scholarly journals Intrinsically disordered protein RBM14 plays a role in generation of RNA:DNA hybrids at double-strand break sites

2020 ◽  
Vol 117 (10) ◽  
pp. 5329-5338 ◽  
Author(s):  
Yumi Jang ◽  
Zeinab Elsayed ◽  
Rebeka Eki ◽  
Shuaixin He ◽  
Kang-Ping Du ◽  
...  
Keyword(s):  
Dna Damage ◽  
Rna Polymerase Ii ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Intrinsically Disordered Protein ◽  
Strand Break ◽  
Dependent Manner ◽  
Intrinsically Disordered ◽  
Disordered Protein ◽  
Rna:Dna Hybrids

Accumulating evidence suggests participation of RNA-binding proteins with intrinsically disordered domains (IDPs) in the DNA damage response (DDR). These IDPs form liquid compartments at DNA damage sites in a poly(ADP ribose) (PAR)-dependent manner. However, it is greatly unknown how the IDPs are involved in DDR. We have shown previously that one of the IDPs RBM14 is required for the canonical nonhomologous end joining (cNHEJ). Here we show that RBM14 is recruited to DNA damage sites in a PARP- and RNA polymerase II (RNAPII)-dependent manner. Both KU and RBM14 are required for RNAPII-dependent generation of RNA:DNA hybrids at DNA damage sites. In fact, RBM14 binds to RNA:DNA hybrids. Furthermore, RNA:DNA hybrids and RNAPII are detected at gene-coding as well as at intergenic areas when double-strand breaks (DSBs) are induced. We propose that the cNHEJ pathway utilizes damage-induced transcription and intrinsically disordered protein RBM14 for efficient repair of DSBs.

scholarly journals The Role of Small Noncoding RNA in DNA Double-Strand Break Repair

2020 ◽  
Vol 21 (21) ◽  
pp. 8039
Author(s):  
Iwona Rzeszutek ◽  
Gabriela Betlej
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Noncoding Rna ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Strand Break ◽  
Double Strand Break ◽  
Wide Range ◽  
Damage Response

DNA damage is a common phenomenon promoted through a variety of exogenous and endogenous factors. The DNA damage response (DDR) pathway involves a wide range of proteins, and as was indicated, small noncoding RNAs (sncRNAs). These are double-strand break-induced RNAs (diRNAs) and DNA damage response small RNA (DDRNA). Moreover, RNA binding proteins (RBPs) and RNA modifications have also been identified to modulate diRNA and DDRNA function in the DDR process. Several theories have been formulated regarding the synthesis and function of these sncRNAs during DNA repair; nevertheless, these pathways’ molecular details remain unclear. Here, we review the current knowledge regarding the mechanisms of diRNA and DDRNA biosynthesis and discuss the role of sncRNAs in maintaining genome stability.

scholarly journals P54nrb Forms a Heterodimer with PSP1 That Localizes to Paraspeckles in an RNA-dependent Manner

2005 ◽  
Vol 16 (11) ◽  
pp. 5304-5315 ◽  
Author(s):  
Archa H. Fox ◽  
Charles S. Bond ◽  
Angus I. Lamond
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Sequence Similarity ◽  
Dependent Manner ◽  
Rna Pol Ii ◽  
Nuclear Processes ◽  
Rna Polymerase Ii Transcription

P54nrb is a protein implicated in multiple nuclear processes whose specific functions may correlate with its presence at different nuclear locations. Here we characterize paraspeckles, a subnuclear domain containing p54nrb and other RNA-binding proteins including PSP1, a protein with sequence similarity to p54nrb that acts as a marker for paraspeckles. We show that PSP1 interacts in vivo with a subset of the total cellular pool of p54nrb. We map the domain within PSP1 that is mediating this interaction and show it is required for the correct localization of PSP1 to paraspeckles. This interaction is necessary but not sufficient for paraspeckle targeting by PSP1, which also requires an RRM capable of RNA binding. Blocking the reinitiation of RNA Pol II transcription at the end of mitosis with DRB prevents paraspeckle formation, which recommences after removal of DRB, indicating that paraspeckle formation is dependent on RNA Polymerase II transcription. Thus paraspeckles are the sites where a subset of the total cellular pool of p54nrb is targeted in a RNA Polymerase II-dependent manner.

scholarly journals Molecular Swiss Army Knives: Tardigrade CAHS Proteins Mediate Desiccation Tolerance Through Multiple Mechanisms

2021 ◽  
Author(s):  
Cherie S. Hesgrove ◽  
Kenny H. Nguyen ◽  
Sourav Biswas ◽  
Charles A. Childs ◽  
Shraddha KC ◽  
...  
Keyword(s):  
Robust Stabilization ◽  
Intrinsically Disordered Protein ◽  
Residual Water ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Intrinsically Disordered ◽  
Disordered Protein ◽  
Animal Physiology ◽  
Gel Phase ◽  
Water Bears

Tardigrades, also known as water bears, make up a phylum of small but extremely robust animals renowned for their ability to survive extreme stresses including desiccation. How tardigrades survive desiccation is one of the enduring mysteries of animal physiology. Here we show that CAHS D, an intrinsically disordered protein belonging to a unique family of proteins possessed only by tardigrades, undergoes a liquid-to-gel phase transition in a concentration dependent manner. Unlike other gelling proteins such as gelatin, our data support a mechanism in which gelation of CAHS D is driven by intermolecular beta-beta interactions. We find that gelation of CAHS D promotes the slowing of diffusion, and coordination of residual water. Slowed diffusion and increased water coordination correlate with the ability of CAHS D to provide robust stabilization of an enzyme, lactate dehydrogenase, which otherwise unfolds when dried. Conversely, slowed diffusion and water coordination do not promote the prevention of protein aggregation during drying. Our study demonstrates that distinct mechanisms are required for holistic protection during desiccation, and that protectants, such as CAHS D, can act as "molecular Swiss army knives" capable of providing protection through several different mechanisms simultaneously.

scholarly journals Spatial patterning of P granules by RNA-induced phase separation of the intrinsically-disordered protein MEG-3

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Jarrett Smith ◽  
Deepika Calidas ◽  
Helen Schmidt ◽  
Tu Lu ◽  
Dominique Rasoloson ◽  
...  
Keyword(s):  
Phase Separation ◽  
Rna Binding ◽  
Intrinsically Disordered Protein ◽  
General Mechanism ◽  
P Granules ◽  
Rna Granules ◽  
Intrinsically Disordered ◽  
Disordered Protein

RNA granules are non-membrane bound cellular compartments that contain RNA and RNA binding proteins. The molecular mechanisms that regulate the spatial distribution of RNA granules in cells are poorly understood. During polarization of the C. elegans zygote, germline RNA granules, called P granules, assemble preferentially in the posterior cytoplasm. We present evidence that P granule asymmetry depends on RNA-induced phase separation of the granule scaffold MEG-3. MEG-3 is an intrinsically disordered protein that binds and phase separates with RNA in vitro. In vivo, MEG-3 forms a posterior-rich concentration gradient that is anti-correlated with a gradient in the RNA-binding protein MEX-5. MEX-5 is necessary and sufficient to suppress MEG-3 granule formation in vivo, and suppresses RNA-induced MEG-3 phase separation in vitro. Our findings suggest that MEX-5 interferes with MEG-3’s access to RNA, thus locally suppressing MEG-3 phase separation to drive P granule asymmetry. Regulated access to RNA, combined with RNA-induced phase separation of key scaffolding proteins, may be a general mechanism for controlling the formation of RNA granules in space and time.

scholarly journals Fission Yeast Puf2, a Pumilio and FBF Family RNA-Binding Protein, Links Stress Granules to Processing Bodies

2020 ◽  
Vol 40 (9) ◽  
Author(s):  
Wan-Yi Hsiao ◽  
Yi-Ting Wang ◽  
Shao-Win Wang
Keyword(s):  
Fission Yeast ◽  
Rna Binding ◽  
Fluorescent Protein ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Intrinsically Disordered Protein ◽  
Stress Granules ◽  
Low Complexity ◽  
Processing Bodies ◽  
Intrinsically Disordered

ABSTRACT Stress granules (SGs) are cytoplasmic aggregates formed upon stress when untranslated messenger ribonucleoproteins accumulate in the cells. In a green fluorescent protein library screening of the fission yeast SG proteins, Puf2 of the PUF family of RNA-binding proteins was identified that is required for SG formation after deprivation of glucose. Accordingly, the puf2 mutant is defective in recovery from glucose starvation with a much longer lag to reenter the cell cycle. In keeping with these results, Puf2 contains several low-complexity and intrinsically disordered protein regions with a tendency to form aggregates and, when overexpressed, it represses translation to induce aggregation of poly(A) binding protein Pabp, the signature constituent of SGs. Intriguingly, overexpression of Puf2 also enhances the structure of processing bodies (PBs), another type of cytoplasmic RNA granule, a complex of factors involved in mRNA degradation. In this study, we demonstrate a function of the fission yeast PB in SG formation and show Puf2 may provide a link between these two structures.

scholarly journals The Non-Fibrillating N-Terminal of α-Synuclein Binds and Co-Fibrillates with Heparin

Biomolecules ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1192
Author(s):  
Line K. Skaanning ◽  
Angelo Santoro ◽  
Thomas Skamris ◽  
Jacob Hertz Martinsen ◽  
Anna Maria D’Ursi ◽  
...  
Keyword(s):  
Heparan Sulfate ◽  
Structural Changes ◽  
Lewy Bodies ◽  
Intrinsically Disordered Protein ◽  
Molar Ratio ◽  
Type I ◽  
Dependent Manner ◽  
Intrinsically Disordered ◽  
Disordered Protein ◽  
Main Component

The intrinsically disordered protein α-synuclein (aSN) is, in its fibrillated state, the main component of Lewy bodies—hallmarks of Parkinson’s disease. Additional Lewy body components include glycosaminoglycans, including heparan sulfate proteoglycans. In humans, heparan sulfate has, in an age-dependent manner, shown increased levels of sulfation. Heparin, a highly sulfated glycosaminoglycan, is a relevant mimic for mature heparan sulfate and has been shown to influence aSN fibrillation. Here, we decompose the underlying properties of the interaction between heparin and aSN and the effect of heparin on fibrillation. Via the isolation of the first 61 residues of aSN, which lacked intrinsic fibrillation propensity, fibrillation could be induced by heparin, and access to the initial steps in fibrillation was possible. Here, structural changes with shifts from disorder via type I β-turns to β-sheets were revealed, correlating with an increase in the aSN1–61/heparin molar ratio. Fluorescence microscopy revealed that heparin and aSN1–61 co-exist in the final fibrils. We conclude that heparin can induce the fibrillation of aSN1–61, through binding to the N-terminal with an affinity that is higher in the truncated form of aSN. It does so by specifically modulating the structure of aSN via the formation of type I β-turn structures likely critical for triggering aSN fibrillation.

scholarly journals Spatial patterning of P granules by RNA-induced phase separation of the intrinsically-disordered protein MEG-3

2016 ◽  
Author(s):  
Jarrett Smith ◽  
Deepika Calidas ◽  
Helen Schmidt ◽  
Tu Lu ◽  
Dominique Rasoloson ◽  
...  
Keyword(s):  
Phase Separation ◽  
Rna Binding ◽  
Intrinsically Disordered Protein ◽  
P Granules ◽  
C Elegans ◽  
Rna Granules ◽  
Intrinsically Disordered ◽  
Disordered Protein

ABSTRACTRNA granules are non-membrane bound cellular compartments that contain RNA and RNA binding proteins. The molecular mechanisms that regulate the spatial distribution of RNA granules in cells are poorly understood. During polarization of the C. elegans zygote, germline RNA granules, called P granules, assemble preferentially in the posterior cytoplasm. We present evidence that P granule asymmetry depends on RNA-induced phase separation of the granule scaffold MEG-3. MEG-3 is an intrinsically disordered protein that binds and phase separates with RNA in vitro. In vivo, MEG-3 forms a posterior-rich concentration gradient that is anti-correlated with a gradient in the RNA-binding protein MEX-5. MEX-5 is necessary and sufficient to suppress MEG-3 granule formation in vivo, and suppresses RNA-induced MEG-3 phase separation in vitro. Our findings support a model whereby MEX-5 functions as an mRNA sink to locally suppress MEG-3 phase separation and drive P granule asymmetry.HIGHLIGHTS- The intrinsically-disordered protein MEG-3 is essential for localized assembly of P granules in C. elegans zygotes.- MEG-3 binds RNA and RNA stimulates MEG-3 phase separation.- The RNA-binding protein MEX-5 inhibits MEG-3 granule assembly in the anterior cytoplasm by sequestering RNA.

Self-Assembling Micelles Based on an Intrinsically Disordered Protein Domain

2018 ◽  
Author(s):  
Sarah Klass ◽  
Matthew J. Smith ◽  
Tahoe Fiala ◽  
Jessica Lee ◽  
Anthony Omole ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Fusion Proteins ◽  
Organic Molecules ◽  
Intrinsically Disordered Protein ◽  
Protein Domain ◽  
Enzymatic Cleavage ◽  
Intrinsically Disordered ◽  
Disordered Protein ◽  
Self Assembling ◽  
Protein Tag

Herein, we describe a new series of fusion proteins that have been developed to self-assemble spontaneously into stable micelles that are 27 nm in diameter after enzymatic cleavage of a solubilizing protein tag. The sequences of the proteins are based on a human intrinsically disordered protein, which has been appended with a hydrophobic segment. The micelles were found to form across a broad range of pH, ionic strength, and temperature conditions, with critical micelle concentration (CMC) values below 1 µM being observed in some cases. The reported micelles were found to solubilize hydrophobic metal complexes and organic molecules, suggesting their potential suitability for catalysis and drug delivery applications.

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