scholarly journals Exploring the role of RRM domains and conserved aromatic residues in RGG motif  of eIF4G-binding translation repressor protein Sbp1

2021 ◽  
Vol 3 ◽  
pp. 102
Author(s):  
Nupur Bhatter ◽  
Rajan Iyyappan ◽  
Gayatri Mohanan ◽  
Purusharth I Rajyaguru
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Genetic Interaction ◽  
Point Mutations ◽  
Site Directed Mutagenesis ◽  
Growth Defect ◽  
Aromatic Residues ◽  
Over Expression ◽  
Rna Granules

Background: RNA binding proteins play crucial role in determining if a given mRNA will be translated, stored, or degraded. Sbp1 is an RGG-motif containing protein that is implicated in affecting mRNA decapping and translation. Sbp1 represses translation by binding eIF4G1 through its RGG-motif and activates decapping when overexpressed. In this report, we have assessed the genetic interaction of Sbp1 with decapping activators such as Dhh1, Pat1, and Scd6. We have further analyzed the importance of different domains and specific conserved residues of Sbp1 in its ability to cause over-expression mediated growth defect. Method: Sequence alignment was performed to identify conserved aromatic residues to be mutated. Using site-directed mutagenesis several point mutations and domain deletions were created in Sbp1 expressed under a galactose-inducible promoter. The mutants were tested for their ability to cause growth defect upon over-expression. The ability of Sbp1 to affect over-expression mediated growth defect of other decapping activators was tested using growth assay. Live cell imaging was done to study localization of Sbp1 and its RRM-deletion mutants to RNA granules upon glucose starvation. Results: Mutation of several aromatic residues in the RGG-motif and that of the phosphorylation sites in the RRM domain of Sbp1 did not affect the growth defect phenotype. Deletion of another eIF4G1-binding RGG-motif protein Scd6 does not affect the ability of Sbp1 to cause growth defect. Moreover, absence of Sbp1 did not affect the growth defect phenotypes observed upon overexpression of decapping activators Dhh1 and Pat1. Strikingly deletion of both the RRM domains (RRM1 and RRM2) and not the RNP motifs within them compromised the growth defect phenotype. Sbp1 mutant lacking both RRM1 and RRM2 was highly defective in localizing to RNA granules.   Conclusion: This study identifies an important role of RRM domains independent of the RNP motif in Sbp1 function.

scholarly journals Exploring the role of RRM domains and conserved aromatic residues in RGG motif  of eIF4G-binding translation repressor protein Sbp1

2020 ◽  
Vol 3 ◽  
pp. 102
Author(s):  
Nupur Bhatter ◽  
Rajan Iyyappan ◽  
Purusharth I Rajyaguru
Keyword(s):  
Genetic Interaction ◽  
Point Mutations ◽  
Inducible Promoter ◽  
Site Directed Mutagenesis ◽  
Growth Defect ◽  
Aromatic Residues ◽  
Over Expression ◽  
Rna Granules ◽  
Rrm Domain

Background: Mechanisms of mRNA fate decisions play an important role in determining if a given mRNA will be translated, stored or degraded upon arrival to cytoplasm. Sbp1 is an important RGG-motif containing protein that is implicated in affecting mRNA decapping and translation. Sbp1 represses translation by binding eIF4G1 through its RGG-motif and activates decapping when overexpressed. In this report we have assessed the genetic interaction of Sbp1 with  decapping activators such as Dhh1, Pat1 and Scd6.  We have further analyzed the importance of different domains and specific conserved residues of Sbp1 in translation repression activity. Method: Sequence alignment was performed to identify conserved aromatic residues to be mutated. Using site-directed mutagenesis several point mutations and domain deletions was created in Sbp1 expressed under a galactose-inducible promoter. The mutants were tested for their ability to cause growth defect upon over-expression. The ability of Sbp1 to affect over expression mediated growth defect of other decapping activators was tested using growth assay. Live cell imaging was done to study localization of Sbp1 and its RRM-deletion mutants to RNA granules upon glucose starvation. Results: Mutation of several aromatic residues in the RGG-motif and that of the phosphorylation sites in the RRM domain of Sbp1 did not affect the growth defect phenotype. Deletion of another eIF4G1-binding RGG-motif protein Scd6 does not affect the ability of Sbp1 to cause growth defect. Moreover, absence of Sbp1 did not affect the growth defect phenotypes observed upon overexpression of decapping activators Dhh1 and Pat1. Strikingly deletion of both the RRM domains (RRM1 and RRM2) and not the RNP motifs within them compromised the growth defect phenotype. Sbp1 mutant lacking both RRM1 and RRM2 was highly defective in localizing to RNA granules.   Conclusion: This study identifies an important role of RRM domains independent of RNP motif in Sbp1 repression activity.

scholarly journals Characterizing mutations in and genetic interactions of RGG-motif translation repressor Sbp1

2018 ◽  
Vol 3 ◽  
pp. 102
Author(s):  
Nupur Bhatter ◽  
Rajan Iyyappan ◽  
Purusharth I Rajyaguru
Keyword(s):  
Mutational Analysis ◽  
Genetic Interaction ◽  
Point Mutations ◽  
Inducible Promoter ◽  
Site Directed Mutagenesis ◽  
Growth Defect ◽  
Aromatic Residues ◽  
Mrna Decapping ◽  
Growth Assay ◽  
Mrna Fate

Background: Mechanisms of mRNA fate decisions play an important role in determining if a given mRNA will be translated, stored or degraded upon arrival to cytoplasm. Sbp1 is an important RGG-motif containing protein that is implicated in mRNA fate decisions since it can affect mRNA decapping and translation. Sbp1 represses translation by binding eIF4G1 through its RGG-motif and activates decapping when overexpressed. In order to understand the amino acids important for translation repression activity of Sbp1 we performed mutational analysis of Sbp1 combined with assessing its genetic interaction with another RGG-motif protein Scd6. We created two classes of point mutations a) in aromatic residues of the RGG-motif and b) in residues reported to be phosphorylated. Method: Sequence alignment was performed to identify aromatic residues to be mutated based on conservation. Site-directed mutagenesis approach was used to create several point mutations in Sbp1 expressed under galactose-inducible promoter. The mutants were tested for their ability to cause growth defect upon overexpression. The ability of Sbp1 to affect repression activity of other decapping activators was tested using the same growth assay. Results: Mutation of several aromatic residues in the RGG-motif of Sbp1 led to a weak rescue phenotype. However the phospho-mimetic mutants of Sbp1 did not lead to any kind of growth defect rescue. Deletion of another eIF4G1-binding RGG-motif protein Scd6 does not affect ability of Sbp1 to cause growth defect. On the other hand absence of Sbp1 does not affect ability of Dhh1 and Pat1 to repress translation. Conclusion: Based on our growth assay analysis we conclude that mutated aromatic residues contribute marginally to repression activity of Sbp1 whereas phospho-mimetic mutants do not alter ability of Sbp1 to cause growth defect. Interestingly Scd6 does not affect ability of Sbp1 to repress translation, which in turn does not affect Dhh1 and Pat1.

scholarly journals The Integral Role of RNA in Stress Granule Formation and Function

2021 ◽  
Vol 9 ◽  
Author(s):  
Danae Campos-Melo ◽  
Zachary C. E. Hawley ◽  
Cristian A. Droppelmann ◽  
Michael J. Strong
Keyword(s):  
Rna Binding ◽  
Viral Infections ◽  
Acute Stress ◽  
Rna Binding Proteins ◽  
Protein Composition ◽  
Current Evidence ◽  
Granule Formation ◽  
Rna Molecules ◽  
Rna Granules

Stress granules (SGs) are phase-separated, membraneless, cytoplasmic ribonucleoprotein (RNP) assemblies whose primary function is to promote cell survival by condensing translationally stalled mRNAs, ribosomal components, translation initiation factors, and RNA-binding proteins (RBPs). While the protein composition and the function of proteins in the compartmentalization and the dynamics of assembly and disassembly of SGs has been a matter of study for several years, the role of RNA in these structures had remained largely unknown. RNA species are, however, not passive members of RNA granules in that RNA by itself can form homo and heterotypic interactions with other RNA molecules leading to phase separation and nucleation of RNA granules. RNA can also function as molecular scaffolds recruiting multivalent RBPs and their interactors to form higher-order structures. With the development of SG purification techniques coupled to RNA-seq, the transcriptomic landscape of SGs is becoming increasingly understood, revealing the enormous potential of RNA to guide the assembly and disassembly of these transient organelles. SGs are not only formed under acute stress conditions but also in response to different diseases such as viral infections, cancer, and neurodegeneration. Importantly, these granules are increasingly being recognized as potential precursors of pathological aggregates in neurodegenerative diseases. In this review, we examine the current evidence in support of RNA playing a significant role in the formation of SGs and explore the concept of SGs as therapeutic targets.

scholarly journals RNA-binding proteins, RNA granules, and gametes: is unity strength?

Reproduction ◽  
2011 ◽  
Vol 142 (6) ◽  
pp. 803-817 ◽  
Author(s):  
Mai Nguyen-Chi ◽  
Dominique Morello
Keyword(s):  
Germ Cells ◽  
Small Rna ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Mrna Translation ◽  
Rna Granules ◽  
Ribonucleoprotein Complexes ◽  
Cytoplasmic Rna

Changes in mRNA translation and degradation represent post-transcriptional processes operating during gametogenesis and early embryogenesis to ensure regulated protein synthesis. Numerous mRNA-binding proteins (RBPs) have been described in multiple animal models that contribute to the control of mRNA translation and decay during oogenesis and spermatogenesis. An emerging view from studies performed in germ cells and somatic cells is that RBPs associate with their target mRNAs in RNA–protein (or ribonucleoprotein) complexes (mRNPs) that assemble in various cytoplasmic RNA granules that communicate with the translation machinery and control mRNA storage, triage, and degradation. In comparison withXenopus, Caenorhabditis elegans, orDrosophila, the composition and role of cytoplasmic RNA-containing granules in mammalian germ cells are still poorly understood. However, regained interest for these structures has emerged with the recent discovery of their role in small RNA synthesis and transposon silencing through DNA methylation. In this review, we will briefly summarize our current knowledge on cytoplasmic RNA granules in murine germ cells and describe the role of some of the RBPs they contain in regulating mRNA metabolism and small RNA processing during gametogenesis.

Translational control mechanisms in metabolic regulation: critical role of RNA binding proteins, microRNAs, and cytoplasmic RNA granules

2011 ◽  
Vol 301 (6) ◽  
pp. E1051-E1064 ◽  
Author(s):  
Khosrow Adeli
Keyword(s):  
Protein Synthesis ◽  
Translational Control ◽  
Metabolic Regulation ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Critical Role ◽  
Mrna Translation ◽  
Rna Granules

Regulated cell metabolism involves acute and chronic regulation of gene expression by various nutritional and endocrine stimuli. To respond effectively to endogenous and exogenous signals, cells require rapid response mechanisms to modulate transcript expression and protein synthesis and cannot, in most cases, rely on control of transcriptional initiation that requires hours to take effect. Thus, co- and posttranslational mechanisms have been increasingly recognized as key modulators of metabolic function. This review highlights the critical role of mRNA translational control in modulation of global protein synthesis as well as specific protein factors that regulate metabolic function. First, the complex lifecycle of eukaryotic mRNAs will be reviewed, including our current understanding of translational control mechanisms, regulation by RNA binding proteins and microRNAs, and the role of RNA granules, including processing bodies and stress granules. Second, the current evidence linking regulation of mRNA translation with normal physiological and metabolic pathways and the associated disease states are reviewed. A growing body of evidence supports a key role of translational control in metabolic regulation and implicates translational mechanisms in the pathogenesis of metabolic disorders such as type 2 diabetes. The review also highlights translational control of apolipoprotein B (apoB) mRNA by insulin as a clear example of endocrine modulation of mRNA translation to bring about changes in specific metabolic pathways. Recent findings made on the role of 5′-untranslated regions (5′-UTR), 3′-UTR, RNA binding proteins, and RNA granules in mediating insulin regulation of apoB mRNA translation, apoB protein synthesis, and hepatic lipoprotein production are discussed.

The Therapeutic Potential and Role of miRNA, lncRNA, and circRNA in Osteoarthritis

2019 ◽  
Vol 19 (4) ◽  
pp. 255-263 ◽  
Author(s):  
Yuangang Wu ◽  
Xiaoxi Lu ◽  
Bin Shen ◽  
Yi Zeng
Keyword(s):  
Gene Expression ◽  
Gene Therapy ◽  
Extracellular Matrix ◽  
Inflammatory Reaction ◽  
Noncoding Rna ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Protein Translation ◽  
Cochrane Library

Background: Osteoarthritis (OA) is a disease characterized by progressive degeneration, joint hyperplasia, narrowing of joint spaces, and extracellular matrix metabolism. Recent studies have shown that the pathogenesis of OA may be related to non-coding RNA, and its pathological mechanism may be an effective way to reduce OA. Objective: The purpose of this review was to investigate the recent progress of miRNA, long noncoding RNA (lncRNA) and circular RNA (circRNA) in gene therapy of OA, discussing the effects of this RNA on gene expression, inflammatory reaction, apoptosis and extracellular matrix in OA. Methods: The following electronic databases were searched, including PubMed, EMBASE, Web of Science, and the Cochrane Library, for published studies involving the miRNA, lncRNA, and circRNA in OA. The outcomes included the gene expression, inflammatory reaction, apoptosis, and extracellular matrix. Results and Discussion: With the development of technology, miRNA, lncRNA, and circRNA have been found in many diseases. More importantly, recent studies have found that RNA interacts with RNA-binding proteins to regulate gene transcription and protein translation, and is involved in various pathological processes of OA, thus becoming a potential therapy for OA. Conclusion: In this paper, we briefly introduced the role of miRNA, lncRNA, and circRNA in the occurrence and development of OA and as a new target for gene therapy.

scholarly journals Current insights into the implications of m6A RNA methylation and autophagy interaction in human diseases

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xuechai Chen ◽  
Jianan Wang ◽  
Muhammad Tahir ◽  
Fangfang Zhang ◽  
Yuanyuan Ran ◽  
...  
Keyword(s):  
Intervertebral Disc Degeneration ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Degradation Process ◽  
Human Diseases ◽  
Rna Modification ◽  
Rna Methylation ◽  
M6a Rna Methylation ◽  
The Impact

AbstractAutophagy is a conserved degradation process crucial to maintaining the primary function of cellular and organismal metabolism. Impaired autophagy could develop numerous diseases, including cancer, cardiomyopathy, neurodegenerative disorders, and aging. N6-methyladenosine (m6A) is the most common RNA modification in eukaryotic cells, and the fate of m6A modified transcripts is controlled by m6A RNA binding proteins. m6A modification influences mRNA alternative splicing, stability, translation, and subcellular localization. Intriguingly, recent studies show that m6A RNA methylation could alter the expression of essential autophagy-related (ATG) genes and influence the autophagy function. Thus, both m6A modification and autophagy could play a crucial role in the onset and progression of various human diseases. In this review, we summarize the latest studies describing the impact of m6A modification in autophagy regulation and discuss the role of m6A modification-autophagy axis in different human diseases, including obesity, heart disease, azoospermatism or oligospermatism, intervertebral disc degeneration, and cancer. The comprehensive understanding of the m6A modification and autophagy interplay may help in interpreting their impact on human diseases and may aid in devising future therapeutic strategies.

DT-03-02: Viewing neurodegeneration beyond the tangle: The role of RNA binding proteins in Alzheimer's disease

2013 ◽  
Vol 9 ◽  
pp. P847-P847
Author(s):  
Benjamin Wolozin ◽  
Tara Vanderweyde ◽  
Liqun Liu-Yesucevitz ◽  
Alpaslan Dedeoglu ◽  
Leonard Petrucelli ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins

scholarly journals Characterization of the Drosophila protein arginine methyltransferases DART1 and DART4

2004 ◽  
Vol 379 (2) ◽  
pp. 283-289 ◽  
Author(s):  
Marie-Chloé BOULANGER ◽  
Tina Branscombe MIRANDA ◽  
Steven CLARKE ◽  
Marco di FRUSCIO ◽  
Beat SUTER ◽  
...  
Keyword(s):  
Rna Binding ◽  
Developmental Stages ◽  
Rna Binding Proteins ◽  
Genetic System ◽  
Arginine Methylation ◽  
Type I ◽  
Protein Arginine Methyltransferases ◽  
Arginine Residues ◽  
Drosophila Protein

The role of arginine methylation in Drosophila melanogaster is unknown. We identified a family of nine PRMTs (protein arginine methyltransferases) by sequence homology with mammalian arginine methyltransferases, which we have named DART1 to DART9 (Drosophilaarginine methyltransferases 1–9). In keeping with the mammalian PRMT nomenclature, DART1, DART4, DART5 and DART7 are the putative homologues of PRMT1, PRMT4, PRMT5 and PRMT7. Other DART family members have a closer resemblance to PRMT1, but do not have identifiable homologues. All nine genes are expressed in Drosophila at various developmental stages. DART1 and DART4 have arginine methyltransferase activity towards substrates, including histones and RNA-binding proteins. Amino acid analysis of the methylated arginine residues confirmed that both DART1 and DART4 catalyse the formation of asymmetrical dimethylated arginine residues and they are type I arginine methyltransferases. The presence of PRMTs in D. melanogaster suggest that flies are a suitable genetic system to study arginine methylation.

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