scholarly journals A 5S rRNA/L5 complex is a precursor to ribosome assembly in mammalian cells.

1988 ◽  
Vol 106 (3) ◽  
pp. 545-556 ◽  
Author(s):  
J A Steitz ◽  
C Berg ◽  
J P Hendrick ◽  
H La Branche-Chabot ◽  
A Metspalu ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
5S Rrna ◽  
5S Rna ◽  
Rna Molecules ◽  
La Protein ◽  
Rnp Complex ◽  
Mouse Cells ◽  
Protein Moiety ◽  
Human And Mouse

A novel 5S RNA-protein (RNP) complex in human and mouse cells has been analyzed using patient autoantibodies. The RNP is small (approximately 7S) and contains most of the nonribosome-associated 5S RNA molecules in HeLa cells. The 5S RNA in the particle is matured at its 3' end, consistent with the results of in vivo pulse-chase experiments which indicate that this RNP represents a later step in 5S biogenesis than a previously described 5S*/La protein complex. The protein moiety of the 5S RNP has been identified as ribosomal protein L5, which is known to be released from ribosomes in a complex with 5S after various treatments of the 60S subunit. Indirect immunofluorescence indicates that the L5/5S complex is concentrated in the nucleolus. L5 may therefore play a role in delivering 5S rRNA to the nucleolus for assembly into ribosomes.

Replication of DNA containing apurinic sites in human and mouse cells probed with parvoviruses MVM and H-1

1987 ◽  
Vol 7 (7) ◽  
pp. 2620-2624
Author(s):  
J M Vos ◽  
J Rommelaere
Keyword(s):  
Mammalian Cells ◽  
Uv Light ◽  
Host Cells ◽  
Minute Virus Of Mice ◽  
Dna Viruses ◽  
Minute Virus ◽  
Mouse Cells ◽  
Viral Mutagenesis ◽  
Human And Mouse

We studied the effect of apurinic sites on DNA replication in mouse and human cells, using parvoviruses MVM (minute virus of mice) and H-1 as probes. Although apurinic sites are efficient blocks to the replication of these single-stranded DNA viruses in vivo, depurinated parvoviruses can be reactivated if host cells have been preexposed to a subtoxic dose of UV light. The target of this conditional reactivation process is the conversion of depurinated input DNA into double-stranded replicative forms; the concomitant increase in viral mutagenesis strongly suggests that apurinic sites can be bypassed in mammalian cells.

scholarly journals Replication of DNA containing apurinic sites in human and mouse cells probed with parvoviruses MVM and H-1.

1987 ◽  
Vol 7 (7) ◽  
pp. 2620-2624 ◽  
Author(s):  
J M Vos ◽  
J Rommelaere
Keyword(s):  
Mammalian Cells ◽  
Uv Light ◽  
Host Cells ◽  
Minute Virus Of Mice ◽  
Dna Viruses ◽  
Minute Virus ◽  
Mouse Cells ◽  
Viral Mutagenesis ◽  
Human And Mouse

We studied the effect of apurinic sites on DNA replication in mouse and human cells, using parvoviruses MVM (minute virus of mice) and H-1 as probes. Although apurinic sites are efficient blocks to the replication of these single-stranded DNA viruses in vivo, depurinated parvoviruses can be reactivated if host cells have been preexposed to a subtoxic dose of UV light. The target of this conditional reactivation process is the conversion of depurinated input DNA into double-stranded replicative forms; the concomitant increase in viral mutagenesis strongly suggests that apurinic sites can be bypassed in mammalian cells.

Alterations in an IRE1-RNA complex in the mammalian unfolded protein response

2001 ◽  
Vol 114 (17) ◽  
pp. 3207-3212
Author(s):  
Anne Bertolotti ◽  
David Ron
Keyword(s):  
Unfolded Protein Response ◽  
Mammalian Cells ◽  
Dynamic Change ◽  
Rna Molecules ◽  
Unfolded Protein ◽  
Rna Fragments ◽  
Stressed Cells ◽  
Rna Complex ◽  
Protein Response

IRE1 proteins mediate cellular responses to accumulation of malfolded proteins in the endoplasmic reticulum in the yeast and mammalian unfolded protein responses. A sensitive in vivo u.v. crosslinking assay showed that IRE1 proteins are intimately associated with RNA in mammalian cells. The IRE1-associated RNA fragments recovered by this assay were different in stressed and unstressed cells. The amount of RNA associated with IRE1 that could be revealed by end-labeling with T4 kinase was greater in IRE1-containing complexes isolated from stressed cells. Furthermore, the RNA fragments recovered from complexes found in stressed cells were shorter than those from unstressed cells, revealing a dynamic change in the IRE1-RNA complex during the UPR. Formation of the complex between IRE1 and RNA was dependent on both the kinase and endonuclease domains of IRE1, and involved pre-existing RNA species. When viewed in the context of the known importance of Ire1p-HAC1 mRNA interactions to the yeast unfolded protein response, these findings suggest that full-length mammalian IRE1s also engage RNA molecules as downstream effectors.

scholarly journals Isolation and sequencing of AGO-bound RNAs reveals characteristics of mammalian stem-loop processing in vivo

2018 ◽  
Author(s):  
Ian M. Silverman ◽  
Sager J. Gosai ◽  
Nicholas Vrettos ◽  
Shawn W. Foley ◽  
Nathan D. Berkowitz ◽  
...  
Keyword(s):  
Mature Mirnas ◽  
Human Cells ◽  
Processing Efficiency ◽  
Stem Loop ◽  
Mature Micrornas ◽  
Mouse Cells ◽  
Low Levels ◽  
Short Hairpin Rnas ◽  
Human And Mouse

ABSTRACTMicroRNA precursors (pre-miRNAs) are short hairpin RNAs that are rapidly processed into mature microRNAs (miRNAs) in the cytoplasm. Due to their low abundance in cells, sequencing-based studies of pre-miRNAs have been limited. We successfully enriched for and deep sequenced pre-miRNAs in human cells by capturing these RNAs during their interaction with Argonaute (AGO) proteins. Using this approach, we detected > 350 pre-miRNAs in human cells and > 250 pre-miRNAs in a reanalysis of a similar study in mouse cells. We uncovered widespread trimming and non-templated additions to the 3’ ends of pre- and mature miRNAs. Additionally, we created an index for microRNA precursor processing efficiency. This analysis revealed a subset of pre-miRNAs that produce low levels of mature miRNAs despite abundant precursors, including an annotated miRNA in the 5’ UTR of the DiGeorge syndrome critical region 8 mRNA transcript. This led us to search for AGO-associated stem-loops originating from other mRNA species, which identified hundreds of putative pre-miRNAs derived from human and mouse mRNAs. In summary, we provide a wealth of information on mammalian pre-miRNAs, and identify novel microRNA and microRNA-like elements localized in mRNAs.

Ro small cytoplasmic ribonucleoproteins are a subclass of La ribonucleoproteins: further characterization of the Ro and La small ribonucleoproteins from uninfected mammalian cells

1981 ◽  
Vol 1 (12) ◽  
pp. 1138-1149
Author(s):  
J P Hendrick ◽  
S L Wolin ◽  
J Rinke ◽  
M R Lerner ◽  
J A Steitz
Keyword(s):  
Rna Polymerase ◽  
Mammalian Cells ◽  
Protein Complexes ◽  
Rna Polymerase Iii ◽  
Protein S ◽  
Human Cells ◽  
Rna Molecules ◽  
Transcription System ◽  
Polymerase Iii ◽  
La Protein

Small ribonucleic acid (RNA)-protein complexes precipitated by anti-Ro and anti-La antibodies from lupus patients have been examined with emphasis on their RNA components. In both ribonucleoprotein (RNP) classes, the numbers of different RNA molecules and their sequences vary between mouse and human cells. The complex mixtures of La RNAs include two previously sequenced 4.5S RNAs from mouse cells and 5S ribosomal RNA-like molecules from both mouse and human cells. All Ro and La RNAs possess 5-triphosphates. Some La RNAs have internal modifications typical of transfer RNAs. The Ro RNPs are quite stable and are localized by immunofluorescence in the cell cytoplasm, whereas the majority of the La RNPs turn over rapidly and reside in the nucleus. Despite these differences, reconstitution experiments show that the Ro particles carry the La as well as the Ro determinant. Studies using a nuclear transcription system demonstrate that most of the La RNAs are synthesized by RNA polymerase III. The possibility that the La protein(s) functions in the transcription or maturation of all RNA polymerase III transcripts is discussed.

scholarly journals p53-dependent release of Alarmin HMGB1 is a central mediator of senescent phenotypes

2013 ◽  
Vol 201 (4) ◽  
pp. 613-629 ◽  
Author(s):  
Albert R. Davalos ◽  
Misako Kawahara ◽  
Gautam K. Malhotra ◽  
Nicholas Schaum ◽  
Jiahao Huang ◽  
...  
Keyword(s):  
Growth Arrest ◽  
High Mobility ◽  
Cytokine Secretion ◽  
Blocking Antibody ◽  
Extracellular Milieu ◽  
Hmgb1 Expression ◽  
Mouse Cells ◽  
Human And Mouse ◽  
Oncogenic Stress

Cellular senescence irreversibly arrests proliferation in response to potentially oncogenic stress. Senescent cells also secrete inflammatory cytokines such as IL-6, which promote age-associated inflammation and pathology. HMGB1 (high mobility group box 1) modulates gene expression in the nucleus, but certain immune cells secrete HMGB1 as an extracellular Alarmin to signal tissue damage. We show that nuclear HMGB1 relocalized to the extracellular milieu in senescent human and mouse cells in culture and in vivo. In contrast to cytokine secretion, HMGB1 redistribution required the p53 tumor suppressor, but not its activator ATM. Moreover, altered HMGB1 expression induced a p53-dependent senescent growth arrest. Senescent fibroblasts secreted oxidized HMGB1, which stimulated cytokine secretion through TLR-4 signaling. HMGB1 depletion, HMGB1 blocking antibody, or TLR-4 inhibition attenuated senescence-associated IL-6 secretion, and exogenous HMGB1 stimulated NF-κB activity and restored IL-6 secretion to HMGB1-depleted cells. Our findings identify senescence as a novel biological setting in which HMGB1 functions and link HMGB1 redistribution to p53 activity and senescence-associated inflammation.

scholarly journals Identification of human and mouse p19, a novel CDK4 and CDK6 inhibitor with homology to p16ink4.

1995 ◽  
Vol 15 (5) ◽  
pp. 2682-2688 ◽  
Author(s):  
F K Chan ◽  
J Zhang ◽  
L Cheng ◽  
D N Shapiro ◽  
A Winoto
Keyword(s):  
Cell Cycle ◽  
T Cell ◽  
Mammalian Cells ◽  
Cyclin E ◽  
G1 Arrest ◽  
Cdk Inhibitor ◽  
Cyclin D ◽  
Human And Mouse

The cell cycle in mammalian cells is regulated by a series of cyclins and cyclin-dependent kinases (CDKs). The G1/S checkpoint is mainly dictated by the kinase activities of the cyclin D-CDK4 and/or cyclin D-CDK6 complex and the cyclin E-CDK2 complex. These G1 kinases can in turn be regulated by cell cycle inhibitors, which may cause the cells to arrest at the G1 phase. In T-cell hybridomas, addition of anti-T-cell receptor antibody results not only in G1 arrest but also in apoptosis. In searching for a protein(s) which might interact with Nur77, an orphan steroid receptor required for activation-induced apoptosis of T-cell hybridomas, we have cloned a novel human and mouse CDK inhibitor, p19. The deduced p19 amino acid sequence consists of four ankyrin repeats with 48% identity to p16. The human p19 gene is located on chromosome 19p13, distinct from the positions of p18, p16, and p15. Its mRNA is expressed in all cell types examined. The p19 fusion protein can associate in vitro with CDK4 but not with CDK2, CDC2, or cyclin A, B, E, or D1 to D3. Addition of p19 protein can lead to inhibition of the in vitro kinase activity of cyclin D-CDK4 but not that of cyclin E-CDK2. In T-cell hybridoma DO11.10, p19 was found in association with CDK4 and CDK6 in vivo, although its association with Nur77 is not clear at this point. Thus, p19 is a novel CDK inhibitor which may play a role in the cell cycle regulation of T cells.

scholarly journals Development of an ObLiGaRe Doxycycline Inducible Cas9 system for pre-clinical cancer drug discovery

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Anders Lundin ◽  
Michelle J. Porritt ◽  
Himjyot Jaiswal ◽  
Frank Seeliger ◽  
Camilla Johansson ◽  
...  
Keyword(s):  
Gene Editing ◽  
Functional Integration ◽  
Cancer Drug ◽  
Cancer Drug Discovery ◽  
Mouse Cells ◽  
Genomic Editing ◽  
Human And Mouse ◽  
Mouse Genomic ◽  
In Cells

Abstract The CRISPR-Cas9 system has increased the speed and precision of genetic editing in cells and animals. However, model generation for drug development is still expensive and time-consuming, demanding more target flexibility and faster turnaround times with high reproducibility. The generation of a tightly controlled ObLiGaRe doxycycline inducible SpCas9 (ODInCas9) transgene and its use in targeted ObLiGaRe results in functional integration into both human and mouse cells culminating in the generation of the ODInCas9 mouse. Genomic editing can be performed in cells of various tissue origins without any detectable gene editing in the absence of doxycycline. Somatic in vivo editing can model non-small cell lung cancer (NSCLC) adenocarcinomas, enabling treatment studies to validate the efficacy of candidate drugs. The ODInCas9 mouse allows robust and tunable genome editing granting flexibility, speed and uniformity at less cost, leading to high throughput and practical preclinical in vivo therapeutic testing.

scholarly journals Ro small cytoplasmic ribonucleoproteins are a subclass of La ribonucleoproteins: further characterization of the Ro and La small ribonucleoproteins from uninfected mammalian cells.

1981 ◽  
Vol 1 (12) ◽  
pp. 1138-1149 ◽  
Author(s):  
J P Hendrick ◽  
S L Wolin ◽  
J Rinke ◽  
M R Lerner ◽  
J A Steitz
Keyword(s):  
Rna Polymerase ◽  
Mammalian Cells ◽  
Protein Complexes ◽  
Rna Polymerase Iii ◽  
Protein S ◽  
Human Cells ◽  
Rna Molecules ◽  
Transcription System ◽  
Polymerase Iii ◽  
La Protein

Small ribonucleic acid (RNA)-protein complexes precipitated by anti-Ro and anti-La antibodies from lupus patients have been examined with emphasis on their RNA components. In both ribonucleoprotein (RNP) classes, the numbers of different RNA molecules and their sequences vary between mouse and human cells. The complex mixtures of La RNAs include two previously sequenced 4.5S RNAs from mouse cells and 5S ribosomal RNA-like molecules from both mouse and human cells. All Ro and La RNAs possess 5-triphosphates. Some La RNAs have internal modifications typical of transfer RNAs. The Ro RNPs are quite stable and are localized by immunofluorescence in the cell cytoplasm, whereas the majority of the La RNPs turn over rapidly and reside in the nucleus. Despite these differences, reconstitution experiments show that the Ro particles carry the La as well as the Ro determinant. Studies using a nuclear transcription system demonstrate that most of the La RNAs are synthesized by RNA polymerase III. The possibility that the La protein(s) functions in the transcription or maturation of all RNA polymerase III transcripts is discussed.

scholarly journals Dicer-Derived MicroRNAs Are Utilized by the Fragile X Mental Retardation Protein for Assembly on Target RNAs

2006 ◽  
Vol 2006 ◽  
pp. 1-12 ◽  
Author(s):  
Isabelle Plante ◽  
Laetitia Davidovic ◽  
Dominique L. Ouellet ◽  
Lise-Andrée Gobeil ◽  
Sandra Tremblay ◽  
...  
Keyword(s):  
Mental Retardation ◽  
Translational Control ◽  
Mammalian Cells ◽  
Rna Binding ◽  
Fragile X ◽  
Rna Sequences ◽  
Fragile X Mental Retardation ◽  
Mental Retardation Protein ◽  
Rnp Complex

In mammalian cells, fragile X mental retardation protein (FMRP) has been reported to be part of a microRNA (miRNA)-containing effector ribonucleoprotien (RNP) complex believed to mediate translational control of specific mRNAs. Here, using recombinant proteins, we demonstrate that human FMRP can act as a miRNA acceptor protein for the ribonuclease Dicer and facilitate the assembly of miRNAs on specific target RNA sequences. The miRNA assembler property of FMRP was abrogated upon deletion of its single-stranded (ss) RNA binding K-homology domains. The requirement of FMRP for efficient RNA interference (RNAi) in vivo was unveiled by reporter gene silencing assays using various small RNA inducers, which also supports its involvement in an ss small interfering RNA (siRNA)-containing RNP (siRNP) effector complex in mammalian cells. Our results define a possible role for FMRP in RNA silencing and may provide further insight into the molecular defects in patients with the fragile X syndrome.

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