scholarly journals An inducible cytoplasmic factor (AU-B) binds selectively to AUUUA multimers in the 3' untranslated region of lymphokine mRNA.

1991 ◽  
Vol 11 (6) ◽  
pp. 3288-3295 ◽  
Author(s):  
P R Bohjanen ◽  
B Petryniak ◽  
C H June ◽  
C B Thompson ◽  
T Lindsten
Keyword(s):  
Untranslated Region ◽  
Rna Binding ◽  
Cell Receptor ◽  
Binding Activity ◽  
Myristate Acetate ◽  
Cytoplasmic Factor ◽  
Mrna Metabolism ◽  
Rna And Protein Synthesis ◽  
Quiescent T Cells ◽  
Stimulation Of

Considerable evidence suggests that the metabolism of lymphokine mRNAs can be selectively regulated within the cytoplasm. However, little is known about the mechanism(s) that cells use to discriminate lymphokine mRNAs from other mRNAs within the cytoplasm. In this study we report a sequence-specific cytoplasmic factor (AU-B) that binds specifically to AUUUA multimers present in the 3' untranslated region of lymphokine mRNAs. AU-B does not bind to monomeric AUUUA motifs nor to other AU-rich sequences present in the 3' untranslated region of c-myc mRNA. AU-B RNA-binding activity is not present in quiescent T cells but is rapidly induced by stimulation of the T-cell receptor/CD3 complex. Induction of AU-B RNA-binding activity requires new RNA and protein synthesis. Stabilization of lymphokine mRNA induced by costimulation with phorbol myristate acetate correlates inversely with binding by AU-B. Together, these data suggest that AU-B is a cytoplasmic regulator of lymphokine mRNA metabolism.

An inducible cytoplasmic factor (AU-B) binds selectively to AUUUA multimers in the 3' untranslated region of lymphokine mRNA

1991 ◽  
Vol 11 (6) ◽  
pp. 3288-3295 ◽  
Author(s):  
P R Bohjanen ◽  
B Petryniak ◽  
C H June ◽  
C B Thompson ◽  
T Lindsten
Keyword(s):  
Untranslated Region ◽  
Rna Binding ◽  
Cell Receptor ◽  
Binding Activity ◽  
Myristate Acetate ◽  
Cytoplasmic Factor ◽  
Mrna Metabolism ◽  
Rna And Protein Synthesis ◽  
Quiescent T Cells ◽  
Stimulation Of

Considerable evidence suggests that the metabolism of lymphokine mRNAs can be selectively regulated within the cytoplasm. However, little is known about the mechanism(s) that cells use to discriminate lymphokine mRNAs from other mRNAs within the cytoplasm. In this study we report a sequence-specific cytoplasmic factor (AU-B) that binds specifically to AUUUA multimers present in the 3' untranslated region of lymphokine mRNAs. AU-B does not bind to monomeric AUUUA motifs nor to other AU-rich sequences present in the 3' untranslated region of c-myc mRNA. AU-B RNA-binding activity is not present in quiescent T cells but is rapidly induced by stimulation of the T-cell receptor/CD3 complex. Induction of AU-B RNA-binding activity requires new RNA and protein synthesis. Stabilization of lymphokine mRNA induced by costimulation with phorbol myristate acetate correlates inversely with binding by AU-B. Together, these data suggest that AU-B is a cytoplasmic regulator of lymphokine mRNA metabolism.

scholarly journals MSY2 and MSY4 Bind a Conserved Sequence in the 3′ Untranslated Region of Protamine 1 mRNA In Vitro and In Vivo

2001 ◽  
Vol 21 (20) ◽  
pp. 7010-7019 ◽  
Author(s):  
Flaviano Giorgini ◽  
Holly G. Davies ◽  
Robert E. Braun
Keyword(s):  
Untranslated Region ◽  
Rna Binding ◽  
Mutational Analysis ◽  
Binding Activity ◽  
Mobility Shift ◽  
Conserved Sequence ◽  
Mobility Shift Assay ◽  
Protamine 1

ABSTRACT Y-box proteins are major constituents of ribonucleoprotein particles (RNPs) which contain translationally silent mRNAs in gametic cells. We have recently shown that a sequence-specific RNA binding activity present in spermatogenic cells contains the two Y-box proteins MSY2 and MSY4. We show here that MSY2 and MSY4 bind a sequence, 5′-UCCAUCA-3′, present in the 3′ untranslated region of the translationally repressed protamine 1 (Prm1) mRNA. Using pre- and post-RNase T1-digested substrate RNAs, it was determined that MSY2 and MSY4 can bind an RNA of eight nucleotides containing the MSY2 and MSY4 binding site. Single nucleotide mutations in the sequence eliminated the binding of MSY2 and MSY4 in an electrophoretic mobility shift assay, and the resulting mutants failed to compete for binding in a competition assay. A consensus site of UACCACAUCCACU(subscripts indicate nucleotides which do not disrupt YRS binding by MSY2 and MSY4), denoted the Y-box recognition site (YRS), was defined from this mutational analysis. These mutations in the YRS were further characterized in vivo using a novel application of the yeast three-hybrid system. Experiments with transgenic mice show that disruption of the YRS in vivo relieves Prm1-like repression of a reporter gene. The conservation of the RNA binding motifs among Y-box protein family members raises the possibility that other Y-box proteins may have previously unrecognized sequence-specific RNA binding activities.

Properties and purification of a glucose-inducible human fatty acid synthase mRNA-binding protein

1998 ◽  
Vol 274 (4) ◽  
pp. E577-E585 ◽  
Author(s):  
Qianmei Li ◽  
Michael S. Chua ◽  
Clay F. Semenkovich
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Rna Binding ◽  
Time Frame ◽  
Binding Activity ◽  
Proteinase K ◽  
Mobility Shift ◽  
Cytoplasmic Factor ◽  
Fas Mrna ◽  
Mrna Binding

Glucose stabilizes the mRNA for human fatty acid synthase (FAS), an enzyme relevant to diverse human disorders, including hyperlipidemia, obesity, and malignancy. To determine the underlying mechanisms, RNA gel mobility shift assays were used to demonstrate that human Hep G2 cells contain a cytoplasmic factor that binds specifically to the 3′-terminus of the human FAS mRNA. d-Glucose increased RNA-binding activity by 2.02-fold ( P = 0.0033), with activity peaking 3 h after glucose feeding. Boiling or treatment of extracts with proteinase K abolished binding. Ultraviolet cross-linking of the FAS mRNA-binding factor followed by SDS-PAGE resolved a proteinase K-sensitive band with an apparent molecular mass of 178 ± 7 kDa. The protein was purified to homogeneity using nondenaturing polyacrylamide gels as an affinity matrix. Acid phosphatase treatment of the protein prevented binding to the FAS mRNA, but binding activity was unaffected by modification of sulfhydryl groups and was not Mg2+ or Ca2+ dependent. Deletion and RNase T1 mapping localized the binding site of the protein to 37 nucleotides characterized by the repetitive motif ACCCC and found within the first 65 bases of the 3′-UTR. Hybridization of the FAS transcript with an oligonucleotide antisense to this sequence abolished binding. These findings indicate that a 178-kDa glucose-inducible phosphoprotein binds to an (ACCCC) n -containing sequence in the 3′-UTR of the FAS mRNA within the same time frame that glucose stabilizes the FAS message. This protein may participate in the posttranscriptional control of FAS gene expression.

scholarly journals All five cold-shock domains of unr (upstream of N- ras) are required for stimulation of human rhinovirus RNA translation

2004 ◽  
Vol 85 (8) ◽  
pp. 2279-2287 ◽  
Author(s):  
Emma C. Brown ◽  
Richard J. Jackson
Keyword(s):  
Cold Shock ◽  
Rna Binding ◽  
Binding Activity ◽  
Human Rhinovirus ◽  
Entry Site ◽  
Internal Ribosome Entry ◽  
Rna Translation ◽  
Polypyrimidine Tract Binding Protein ◽  
Stimulation Of

Efficient translation of human rhinovirus-2 (HRV-2) RNA from its internal ribosome entry site (IRES) depends on the presence of cellular trans-acting factors upstream of N- ras (unr) and polypyrimidine-tract-binding protein. unr contains five cold-shock domains (CSDs) and is predicted to act as an RNA chaperone, allowing the HRV-2 IRES to attain the correct conformation for ribosome binding. To investigate the role of each of the CSDs in IRES-dependent translation, five unr mutants, each harbouring a point mutation in a different CSD, were generated. All five mutants were severely impaired in their ability to bind to the IRES and to stimulate translation from it. This showed that the ability of unr to function as an activator of HRV-2 RNA translation requires the RNA-binding activity of all five CSDs.

The rubella virus RNA binding activity of human calreticulin is localized to the N-terminal domain.

1995 ◽  
Vol 69 (6) ◽  
pp. 3848-3851 ◽  
Author(s):  
C D Atreya ◽  
N K Singh ◽  
H L Nakhasi
Keyword(s):  
Rubella Virus ◽  
Rna Binding ◽  
Binding Activity ◽  
Terminal Domain ◽  
Virus Rna

scholarly journals Quantitative proteomics revealed C6orf203/MTRES1 as a factor preventing stress-induced transcription deficiency in human mitochondria

2019 ◽  
Vol 47 (14) ◽  
pp. 7502-7517 ◽  
Author(s):  
Anna V Kotrys ◽  
Dominik Cysewski ◽  
Sylwia D Czarnomska ◽  
Zbigniew Pietras ◽  
Lukasz S Borowski ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Binding ◽  
Mitochondrial Gene ◽  
Binding Activity ◽  
Stress Conditions ◽  
Mitochondrial Rna ◽  
Mitochondrial Gene Expression ◽  
Compensatory Mechanisms ◽  
Temporary Reduction ◽  
Mitochondrial Transcription

AbstractMaintenance of mitochondrial gene expression is crucial for cellular homeostasis. Stress conditions may lead to a temporary reduction of mitochondrial genome copy number, raising the risk of insufficient expression of mitochondrial encoded genes. Little is known how compensatory mechanisms operate to maintain proper mitochondrial transcripts levels upon disturbed transcription and which proteins are involved in them. Here we performed a quantitative proteomic screen to search for proteins that sustain expression of mtDNA under stress conditions. Analysis of stress-induced changes of the human mitochondrial proteome led to the identification of several proteins with poorly defined functions among which we focused on C6orf203, which we named MTRES1 (Mitochondrial Transcription Rescue Factor 1). We found that the level of MTRES1 is elevated in cells under stress and we show that this upregulation of MTRES1 prevents mitochondrial transcript loss under perturbed mitochondrial gene expression. This protective effect depends on the RNA binding activity of MTRES1. Functional analysis revealed that MTRES1 associates with mitochondrial RNA polymerase POLRMT and acts by increasing mitochondrial transcription, without changing the stability of mitochondrial RNAs. We propose that MTRES1 is an example of a protein that protects the cell from mitochondrial RNA loss during stress.

Stimulation of a major subset of lymphocytes expressing T cell receptor γδ by an antigen derived from mycobacterium tuberculosis

Cell ◽  
1989 ◽  
Vol 57 (4) ◽  
pp. 667-674 ◽  
Author(s):  
Rebecca L. O'Brien ◽  
Mary Pat Happ ◽  
Angela Dallas ◽  
Ed Palmer ◽  
Ralph Kubo ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Major Subset ◽  
Stimulation Of

Overexpression of mitochondrial ferritin causes cytosolic iron depletion and changes cellular iron homeostasis

Blood ◽  
2005 ◽  
Vol 105 (5) ◽  
pp. 2161-2167 ◽  
Author(s):  
Guangjun Nie ◽  
Alex D. Sheftel ◽  
Sangwon F. Kim ◽  
Prem Ponka
Keyword(s):  
Iron Homeostasis ◽  
Rna Binding ◽  
Binding Activity ◽  
Intracellular Iron ◽  
Free Radical Damage ◽  
Iron Regulatory Proteins ◽  
Cellular Iron ◽  
Cellular Iron Uptake ◽  
A Cell ◽  
Cellular Iron Homeostasis

AbstractCytosolic ferritin sequesters and stores iron and, consequently, protects cells against iron-mediated free radical damage. However, the function of the newly discovered mitochondrial ferritin (MtFt) is unknown. To examine the role of MtFt in cellular iron metabolism, we established a cell line that stably overexpresses mouse MtFt under the control of a tetracycline-responsive promoter. The overexpression of MtFt caused a dose-dependent iron deficiency in the cytosol that was revealed by increased RNA-binding activity of iron regulatory proteins (IRPs) along with an increase in transferrin receptor levels and decrease in cytosolic ferritin. Consequently, the induction of MtFt resulted in a dramatic increase in cellular iron uptake from transferrin, most of which was incorporated into MtFt. The induction of MtFt caused a shift of iron from cytosolic ferritin to MtFt. In addition, iron inserted into MtFt was less available for chelation than that in cytosolic ferritin and the expression of MtFt was associated with decreased mitochondrial and cytosolic aconitase activities, the latter being consistent with the increase in IRP-binding activity. In conclusion, our results indicate that overexpression of MtFt causes a dramatic change in intracellular iron homeostasis and that shunting iron to MtFt likely limits its availability for active iron proteins.

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