Identification of a classic nuclear localization signal at the N terminus that regulates the subcellular localization of Rbfox2 isoforms during differentiation of NMuMG and P19 cells

FEBS Letters ◽  
2016 ◽  
Vol 590 (24) ◽  
pp. 4453-4460 ◽  
Author(s):  
Manuel Wenzel ◽  
Martin Schüle ◽  
Sonia Casanovas ◽  
Dennis Strand ◽  
Susanne Strand ◽  
...  
Keyword(s):  
Subcellular Localization ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
P19 Cells ◽  
N Terminus ◽  
Localization Signal

scholarly journals The N-Terminal Domain of IκBα Masks the Nuclear Localization Signal(s) of p50 and c-Rel Homodimers

1998 ◽  
Vol 18 (5) ◽  
pp. 2640-2649 ◽  
Author(s):  
Matthew Latimer ◽  
Mary K. Ernst ◽  
Linda L. Dunn ◽  
Marina Drutskaya ◽  
Nancy R. Rice
Keyword(s):  
Amino Acids ◽  
Transcription Factors ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Mutational Analysis ◽  
Inhibitor Protein ◽  
N Terminus ◽  
Localization Signal ◽  
Terminal Section ◽  
Rel Homology Domain

ABSTRACT Members of the Rel/NF-κB family of transcription factors are related to each other over a region of about 300 amino acids called the Rel Homology Domain (RHD), which governs DNA binding, dimerization, and binding to inhibitor. At the C-terminal end of the RHD, each protein has a nuclear localization signal (NLS). The crystal structures of the p50 and RelA family members show that the RHD consists of two regions: an N-terminal section which contains some of the DNA contacts and a C-terminal section which contains the remaining DNA contacts and controls dimerization. In unstimulated cells, the homo- or heterodimeric Rel/NF-κB proteins are cytoplasmic by virtue of binding to an inhibitor protein (IκB) which somehow masks the NLS of each member of the dimer. The IκB proteins consist of an ankyrin-repeat-containing domain that is required for binding to dimers and N- and C-terminal domains that are dispensable for binding to most dimers. In this study, we examined the interaction between IκBα and Rel family homodimers by mutational analysis. We show that (i) the dimerization regions of p50, RelA, and c-Rel are sufficient for binding to IκBα, (ii) the NLSs of RelA and c-Rel are not required for binding to IκBα but do stabilize the interaction, (iii) the NLS of p50 is required for binding to IκBα, (iv) only certain residues within the p50 NLS are required for binding, and (v) in a p50-IκBα complex or a c-Rel-IκBα complex, the N terminus of IκBα either directly or indirectly masks one or both of the dimer NLSs.

scholarly journals Identification of a putative nuclear localization signal in maspin protein shed light into its nuclear import regulation

2018 ◽  
Author(s):  
Jeffrey Reina ◽  
Lixin Zhou ◽  
Marcos R.M. Fontes ◽  
Nelly Panté ◽  
Nathalie Cella
Keyword(s):  
Subcellular Localization ◽  
Nuclear Localization ◽  
Hela Cells ◽  
Nuclear Import ◽  
Nuclear Localization Signal ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Biological Activities ◽  
Dependent Manner ◽  
Localization Signal

AbstractMaspin (SERPINB5) is a potential tumor suppressor gene with pleiotropic biological activities, including regulation of cell proliferation, death, adhesion, migration and gene expression. Several studies suggest that subcellular localization plays an essential role on maspin tumor suppression activity. In this study we investigated the molecular mechanisms underlying maspin nucleocytoplasmic shuttling. Anin vitronuclear-import assay using digitonin-permeabilized HeLa cells demonstrated that maspin enters the nucleus by an energy-and carrier-independent mechanism. However, previous studies indicated that maspin subcellular localization is regulated in the cell. Using a nuclear localization signal (NLS) prediction software, we identified a putative NLS in the maspin amino acid sequence. To distinguish between passive and regulated nuclear translocation, maspinNLS or the full-length protein (MaspinFL) were fused to 5GFP, rendering the construct too large to enter the nucleus passively. Unexpectedly, 5GFP-maspinNLS, but not maspinFL-5GFP, entered the nucleus of HeLa cells. Dominant-negative Ran-GTPase mutants RanQ69L or RanT24N, suppressed 5GFP-maspinNLS nuclear localization. In summary, we provide evidence that maspin translocates to the nucleus passively. In addition, we identified a peptide in the maspin protein sequence, which is able to drive a 5GFP construct to the nucleus in an energy-dependent manner.

scholarly journals Protein Kinase C Phosphorylates Ribosomal Protein S6 Kinase βII and Regulates Its Subcellular Localization

2003 ◽  
Vol 23 (3) ◽  
pp. 852-863 ◽  
Author(s):  
Taras Valovka ◽  
Frederique Verdier ◽  
Rainer Cramer ◽  
Alexander Zhyvoloup ◽  
Timothy Fenton ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Subcellular Localization ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Nucleocytoplasmic Shuttling ◽  
S6 Kinase ◽  
Ribosomal Protein S6 ◽  
Kinase C ◽  
Localization Signal

ABSTRACT The ribosomal protein S6 kinase (S6K) belongs to the AGC family of Ser/Thr kinases and is known to be involved in the regulation of protein synthesis and the G1/S transition of the cell cycle. There are two forms of S6K, termed S6Kα and S6Kβ, which have cytoplasmic and nuclear splice variants. Nucleocytoplasmic shuttling has been recently proposed for S6Kα, based on the use of the nuclear export inhibitor, leptomycin B. However, the molecular mechanisms regulating subcellular localization of S6Ks in response to mitogenic stimuli remain to be elucidated. Here we present data on the in vitro and in vivo phosphorylation of S6Kβ, but not S6Kα, by protein kinase C (PKC). The site of phosphorylation was identified as S486, which is located within the C-terminal nuclear localization signal. Mutational analysis and the use of phosphospecific antibodies provided evidence that PKC-mediated phosphorylation at S486 does not affect S6K activity but eliminates the function of its nuclear localization signal and causes retention of an activated form of the kinase in the cytoplasm. Taken together, this study uncovers a novel mechanism for the regulation of nucleocytoplasmic shuttling of S6KβII by PKC-mediated phosphorylation.

scholarly journals DNA polymerase β contains a functional nuclear localization signal at its N-terminus

2016 ◽  
Vol 45 (4) ◽  
pp. 1958-1970 ◽  
Author(s):  
Thomas W. Kirby ◽  
Natalie R. Gassman ◽  
Cassandra E. Smith ◽  
Ming-Lang Zhao ◽  
Julie K. Horton ◽  
...  
Keyword(s):  
Dna Polymerase ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Dna Polymerase Β ◽  
N Terminus ◽  
Localization Signal ◽  
Functional Nuclear Localization Signal
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