scholarly journals Inhibition of Transcription Induces Phosphorylation of YB-1 at Ser102 and Its Accumulation in the Nucleus

Cells ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 104 ◽  
Author(s):  
Dmitry A. Kretov ◽  
Daria A. Mordovkina ◽  
Irina A. Eliseeva ◽  
Dmitry N. Lyabin ◽  
Dmitry N. Polyakov ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Polymerase Ii ◽  
Nuclear Localization ◽  
Kinase Activity ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Regulatory Mechanisms ◽  
Nuclear Accumulation ◽  
Nuclear Retention ◽  
Post Translational Modifications

The Y-box binding protein 1 (YB-1) is an RNA/DNA-binding protein regulating gene expression in the cytoplasm and the nucleus. Although mostly cytoplasmic, YB-1 accumulates in the nucleus under stress conditions. Its nuclear localization is associated with aggressiveness and multidrug resistance of cancer cells, which makes the understanding of the regulatory mechanisms of YB-1 subcellular distribution essential. Here, we report that inhibition of RNA polymerase II (RNAPII) activity results in the nuclear accumulation of YB-1 accompanied by its phosphorylation at Ser102. The inhibition of kinase activity reduces YB-1 phosphorylation and its accumulation in the nucleus. The presence of RNA in the nucleus is shown to be required for the nuclear retention of YB-1. Thus, the subcellular localization of YB-1 depends on its post-translational modifications (PTMs) and intracellular RNA distribution.

scholarly journals TOR signaling modulates Cdk8-dependent GAL gene expression in Saccharomyces cerevisiae

2020 ◽  
Author(s):  
Nicole Hawe ◽  
Konstantin Mestnikov ◽  
Riley Horvath ◽  
Mariam Eji-Lasisi ◽  
Cindy Lam ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Polymerase Ii ◽  
Nuclear Localization ◽  
Kinase Activity ◽  
Mediator Complex ◽  
Tor Signaling ◽  
A Subunit ◽  
Insight Into

AbstractCdk8 of the RNA Polymerase II mediator complex regulates genes by phosphorylating sequence specific transcription factors. Despite conserved importance for eukaryotic transcriptional regulation, the signals regulating Cdk8 are unknown. Full induction of the yeast GAL genes requires phosphorylation of Gal4 by Cdk8, and we exploited this requirement for growth of gal3 yeast on galactose to identify mutants affecting Cdk8 activity. Several mutants from the screen produced defects in TOR signaling. A mutant designated gal four throttle (gft) 1, gft1, was identified as an allele of hom3, encoding aspartokinase. Defects in gft1/ hom3 caused hypersensitivity to rapamycin, and constitutive nuclear localization of Gat1. Furthermore, mutations of tor1 or tco89, encoding TORC1 components, also prevented GAL expression in gal3 yeast, and tco89 was determined to be allelic to gft7. Disruption of cdc55, encoding a subunit of PP2A regulated by TOR signaling, suppressed the effect of gft1/ hom3, gft7/ tco89, and tor1 mutations on GAL expression in gal3 yeast, but not of cdk8/ srb10 disruptions or Gal4 S699A mutation. Mutations of gft1/ hom3 and tor1 did not affect kinase activity of Cdk8 in vitro, but caused loss of Gal4 phosphorylation in vivo. These observations demonstrate that TOR signaling regulates GAL induction through the activity of PP2A/ Cdc55, and are consistent with the contention that Cdk8-dependent phosphorylation of Gal4 S699 is opposed by PP2A/ Cdc55 dephosphorylation. These results provide insight into how induction of transcription by a specific inducer can be modulated by global nutritional signals through regulation of Cdk8-dependent phosphorylation.

scholarly journals Nuclear Import of Cytoplasmic Poly(A) Binding Protein Restricts Gene Expression via Hyperadenylation and Nuclear Retention of mRNA

2010 ◽  
Vol 30 (21) ◽  
pp. 4996-5008 ◽  
Author(s):  
G. Renuka Kumar ◽  
Britt A. Glaunsinger
Keyword(s):  
Gene Expression ◽  
Binding Protein ◽  
Tail Length ◽  
Nuclear Accumulation ◽  
Cellular Gene ◽  
Nuclear Retention ◽  
Signal Degradation ◽  
Mrna Fate ◽  
Influence Gene Expression ◽  
Important Marker

ABSTRACT Poly(A) tail length is emerging as an important marker of mRNA fate, where deviations from the canonical length can signal degradation or nuclear retention of transcripts. Pathways regulating polyadenylation thus have the potential to broadly influence gene expression. Here we demonstrate that accumulation of cytoplasmic poly(A) binding protein (PABPC) in the nucleus, which can occur during viral infection or other forms of cellular stress, causes mRNA hyperadenylation and nuclear accumulation of poly(A) RNA. This inhibits gene expression but does not affect mRNA stability. Unexpectedly, PABPC-induced hyperadenylation can occur independently of mRNA 3′-end processing yet requires the canonical mRNA poly(A) polymerase II. We find that nuclear PABPC-induced hyperadenylation is triggered by multiple divergent viral factors, suggesting that altering the subcellular localization of PABPC may be a commonly used mechanism to regulate cellular gene expression in a polyadenylation-linked manner.

scholarly journals A novel DNA-binding protein regulates sexual differentiation in malaria parasites and is essential for transmission

2020 ◽  
Author(s):  
Riward Campelo Morillo ◽  
Xinran Tong ◽  
Wei Xie ◽  
Todd Lenz ◽  
Gayani Batugedara ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Binding ◽  
Sexual Differentiation ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Homeodomain Protein ◽  
Mosquito Vector ◽  
Malaria Parasites ◽  
Membrane Complex ◽  
Inner Membrane Complex

ABSTRACTTransmission of Plasmodium falciparum and other malaria parasites requires their differentiation from asexual blood stages into gametocytes, the non-replicative sexual stage necessary for transmission to the mosquito vector. This transition involves changes in gene expression and chromatin reorganization mediating the silencing and activation of stage-specific genes. However, malaria parasites have been noted for their dearth of transcriptional and chromatin regulators and the molecular mediators of these changes remain largely unknown. We identified Homeodomain protein 1 (HDP1) as a novel chromatin-associated DNA-binding protein that drives changes in chromatin structure and gene expression during early sexual differentiation. This discovery of a homeodomain-like DNA-binding protein marks a new class of transcriptional regulator in malaria parasites outside of the better-characterized ApiAP2 family. In this study, we demonstrate that HDP1 is required for gametocyte maturation and parasite transmission by driving the necessary upregulation of inner membrane complex components in early gametocytes.

scholarly journals Gene D5 product of bacteriophage T5: DNA-binding protein affecting DNA replication and late gene expression.

1979 ◽  
Vol 29 (1) ◽  
pp. 322-327 ◽  
Author(s):  
D J McCorquodale ◽  
J Gossling ◽  
R Benzinger ◽  
R Chesney ◽  
L Lawhorne ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Replication ◽  
Dna Binding ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Late Gene ◽  
Late Gene Expression ◽  
Bacteriophage T5

scholarly journals Nuclear Accumulation of IE62, the Varicella-Zoster Virus (VZV) Major Transcriptional Regulatory Protein, Is Inhibited by Phosphorylation Mediated by the VZV Open Reading Frame 66 Protein Kinase

2000 ◽  
Vol 74 (5) ◽  
pp. 2265-2277 ◽  
Author(s):  
Paul R. Kinchington ◽  
Karen Fite ◽  
Stephanie E. Turse
Keyword(s):  
Protein Kinase ◽  
Varicella Zoster Virus ◽  
Nuclear Localization ◽  
Kinase Activity ◽  
Open Reading Frame ◽  
Nuclear Accumulation ◽  
Protein Kinase Activity ◽  
Reading Frame ◽  
Varicella Zoster ◽  
In Cells

ABSTRACT IE62, the major transcriptional activator protein encoded by varicella-zoster virus (VZV), locates to the nucleus when expressed in transfected cells. We show here that cytoplasmic forms of IE62 accumulate in transfected and VZV-infected cells as the result of the protein kinase activity associated with VZV open reading frame 66 (ORF66). Expression of the ORF66 protein kinase but not the VZV ORF47 protein kinase impaired the ability of coexpressed IE62 to transactivate promoter-reporter constructs. IE62 that was coexpressed with the ORF66 protein accumulated predominantly in the cytoplasm, whereas the normal nuclear localization of other proteins was not affected by the ORF66 protein. In cells infected with VZV, IE62 accumulated in the cytoplasm at late times of infection, whereas in cells infected with a VZV recombinant unable to express ORF66 protein (ROka66S), IE62 was completely nuclear. Point mutations introduced into the predicted serine/threonine catalytic domain and ATP binding domain of ORF66 abrogated its ability to influence IE62 nuclear localization, indicating that the protein kinase activity was required. The region of IE62 that was targeted by ORF66 was mapped to amino acids 602 to 733. IE62 peptides containing this region were specifically phosphorylated in cells coexpressing the ORF66 protein kinase and in cells infected with wild-type VZV but were not phosphorylated in cells infected with ROka66S. We conclude that the ORF66 protein kinase phosphorylates IE62 to induce its cytoplasmic accumulation, most likely by inhibiting IE62 nuclear import.

scholarly journals REB1, a yeast DNA-binding protein with many targets, is essential for growth and bears some resemblance to the oncogene myb.

1990 ◽  
Vol 10 (10) ◽  
pp. 5226-5234 ◽  
Author(s):  
Q D Ju ◽  
B E Morrow ◽  
J R Warner
Keyword(s):  
Amino Acids ◽  
Dna Binding ◽  
Rna Polymerase Ii ◽  
Essential Gene ◽  
Binding Protein ◽  
Consensus Sequence ◽  
Physiological Role ◽  
Dna Binding Protein ◽  
Reading Frame ◽  
Chromosome Ii

REB1 is a DNA-binding protein that recognizes sites within both the enhancer and the promoter of rRNA transcription as well as upstream of many genes transcribed by RNA polymerase II. We report here the cloning of the gene for REB1 by screening a yeast genomic lambda gt11 library with specific oligonucleotides containing the REB1 binding site consensus sequence. The REB1 gene was sequenced, revealing an open reading frame encoding 809 amino acids. The predicted protein was highly hydrophilic, with numerous OH-containing amino acids and glutamines, features common to many of the general DNA-binding proteins of Saccharomyces cerevisiae, such as ABF1, RAP1, GCN4, and HSF1. There was some homology between a portion of REB1 and the DNA-binding domain of the oncogene myb. REB1 is an essential gene that maps on chromosome II. However, the physiological role that it plays in the cell has yet to be established.

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