The Identification of a Novel Nucleomodulin MbovP467 of Mycoplasmopsis bovis and Its Potential Contribution in Pathogenesis.

Mycoplasmopsis bovis is a causative agent of crucial diseases in both dairy and beef cattle leading to substantial economic losses. However, limited control measures for M. bovis-related diseases exist due to a lack of understanding about the virulence factors of this pathogen, a common challenge in mycoplasma research. Consequently, this study aimed to characterize a novel nucleomodulin as a virulence-related factor of M. bovis. Employing bioinformatic tools, we initially predicted MbovP467 to be a secreted protein with a nuclear localization signal based on SignalP scores and the cNLS (Nuclear Localization Signal) Mapper, respectively. Subsequently, the MbovP467 gene was synthesized and cloned into a pEGFP plasmid with EGFP labeling to obtain a recombinant plasmid (rpEGFP-MbovP467) and then was also cloned in pET-30a with a consideration for an Escherichia coli codon bias and expressed and purified for the production of polyclonal antibodies against the recombinant MbovP467 protein. Confocal microscopy and a Western blotting assay confirmed the nuclear location of MbovP467 in bovine macrophages (BoMacs). RNA-seq data revealed 220 up-regulated and 20 down-regulated genes in the rpEGFP-MbovP467-treated BoMac group compared to the control group (pEGFP). A GO- and KEGG-enrichment analysis identified associations with inflammatory responses, G protein-coupled receptor signaling pathways, nuclear receptor activity, sequence-specific DNA binding, the regulation of cell proliferation, IL-8, apoptotic processes, cell growth and death, the TNF signaling pathway, the NF-κB signaling pathway, pathways in cancer, and protein families of signaling and cellular processes among the differentially expressed up-regulated mRNAs. Further experiments, investigating cell viability and the inflammatory response, demonstrated that MbovP467 reduces BoMac cell viability and induces the mRNA expression of IL-1ß, IL-6, IL-8, TNF-α, and apoptosis in BoMac cells. Further, MbovP467 increased the promoter activity of TNF-α. In conclusion, this study identified a new nucleomodulin, MbovP467, for M. bovis, which might have an important role in M. bovis pathogenesis.

The Nuclear Localization Signal of Porcine Circovirus Type 4 Affects the Subcellular Localization of the Virus Capsid and the Production of Virus-like Particles.

Porcine circovirus 4 (PCV4) is a newly identified virus belonging to PCV of the Circoviridae family, the Circovirus genus. We previously found that PCV4 is pathogenic in vitro, while the virus's replication in cells is still unknown. In this study, we evaluated the N-terminal of the PCV4 capsid (Cap) and identified an NLS at amino acid residues 4-37 of the N-terminus of the PCV4 Cap, 4RSRYSRRRRNRRNQRRRGLWPRASRRRYRWRRKN37. The NLS was further divided into two fragments (NLS-A and NLS-B) based on the predicted structure, including two α-helixes, which were located at 4RSRYSRRRRNRRNQRR19 and 24PRASRRRYRWRRK36, respectively. Further studies showed that the NLS, especially the first α-helixes formed by the NLS-A fragment, determined the nuclear localization of the Cap protein, and the amino acid 4RSRY7 in the NLS of the PCV4 Cap was the critical motif affecting the VLP packaging. These results will provide a theoretical basis for elucidating the infection mechanism of PCV4 and developing subunit vaccines based on VLPs.

WW domains form a folded type of nuclear localization signal to guide YAP1 nuclear import.

The nuclear translocation of YAP1 is significantly implicated in the proliferation, stemness, and metastasis of cancer cells. Although the molecular basis underlying YAP1 subcellular distribution has been extensively explored, it remains to be elucidated how the nuclear localization signal guides YAP1 to pass through the nuclear pore complex. Here, we define a globular type of nuclear localization signal composed of folded WW domains, named as WW-NLS. It directs YAP1 nuclear import through the heterodimeric nuclear transport receptors KPNA-KPNB1, bypassing the canonical nuclear localization signal that has been well documented in KPNA/KPNB1-mediated nuclear import. Strikingly, competitive interference with the function of the WW-NLS significantly attenuates YAP1 nuclear translocation and damages stemness gene activation and sphere formation in malignant breast cancer cells. Our findings elucidate a novel globular type of nuclear localization signal to facilitate nuclear entry of WW-containing proteins including YAP1.

Identification and characterization of nuclear localization signals in the circumsporozoite protein of Plasmodium falciparum.

Secretory proteins of Plasmodium exhibit differential spatial and functional activity within the host cell nucleus. However, the nuclear localization signals (NLSs) for these proteins remain largely uncharacterized. In this study, we have identified and characterized two NLSs in the circumsporozoite protein of Plasmodium falciparum (Pf-CSP). Both NLSs in the Pf-CSP contain clusters of lysine and arginine residues essential for specific interactions with the conserved tryptophan and asparagine residues of importin-α, facilitating nuclear translocation of Pf-CSP. While the two NLSs of Pf-CSP function independently and are both crucial for nuclear localization, a single NLS of Pf-CSP leads to weak nuclear localization. These findings shed light on the mechanism of nuclear penetrability of secretory proteins of Plasmodium proteins.

Analysis of the effects of importin α1 on the nuclear translocation of IL-1α in HeLa cells.

Interleukin-1α (IL-1α), a cytokine released by necrotic cells, causes sterile inflammation. On the other hand, IL-1α is present in the nucleus and also regulates the expression of many proteins. A protein substrate containing a classical nuclear localization signal (cNLS) typically forms a substrate/importin α/ß complex, which is subsequently transported to the nucleus. To the best of our knowledge, no study has directly investigated whether IL-1α-which includes cNLS-is imported into the nucleus in an importin α/ß-dependent manner. In this study, we noted that all detected importin α subtypes interacted with IL-1α. In HeLa cells, importin α1-mediated nuclear translocation of IL-1α occurred at steady state and was independent of importin ß1. Importin α1 not only was engaged in IL-1α nuclear transport but also concurrently functioned as a molecule that regulated IL-1α protein level in the cell. Furthermore, we discussed the underlying mechanism of IL-1α nuclear translocation by importin α1 based on our findings.

LAIR1-mediated resistance of hepatocellular carcinoma cells to T cells through a GSK-3ß/ß-catenin/MYC/PD-L1 pathway.

BACKGROUND: An increasing number of studies have reported the involvement of oncogenes in the regulation of the immune system. LAIR1 is an immunosuppressive molecule and its role in immune-related diseases has been mainly reported. To date, it is unclear whether LAIR1 in tumor cells is involved in immune regulation. Therefore, the aim of this study was to investigate the role of LAIR1 in the immune microenvironment of hepatocellular carcinoma (HCC) to seek the novel therapeutic discoveries. METHODS: Tumor Immune Dysfunction and Exclusion database was used to predict the response of LAIR1 expression to immune checkpoint blockade. CD8+ T cells were co-cultured with HCC cells, and the killing efficiency of leukocytes on HCC cells was detected by flow cytometry. Flow cytometry was also used to detect the expression of inhibitory receptors. In addition, Western blot, immunofluorescence, and nucleus/cytoplasm fractionation experiments were performed to explore the molecular mechanisms by which LAIR1 created a suppressive tumor microenvironment. RESULTS: LAIR1 expression in HCC was associated with worse immune prognosis and T-cell dysfunction. HCC cells overexpressing LAIR1 co-cultured with CD8+ T cells induced exhaustion of latter. Mechanism studies indicated that LAIR1 in HCC cells up-regulated the phosphorylation of ß-catenin by inducing the phosphorylation of GSK-3ß, leading to the impairment of the expression and the nuclear localization signal of ß-catenin. Low ß-catenin expression and nuclear localization signal inhibited MYC-mediated PD-L1 expression. Therefore, PD-L1 up-regulated by LAIR1 caused the exhaustion of infiltrating CD8+ T cells in HCC, which aggravated the malignant progression of HCC. CONCLUSION: LAIR1 increased PD-L1 expression through the GSK-3ß/ß-catenin/MYC/PD-L1 pathway and promoted immune evasion of HCC cells. Targeted inhibition of LAIR1 helped to enhance the immune killing effect of CD8+ T cells in HCC.

Nuclear localization signal-tagged systems: relevant nuclear import principles in the context of current therapeutic design.

Nuclear targeting of therapeutics provides a strategy for enhancing efficacy of molecules active in the nucleus and minimizing off-target effects. 'Active' nuclear-directed transport and efficient translocations across nuclear pore complexes provide the most effective means of maximizing nuclear localization. Nuclear-targeting systems based on nuclear localization signal (NLS) motifs have progressed significantly since the beginning of the current millennium. Here, we offer a roadmap for understanding the basic mechanisms of nuclear import in the context of actionable therapeutic design for developing NLS-therapeutics with improved treatment efficacy.

A functional and structural comparative analysis of large tumor antigens reveals evolution of different importin α-dependent nuclear localization signals.

Nucleocytoplasmic transport regulates the passage of proteins between the nucleus and cytoplasm. In the best characterized pathway, importin (IMP) α bridges cargoes bearing basic, classical nuclear localization signals (cNLSs) to IMPß1, which mediates transport through the nuclear pore complex. IMPα recognizes three types of cNLSs via two binding sites: the major binding site accommodates monopartite cNLSs, the minor binding site recognizes atypical cNLSs, while bipartite cNLSs simultaneously interact with both major and minor sites. Despite the growing knowledge regarding IMPα-cNLS interactions, our understanding of the evolution of cNLSs is limited. We combined bioinformatic, biochemical, functional, and structural approaches to study this phenomenon, using polyomaviruses (PyVs) large tumor antigens (LTAs) as a model. We characterized functional cNLSs from all human (H)PyV LTAs, located between the LXCXE motif and origin binding domain. Surprisingly, the prototypical SV40 monopartite NLS is not well conserved; HPyV LTA NLSs are extremely heterogenous in terms of structural organization, IMPα isoform binding, and nuclear targeting abilities, thus influencing the nuclear accumulation properties of full-length proteins. While several LTAs possess bipartite cNLSs, merkel cell PyV contains a hybrid bipartite cNLS whose upstream stretch of basic amino acids can function as an atypical cNLS, specifically binding to the IMPα minor site upon deletion of the downstream amino acids after viral integration in the host genome. Therefore, duplication of a monopartite cNLS and subsequent accumulation of point mutations, optimizing interaction with distinct IMPα binding sites, led to the evolution of bipartite and atypical NLSs binding at the minor site.

Structural determinants of phosphorylation-dependent nuclear transport of HCMV DNA polymerase processivity factor UL44.

Human cytomegalovirus DNA polymerase processivity factor UL44 is transported into the nucleus by importin (IMP) α/ß through a classical nuclear localization signal (NLS), and this region is susceptible to cdc2-mediated phosphorylation at position T427. Whilst phosphorylation within and close to the UL44 NLS regulates nuclear transport, the details remain elusive, due to the paucity of structural information regarding the role of negatively charged cargo phosphate groups. We addressed this issue by studying the effect of UL44 T427 phosphorylation on interaction with several IMPα isoforms by biochemical and structural approaches. Phosphorylation decreased UL44/IMPα affinity 10-fold, and a comparative structural analysis of UL44 NLS phosphorylated and non-phosphorylated peptides complexed with mouse IMPα2 revealed the structural rearrangements responsible for phosphorylation-dependent inhibition of UL44 nuclear import.

Structure-Function Analysis of p57KIP2 in the Human Pancreatic Beta Cell Reveals a Bipartite Nuclear Localization Signal.

Mutations in CDKN1C, encoding p57KIP2, a canonical cell cycle inhibitor, underlie multiple pediatric endocrine syndromes. Despite this central role in disease, little is known about the structure and function of p57KIP2 in the human pancreatic beta cell. Since p57KIP2 is predominantly nuclear in human beta cells, we hypothesized that disease-causing mutations in its nuclear localization sequence (NLS) may correlate with abnormal phenotypes. We prepared RIP1 insulin promoter-driven adenoviruses encoding deletions of multiple disease-associated but unexplored regions of p57KIP2 and performed a comprehensive structure-function analysis of CDKN1C/p57KIP2. Real-time polymerase chain reaction and immunoblot analyses confirmed p57KIP2 overexpression, construct size, and beta cell specificity. By immunocytochemistry, wild-type (WT) p57KIP2 displayed nuclear localization. In contrast, deletion of a putative NLS at amino acids 278-281 failed to access the nucleus. Unexpectedly, we identified a second downstream NLS at amino acids 312-316. Further analysis showed that each individual NLS is required for nuclear localization, but neither alone is sufficient. In summary, p57KIP2 contains a classical bipartite NLS characterized by 2 clusters of positively charged amino acids separated by a proline-rich linker region. Variants in the sequences encoding these 2 NLS sequences account for functional p57KIP2 loss and beta cell expansion seen in human disease.

The nuclear entry of the aryl hydrocarbon receptor (AHR) relies on the first nuclear localization signal and can be negatively regulated through IMPα/ß specific inhibitors.

The human aryl hydrocarbon receptor (AHR) undergoes continuous shuttling between nucleus and cytoplasm. Binding to exogenous or endogenous ligands promotes its rapid nuclear import. The proposed mechanism for the ligand-dependent import is based on exposing the bipartite nuclear localisation signal (NLS) to members of the importin (IMP) superfamily. Among this, the molecular interactions involved in the basal import still need to be clarified. Utilizing fluorescently fused AHR variants, we recapitulated and characterized AHR localization and nucleo-cytoplasmic shuttling in living cells. Analysis of AHR variants carrying NLS point mutations demonstrated a mandatory role of first (13RKRRK17) and second (37KR-R40) NLS segments on the basal import of AHR. Further experiments indicated that ligand-induced import is mainly regulated through the first NLS, while the second NLS is supportive but not essential. Additionally, applying IMPα/ß specific inhibitors, ivermectin (IVM) and importazole (IPZ), slowed down the ligand-induced import and, correspondingly, decreased the basal nuclear accumulation of the receptor. In conclusion, our data show that ligand-induced and basal nuclear entry of AHR rely on the same mechanism but are controlled uniquely by the two NLS components.

Trypanosoma cruzi Fibrillarins: Two paralogous proteins with non-identical signals for nuclear transport.

Trypanosoma cruzi is a parasitic protozoa causative of Chagas disease. As part of our interest in studying the basic biology of this microorganism, this work reports our observations related to the characterization of motifs and structural domains present in two fibrillarin isoforms (TcFib1 and TcFib2) that were found to be necessary for the nuclear targeting of these nucleolar proteins. Previous characterization of these proteins indicated that they share 68.67% of identical amino acids and are both expressed as nucleolar proteins in T. cruzi epimastigotes. Using an approach based on the transfection of recombinant genes encoding fluorescent fibrillarin-EGFP fusion proteins, this study found evidence for the presence of 4 motifs or protein domains that help target these proteins to the nucleus: The GAR domain and carboxyl terminus in both TcFibs, as well as two lysines and a computationally predicted cNLS in TcFib1. As a distinctive feature, the GAR domain of TcFib2 proved to be essential for the nuclear localization of this protein paralog. Such a difference between TcFib1 and Tcfib2 nuclear localization signals can be explained as the presence of two partially related nuclear import pathways for the two fibrillarin homologues in this organism.

Mutation in the FUS nuclear localisation signal domain causes neurodevelopmental and systemic metabolic alterations.

Variants in the ubiquitously expressed DNA/RNA-binding protein FUS cause aggressive juvenile forms of amyotrophic lateral sclerosis (ALS). Most FUS mutation studies have focused on motor neuron degeneration; little is known about wider systemic or developmental effects. We studied pleiotropic phenotypes in a physiological knock-in mouse model carrying the pathogenic FUSDelta14 mutation in homozygosity. RNA sequencing of multiple organs aimed to identify pathways altered by the mutant protein in the systemic transcriptome, including metabolic tissues, given the link between ALS-frontotemporal dementia and altered metabolism. Few genes were commonly altered across all tissues, and most genes and pathways affected were generally tissue specific. Phenotypic assessment of mice revealed systemic metabolic alterations related to the pathway changes identified. Magnetic resonance imaging brain scans and histological characterisation revealed that homozygous FUSDelta14 brains were smaller than heterozygous and wild-type brains and displayed significant morphological alterations, including a thinner cortex, reduced neuronal number and increased gliosis, which correlated with early cognitive impairment and fatal seizures. These findings show that the disease aetiology of FUS variants can include both neurodevelopmental and systemic alterations.

Experience-dependent Tip60 nucleocytoplasmic transport is regulated by its NLS/NES sequences for neuroplasticity gene control.

Nucleocytoplasmic transport (NCT) in neurons is critical for enabling proteins to enter the nucleus and regulate plasticity genes in response to environmental cues. Such experience-dependent (ED) neural plasticity is central for establishing memory formation and cognitive function and can influence the severity of neurodegenerative disorders like Alzheimer's disease (AD). ED neural plasticity is driven by histone acetylation (HA) mediated epigenetic mechanisms that regulate dynamic activity-dependent gene transcription profiles in response to neuronal stimulation. Yet, how histone acetyltransferases (HATs) respond to extracellular cues in the in vivo brain to drive HA-mediated activity-dependent gene control remains unclear. We previously demonstrated that extracellular stimulation of rat hippocampal neurons in vitro triggers Tip60 HAT nuclear import with concomitant synaptic gene induction. Here, we focus on investigating Tip60 HAT subcellular localization and NCT specifically in neuronal activity-dependent gene control by using the learning and memory mushroom body (MB) region of the Drosophila brain as a powerful in vivo cognitive model system. We used immunohistochemistry (IHC) to compare the subcellular localization of Tip60 HAT in the Drosophila brain under normal conditions and in response to stimulation of fly brain neurons in vivo either by genetically inducing potassium channels activation or by exposure to natural positive ED conditions. Furthermore, we found that both inducible and ED condition-mediated neural induction triggered Tip60 nuclear import with concomitant induction of previously identified Tip60 target genes and that Tip60 levels in both the nucleus and cytoplasm were significantly decreased in our well-characterized Drosophila AD model. Mutagenesis of a putative nuclear localization signal (NLS) sequence and nuclear export signal (NES) sequence that we identified in the Drosophila Tip60 protein revealed that both are functionally required for appropriate Tip60 subcellular localization. Our results support a model by which neuronal stimulation triggers Tip60 NCT via its NLS and NES sequences to promote induction of activity-dependent neuroplasticity gene transcription and that this process may be disrupted in AD.

Binding of viral nuclear localization signal peptides to importin-α nuclear transport protein.

Using all-atom replica-exchange molecular dynamics simulations, we mapped the mechanisms of binding of the nuclear localization signal (NLS) sequence from Venezuelan equine encephalitis virus (VEEV) capsid protein to importin-α (impα) transport protein. Our objective was to identify the VEEV NLS sequence fragment that confers native, experimentally resolved binding to impα as well as to study associated binding energetics and conformational ensembles. The two selected VEEV NLS peptide fragments, KKPK and KKPKKE, show strikingly different binding mechanisms. The minNLS peptide KKPK binds non-natively and nonspecifically by adopting five diverse conformational clusters with low similarity to the x-ray structure 3VE6 of NLS-impα complex. Despite the prevalence of non-native interactions, the minNLS peptide still largely binds to the impα major NLS binding site. In contrast, the coreNLS peptide KKPKKE binds specifically and natively, adopting a largely homogeneous binding ensemble with a dominant, highly native-like conformational cluster. The coreNLS peptide retains most of native binding interactions, including π-cation contacts and a tryptophan cage. While KKPK binding is governed by a complex multistate free energy landscape featuring transitions between multiple binding poses, the coreNLS peptide free energy map is simple, exhibiting a single dominant native-like bound basin. We argue that the origin of the coreNLS peptide binding specificity is several electrostatic interactions formed by the two C-terminal amino acids, Lys10 and Glu11, with impα. The coreNLS sequence is then sufficient for native binding, but none of the amino acids flanking minNLS, including Lys10 and Glu11, are strictly necessary for the native pose. Our analyses indicate that the VEEV coreNLS sequence is virtually unique among human and viral proteins interacting with impα making it a potential target for VEEV-specific inhibitors.

Defective recognition of a nonclassical nuclear localization signal in neurodevelopmental disorders.

In this issue of Structure, Gonzalez et al. present the cryo-EM structure of Karyopherin-ß2 bound to the proline-tyrosine nuclear localization signal (PY-NLS) of heterogeneous nuclear ribonucleoprotein H2 (HNRNPH2). The structure advances our understanding of not only the diversity of PY-NLSs but also the pathogenic mechanisms arising from HNRNPH2 variants.

Improved biocompatibility of dendrimer-based gene delivery by histidine-modified nuclear localization signals.

Polyamidoamine (PAMAM) dendrimers have been explored as an alternative to polyethylenimine (PEI) as a gene delivery carrier because of their relatively low cytotoxicity and excellent biocompatibility. The transfection efficiency of PAMAM dendrimers can be improved by the addition of nuclear localization signal (NLS), a positively charged peptide sequence recognized by cargo proteins in the cytoplasm for nuclear transport. However, increased positive charges from NLS can cause damage to the cytoplasmic and mitochondrial membranes and lead to reactive oxygen species (ROS)-induced cytotoxicity. This negative effect of NLS can be negated without a significant reduction in transfection efficiency by adding histidine, an essential amino acid known as a natural antioxidant, to NLS. However, little is known about the exact mechanism by which histidine reduces cytotoxicity of NLS-modified dendrimers. In this study, we selected cystamine core PAMAM dendrimer generation 2 (cPG2) and conjugated it with NLS derived from Merkel cell polyomavirus large T antigen and histidine (n = 0-3) to improve transfection efficiency and reduce cytoxicity. NLS-modified cPG2 derivatives showed similar or higher transfection efficiency than PEI 25 kDa in NIH3T3 and human mesenchymal stem cells (hMSC). The cytotoxicity of NLS-modified cPG2 derivatives was substantially lower than PEI 25 kDa and was further reduced as the number of histidine in NLS increased. To understand the mechanism of cytoprotective effect of histidine-conjugated NLS, we examined ROS scavenging, hydroxyl radical generation and mitochondrial membrane potential as a function of the number of histidine in NLS. As the number of hisidine increased, cPG2 scavenged ROS more effectively as evidenced by the hydroxyl radical antioxidant capacity (HORAC) assay. This was consistent with the reduced intracellular hydroxyl radical concentration measured by 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) assay in NIH3T3. Finally, fluorescence imaging with JC-1 confirmed that the mitochondrial membranes of NIH 3T3 were well-protected during the transfection when NLS contained histidine. These experimental results confirm the hypothesis that histidine residues scavenge ROS that is generated during the transfection process, preventing the excessive damage to mitochondrial membranes, leading to reduced cytotoxicity.

Identification of the nuclear localization signal in the Saccharomyces cerevisiae Pif1 DNA helicase.

Saccharomyces cerevisiae Pif1 is a multi-functional DNA helicase that plays diverse roles in the maintenance of the nuclear and mitochondrial genomes. Two isoforms of Pif1 are generated from a single open reading frame by the use of alternative translational start sites. The Mitochondrial Targeting Signal (MTS) of Pif1 is located between the two start sites, but a Nuclear Localization Signal (NLS) has not been identified. Here we used sequence and functional analysis to identify an NLS element. A mutant allele of PIF1 (pif1-NLSΔ) that lacks four basic amino acids (781KKRK784) in the carboxyl-terminal domain of the 859 amino acid Pif1 was expressed at wild type levels and retained wild type mitochondrial function. However, pif1-NLSΔ cells were defective in four tests for nuclear function: telomere length maintenance, Okazaki fragment processing, break-induced replication (BIR), and binding to nuclear target sites. Fusing the NLS from the simian virus 40 (SV40) T-antigen to the Pif1-NLSΔ protein reduced the nuclear defects of pif1-NLSΔ cells. Thus, four basic amino acids near the carboxyl end of Pif1 are required for the vast majority of nuclear Pif1 function. Our study also reveals phenotypic differences between the previously described loss of function pif1-m2 allele and three other pif1 mutant alleles generated in this work, which will be useful to study nuclear Pif1 functions.

Identification and functional characterization of a bipartite nuclear localization signal in ANKRD11.

ANKRD11 gene encodes for the large nuclear protein essential for multiple system development including the nervous system. However, the molecular basis for the proper nuclear localization of ANKRD11 has not yet been elucidated. In this study, we have identified a functional bipartite nuclear localization signal (bNLS) between residues 53 and 87 of ANKRD11. Using biochemical approaches, we discovered two major binding sites in this bipartite NLS for Importin α1. Through site-directed mutagenesis and functional analysis, we further found that this bipartite NLS is sufficient for nuclear import of overexpressing GFP in HeLa cells and necessary for nuclear localization of ANKRD11. Importantly, our study provides a possible pathogenic mechanism for certain clinical variants located within the bipartite nuclear localization signal of ANKRD11.

Discovering the nuclear localization signal of Werner Helicase Interacting Protein 1.

Our study maps the classic nuclear localization signal (cNLS) domain within WRNIP that directs the protein's nuclear positioning.