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 Identification of calreticulin as a rubella virus RNA binding protein.

1994 ◽  
Vol 91 (26) ◽  
pp. 12770-12774 ◽  
Author(s):  
N. K. Singh ◽  
C. D. Atreya ◽  
H. L. Nakhasi
Keyword(s):  
Rubella Virus ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Virus Rna

scholarly journals Arginine-Rich Motifs Are Not Required for Hepatitis Delta Virus RNA Binding Activity of the Hepatitis Delta Antigen

2013 ◽  
Vol 87 (15) ◽  
pp. 8665-8674 ◽  
Author(s):  
L. H. Daigh ◽  
B. L. Griffin ◽  
A. Soroush ◽  
M. R. Mamedov ◽  
J. L. Casey
Keyword(s):  
Hepatitis Delta Virus ◽  
Rna Binding ◽  
Binding Activity ◽  
Hepatitis Delta ◽  
Delta Antigen ◽  
Virus Rna ◽  
Hepatitis Delta Antigen ◽  
Delta Virus

scholarly journals Phosphorylation of Rubella Virus Capsid Regulates Its RNA Binding Activity and Virus Replication

2003 ◽  
Vol 77 (3) ◽  
pp. 1764-1771 ◽  
Author(s):  
Lok Man J. Law ◽  
Jason C. Everitt ◽  
Martin D. Beatch ◽  
Charles F. B. Holmes ◽  
Tom C. Hobman
Keyword(s):  
Virus Replication ◽  
Rubella Virus ◽  
Rna Binding ◽  
Virus Assembly ◽  
Binding Activity ◽  
Viral Rna ◽  
Wild Type Virus ◽  
Genomic Rna ◽  
Wild Type ◽  
Positive Strand Rna

ABSTRACT Rubella virus is an enveloped positive-strand RNA virus of the family Togaviridae. Virions are composed of three structural proteins: a capsid and two membrane-spanning glycoproteins, E2 and E1. During virus assembly, the capsid interacts with genomic RNA to form nucleocapsids. In the present study, we have investigated the role of capsid phosphorylation in virus replication. We have identified a single serine residue within the RNA binding region that is required for normal phosphorylation of this protein. The importance of capsid phosphorylation in virus replication was demonstrated by the fact that recombinant viruses encoding hypophosphorylated capsids replicated at much lower titers and were less cytopathic than wild-type virus. Nonphosphorylated mutant capsid proteins exhibited higher affinities for viral RNA than wild-type phosphorylated capsids. Capsid protein isolated from wild-type strain virions bound viral RNA more efficiently than cell-associated capsid. However, the RNA-binding activity of cell-associated capsids increased dramatically after treatment with phosphatase, suggesting that the capsid is dephosphorylated during virus assembly. In vitro assays indicate that the capsid may be a substrate for protein phosphatase 1A. As capsid is heavily phosphorylated under conditions where virus assembly does not occur, we propose that phosphorylation serves to negatively regulate binding of viral genomic RNA. This may delay the initiation of nucleocapsid assembly until sufficient amounts of virus glycoproteins accumulate at the budding site and/or prevent nonspecific binding to cellular RNA when levels of genomic RNA are low. It follows that at a late stage in replication, the capsid may undergo dephosphorylation before nucleocapsid assembly occurs.

scholarly journals Analyses of Phosphorylation Events in the Rubella Virus Capsid Protein: Role in Early Replication Events

2006 ◽  
Vol 80 (14) ◽  
pp. 6917-6925 ◽  
Author(s):  
LokMan J. Law ◽  
Carolina S. Ilkow ◽  
Wen-Pin Tzeng ◽  
Matthew Rawluk ◽  
David T. Stuart ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Rubella Virus ◽  
Rna Binding ◽  
Virus Assembly ◽  
Binding Activity ◽  
Amino Acid Residues ◽  
Direct Role ◽  
Virus Capsid ◽  
Early Replication ◽  
Virus Capsid Protein

ABSTRACT The Rubella virus capsid protein is phosphorylated prior to virus assembly. Our previous data are consistent with a model in which dynamic phosphorylation of the capsid regulates its RNA binding activity and, in turn, nucleocapsid assembly. In the present study, the process of capsid phosphorylation was examined in further detail. We show that phosphorylation of serine 46 in the RNA binding region of the capsid is required to trigger phosphorylation of additional amino acid residues that include threonine 47. This residue likely plays a direct role in regulating the binding of genomic RNA to the capsid. We also provide evidence which suggests that the capsid is dephosphorylated prior to or during virus budding. Finally, whereas the phosphorylation state of the capsid does not directly influence the rate of synthesis of viral RNA and proteins or the assembly and secretion of virions, the presence of phosphate on the capsid is critical for early events in virus replication, most likely the uncoating of virions and/or disassembly of nucleocapsids.

RNA secondary structure dependence in METTL3–METTL14 mRNA methylation is modulated by the N-terminal domain of METTL3

2020 ◽  
Vol 402 (1) ◽  
pp. 89-98
Author(s):  
Nathalie Meiser ◽  
Nicole Mench ◽  
Martin Hengesbach
Keyword(s):  
Secondary Structure ◽  
Rna Binding ◽  
Specific Protein ◽  
Structure Dependence ◽  
Terminal Domain ◽  
Methylation Assay ◽  
A Site ◽  
Methylation Activity

AbstractN6-methyladenosine (m6A) is the most abundant modification in mRNA. The core of the human N6-methyltransferase complex (MTC) is formed by a heterodimer consisting of METTL3 and METTL14, which specifically catalyzes m6A formation within an RRACH sequence context. Using recombinant proteins in a site-specific methylation assay that allows determination of quantitative methylation yields, our results show that this complex methylates its target RNAs not only sequence but also secondary structure dependent. Furthermore, we demonstrate the role of specific protein domains on both RNA binding and substrate turnover, focusing on postulated RNA binding elements. Our results show that one zinc finger motif within the complex is sufficient to bind RNA, however, both zinc fingers are required for methylation activity. We show that the N-terminal domain of METTL3 alters the secondary structure dependence of methylation yields. Our results demonstrate that a cooperative effect of all RNA-binding elements in the METTL3–METTL14 complex is required for efficient catalysis, and that binding of further proteins affecting the NTD of METTL3 may regulate substrate specificity.

scholarly journals A Putative Amidase Endolysin Encoded by Clostridium perfringens St13 Exhibits Specific Lytic Activity and Synergizes with the Muramidase Endolysin Psm

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 245
Author(s):  
Hiroshi Sekiya ◽  
Maho Okada ◽  
Eiji Tamai ◽  
Toshi Shimamoto ◽  
Tadashi Shimamoto ◽  
...  
Keyword(s):  
Cell Wall ◽  
Clostridium Perfringens ◽  
Antimicrobial Agents ◽  
Catalytic Domain ◽  
Food Poisoning ◽  
Binding Activity ◽  
Lytic Activity ◽  
Intestinal Bacterium ◽  
Terminal Domain ◽  
Cell Wall Binding

Clostridium perfringens is an often-harmful intestinal bacterium that causes various diseases ranging from food poisoning to life-threatening fulminant disease. Potential treatments include phage-derived endolysins, a promising family of alternative antimicrobial agents. We surveyed the genome of the C. perfringens st13 strain and identified an endolysin gene, psa, in the phage remnant region. Psa has an N-terminal catalytic domain that is homologous to the amidase_2 domain, and a C-terminal domain of unknown function. psa and gene derivatives encoding various Psa subdomains were cloned and expressed in Escherichia coli as N-terminal histidine-tagged proteins. Purified His-tagged full-length Psa protein (Psa-his) showed C. perfringens-specific lytic activity in turbidity reduction assays. In addition, we demonstrated that the uncharacterized C-terminal domain has cell wall-binding activity. Furthermore, cell wall-binding measurements showed that Psa binding was highly specific to C. perfringens. These results indicated that Psa is an amidase endolysin that specifically lyses C. perfringens; the enzyme’s specificity is highly dependent on the binding of the C-terminal domain. Moreover, Psa was shown to have a synergistic effect with another C. perfringens-specific endolysin, Psm, which is a muramidase that cleaves peptidoglycan at a site distinct from that targeted by Psa. The combination of Psa and Psm may be effective in the treatment and prevention of C. perfringens infections.

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.

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