The presence of the nuclear membrane that sequesters the cellular DNA is the defining feature of eukaryotic cells. (wikipedia.org)
The nuclear membrane, therefore, separates the nuclear processes of DNA replication and RNA transcription from the cytoplasmic process of protein production. (wikipedia.org)
The presence of several million pore complexes in the oocyte nuclear membrane and the fact that they appeared to admit many different molecules (insulin, bovine serum albumin, gold nanoparticles) led to the view that the pores are open channels and nuclear proteins freely enter the nucleus through the pore and must accumulate by binding to DNA or some other nuclear component. (wikipedia.org)
Retroviral particles must bind specifically to their target cells, cross the plasma membrane, reverse-transcribe their RNA genome, while uncoating the cores, find their way to the nuclear membrane and penetrate into the nucleus to finally dock and integrate into the cellular genome. (biomedcentral.com)
An NLS has the opposite function of a nuclear export signal (NES), which targets proteins out of the nucleus. (wikipedia.org)
A signal that appears to be specific for the massively produced and transported ribosomal proteins, seems to come with a specialized set of importin β-like nuclear import receptors. (wikipedia.org)
The first direct experimental examination of the ability of nuclear proteins to accumulate in the nucleus was carried out by John Gurdon when he showed that purified nuclear proteins accumulate in the nucleus of frog (Xenopus) oocytes after being micro-injected into the cytoplasm. (wikipedia.org)
In fact, only a small percentage of cellular (non-viral) nuclear proteins contained a sequence similar to the SV40 NLS. (wikipedia.org)
Much has been learned regarding nuclear entry, but the cellular proteins involved are still unknown and the exact role of each viral component remains controversial [ 7 ]. (biomedcentral.com)
This PY-NLS motif, so named because of the proline-tyrosine amino acid pairing in it, allows the protein to bind to Importin β2 (also known as transportin or karyopherin β2), which then translocates the cargo protein into the nucleus. (wikipedia.org)
During the long journey from the cell surface to the nucleus, retroviruses will face multiple obstacles, since in addition to finding a path through the cytoplasm to the nucleus they have to cross two main barriers, the plasma and nuclear membranes, whilst at the same time avoiding or counteracting cellular defences that can interfere with many of these steps. (biomedcentral.com)
Entry1
Using a protein called nucleoplasmin, the archetypal 'molecular chaperone', they identified a domain in the protein that acts as a signal for nuclear entry. (wikipedia.org)
Monopartite5
These types of NLSs can be further classified as either monopartite or bipartite. (wikipedia.org)
The major structural differences between the two are that the two basic amino acid clusters in bipartite NLSs are separated by a relatively short spacer sequence (hence bipartite - 2 parts), while monopartite NLSs are not. (wikipedia.org)
carried out comparative mutagenesis on the nuclear localization signals of SV40 T-Antigen (monopartite), C-myc (monopartite), and nucleoplasmin (bipartite), and showed amino acid features common to all three. (wikipedia.org)
We also explored using specific models for the monopartite and bipartite NLSs, but surprisingly, found no significant improvement in positive predictive value. (biomedcentral.com)
Translocation1
We found that RKIP interacts with the nuclear transport factor importin α in BT-20 and MDA-MB-231 human breast cancer cells, suggesting importin-mediated active nuclear translocation. (bvsalud.org)
Targeted mutations substituting lysines for alanines in the downstream cluster of the bipartite motif abolished the capacity of cNLS to mediate nuclear import. (nih.gov)
Mutating NAS alone, or in combination with cNLS, had no gross effect on the intracellular distribution of the protein, indicating that a functional NAS is not required for nuclear accumulation of THOV NP in mammalian cells. (nih.gov)
Karyopherin2
This PY-NLS motif, so named because of the proline-tyrosine amino acid pairing in it, allows the protein to bind to Importin β2 (also known as transportin or karyopherin β2), which then translocates the cargo protein into the nucleus. (wikipedia.org)
The pores allow the passive diffusion of small proteins, but bigger proteins entering the nucleus are usually bound by karyopherin complexes on their nuclear localization signal [ 5 ]. (biomedcentral.com)
Amino acids2
The NLS of nucleoplasmin, KR[PAATKKAGQA]KKKK, is the prototype of the ubiquitous bipartite signal: two clusters of basic amino acids, separated by a spacer of about 10 amino acids. (wikipedia.org)
We searched the literature for papers in which specific stretches of amino acids have been shown to act as functional NLSs in yeast. (biomedcentral.com)
Eukaryotic cells2
The presence of the nuclear membrane that sequesters the cellular DNA is the defining feature of eukaryotic cells. (wikipedia.org)
Although there are many nuclear import pathways in eukaryotic cells, most of these have not been characterized in detail. (biomedcentral.com)
Sequences4
Typically, this signal consists of one or more short sequences of positively charged lysines or arginines exposed on the protein surface. (wikipedia.org)
However, many known NLSs do not match any of the consensus sequences described above. (biomedcentral.com)
Therefore, other computational methods have been proposed to predict NLSs based on amino acid sequences. (biomedcentral.com)
Like classical NLS sequences, the putative NLS of RKIP is rich in arginine and lysine residues. (bvsalud.org)
Yeast5
There are many other types of NLS, such as the acidic M9 domain of hnRNP A1, the sequence KIPIK in yeast transcription repressor Matα2, and the complex signals of U snRNPs. (wikipedia.org)
Of the many import pathways that exist in yeast, the best characterized is termed the 'classical' NLS pathway. (biomedcentral.com)
In this paper, we present an analysis of characterized NLSs in yeast, and find, despite the large number of nuclear import pathways, that NLSs seem to show similar patterns of amino acid residues. (biomedcentral.com)
We show that our method is able to consistently find 37% of the NLSs with a low false positive rate and that our method retains its true positive rate outside of the yeast data set used for the training parameters. (biomedcentral.com)
We compiled a list of experimentally verified NLSs in yeast and found that PredictNLS [ 8 ] predicts 10% of the NLSs in this set. (biomedcentral.com)
Functional1
However, a functional NLS could not be identified in another nuclear protein simply on the basis of similarity to the SV40 NLS. (wikipedia.org)
Protein8
compared the nuclear localization efficiencies of eGFP fused NLSs of SV40 Large T-Antigen, nucleoplasmin (AVKRPAATKKAGQAKKKKLD), EGL-13 (MSRRRKANPTKLSENAKKLAKEVEN), c-Myc (PAAKRVKLD) and TUS-protein (KLKIKRPVK) through rapid intracellular protein delivery. (wikipedia.org)
Most of these NLSs appear to be recognized directly by specific receptors of the importin β family without the intervention of an importin α-like protein. (wikipedia.org)
The nuclear membrane, therefore, separates the nuclear processes of DNA replication and RNA transcription from the cytoplasmic process of protein production. (wikipedia.org)
Using a protein called nucleoplasmin, the archetypal 'molecular chaperone', they identified a domain in the protein that acts as a signal for nuclear entry. (wikipedia.org)
Nuclear localization signals (NLSs) are stretches of residues within a protein that are important for the regulated nuclear import of the protein. (biomedcentral.com)
PSORT [ 7 ] accurately predicts protein localization by including heuristic scores based on residues frequencies, protein domains as well as motifs. (biomedcentral.com)
We have identified a putative bipartite nuclear localization signal (NLS) in RKIP that maps to the surface of the protein surrounding a known regulatory region. (bvsalud.org)
Downstream1
A Chelsky sequence may, therefore, be part of the downstream basic cluster of a bipartite NLS. (wikipedia.org)
Inhibitor1
The structural basis for the binding of the PY-NLS contained in Importin β2 has been determined and an inhibitor of import designed. (wikipedia.org)
Found3
They found significantly higher nuclear localization efficiency of c-Myc NLS compared to that of SV40 NLS. (wikipedia.org)
Evaluating the biological function of nuclear localization of RKIP, we found that the presence of the putative NLS is important for the role of RKIP in mitotic checkpoint regulation in MCF-7 human breast cancer cells. (bvsalud.org)
Cytoplasmic localization of BMP2K is managed by inhibition of NLS function through phosphorylation of Ser-1010 and by a newly found cytoplasmic localization region that antagonizes the NLS. (bvsalud.org)
Transport1
In contrast, identical mutations had no effect on nuclear localization when introduced into THOV NP, indicating that additional transport signals are present in NP. (nih.gov)
Show2
Although most of its functions have been considered cytosolic, we show here that the localization of RKIP is primarily nuclear in both growing and quiescent Madin-Darby canine kidney epithelial cells and in Cal-51 and BT-20 human breast cancer cells. (bvsalud.org)
Here we show the element that controls BMP2K's LLPS and cytoplasmic localization. (bvsalud.org)
Basic1
Point mutation of all the basic residues in the putative NLS of RKIP particularly strongly reduces nuclear localization. (bvsalud.org)
Import1
Amino-acid sequence comparisons revealed that THOV NP lacks the N-terminal nonconvential NLS (named here nNLS), which has been implicated in nuclear import of influenza A virus NP. (nih.gov)
Directly1
These experiments were part of a series that subsequently led to studies of nuclear reprogramming, directly relevant to stem cell research. (wikipedia.org)
Find1
We find that the p53K316P mutation increases cytoplasmic localization of p53 and promotes a pleiotropic metabolic phenotype that includes increased adiposity, increased de novo lipogenesis, and decreased lactate generation. (bvsalud.org)