Charakterisierung von Alien Isoformen in Vertebraten

Alien protein isoforms have been described to be involved in a number of biological processes. Alienalpha is a corepressor of the thyroid hormone receptor mediating transcriptional repression in a ligand-sensitive manner. Furthermore, Alienalpha is a corepressor for the orphan receptor DAX1 and the vitamin-D3 receptor. Alienbetta/CSN2 is part of the COP9-signalosome complex that acts in protein phosphorylation, protein degradation and cell cycle regulation. The major goal of this work was to characterize the Alienalpha and Alienbetta isoforms. Little was known about their expression pattern and the regulation of their expression had not been addressed. It was determined in this work that the expression pattern of Alien is rather ubiquitous in rat tissues. Interestingly, a putative novel Alien protein isoform and an additional alien messenger specific for adrenal gland were identified. Furthermore, it was shown in vivo and in vitro, by in situ hybridization, Northern and Western blotting that Alien expression is regulated by thyroid hormone in the rat brain and brain-derived cell lines. Subsequently, hints for a second T3-independent mechanism of regulation of Alien expression depending on cell confluence or quiescence were discovered. The comparison of Alien isoforms in functional aspects identified Rb and E2F as novel Alien-interacting proteins with similar binding characteristics in vitro and in yeast but functional differences in vivo. Alienbetta interfered with Rb-mediated superactivation of Sp1-driven transcription, whereas Aliena exerted strong repression on E2F transactivation. Common traits for both Alienalpha and Alienbetta are their silencing potential, interaction with TR and activation of AP1-driven transcription. Phosphorylation studies raised the possibility of regulation by non-hormonal signaling since Alienalpha and Alienbetta are phosphorylated in vivo. In gel kinase assays suggested the existence of two different Alien-phosphorylating kinases. Further experiments identified MLK2 and the cell cycle kinase p34cdc2 as such kinases, suggesting a possible function of Alien in cell cycle regulation. Taken together, the expression of Alien is regulated by thyroid hormone, and by cell density; the isoforms can be phosphorylated and can act either as transcriptional repressors or as activators. Additional data indicate a role of Alien isoforms in cell cycle regulation through p34cdc2 phosphorylation and isoform-specific interference with Rb and E2F

Dispositional and performance-specific music performance anxiety in young amateur musicians

IntroductionResearch on Music Performance Anxiety (MPA) among amateur musicians is of great interest due to inconsistent results in literature. In addition, amateur music represents an important part of musical culture in Germany. Accordingly, the performance experiences of young wind players represent a relevant issue for research and musical practice.MethodsIn the present study, 67 young amateur musicians of a brass choir were examined. Using two different questionnaires, both the dispositional MPA (K-MPAI) and the performance-specific MPA during a joint concert (Performance-specific Questionnaire for Musicians, PQM) were assessed. The PQM measures the symptoms of MPA, functional coping with MPA and self-efficacy before, during and after a specific performance. The PQM was completed by the musicians via an app directly after the concert.ResultsResults showed that about 90% of the young amateur musicians had a low dispositional MPA, but about 10% showed high values. For the concrete performance, however, musicians with high dispositional MPA also experienced a very moderate to low MPA in the concert. On average, the musicians were quite nervous before the performance. After the performance, they showed low levels of MPA. Three types of MPA found in previous studies could be confirmed among the amateur musicians, with three quarters being assigned to the positive type, showing low levels of symptoms associated with consistently high levels of self-efficacy and positive functional coping.DiscussionThe results provide a differentiated picture of different expressions of MPA in young amateur musicians. They also raise further questions about the correlation between dispositional and performance-specific assessment of MPA in musicians in general

Völkisch und sozial? : Neonazistische Agitation gegen die neue EU-Freizügigkeit für Arbeitnehmerinnen

Wnt/β-catenin signalling pathway is crucial for the formation of many tissues and organs during development. In recent years, this pathway has also been found to regulate the biology of stem cells in the intestine and probably in other organs in adult life. Abnormal activation of Wnt/β-catenin signalling, which controls the expression of a high number of genes, is critical for the initiation and progression of most colorectal cancers. In line with this, the gene expression signature induced by activation of the Wnt/β-catenin pathway defines the intestinal stem cells present at the bottom of the crypts and also colon cancer stem cells. This supports the importance of inhibitors of the Wnt/β-catenin pathway as potential agents in colorectal cancer therapy. However, the complexity, wide activity in the organism modulating the biology of several cell types, and characteristics of this pathway have delayed the identification of suitable targets and so, the development of such inhibitors that are only now reaching the clinic.Peer reviewe

Reduced type II interleukin-4 receptor signalling drives initiation, but not progression, of colorectal carcinogenesis: evidence from transgenic mouse models and human case-control epidemiological observations.

We investigated the role of interleukin (IL)-4 receptor (IL-4R) signalling during mouse carcinogen-induced colorectal carcinogenesis and in a case-control genetic epidemiological study of IL-4Rα single nucleotide polymorphisms (SNPs). Azoxymethane-induced aberrant crypt focus (ACF; 6 weeks) and tumours (32 weeks) were analysed in wild-type (WT) BALB/c mice, as well as in IL-4Rα (-) (/-) , IL-13 (-/-) and 'double-knockout' (DKO) animals. Colorectal cancer (CRC) cases (1502) and controls (584) were genotyped for six coding IL-4Rα SNPs. The association with CRC risk and CRC-specific mortality was analysed by logistic regression. Lack of IL-4Rα expression was associated with increased ACFs [median 8.5 ACFs per mouse (IL-4Rα (-/-) ) versus 3 (WT); P = 0.007], but no difference in the number of colorectal tumours [mean 1.4 per mouse (IL-4Rα (-/-) ) versus 2 (WT)], which were smaller and demonstrated reduced nuclear/cytoplasmic β-catenin translocation compared with WT tumours. Tumour-bearing IL-4Rα (-/-) mice had fewer CD11b(+)/Gr1(+) myeloid-derived suppressor splenocytes than WT animals. IL-13 (-/-) mice developed a similar number of ACFs to IL-4Rα (-/-) and DKO mice. There was a significant increase in CRC risk associated with the functional SNP Q576R [odds ratio 1.54 (95% confidence interval 0.94-2.54), P trend 0.03 for the minor G allele]. There was no effect of IL-4Rα genotype on either CRC-specific or all-cause mortality. These combined pre-clinical and human data together demonstrate that reduced IL-4R signalling has stage-specific effects on colorectal carcinogenesis (increased CRC initiation and risk but reduced tumour progression and no effect on CRC mortality). These results should prompt evaluation of the effect of pharmacological manipulation of IL-4R signalling on future CRC risk and for CRC treatment

hSrb7, an essential human Mediator component, acts as a coactivator for the thyroid hormone receptor

Nuclear hormone receptors interact with the basal-transcriptional complex and/or coactivators to regulate transcriptional activation. These activator-target interactions recruit the transcriptional machinery to the promoter and may also stimulate transcriptional events subsequent to the binding of the machinery to the promoter or enhancer element. We describe a novel functional interaction of the nuclear thyroid receptor (TR), with a human Mediator component (hSrb7), and a human TFIIH component (hMo15). In mammalian two-hybrid experiments as well as in GST-pull down assays, hSrb7 interacts with TR but not with other nuclear receptors such as the retinoic acid receptor (RAR) or the vitamin D receptor (VDR). Whereas hMo15 also interacts with VDR and RAR in mammalian two-hybrid assays, no association of hSrb7 with VDR or RAR is found. Accordingly, cotransfection of TR and hSrb7 increases thyroid hormone (T3)-dependent transcription in an AF-2-dependent manner, while hSrb7 causes no stimulation of vitamin D- or retinoic acid-mediated transactivation. These results reveal a novel co-activator role for hSrb7 and hMo15 on TR transcriptional responses, and demonstrate that different receptors can selectively target different co-activators or general transcription factors to stimulate transcription.This work has been supported by the grant BMC2001-2275 from the Dirección General de Enseñanza Superior e Investigación of the Ministerio de Ciencia y Tecnologı́a of Spain. Dr. J. Nevado is a recipient of a Research Contract from ISCIII (FIS 99/3077)