Search results for "Nucleoprotein"
showing 10 items of 86 documents
Pseudouridine: Still mysterious, but never a fake (uridine)!
2014
International audience; Pseudouridine () is the most abundant of >150 nucleoside modifications in RNA. Although was discovered as the first modified nucleoside more than half a century ago, neither the enzymatic mechanism of its formation, nor the function of this modification are fully elucidated. We present the consistent picture of synthases, their substrates and their substrate positions in model organisms of all domains of life as it has emerged to date and point out the challenges that remain concerning higher eukaryotes and the elucidation of the enzymatic mechanism.
Rev protein suppression of complex formation between nuclear proteins and rev-responsive element-containing RNA of human immunodeficiency virus-1
1995
The Rev protein from human immunodeficiency virus type 1 (HIV-1) is known to bind Rev responsive element (RRE) sequence of HIV-1 mRNA. This interaction is thought to enhance expression of viral structural proteins but the mechanism for this effect is uncertain. The aim of this study was to investigate (i) whether other cellular proteins also bind to the RRE sequence and (ii) whether binding of cellular proteins to RRE RNA is influenced by Rev protein. Our results revealed that a variety of RNA-protein complexes are formed when in vitro transcribed RRE-containing RNA is incubated with proteins present in HeLa nuclear extracts. The molecular masses of the most prominent bands in RNase protect…
Cross-Reactivity of Antibodies Immunoadsorbed to Laminin with Recombinant Human La (SS-B) Protein
1998
Anti-La (SS-B) antibodies cross-reacting with mouse B1 laminin were reported in sera of patients with systemic lupus erythematosus. However, the common epitope had not been characterized. Immunoblotting conditions were established, allowing detection and elution of anti-La (SS-B)/laminin cross-reacting antibodies. Antibodies adsorbed to mouse B1 laminin represented a subclass of anti-La antibodies. They strongly reacted with human full length recombinant La protein. However, they failed to react with either an N-terminal La peptide consisting of amino acids 1-192 or a C-terminal La peptide starting at methionine 223, while they still reacted with recombinant La peptides consisting of the am…
Unveiling novel interactions of histone chaperone Asf1 linked to TREX-2 factors Sus1 and Thp1
2014
13 páginas, 7 figuras, 2 yablas
The Lsm1-7/Pat1 complex binds to stress-activated mRNAs and modulates the response to hyperosmotic shock.
2018
RNA-binding proteins (RBPs) establish the cellular fate of a transcript, but an understanding of these processes has been limited by a lack of identified specific interactions between RNA and protein molecules. Using MS2 RNA tagging, we have purified proteins associated with individual mRNA species induced by osmotic stress, STL1 and GPD1. We found members of the Lsm1-7/Pat1 RBP complex to preferentially bind these mRNAs, relative to the non-stress induced mRNAs, HYP2 and ASH1. To assess the functional importance, we mutated components of the Lsm1-7/Pat1 RBP complex and analyzed the impact on expression of osmostress gene products. We observed a defect in global translation inhibition under…
Proteomic analysis reveals a role for Bcl2-associated athanogene 3 and major vault protein in resistance to apoptosis in senescent cells by regulatin…
2014
Senescence is a prominent solid tumor response to therapy in which cells avoid apoptosis and instead enter into prolonged cell cycle arrest. We applied a quantitative proteomics screen to identify signals that lead to therapy-induced senescence and discovered that Bcl2-associated athanogene 3 (Bag3) is up-regulated after adriamycin treatment in MCF7 cells. Bag3 is a member of the BAG family of co-chaperones that interacts with Hsp70. Bag3 also regulates major cell-signaling pathways. Mass spectrometry analysis of the Bag3 Complex revealed a novel interaction between Bag3 and Major Vault Protein (MVP). Silencing of Bag3 or MVP shifts the cellular response to adriamycin to favor apoptosis. We…
HNRNPR Variants that Impair Homeobox Gene Expression Drive Developmental Disorders in Humans
2019
The heterogeneous nuclear ribonucleoprotein (HNRNP) genes code for a set of RNA-binding proteins that function primarily in the spliceosome C complex. Pathogenic variants in these genes can drive neurodegeneration, through a mechanism involving excessive stress-granule formation, or developmental defects, through mechanisms that are not known. Here, we report four unrelated individuals who have truncating or missense variants in the same C-terminal region of hnRNPR and who have multisystem developmental defects including abnormalities of the brain and skeleton, dysmorphic facies, brachydactyly, seizures, and hypoplastic external genitalia. We further identified in the literature a fifth ind…
snoRNPs Regulate Telomerase Activity in Neuroblastoma and Are Associated with Poor Prognosis
2013
AbstractAmplification of the MYCN oncogene is strongly associated with poor prognosis in neuroblastoma (NB). In addition to MYCN amplification, many studies have focused on identifying patients with a poor prognosis based on gene expression profiling. The majority of prognostic signatures today are comprised of large gene lists limiting their clinical application. In addition, although of prognostic significance,most of these signatures fail to identify cellular processes that can explain their relation to prognosis. Here, we determined prognostically predictive genes in a data set containing 251 NBs. Gene Ontology analysis was performed on significant genes with a positive hazard ratio to …
Dendritic cell aggresome-like-induced structure formation and delayed antigen presentation coincide in influenza virus-infected dendritic cells.
2005
Abstract Influenza virus infection induces maturation of murine dendritic cells (DCs), which is most important for the initiation of an immune response. However, in contrast to EL-4 and MC57 cells, DCs present viral CTL epitopes with a delay of up to 10 h. This delay in Ag presentation coincides with the up-regulation of MHC class I molecules as well as costimulatory molecules on the cell surface and the accumulation of newly synthesized ubiquitinated proteins in large cytosolic structures, called DC aggresome-like-induced structures (DALIS). These structures were observed previously after LPS-induced maturation of DCs, and it was speculated that they play a role in the regulation of MHC cl…
One gene, two transcripts: isolation of an alternative transcript encoding for the autoantigen La/SS-B from a cDNA library of a patient with primary …
1994
A cDNA library was prepared from peripheral blood lymphocytes of an autoimmune patient with primary Sjögrens' syndrome. The cDNA library was screened with the patients own autoimmune serum being monospecific for the nuclear autoantigen La/SS-B. Thereby an alternative type of La mRNA was identified that differed from the known La mRNA due to an exchange of the exon 1. Sequencing of the genomic region between the exons 1 and 2 showed that the alternative 5'-end is a part of the intron. In addition, the presence of an alternative promoter site, which exists within the intron downstream of the exon 1, became evident. In consequence, the alternative La mRNA is the result of a promoter switching …