scholarly journals Cytoplasmic Mislocalization of RNA Polymerase II Subunit RPB1 in Alzheimer Disease Is Linked to Pathologic Tau

2021 ◽  
Author(s):  
John R Dickson ◽  
Hyejin Yoon ◽  
Matthew P Frosch ◽  
Bradley T Hyman
Keyword(s):  
Alzheimer Disease ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Critical Role ◽  
Nucleocytoplasmic Transport ◽  
Immunofluorescence Staining ◽  
Protein Accumulation ◽  
Rtg4510 Mouse ◽  
Age Dependent ◽  
P301l Mutation

Abstract Abnormal protein accumulation and mislocalization is a general hallmark of Alzheimer disease. Recent data suggest nucleocytoplasmic transport may be compromised by tau in Alzheimer disease. In this context, we have examined the RNA polymerase II subunit RPB1, which is the catalytic subunit that plays a critical role in transcription. Using immunofluorescence staining in control and Alzheimer disease hippocampal tissue, we show that 2 phosphoisoforms of RPB1 mislocalize from the nucleus to the cytoplasm of neurons in Alzheimer disease. The number of neurons with this cytoplasmic mislocalization is correlated with the burden of pathologic tau (AT8-immunopositive neurons). In order to test whether there is a causal relationship between pathologic tau and cytoplasmic RPB1 accumulation, we used the rTg4510 mouse model, which expresses a regulatable pathologic human tau species harboring the P301L mutation. Using immunofluorescence staining on brain tissue from young (2.5-month-old) and aged (8.5- to 10-month-old) rTg4510 mice, we found a tau- and age-dependent increase in cytoplasmic mislocalization of Rpb1. In summary, this study provides evidence that tau induces mislocalization of RPB1 in Alzheimer disease, and since RPB1 is essential for transcription, this raises the possibility that RPB1 mislocalization could lead to fundamental alterations in neuronal health.

The roles of nucleolar structure and function in the subcellular location of the HIV-1 Rev protein

1995 ◽  
Vol 108 (8) ◽  
pp. 2811-2823 ◽  
Author(s):  
M. Dundr ◽  
G.H. Leno ◽  
M.L. Hammarskjold ◽  
D. Rekosh ◽  
C. Helga-Maria ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Critical Role ◽  
Regulation Of Expression ◽  
Rna Transcription ◽  
Nucleolar Structure ◽  
Class 1 ◽  
Protein B23 ◽  
Hiv 1 ◽  
Rev Protein

The human immunodeficiency virus 1 (HIV-1) Rev transactivator protein plays a critical role in the regulation of expression of structural proteins by controlling the pathway of mRNA transport. The Rev protein is located predominantly in the nucleoli of HIV-1 infected or Rev-expressing cells. Previous studies demonstrated that the Rev protein forms a specific complex in vitro with protein B23 which is suggested to be a nucleolar receptor and/or carrier for the Rev protein. To study the role of the nucleolus and nucleolar proteins in Rev function, transfected COS-7 or transformed CMT3 cells expressing the Rev protein were examined for subcellular locations of Rev and other proteins using indirect immunofluorescence and immunoelectron microscopy. One day after transfection the Rev protein was found in most cells only in the nucleolar dense fibrillar and granular components where it colocalized with protein B23. These were designated class 1 cells. In a second class of cells Rev and B23 accumulated in the nucleoplasm as well as in nucleoli. Treatment of class 1 cells with actinomycin D (AMD) under conditions that blocked only RNA polymerase I transcription caused Rev to completely redistribute from nucleoli to the cytoplasm. Simultaneously, protein B23 was partially released from nucleoli, mostly into the nucleoplasm, with detectable amounts in the cytoplasm. In cells recovering from AMD treatment in the presence of cycloheximide Rev and B23 showed coincident relocation to nucleoli. Class 2 cells were resistant to AMD-induced Rev redistribution. Selective inhibition of RNA polymerase II transcription by alpha-amanitin or by DRB did not cause Rev to be released into the cytoplasm suggesting that active preribosomal RNA transcription is required for the nucleolar location of Rev. However, treatment with either of the latter two drugs at higher doses and for longer times caused partial disruption of nucleoli accompanied by translocation of the Rev protein to the cytoplasm. These results suggest that the nucleolar location of Rev depends on continuous preribosomal RNA transcription and a substantially intact nucleolar structure.

scholarly journals Novel critical role of a human Mediator complex for basal RNA polymerase II transcription

EMBO Reports ◽  
2001 ◽  
Vol 2 (9) ◽  
pp. 808-813 ◽  
Author(s):  
Gerhard Mittler ◽  
Elisabeth Kremmer ◽  
H Th. Marc Timmers ◽  
Michael Meisterernst
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Critical Role ◽  
Mediator Complex ◽  
Rna Polymerase Ii Transcription

scholarly journals An N-Terminal Region of Lassa Virus L Protein Plays a Critical Role in Transcription but Not Replication of the Virus Genome

2009 ◽  
Vol 84 (4) ◽  
pp. 1934-1944 ◽  
Author(s):  
Michaela Lelke ◽  
Linda Brunotte ◽  
Carola Busch ◽  
Stephan Günther
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Large Scale ◽  
Critical Role ◽  
Terminal Region ◽  
Lassa Virus ◽  
Mrna Synthesis ◽  
L Protein ◽  
Mrna Pool ◽  
Capping Enzymes

ABSTRACT The central domain of the 200-kDa Lassa virus L protein is a putative RNA-dependent RNA polymerase. N- and C-terminal domains may harbor enzymatic functions important for viral mRNA synthesis, including capping enzymes or cap-snatching endoribonucleases. In the present study, we have employed a large-scale mutagenesis approach to map functionally relevant residues in these regions. The main targets were acidic (Asp and Glu) and basic residues (Lys and Arg) known to form catalytic and binding sites of capping enzymes and endoribonucleases. A total of 149 different mutants were generated and tested in the Lassa virus replicon system. Nearly 25% of evolutionarily highly conserved acidic and basic side chains were dispensable for function of L protein in the replicon context. The vast majority of the remaining mutants had defects in both transcription and replication. Seven residues (Asp-89, Glu-102, Asp-119, Lys-122, Asp-129, Glu-180, and Arg-185) were selectively important for mRNA synthesis. The phenotype was particularly pronounced for Asp-89, Glu-102, and Asp-129, which were indispensable for transcription but could be replaced by a variety of amino acid residues without affecting genome replication. Bioinformatics disclosed the remote similarity of this region to type IIs endonucleases. The mutagenesis was complemented by experiments with the RNA polymerase II inhibitor α-amanitin, demonstrating dependence of viral transcription from the cellular mRNA pool. In conclusion, this paper describes an N-terminal region in L protein being important for mRNA, but not genome synthesis. Bioinformatics and cell biological experiments lend support to the hypothesis that this region could be part of a cap-snatching enzyme.

scholarly journals Critical Role of Transcript Cleavage in Arabidopsis RNA Polymerase II Transcriptional Elongation

2020 ◽  
Vol 32 (5) ◽  
pp. 1449-1463 ◽  
Author(s):  
Wojciech Antosz ◽  
Jules Deforges ◽  
Kevin Begcy ◽  
Astrid Bruckmann ◽  
Yves Poirier ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Critical Role ◽  
Transcriptional Elongation ◽  
Transcript Cleavage

scholarly journals Hyperphosphorylation of RNA Polymerase II and Reduced Neuronal RNA Levels Precede Neurofibrillary Tangles in Alzheimer Disease

2001 ◽  
Vol 60 (12) ◽  
pp. 1219-1232 ◽  
Author(s):  
Jacob W. Husseman ◽  
Janice L. Hallows ◽  
David B. Bregman ◽  
James B. Leverenz ◽  
David Nochlin ◽  
...  
Keyword(s):  
Alzheimer Disease ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Neurofibrillary Tangles ◽  
Rna Levels

scholarly journals Probing Zn2+-binding effects on the zinc-ribbon domain of human general transcription factor TFIIB

2004 ◽  
Vol 378 (2) ◽  
pp. 317-324 ◽  
Author(s):  
Mahua GHOSH ◽  
Laura M. ELSBY ◽  
Tapas K. MAL ◽  
Jane M. GOODING ◽  
Stefan G. E. ROBERTS ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Structural Changes ◽  
Core Promoter ◽  
Critical Role ◽  
General Transcription Factor ◽  
Structural Rigidity ◽  
Zinc Ribbon

The general transcription factor, TFIIB, plays an important role in the assembly of the pre-initiation complex. The N-terminal domain (NTD) of TFIIB contains a zinc-ribbon motif, which is responsible for the recruitment of RNA polymerase II and TFIIF to the core promoter region. Although zinc-ribbon motif structures of eukaryotic and archaeal TFIIBs have been reported previously, the structural role of Zn2+ binding to TFIIB remains to be determined. In the present paper, we report NMR and biochemical studies of human TFIIB NTD, which characterize the structure and dynamics of the TFIIB Zn2+-binding domain in both Zn2+-bound and -free states. The NMR data show that, whereas the backbone fold of NTD is pre-formed in the apo state, Zn2+ binding reduces backbone mobility in the β-turn (Arg28–Gly30), induces enhanced structural rigidity of the charged-cluster domain in the central linker region of TFIIB and appends a positive surface charge within the Zn2+-binding site. V8 protease-sensitivity assays of full-length TFIIB support the Zn2+-dependent structural changes. These structural effects of Zn2+ binding on TFIIB may have a critical role in interactions with its binding partners, such as the Rpb1 subunit of RNA polymerase II.

scholarly journals SETD5 modulates homeostasis of hematopoietic stem cells by mediating RNA Polymerase II pausing in cooperation with HCF-1

Leukemia ◽  
2021 ◽  
Author(s):  
Mengke Li ◽  
Chen Qiu ◽  
Yujie Bian ◽  
Deyang Shi ◽  
Bichen Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Rna Polymerase ◽  
Hematopoietic Stem Cells ◽  
Rna Polymerase Ii ◽  
Critical Role ◽  
Whole Body ◽  
Hematopoietic Stem ◽  
Pol Ii

AbstractSETD5 mutations were identified as the genetic causes of neurodevelopmental disorders. While the whole-body knockout of Setd5 in mice leads to embryonic lethality, the role of SETD5 in adult stem cell remains unexplored. Here, a critical role of Setd5 in hematopoietic stem cells (HSCs) is identified. Specific deletion of Setd5 in hematopoietic system significantly increased the number of immunophenotypic HSCs by promoting HSC proliferation. Setd5-deficient HSCs exhibited impaired long-term self-renewal capacity and multiple-lineage differentiation potentials under transplantation pressure. Transcriptome analysis of Setd5-deficient HSCs revealed a disruption of quiescence state of long-term HSCs, a cause of the exhaustion of functional HSCs. Mechanistically, SETD5 was shown to regulate HSC quiescence by mediating the release of promoter-proximal paused RNA polymerase II (Pol II) on E2F targets in cooperation with HCF-1 and PAF1 complex. Taken together, these findings reveal an essential role of SETD5 in regulating Pol II pausing-mediated maintenance of adult stem cells.

scholarly journals RPAP2 regulates a transcription initiation checkpoint by prohibiting assembly of preinitiation complex

2021 ◽  
Author(s):  
Xizi Chen ◽  
Yilun Qi ◽  
Xinxin Wang ◽  
Zhenning Wang ◽  
Li Wang ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Phosphatase Activity ◽  
Transcription Initiation ◽  
Critical Role ◽  
In Vitro Transcription ◽  
Pol Ii ◽  
Activity Structure

RNA polymerase II (Pol II)-mediated transcription in metazoan requires precise regulation. RNA polymerase II-associated protein 2 (RPAP2) was previously identified to transport Pol II from cytoplasm to nucleus and dephosphorylates Pol II C-terminal domain (CTD). We found that RPAP2 binds hypo/hyper-phosphorylated Pol II with undetectable phosphatase activity. Structure of RPAP2-Pol II shows mutually exclusive assembly of RPAP2-Pol II and pre-initiation complex (PIC) due to three steric clashes. RPAP2 prevents/disrupts Pol II-TFIIF interaction and impairs in vitro transcription initiation, suggesting a function in prohibiting PIC assembly. Loss of RPAP2 in cells leads to global accumulation of TFIIF and Pol II at promoters, indicating critical role of RPAP2 in inhibiting PIC assembly independent of its putative phosphatase activity. Our study indicates that RPAP2 functions as a gatekeeper to prohibit PIC assembly and transcription initiation and suggests a novel transcription checkpoint.

Kinetics of HCMV immediate early mRNA expression in stably transfected fibroblasts

2002 ◽  
Vol 115 (2) ◽  
pp. 321-328
Author(s):  
Sabine P. Snaar ◽  
Pauline Verdijk ◽  
Hans J. Tanke ◽  
Roeland W. Dirks
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Expression System ◽  
Nucleocytoplasmic Transport ◽  
Immediate Early ◽  
Confocal Scanning Laser Microscopy ◽  
Limiting Factor ◽  
Half Time ◽  
Time And Space ◽  
Confocal Scanning Laser

Compelling evidence supports an intimate link in time and space between eukaryotic pre-mRNA synthesis and processing and nucleocytoplasmic transport of mature mRNA. In this study, we analyzed the kinetic behavior of these processes in a quantitative manner. We used FISH and confocal scanning laser microscopy to detect transcripts produced by an inducible human cytomegalovirus immediate early (HCMV-IE) expression system. Upon induction, a large amount of pre-mRNA accumulated in nuclear foci at or near their transcription sites and, at later time, throughout the nucleoplasm. Inhibition of RNA polymerase II activity resulted in a rapid decrease in the number of transcripts in the nuclear RNA foci (half time ∼two minutes), indicating that accumulated transcripts were rapidly spliced and then released. The dispersed nucleoplasmic transcripts exited the nucleus with a half time of ∼10 minutes. Both processes were temperature dependent, suggesting that mRNA export is an active process. RNA polymerase II activation revealed that production of mature HCMV IE mRNAs required less than five minutes. Transcripts radiated from the gene at an average speed of ∼0.13 μm2/sec from this time on. Thus, it appears that these processes are tightly linked in time and space, with the splicing reaction as a rate-limiting factor.

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