds. Globale Jugend und Jugendkulturen. Aufwachsen im Zeitalter der Globaliiserung. Weinheim und München: Juventa; 2007: 233-253

"Die Globalisierung reißt die Welt noch weiter auseinander" - Globalisierungskritischer Jugendprotest in Deutschland

Möller R, Sander U, Schäfer A, Villanyi D, Witte MD. "Die Globalisierung reißt die Welt noch weiter auseinander" - Globalisierungskritischer Jugendprotest in Deutschland. In: Schäfer A, Witte MD, Sander U, eds. Kulturen jugendlichen Aufbegehrens. Jugendprotest und soziale Ungleichheit. Weinheim, Basel: Beltz Juventa; 2011

Co-translational assembly of proteasome subunits in NOT1-containing assemblysomes

The assembly of large multimeric complexes in the crowded cytoplasm is challenging. Here we reveal a mechanism that ensures accurate production of the yeast proteasome, involving ribosome pausing and co-translational assembly of Rpt1 and Rpt2. Interaction of nascent Rpt1 and Rpt2 then lifts ribosome pausing. We show that the N-terminal disordered domain of Rpt1 is required to ensure efficient ribosome pausing and association of nascent Rpt1 protein complexes into heavy particles, wherein the nascent protein complexes escape ribosome quality control. Immunofluorescence and in situ hybridization studies indicate that Rpt1- and Rpt2-encoding messenger RNAs co-localize in these particles that contain, and are dependent on, Not1, the scaffold of the Ccr4-Not complex. We refer to these particles as Not1-containing assemblysomes, as they are smaller than and distinct from other RNA granules such as stress granules and GW- or P-bodies. Synthesis of Rpt1 with ribosome pausing and Not1-containing assemblysome induction is conserved from yeast to human cells

The Not5 Subunit of the Ccr4-Not Complex Connects Transcription and Translation

Recent studies have suggested that a sub-complex of RNA polymerase II composed of Rpb4 and Rpb7 couples the nuclear and cytoplasmic stages of gene expression by associating with newly made mRNAs in the nucleus, and contributing to their translation and degradation in the cytoplasm. Here we show by yeast two hybrid and co-immunoprecipitation experiments, followed by ribosome fractionation and fluorescent microscopy, that a subunit of the Ccr4-Not complex, Not5, is essential in the nucleus for the cytoplasmic functions of Rpb4. Not5 interacts with Rpb4; it is required for the presence of Rpb4 in polysomes, for interaction of Rpb4 with the translation initiation factor eIF3 and for association of Rpb4 with mRNAs. We find that Rpb7 presence in the cytoplasm and polysomes is much less significant than that of Rpb4, and that it does not depend upon Not5. Hence Not5-dependence unlinks the cytoplasmic functions of Rpb4 and Rpb7. We additionally determine with RNA immunoprecipitation and native gel analysis that Not5 is needed in the cytoplasm for the co-translational assembly of RNA polymerase II. This stems from the importance of Not5 for the association of the R2TP Hsp90 co-chaperone with polysomes translating RPB1 mRNA to protect newly synthesized Rpb1 from aggregation. Hence taken together our results show that Not5 interconnects translation and transcription

Phosphoinositides and Cell Polarity in the Drosophila Egg Chamber

International audiencePhosphatidylinositol phosphates (PIPs) are essential membrane components. They are localized at distinct membrane domains and recruit distinct effectors; they play an important role in the maintenance of membrane identity. They are essential for many cellular functions that include membrane trafficking, cytoskeletal organization, cell polarity and tissue morphogenesis. Cell polarity is also controlled by a set of polarity proteins, the PAR proteins, well conserved among bilaterians. These proteins are part of two dynamic networks that are engaged in a mutual negative-feedback regulation. PAR proteins control cell polarity by regulating cytoskeletal organization, asymmetric distributions of cellular components and directional transport through the cells. They share common activities with the PIPs in the control of intracellular polarity. Therefore, the analysis of potential cross talks between polarity proteins and PIPs is particularly important. The Drosophila egg chamber provides a very good model system to study the processes that control cell polarity. It includes the oocyte, a large cell in which asymmetric transport is very easy to monitor. Furthermore, the oocyte is surrounded by a follicular epithelium that allows the study of cross talks between polarity and tissue morphogenesis. This review focuses on the polarization of Drosophila egg chamber and our understanding of PIPs requirement during Drosophila oogenesis and discusses the relationship between PIPs and polarity proteins