Repressor domain and nuclear localization signal of the murine Hoxa-11 protein are located in the homeodomain: no evidence for role of poly alanine stretches in transcriptional repression

2005 ◽  
Vol 304B (5) ◽  
pp. 468-475 ◽  
Author(s):  
Jutta Johanna Roth ◽  
Michael Breitenbach ◽  
Günter Paul Wagner
Keyword(s):  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Transcriptional Repression ◽  
Localization Signal

scholarly journals Dual role of the adenovirus pVI C terminus as a nuclear localization signal and activator of the viral protease

2004 ◽  
Vol 85 (11) ◽  
pp. 3367-3376 ◽  
Author(s):  
K. S. Honkavuori ◽  
B. D. Pollard ◽  
M. S. Rodriguez ◽  
R. T. Hay ◽  
G. D. Kemp
Keyword(s):  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Human Adenovirus ◽  
Dual Role ◽  
Adenovirus Infection ◽  
Heterologous Proteins ◽  
Viral Protease ◽  
C Terminus ◽  
Localization Signal

Adenain, the protease produced by adenovirus, is regulated by formation of a heterodimer with an 11 aa peptide derived from the C terminus of another adenoviral protein, pVI. Here, the role of the basic motif KRRR, which is conserved in pVI sequences from human adenovirus serotypes, was investigated. It was shown that this motif is less important than the N- or C-terminal regions in the formation of the adenain–peptide heterodimer and in the activity of the subsequent complex. This motif, however, acted as a nuclear localization signal that was capable of targeting heterologous proteins to the nucleus, resulting in a distinctive intranuclear distribution consisting of discrete foci, which is similar to that found for pVI during adenovirus infection.

scholarly journals Mechanisms Directing the Nuclear Localization of the CtBP Family Proteins

2006 ◽  
Vol 26 (13) ◽  
pp. 4882-4894 ◽  
Author(s):  
Alexis Verger ◽  
Kate G. R. Quinlan ◽  
Linda A. Crofts ◽  
Stefania Spanò ◽  
Daniela Corda ◽  
...  
Keyword(s):  
Nuclear Localization ◽  
Nuclear Import ◽  
Nuclear Localization Signal ◽  
Transcriptional Repression ◽  
Intracellular Trafficking ◽  
Nuclear Accumulation ◽  
Splice Isoforms ◽  
Localization Signal ◽  
Splice Isoform ◽  
Partner Proteins

ABSTRACT The C-terminal binding protein (CtBP) family includes four proteins (CtBP1 [CtBP1-L], CtBP3/BARS [CtBP1-S], CtBP2, and RIBEYE) which are implicated both in transcriptional repression and in intracellular trafficking. However, the precise mechanisms by which different CtBP proteins are targeted to different subcellular regions remains unknown. Here, we report that the nuclear import of the various CtBP proteins and splice isoforms is differentially regulated. We show that CtBP2 contains a unique nuclear localization signal (NLS) located within its N-terminal region, which contributes to its nuclear accumulation. Using heterokaryon assays, we show that CtBP2 is capable of shuttling between the nucleus and cytoplasm of the cell. Moreover, CtBP2 can heterodimerize with CtBP1-L and CtBP1-S and direct them to the nucleus. This effect strongly depends on the CtBP2 NLS. PXDLS motif-containing transcription factors, such as BKLF, that bind CtBP proteins can also direct them to the nucleus. We also report the identification of a splice isoform of CtBP2, CtBP2-S, that lacks the N-terminal NLS and localizes to the cytoplasm. Finally, we show that mutation of the CtBP NADH binding site impairs the ability of the proteins to dimerize and to associate with BKLF. This reduces the nuclear accumulation of CtBP1. Our results suggest a model in which the nuclear localization of CtBP proteins is influenced by the CtBP2 NLS, by binding to PXDLS motif partner proteins, and through the effect of NADH on CtBP dimerization.

scholarly journals Tumor suppressor menin: the essential role of nuclear localization signal domains in coordinating gene expression

Oncogene ◽  
2006 ◽  
Vol 25 (25) ◽  
pp. 3537-3546 ◽  
Author(s):  
P La ◽  
A Desmond ◽  
Z Hou ◽  
A C Silva ◽  
R W Schnepp ◽  
...  
Keyword(s):  
Gene Expression ◽  
Tumor Suppressor ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Essential Role ◽  
Localization Signal

scholarly journals Role of unphosphorylated, newly synthesized I kappa B beta in persistent activation of NF-kappa B.

1996 ◽  
Vol 16 (10) ◽  
pp. 5444-5449 ◽  
Author(s):  
H Suyang ◽  
R Phillips ◽  
I Douglas ◽  
S Ghosh
Keyword(s):  
Dna Binding ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Stable Complex ◽  
Dna Binding Domain ◽  
Nf Kappa B ◽  
Prolonged Stimulation ◽  
I Kappa B Alpha ◽  
Localization Signal

Stimulation with inducers that cause persistent activation of NF-kappa B results in the degradation of the NF-kappa B inhibitors, I kappa B alpha and I kappa B beta. Despite the rapid resynthesis and accumulation of I kappa B alpha, NF-kappa B remains induced under these conditions. We now report that I kappa B beta is also resynthesized in stimulated cells and appears as an unphosphorylated protein. The unphosphorylated I kappa B beta forms a stable complex with NF-kappa B in the cytosol; however, this binding fails to mask the nuclear localization signal and DNA binding domain on NF-kappa B, and the I kappa B beta-NF-kappa B complex enters the nucleus. It appears therefore that during prolonged stimulation, I kappa B beta functions as a chaperone for NF-kappa B by protecting it from I kappa B alpha and allowing it to be transported to the nucleus.

scholarly journals Residues within the Foot-and-Mouth Disease Virus 3Dpol Nuclear Localization Signal Affect Polymerase Fidelity

2020 ◽  
Vol 94 (17) ◽  
Author(s):  
Anna Kloc ◽  
Devendra K. Rai ◽  
Douglas P. Gladue ◽  
Elizabeth Schafer ◽  
Mary Kenney ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Amino Acids ◽  
Molecular Dynamics Simulation ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Foot And Mouth Disease ◽  
Dynamics Simulation ◽  
Mouth Disease Virus ◽  
Localization Signal

ABSTRACT Many RNA viruses encode a proof-reading deficient, low-fidelity RNA-dependent polymerase (RdRp), which generates genetically diverse populations that can adapt to changing environments and thwart antiviral therapies. 3Dpol, the RdRp of the foot-and-mouth disease virus (FMDV), is responsible for replication of viral genomes. The 3Dpol N terminus encodes a nuclear localization signal (NLS) sequence,MRKTKLAPT, important for import of the protein to host nucleus. Previous studies showed that substitutions at residues 18 and 20 of the NLS are defective in proper incorporation of nucleotides and RNA binding. Here, we use a systematic alanine scanning mutagenesis approach to understand the role of individual residues of the NLS in nuclear localization and nucleotide incorporation activities of 3Dpol. We identify two residues of 3Dpol NLS, T19 and L21, that are important for the maintenance of enzyme fidelity. The 3Dpol NLS alanine substitutions of T19 and L21 results in aberrant incorporation of nucleoside analogs, conferring a low fidelity phenotype of the enzyme. A molecular dynamics simulation of RNA- and mutagen (RTP)-bound 3Dpol revealed that the T19 residue participates in a hydrogen bond network, including D165 in motif F and R416 at the C terminus of the FMDV 3Dpol and RNA template-primer. Based on these findings and previous studies, we conclude that at least the first six residues of theMRKTKLAPT sequence motif play a vital role in the maintenance of faithful RNA synthesis activity (fidelity) of FMDV 3Dpol, suggesting that the role of the NLS motif in similar viral polymerases needs to be revisited. IMPORTANCE In this study, we employed genetic and molecular dynamics approaches to analyze the role of individual amino acids of the FMDV 3Dpol nuclear localization signal (NLS). The NLS residues were mutated to alanine using a type A full-genome cDNA clone, and the virus progeny was analyzed for defects in growth and in competition with the parental virus. We identified two mutants in 3Dpol, T19A and L21A, that exhibited high rate of mutation, were sensitive to nucleotide analogs, and displayed reduced replicative fitness compared to the parental virus. Using molecular dynamics simulation, we demonstrated that residues T19 and L21 played a role in the structural configuration of the interaction network at the 3Dpol palm subdomain. Cumulatively, our data suggest that the T19 and L21 3Dpol amino acids are important for maintaining the fidelity of the FMDV polymerase and ensuring faithful replication of the FMDV genome.

scholarly journals The role of nuclear localization signal in parvovirus life cycle

2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Peng Liu ◽  
Shun Chen ◽  
Mingshu Wang ◽  
Anchun Cheng
Keyword(s):  
Life Cycle ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Localization Signal
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