Mammalian mRNAs are generated by complex and coordinated biogenesis pathways and acquire 5'-end m7G caps that play fundamental roles in processing and translation. Here we show that several selenoprotein mRNAs are not recognized efficiently by translation initiation factor eIF4E because they bear a hypermethylated cap. This cap modification is acquired via a 5end maturation pathway similar to that of the small nucle(ol)ar RNAs (sn- and snoRNAs). Our findings also establish that the trimethylguanosine synthase 1 (Tgs1) interacts with selenoprotein mRNAs for cap hypermethylation and that assembly chaperones and core proteins devoted to sn- and snoRNP maturation contribute to recruiting Tgs1 to selenoprotein mRNPs. We further demonstrate that the hypermethylated-capped selenoprotein mRNAs localize to the cytoplasm, are associated with polysomes and thus translated. Moreover, we found that the activity of Tgs1, but not of eIF4E, is required for the synthesis of the GPx1 selenoprotein in vivo.
Hypermethylated-capped selenoprotein mRNAs in mammals.
Cell line
View SamplesNTHi bacteria or saline were inoculated into the middle ears of mice. Mice were sacrificed at various times to monitor the course of infection.
The transcriptome of a complete episode of acute otitis media.
Specimen part, Treatment, Time
View SamplesWe generated Gadd45a,b,g triple-knockout mouse embryonic stem cells and performed RNA-seq expression profiling under six different conditions of cell culture and in vitro differentiation. Overall design: Gadd45a,b,g triple knockout (TKO) mouse embryonic stem cells (mESC) were generated by CRISPR/Cas9. RNA-Seq was performed to compare the transcriptome in three independent Gadd45 TKO versus three independent control mESC lines under different conditions: (i) Serum cultured mESC, (ii) Vitamin C treated mESC, (iii) 2i treated mESC, (iv) mESC differentiated as embryoid bodies (EB), (v) mESC differentiated as a serum-free monolayer, and (vi) EB stimulated with retinoic acid (RA).
GADD45 promotes locus-specific DNA demethylation and 2C cycling in embryonic stem cells.
Specimen part, Cell line, Subject
View SamplesNatalizumab is a recombinant monoclonal antibody raised against integrin alpha-4 (CD49d). It is approved for the treatment of patients with multiple sclerosis (MS), a chronic inflammatory autoimmune disease of the CNS. Natalizumab blocks leukocyte extravasation across the blood-brain barrier by inhibiting the molecular interaction between integrin alpha-4/beta-1 heterodimers expressed on leukocytes and VCAM-1 on inflammatory-activated CNS endothelium. Here we investigated whether binding of this adhesion-blocking antibody to T lymphocytes modulated their phenotype by direct induction of intracellular signaling events. Natalizumab induced a mild upregulation of IL-2, IFN-gamma and IL-17 expression in activated primary human CD4+ T cells propagated ex vivo from healthy donors, consistent with a pro-inflammatory costimulatory effect on lymphokine expression. Overall, the relative effect of natalizumab was more pronounced in less than in fully activated T cells. Along with this, natalizumab binding triggered rapid MAPK/ERK phosphorylation. Furthermore, it decreased CD49d surface expression on effector cells within a few hours. Sustained CD49d downregulation could be attributed to integrin internalization and degradation. Importantly, also CD4+ T cells from some MS patients receiving their very first dose of natalizumab produced more IL-2, IFN-gamma and IL-17 already 24 h after infusion. Together these data indicate that in addition to its adhesion-blocking mode of action, natalizumab possesses mild direct signaling capacities, which may support a pro-inflammatory phenotype of peripheral blood T lymphocytes. This might explain why a rebound of disease activity is observed in some MS patients after natalizumab cessation.
Natalizumab exerts direct signaling capacity and supports a pro-inflammatory phenotype in some patients with multiple sclerosis.
Specimen part, Disease, Disease stage, Treatment
View SamplesOf the members of mitochondrial transcription termination factors (mTERFs) found in metazoans and plants known to regulate organellar gene expression at various levels, plant mTERF6 promotes maturation of a tRNA
Definition of a core module for the nuclear retrograde response to altered organellar gene expression identifies GLK overexpressors as gun mutants.
No sample metadata fields
View SamplesTransformation of follicular lymphoma (FL) to a more aggressive disease is associated with rapid progression and death. Existing molecular markers for transformation are few and their clinical impact is limited. Here, we report on a whole-genome study of DNA copy numbers and gene expression profiles in serial FL biopsies. We identified 698 genes with high correlation between gene expression and copy number and the molecular network most enriched for these cis-associated genes. This network includes 14 cis-associated genes directly related to the NFB pathway. For each of these 14 genes, the correlated NFB target genes were identified and corresponding expression scores defined. The scores for six of the cis-associated NFB pathway genes (BTK, IGBP1, IRAK1, ROCK1, TMED7-TICAM2 and TRIM37) were significantly associated with transformation. The results suggest that genes regulating B-cell survival and activation are involved in transformation of FL
Whole-genome integrative analysis reveals expression signatures predicting transformation in follicular lymphoma.
Specimen part
View SamplesGUN1 integrates retrograde signals in the chloroplast but the underlying mechanism is elusive. FUG1, a chloroplast translation initiation factor, and GUN1 are co-expressed at the transcript level, and FUG1 co-immunoprecipitates with GUN1. We used mutants of GUN1 (gun1-103) and FUG1 (fug1-3) to analyse their functional relationship at the physiological and systems-wide level, the latter including transcriptome and proteome analyses. Absence of GUN1 aggravates the effects of decreased FUG1 levels on chloroplast protein translation, resulting in transient additive phenotypes with respect to photosynthesis, leaf coloration, growth and cold acclimation. Variegation of the var2 mutant is enhanced by gun1-103 in terms of increasing the fraction of white sectors, in contrast to fug1-3 that acts as suppressor. The transcriptomes of fug1-3 and gun1-103 are very similar, but absence of GUN1 alone has almost no effects on protein levels, whereas chloroplast protein accumulation is markedly decreased in fug1-3. In gun1 fug1 double mutants, effects on transcriptomes and particularly proteomes are enhanced. Our results show that GUN1 function becomes critical when chloroplast proteostasis is perturbed by decreased translation (fug1) or degradation (var2) of chloroplast proteins. The functions of FUG1 and GUN1 appear to be related, corroborating the view that GUN1 operates in chloroplast proteostasis. Overall design: Examination of differential gene expression in the Arabdidopsis thaliana gun1, fug1 and gun1 fug1 mutants compared to wild type in three replicates
Relationship of GUN1 to FUG1 in chloroplast protein homeostasis.
Subject
View SamplesChanges ins organellar gene expression trigger retrograde signalling. Prolyl-tRNA synthetase (PRORS1) is located in chloroplasts and mitochondria. Thus, prors1-2 mutants are impaired in chloroplast and mitochondrial gene expression.
Identification of target genes and transcription factors implicated in translation-dependent retrograde signaling in Arabidopsis.
Age, Specimen part
View SamplesSince follicular lymphoma (FL) grade 3A often coexist with a FL1/2 component a linear progression model of FL1, FL2 and FL3A has been developed. FL3B, on the other hand, is supposed to be more closely related to diffuse large B-cell lymphoma (DLBCL) and both FL3B and DLBCL are often simultaneously present in one tumor (DLBCL/FL3B).
Gene expression profiling reveals a close relationship between follicular lymphoma grade 3A and 3B, but distinct profiles of follicular lymphoma grade 1 and 2.
Sex, Age, Specimen part
View SamplesFollicular lymphoma (FL) is genetically characterized by the presence of the t(14;18)(q32;q21) chromosomal translocation in approximately 90% of cases. In contrast to FL carrying the t(14;18), their t(14;18)-negative counterparts are less well studied regarding their immunohistochemical, genetic, molecular and clinical features. Within a previously published series of 184 FL grade 1-3A with available gene expression data, we identified 17 FL lacking the t(14;18). Comparative genomic hybridization and high resolution SNP array profiling demonstrated that gains/amplifications of the BCL2 gene locus in 18q were restricted to the t(14;18)-positive FL subgroup. A comparison of gene expression profiles revealed an enrichment of germinal center B-cell associated signatures in t(14;18)-positive FL, whereas activated B-cell like, NFB, proliferation and bystander cell signatures were enriched in t(14;18)-negative FL. These findings were confirmed by immunohistochemistry in an independent validation series of 84 FL, in which 32% of t(14;18)-negative FL showed weak or absent CD10 expression and 91% an increased Ki67 proliferation rate. Although overall survival did not differ between FL with and without t(14;18), our findings suggest distinct molecular features of t(14;18)-negative FL.
Follicular lymphomas with and without translocation t(14;18) differ in gene expression profiles and genetic alterations.
Specimen part, Disease, Disease stage, Subject
View Samples