Synthesis and Binding Properties of Oligonucleotides Carrying Nuclear Localization Sequences

1999 ◽  
Vol 10 (6) ◽  
pp. 1005-1012 ◽  
Author(s):  
Beatriz García de la Torre ◽  
Fernando Albericio ◽  
Ester Saison-Behmoaras ◽  
Angela Bachi ◽  
Ramon Eritja
2021 ◽  
Author(s):  
Raphaël Jami ◽  
Emilie Mérour ◽  
Julie Bernard ◽  
Annie Lamoureux ◽  
Jean K. Millet ◽  
...  

Salmonid alphavirus (SAV) is an atypical alphavirus, which has a considerable impact on salmon and trout farms. Unlike other alphaviruses such as the chikungunya virus, SAV is transmitted without an arthropod vector, and does not cause cell shut-off during infection. The mechanisms by which SAV escapes the host immune system remain unknown. By studying the role of SAV proteins on the RIG-I signaling cascade, the first line of defense of the immune system during infection, we demonstrated that non-structural protein 2 (nsP2) effectively blocks the induction of type I interferon (IFN). This inhibition, independent of the protease activity carried by nsP2, occurs downstream of IRF3 which is the transcription factor allowing the activation of the IFN promoter and its expression. The inhibitory effect of nsP2 on the RIG-I pathway depends on the localization of nsP2 in the host cell nucleus which is linked to two nuclear localization sequences (NLS) located in its C-terminal part. The C-terminal domain of nsP2 by itself is sufficient and necessary to block IFN induction. Mutation of the NLS of nsP2 is deleterious to the virus. Finally, nsP2 does not interact with IRF3, indicating that its action is possible through a targeted interaction within discrete areas of chromatin, as suggested by its punctate distribution observed in the nucleus. These results therefore demonstrate a major role for nsP2 in the control by SAV of the host cell’s innate immune response. Importance The global consumption of fish continues to rise and the future demand cannot be met by capture fisheries alone due to limited stocks of wild fish. Aquaculture is currently the world’s fastest growing food production sector with an annual growth rate of 6-8 %. Recurrent outbreaks of SAV result in significant economic losses with serious environmental consequences on wild stocks. While the clinical and pathological signs of SAV infection are fairly well known, the molecular mechanisms involved are poorly described. In the present study, we focus on the non-structural protein nsP2 and characterize a specific domain containing nuclear localization sequences that are critical for the inhibition of the host innate immune response mediated by the RIG-I pathway.


2016 ◽  
pp. 53-58
Author(s):  
SM Sabbir Alam ◽  
M Ruhul Amin ◽  
M Anwar Hossain

Domains of unknown functions (DUFs) are a big set of protein families within the Pfam database that includes proteins of unknown function. In the absence of functional information, proteins are classified into different families based on conserved amino acid sequences and are potentially functionally important. In Pfam database, the numbers of families of DUFs are rapidly increasing and in current the fraction of DUF families had increased to about twenty two percent of all protein families. In this study we targeted DUF2726 member proteins which are mainly present in different bacterial species of Gamma-proteobacteria and have a particular domain organization. We analyzed the protein sequences of domain DUF2726 using different computational tools and databases. We found that this domain contains a nuclear localization signal peptide, which is conserved in Escherichia spp. and Shigella spp. It were also predicted that it has nucleic acid binding properties. Analyzing protein-protein interactions functional partners associated with DUF 2726 were revealed. Protein secondary structure, transmembrane helices structure were predicted. We have found that it has gene neighbourhood and co-occurrences with protein RepA and RepB. RepA and RepB are functionally associated with replication. RepA is a replication protein and RepB is a replication regulatory protein. Presence of a nucleic acid binding properties, a nuclear localization signal (NLS) signalling peptide, and possible interaction pattern with replication proteins, conjectures its possible role as a NLS like signalling peptide.Bangladesh J Microbiol, Volume 31, Number 1-2,June-Dec 2014, pp 53-58


2008 ◽  
Vol 82 (11) ◽  
pp. 5381-5389 ◽  
Author(s):  
Nang L. Nguyen ◽  
Amy N. Loveland ◽  
Wade Gibson

ABSTRACT Scaffolding proteins of spherical prokaryotic and eukaryotic viruses have critical roles in capsid assembly. The primary scaffolding components of cytomegalovirus, called the assembly protein precursor (pAP, pUL80.5) and the maturational protease precursor (pPR, pUL80a), contain two nuclear localization sequences (NLS1 and NLS2), at least one of which is required in coexpression experiments to translocate the major capsid protein (MCP, pUL85) into the nucleus. In the work reported here, we have mutated NLS1 and NLS2, individually or together, in human cytomegalovirus (HCMV, strain AD169) bacmid-derived viruses to test their effects on virus replication. Consistent with results from earlier transfection/coexpression experiments, both single-mutant bacmids gave rise to infectious virus but the double mutant did not. In comparisons with the wild-type virus, both mutants showed slower cell-to-cell spread; decreased yields of infectious virus (3-fold lower for NLS1− and 140-fold lower for NLS2−); reduced efficiency of pAP, pPR, and MCP nuclear translocation (sixfold lower for NLS1− and eightfold lower for NLS2−); increased amounts of a 120-kDa MCP fragment; and reduced numbers of intranuclear capsids. All effects were more severe for the NLS2− mutant than the NLS1− mutant, and a distinguishing feature of cells infected with the NLS2− mutant was the accumulation of large, UL80 protein-containing structures within the nucleus. We conclude that these NLS assist in the nuclear translocation of MCP during HCMV replication and that NLS2, which is unique to the betaherpesvirus UL80 homologs, may have additional involvements during replication.


2003 ◽  
Vol 23 (24) ◽  
pp. 9025-9031 ◽  
Author(s):  
Masahito Shimojo ◽  
Louis B. Hersh

ABSTRACT The transcriptional repressor REST/NRSF (RE-1 silencing transcription factor/neuron-restrictive silencer factor) and the transcriptional regulator REST4 share an N-terminal zinc finger domain structure involved in nuclear targeting. Using this domain as bait in a yeast two-hybrid screen, a novel protein that contains three LIM domains, putative nuclear localization sequences, protein kinase A phosphorylation sites, and a CAAX prenylation motif was isolated. This protein, which is localized around the nucleus, is involved in determining the nuclear localization of REST4 and REST/NRSF. We propose the name RILP, for REST/NRSF-interacting LIM domain protein, to label this novel protein. RILP appears to serve as a nuclear receptor for REST/NRSF, REST4, and possibly other transcription factors.


1996 ◽  
Vol 74 (3) ◽  
pp. 363-372 ◽  
Author(s):  
Werner Barth ◽  
Ursula Stochaj

Facilitated transport of proteins into the nucleus requires nuclear localization sequences (NLSs) be present in the protein destined for the nucleus. The specific binding of NLSs by components of the nuclear transport apparatus is essential for these targeting reactions. We now report that the yeast nucleoporin Nsp1 binds specifically nuclear localization sequences in vitro. This nucleoporin recognizes several NLSs that are functional for nuclear targeting in vivo, including the NLS of SV40 T-antigen and of the yeast transcription factor Gal4. Nsp1 is organized into three domains, and we have located NLS binding sites to the N-terminal portion and the middle repetitive region of the protein. For the interaction between the NLS of SV40 T-antigen and Nsp1, we obtained association constants of 1.2 × 107 M−1 and 5 × 107 M−1. An association constant of 5 × 107 M−1 was determined for NLS binding to the repetitive domain of Nsp1. We analyzed binding of Nsp1 and its domains to a mutant version of the NLS derived from SV40 T-antigen, which poorly functions for nuclear targeting in vivo. The affinity for the mutant signal was about two orders of magnitude lower than for the wild-type NLS.Key words: Nsp1, nuclear pore complex, nucleoporin, nuclear localization sequence, protein targeting, yeast.


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