Enhanced Nuclear Import and Transfection Efficiency of TAT Peptide-Based Gene Delivery Systems Modified by Additional Nuclear Localization Signals

2011 ◽  
Vol 23 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Wen-Jie Yi ◽  
Juan Yang ◽  
Cao Li ◽  
Hui-Yuan Wang ◽  
Chen-Wei Liu ◽  
...  

Pharmaceutics ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 608 ◽  
Author(s):  
Guan ◽  
Song ◽  
Zhang ◽  
Chen ◽  
Hu ◽  
...  

Considerable effort has been devoted to the development of gene carriers over the years. However, toxicity, immunogenicity, and low transfection efficiency are still major barriers. How to overcome these obstacles has become a burning question in gene delivery. In the present study, a simple cationic human serum albumin (CHSA)-based gene-delivery system containing nuclear localization signals (NLSs) was constructed to conquer the limitations. CHSA/NLS/plasmid DNA (pDNA) complexes were prepared and characterized by Hoechst 33258 intercalation, gel retardation assay, morphological analysis, circular dichroism (CD) spectroscopy, particle size, and zeta potential measurements. Results showed that CHSA/NLS/pDNA complexes were able to condense and protect pDNA with high encapsulation efficiency. The complexes displayed a nutritional effect on cells at a low concentration and there was no significant cytotoxicity or immunogenicity. In addition, CHSA/NLS/pDNA complexes exhibited excellent cellular uptake rates and the mechanism was mainly the clathrin or macropinocytosis-dependent endocytosis pathway. Furthermore, CHSA/NLS/pDNA significantly enhanced gene expression efficiency in vitro. More importantly, CHSA/NLS/pDNA complexes showed a desired antitumor effect in vivo, exhibiting the highest inhibition rate (57.3%) and significant upregulation in p53 protein. All these results confirm that CHSA/NLS/pDNA complexes have a bright future as a safe and effective delivery system for gene therapy.



Pharmaceutics ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 87
Author(s):  
Jaehong Park ◽  
Kyusik Kim ◽  
Sohee Jeong ◽  
Migyeom Lee ◽  
Tae-il Kim

In this work, highly osmotic oxidized sucrose-crosslinked polyethylenimine (SP2K) polymers were developed for gene delivery systems, and the transfection mechanism is examined. First, periodate-oxidized sucrose and polyethylenimine 2K (PEI2K) were crosslinked with various feed ratios via reductive amination. The synthesis was confirmed by 1H NMR and FTIR. The synthesized SP2K polymers could form positively charged (~40 mV zeta-potential) and nano-sized (150–200 nm) spherical polyplexes with plasmid DNA (pDNA). They showed lower cytotoxicity than PEI25K but concentration-dependent cytotoxicity. Among them, SP2K7 and SP2K10 showed higher transfection efficiency than PEI25K in both serum and serum-free conditions, revealing the good serum stability. It was found that SP2K polymers possessed high osmolality and endosome buffering capacity. The transfection experiments with cellular uptake inhibitors suggest that the transfection of SP2K polymers would progress by multiple pathways, including caveolae-mediated endocytosis. It was also thought that caveolae-mediated endocytosis of SP2K polyplexes would be facilitated through cyclooxygenase-2 (COX-2) expression induced by high osmotic pressure of SP2K polymers. Confocal microscopy results also supported that SP2K polyplexes would be internalized into cells via multiple pathways and escape endosomes efficiently via high osmolality and endosome buffering capacity. These results demonstrate the potential of SP2K polymers for gene delivery systems.



2020 ◽  
Vol 94 (17) ◽  
Author(s):  
Breanna L. Rice ◽  
Matthew S. Stake ◽  
Leslie J. Parent

ABSTRACT Retroviral Gag polyproteins orchestrate the assembly and release of nascent virus particles from the plasma membranes of infected cells. Although it was traditionally thought that Gag proteins trafficked directly from the cytosol to the plasma membrane, we discovered that the oncogenic avian alpharetrovirus Rous sarcoma virus (RSV) Gag protein undergoes transient nucleocytoplasmic transport as an intrinsic step in virus assembly. Using a genetic approach in yeast, we identified three karyopherins that engage the two independent nuclear localization signals (NLSs) in Gag. The primary NLS is in the nucleocapsid (NC) domain of Gag and binds directly to importin-α, which recruits importin-β to mediate nuclear entry. The second NLS (TNPO3), which resides in the matrix (MA) domain, is dependent on importin-11 and transportin-3 (TNPO3), which are known as MTR10p and Kap120p in yeast, although it is not clear whether these import factors are independent or additive. The functions of importin-α/importin-β and importin-11 have been verified in avian cells, whereas the role of TNPO3 has not been studied. In this report, we demonstrate that TNPO3 directly binds to Gag and mediates its nuclear entry. To our surprise, this interaction did not require the cargo-binding domain (CBD) of TNPO3, which typically mediates nuclear entry for other binding partners of TNPO3, including SR domain-containing splicing factors and tRNAs that reenter the nucleus. These results suggest that RSV hijacks this host nuclear import pathway using a unique mechanism, potentially allowing other cargo to simultaneously bind TNPO3. IMPORTANCE RSV Gag nuclear entry is facilitated using three distinct host import factors that interact with nuclear localization signals in the Gag MA and NC domains. Here, we show that the MA region is required for nuclear import of Gag through the TNPO3 pathway. Gag nuclear entry does not require the CBD of TNPO3. Understanding the molecular basis for TNPO3-mediated nuclear trafficking of the RSV Gag protein may lead to a deeper appreciation for whether different import factors play distinct roles in retrovirus replication.



Nano LIFE ◽  
2010 ◽  
Vol 01 (03n04) ◽  
pp. 219-237 ◽  
Author(s):  
SHARDOOL JAIN ◽  
HUSAIN ATTARWALA ◽  
MANSOOR AMIJI

Gene therapy holds tremendous promise in prevention and treatment of diseases as the approach is based on regulating the expression of genes that are responsible for pathological conditions. The biggest bottleneck for gene delivery has been the development of safe and efficacious delivery systems. Although non-viral vectors are considered as much safer options than their viral counterparts, they suffer from low transfection efficiency. In this review, we highlight the role of non-condensing polymeric delivery systems for oral and systemic gene delivery. Using evidence from contemporary literature, non-condensing polymeric microparticle and nanoparticle systems afford physical encapsulation of the nucleic acid construct and can be engineered for targeted delivery to tissues and cells. Additionally, these systems have shown less toxicity and afford sustained cytoplasmic DNA delivery for efficient nuclear uptake and transfection for both DNA vaccines and therapeutic genes.



2005 ◽  
Vol 17 (9) ◽  
pp. 64
Author(s):  
D. A. Jans ◽  
G. Kaur ◽  
I. K. H. Poon ◽  
A. Delluc-Clavieries ◽  
K. M. Wagstaff

15% of cases of human XY sex reversal are due to mutations in SRY (sex determining region on the Y chromosome), many of which map to one of SRY’s two independently acting nuclear localization signals (NLSs) flanking its DNA binding domain. The C-terminal NLS (C-NLS) targets SRY to the nucleus through a ‘conventional’ pathway dependent on the nuclear import receptor importin-β (Imp-β). No importin has been shown to bind the N-terminal NLS (N-NLS), but it is known to interact with the Ca2+-binding protein calmodulin (CaM). We examined seven distinct missense mutations in the SRY NLSs from XY sex-reversed human females for effects on nuclear import and ability to interact with CaM/Imp-β1. All mutations were found to result in reduced nuclear localization in transfected testicular cells compared to wild type. The CaM antagonist, calmidazolium chloride (CDZ), was found to significantly reduce SRY nuclear accumulation, indicating a dependence of SRY nuclear import on CaM. Intriguingly, N-NLS mutants were resistant to CDZ’s effects, implying a loss of interaction with CaM; this was confirmed directly by in vitro binding experiments using recombinantly expressed protein. Either impaired CaM or Imp-β1 binding can thus be the basis of sex-reversal in human patients. Our results implicate a CaM-dependent nuclear import pathway for SRY mediated by the N-NLS that, together with the C-NLS, is required to achieve threshold levels of SRY in the nucleus for male sex determination.



2020 ◽  
Vol 117 (15) ◽  
pp. 8503-8514 ◽  
Author(s):  
Benjamin Bourgeois ◽  
Saskia Hutten ◽  
Benjamin Gottschalk ◽  
Mario Hofweber ◽  
Gesa Richter ◽  
...  

The specific interaction of importins with nuclear localization signals (NLSs) of cargo proteins not only mediates nuclear import but also, prevents their aberrant phase separation and stress granule recruitment in the cytoplasm. The importin Transportin-1 (TNPO1) plays a key role in the (patho-)physiology of both processes. Here, we report that both TNPO1 and Transportin-3 (TNPO3) recognize two nonclassical NLSs within the cold-inducible RNA-binding protein (CIRBP). Our biophysical investigations show that TNPO1 recognizes an arginine-glycine(-glycine) (RG/RGG)–rich region, whereas TNPO3 recognizes a region rich in arginine-serine-tyrosine (RSY) residues. These interactions regulate nuclear localization, phase separation, and stress granule recruitment of CIRBP in cells. The presence of both RG/RGG and RSY regions in numerous other RNA-binding proteins suggests that the interaction of TNPO1 and TNPO3 with these nonclassical NLSs may regulate the formation of membraneless organelles and subcellular localization of numerous proteins.



2006 ◽  
Vol 175 (4) ◽  
pp. 579-593 ◽  
Author(s):  
Benjamin L. Timney ◽  
Jaclyn Tetenbaum-Novatt ◽  
Diana S. Agate ◽  
Rosemary Williams ◽  
Wenzhu Zhang ◽  
...  

Many cargoes destined for nuclear import carry nuclear localization signals that are recognized by karyopherins (Kaps). We present methods to quantitate import rates and measure Kap and cargo concentrations in single yeast cells in vivo, providing new insights into import kinetics. By systematically manipulating the amounts, types, and affinities of Kaps and cargos, we show that import rates in vivo are simply governed by the concentrations of Kaps and their cargo and the affinity between them. These rates fit to a straightforward pump–leak model for the import process. Unexpectedly, we deduced that the main limiting factor for import is the poor ability of Kaps and cargos to find each other in the cytoplasm in a background of overwhelming nonspecific competition, rather than other more obvious candidates such as the nuclear pore complex and Ran. It is likely that most of every import round is taken up by Kaps and nuclear localization signals sampling other cytoplasmic proteins as they locate each other in the cytoplasm.



2017 ◽  
Vol 5 (42) ◽  
pp. 8322-8329 ◽  
Author(s):  
Shuqi Dong ◽  
Qixian Chen ◽  
Wei Li ◽  
Zhu Jiang ◽  
Jianbiao Ma ◽  
...  

The dendritic catiomer using biocompatible Zr-MOFs as the core exhibited a markedly higher transfection efficiency and lower cytotoxicity than the commercial gold standard branched PEI25k in A549 cells.



1995 ◽  
Vol 8 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Katayoon Dehesh ◽  
Laurie G. Smith ◽  
James M. Tepperman ◽  
Peter H. Quail


1999 ◽  
Vol 19 (2) ◽  
pp. 1210-1217 ◽  
Author(s):  
Ray Truant ◽  
Bryan R. Cullen

ABSTRACT Protein nuclear import is generally mediated by basic nuclear localization signals (NLSs) that serve as targets for the importin α (Imp α) NLS receptor. Imp α is in turn bound by importin β (Imp β), which targets the resultant protein complex to the nucleus. Here, we report that the arginine-rich NLS sequences present in the human immunodeficiency virus type 1 regulatory proteins Tat and Rev fail to interact with Imp α and instead bind directly to Imp β. Using in vitro nuclear import assays, we demonstrate that Imp α is entirely dispensable for Tat and Rev nuclear import. In contrast, Imp β proved both sufficient and necessary, in that other β-like import factors, such as transportin, were unable to support Tat or Rev nuclear import. Using in vitro competition assays, it was demonstrated that the target sites on Imp β for Imp α, Tat, and Rev binding either are identical or at least overlap. The interaction of Tat and Rev with Imp β is also similar to Imp α binding in that it is inhibited by RanGTP but not RanGDP, a finding that may in part explain why the interaction of the Rev nuclear RNA export factor with target RNA species is efficient in the cell nucleus yet is released in the cytoplasm. Together, these studies define a novel class of arginine-rich NLS sequences that are direct targets for Imp β and that therefore function independently of Imp α.



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