Speckles are nuclear bodies that contain pre-mRNA splicing factors and polyadenylated RNA. Because nuclear poly(A) RNA consists of both mRNA transcripts and nucleus-restricted RNAs, we tested whether poly(A) RNA in speckles is dynamic or rather an immobile, perhaps structural, component. Fluorescein-labeled oligo(dT) was introduced into HeLa cells stably expressing a red fluorescent protein chi...

RIP-B7.1 transgenic mice express B7.1 costimulatory molecules in pancreatic islets and develop diabetes after treatment with polyinosinic:polycytidylic acid (poly I:C), a synthetic double-stranded RNA and agonist of Toll-like receptor (TLR) 3 and retinoic acid-inducible protein I. We used this model to investigate the role of TLR pathways and intestinal microbiota in disease progression. RIP-B7...

Infectious agents can reach the placenta either via the maternal blood or by ascending the genito-urinary tract, and then initially colonizing the maternal decidua. Decidual stromal cells (DSCs) are the major cellular component of the decidua. Although DSCs at the maternal-fetal interface contribute to the regulation of immunity in pregnancy in the face of immunological and physiological challe...

Speckles are nuclear bodies that contain pre-mRNA splicing factors and polyadenylated RNA. Because nuclear poly(A) RNA consists of both mRNA transcripts and nucleus-restricted RNAs, we tested whether poly(A) RNA in speckles is dynamic or rather an immobile, perhaps structural, component. Fluorescein-labeled oligo(dT) was introduced into HeLa cells stably expressing a red fluorescent protein chi...

In Saccharomyces cerevisiae, the single poly(A) binding protein, Pab1, is the major ribonucleoprotein associated with the poly(A) tails of mRNAs in both the nucleus and the cytoplasm. We found that Pab1 interacts with Rna15 in two-hybrid assays and in coimmunoprecipitation experiments. Overexpression of PAB1 partially but specifically suppressed the rna15-2 mutation in vivo. RNA15 codes for a c...

BIM-extra long (BIM(EL)), a pro-apoptotic BH3-only protein and part of the BCL-2 family, is degraded by the proteasome following activation of the ERK1/2 signalling pathway. Although studies have demonstrated poly-ubiquitylation of BIM(EL) in cells, the nature of the ubiquitin chain linkage has not been defined. Using ubiquitin-binding domains (UBDs) specific for defined ubiquitin chain linkage...

Two papers in this issue of Cell describe two roles of poly(ADP-ribose) polymerase (PARP) in modulating chromatin structure: as a structural component replacing linker histone (Kim et al., 2004) and as a constituent of a corepressor complex poised to dismiss repression upon receipt of an activating signal (Ju et al., 2004).

Associated with any oligomorphic permutation group G there is a graded algebra A such that the dimension of its nth homogeneous component is equal to the number of G orbits on n sets I show that the algebra is a poly nomial algebra free commutative associative algebra in some cases and pose some questions about transitive extensions

Inorganic poly P (polyphosphate) is an abundant component of acidocalcisomes of Trypanosoma brucei. In the present study we report the presence of a protein homologous with the yeast Vtc1p (vacuolar transporter chaperone 1) in T. brucei that is essential for poly P synthesis, acidocalcisome biogenesis and cytokinesis. Localization studies in a cell line expressing a TbVTC1 fused to GFP (green f...

Picornavirus infectivity is dependent on the RNA poly(A) tail, which binds the poly(A) binding protein (PABP). PABP was reported to stimulate viral translation and RNA synthesis. Here, we studied encephalomyocarditis virus (EMCV) and poliovirus (PV) genome expression in Krebs-2 and HeLa cell-free extracts that were drastically depleted of PABP (96%-99%). Although PABP depletion markedly diminis...