scholarly journals The Extracellular Matrix Receptor Discoidin Domain Receptor 1 Regulates Collagen Transcription by Translocating to the Nucleus

2019 ◽  
Vol 30 (9) ◽  
pp. 1605-1624 ◽  
Author(s):  
Manuel Chiusa ◽  
Wen Hu ◽  
Hong-Jun Liao ◽  
Yan Su ◽  
Corina M. Borza ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Nuclear Translocation ◽  
Receptor Activation ◽  
Nuclear Localization Sequence ◽  
Discoidin Domain Receptor ◽  
Natural Ligand ◽  
Biochemical Assays ◽  
Localization Sequence ◽  
Mutant Forms ◽  
Discoidin Domain Receptor 1

BackgroundThe discoidin domain receptor 1 (DDR1) is activated by collagens, upregulated in injured and fibrotic kidneys, and contributes to fibrosis by regulating extracellular matrix production, but how DDR1 controls fibrosis is poorly understood. DDR1 is a receptor tyrosine kinase (RTK). RTKs can translocate to the nucleus via a nuclear localization sequence (NLS) present on the receptor itself or a ligand it is bound to. In the nucleus, RTKs regulate gene expression by binding chromatin directly or by interacting with transcription factors.MethodsTo determine whether DDR1 translocates to the nucleus and whether this event is mediated by collagen-induced DDR1 activation, we generated renal cells expressing wild-type or mutant forms of DDR1 no longer able to bind collagen. Then, we determined the location of the DDR1 upon collagen stimulation. Using both biochemical assays and immunofluorescence, we analyzed the steps involved in DDR1 nuclear translocation.ResultsWe show that although DDR1 and its natural ligand, collagen, lack an NLS, DDR1 is present in the nucleus of injured human and mouse kidney proximal tubules. We show that DDR1 nuclear translocation requires collagen-mediated receptor activation and interaction of DDR1 with SEC61B, a component of the Sec61 translocon, and nonmuscle myosin IIA and β-actin. Once in the nucleus, DDR1 binds to chromatin to increase the transcription of collagen IV, a major collagen upregulated in fibrosis.ConclusionsThese findings reveal a novel mechanism whereby activated DDR1 translates to the nucleus to regulate synthesis of profibrotic molecules.

The COOH-terminal nuclear localization sequence of interferon gamma regulates STAT1 alpha nuclear translocation at an intracellular site

2000 ◽  
Vol 113 (15) ◽  
pp. 2771-2781
Author(s):  
P.S. Subramaniam ◽  
J. Larkin ◽  
M.G. Mujtaba ◽  
M.R. Walter ◽  
H.M. Johnson
Keyword(s):  
Nuclear Localization ◽  
Nuclear Import ◽  
Nuclear Translocation ◽  
Biological Activities ◽  
Nuclear Localization Sequence ◽  
Receptor Complex ◽  
Ifn Gamma ◽  
High Affinity ◽  
Gamma Receptor ◽  
Localization Sequence

We have recently shown that the nuclear localization of IFN gamma is mediated by a polybasic nuclear localization sequence (NLS) in its C terminus. This NLS is required for the full expression of biological activity of IFN gamma, both extracellularly and intracellularly. We now show that this NLS plays an integral intracellular role in the nuclear translocation of the transcription factor STAT1 alpha activated by IFN gamma. Treatment of IFN gamma with antibodies to the C-terminal region (95–133) containing the NLS blocked the induction of STAT1 alpha nuclear translocation. The antibodies had no effect on nuclear translocation of STAT1 alpha in IFN gamma treated cells. A deletion mutant of human IFN gamma, IFN gamma (1–123), which is devoid of the C-terminal NLS region was found to be biologically inactive, but was still able to bind to the IFN gamma receptor complex on cells with a K(d) similar to that of the wild-type protein. Deletion of the NLS specifically abolished the ability of IFN gamma(1–123) to initiate the nuclear translocation of STAT1 alpha, which is required for the biological activities of IFN gamma following binding to the IFN gamma receptor complex. Thus, the NLS region appears to contribute minimally to extracellular high-affinity receptor-ligand binding, yet exerts a strong functional role in STAT1 alpha nuclear localization. A high-affinity site for the interaction of the C-terminal NLS domain of IFN gamma with a K(d) approx. 3 × 10(−8) M(−1) has been described by previous studies on the intracellular cytoplasmic domain of the IFN gamma receptor alpha-chain. To examine the role of the NLS at the intracellular level, we microinjected neutralizing antibodies raised against the C-terminal NLS domain of IFN gamma into the cytoplasm of cells before treatment of cells with IFN gamma. These intracellular antibodies specifically blocked the nuclear translocation of STAT1 alpha following the subsequent treatment of these cells extracellularly with IFN gamma. These data show that the NLS domain of IFN gamma interacts at an intracellular site to regulate STAT1 alpha nuclear import. A C-terminal peptide of murine IFN gamma, IFN gamma(95–133), that contains the NLS motif, induced nuclear translocation of STAT1 alpha when taken up intracellularly by a murine macrophage cell line. Deletion of the NLS motif specifically abrogated the ability of this intracellular peptide to cause STAT1 alpha nuclear translocation. In cells activated with IFN gamma, IFN gamma was found to as part of a complex that contained STAT1 alpha and the importin-alpha analog Npi-1, which mediates STAT1 alpha nuclear import. The tyrosine phosphorylation of STAT1 alpha, the formation of the complex IFN gamma/Npi-1/STAT1 alpha complex and the subsequent nuclear translocation of STAT1 alpha were all found to be dependent on the presence of the IFN gamma NLS. Thus, the NLS of IFN gamma functions intracellularly to directly regulate the activation and ultimate nuclear translocation STAT1 alpha.

scholarly journals Complex Formation with Monomeric α-Tubulin and Importin 13 Fosters c-Jun Protein Stability and Is Required for c-Jun’s Nuclear Translocation and Activity

Cancers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1806
Author(s):  
Melanie Kappelmann-Fenzl ◽  
Silke Kuphal ◽  
Rosemarie Krupar ◽  
Dirk Schadendorf ◽  
Viktor Umansky ◽  
...  
Keyword(s):  
Complex Formation ◽  
Protein Stability ◽  
Nuclear Translocation ◽  
Nuclear Accumulation ◽  
Nuclear Localization Sequence ◽  
Microtubule Network ◽  
Localization Sequence ◽  
Dynamic Structures ◽  
Main Regulator ◽  
Factor C

Microtubules are highly dynamic structures, which consist of α- and β-tubulin heterodimers. They are essential for a number of cellular processes, including intracellular trafficking and mitosis. Tubulin-binding chemotherapeutics are used to treat different types of tumors, including malignant melanoma. The transcription factor c-Jun is a central driver of melanoma development and progression. Here, we identify the microtubule network as a main regulator of c-Jun activity. Monomeric α-tubulin fosters c-Jun protein stability by protein–protein interaction. In addition, this complex formation is necessary for c-Jun’s nuclear localization sequence binding to importin 13, and consequent nuclear import and activity of c-Jun. A reduction in monomeric α-tubulin levels by treatment with the chemotherapeutic paclitaxel resulted in a decline in the nuclear accumulation of c-Jun in melanoma cells in an experimental murine model and in patients’ tissues. These findings add important knowledge to the mechanism of the action of microtubule-targeting drugs and indicate the newly discovered regulation of c-Jun by the microtubule cytoskeleton as a novel therapeutic target for melanoma and potentially also other types of cancer.

scholarly journals PlexinB1 Promotes Nuclear Translocation of the Glucocorticoid Receptor

Cells ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 3
Author(s):  
Magali Williamson ◽  
Ritu Garg ◽  
Claire M. Wells
Keyword(s):  
Prostate Cancer ◽  
Glucocorticoid Receptor ◽  
Cancer Cells ◽  
Androgen Deprivation Therapy ◽  
Late Stage ◽  
Nuclear Translocation ◽  
Androgen Deprivation ◽  
Nuclear Localization Sequence ◽  
Prostate Cancer Cells ◽  
Localization Sequence

Androgen receptor (AR) and glucocorticoid receptor (GR) are nuclear receptors whose function depends on their entry into the nucleus where they activate transcription of an overlapping set of genes. Both AR and GR have a role in resistance to androgen deprivation therapy (ADT), the mainstay of treatment for late stage prostate cancer. PlexinB1, a receptor for semaphorins, has been implicated in various cancers including prostate cancer and has a role in resistance to ADT. We show here that activation of PlexinB1 by Sema4D and Sema3C results in translocation of endogenous GR to the nucleus in prostate cancer cells, and that this effect is dependent on PlexinB1 expression. Sema4D/Sema3C promotes the translocation of GR-GFP to the nucleus and mutation of the nuclear localization sequence (NLS1) of GR abrogates this response. These findings implicate the importin α/β system in the Sema4D/Sema3C-mediated nuclear import of GR. Knockdown of PlexinB1 in prostate cancer cells decreases the levels of glucocorticoid-responsive gene products and antagonizes the decrease in cell motility and cell area of prostate cancer cells upon dexamethasone treatment, demonstrating the functional significance of these findings. These results show that PlexinB1 activation has a role in the trafficking and activation of the nuclear receptor GR and thus may have a role in resistance to androgen deprivation therapy in late stage prostate cancer.

scholarly journals SCCRO (DCUN1D1) Promotes Nuclear Translocation and Assembly of the Neddylation E3 Complex

2011 ◽  
Vol 286 (12) ◽  
pp. 10297-10304 ◽  
Author(s):  
Guochang Huang ◽  
Andrew J. Kaufman ◽  
Y. Ramanathan ◽  
Bhuvanesh Singh
Keyword(s):  
Nuclear Localization ◽  
Essential Role ◽  
Nuclear Translocation ◽  
Nuclear Localization Sequence ◽  
Mouse Embryonic Fibroblasts ◽  
Embryonic Fibroblasts ◽  
Transgenic Expression ◽  
Localization Sequence ◽  
Efficient Transfer

SCCRO/DCUN1D1/DCN1 (squamous cell carcinoma-related oncogene/defective in cullin neddylation 1 domain containing 1/defective in cullin neddylation) serves as an accessory E3 in neddylation by binding to cullin and Ubc12 to allow efficient transfer of Nedd8. In this work we show that SCCRO has broader, pleiotropic effects that are essential for cullin neddylation in vivo. Reduced primary nuclear localization of Cul1 accompanying decreased neddylation and proliferation in SCCRO−/− mouse embryonic fibroblasts led us to investigate whether compartmentalization plays a regulatory role. Decreased nuclear localization, neddylation, and defective proliferation in SCCRO−/− mouse embryonic fibroblasts were rescued by transgenic expression of SCCRO. Expression of reciprocal SCCRO and Cul1-binding mutants confirmed the requirement for SCCRO in nuclear translocation and neddylation of cullins in vivo. Nuclear translocation of Cul1 by tagging with a nuclear localization sequence allowed neddylation independent of SCCRO, but at a lower level. We found that in the nucleus, SCCRO enhances recruitment of Ubc12 to Cul1 to promote neddylation. These findings suggest that SCCRO has an essential role in neddylation in vivo involving nuclear localization of neddylation components and recruitment and proper positioning of Ubc12.

scholarly journals Discoidin domain receptor 1 activation links extracellular matrix to podocyte lipotoxicity in Alport syndrome

EBioMedicine ◽  
2021 ◽  
Vol 63 ◽  
pp. 103162
Author(s):  
Jin-Ju Kim ◽  
Judith M. David ◽  
Sydney S. Wilbon ◽  
Javier V. Santos ◽  
Devang M. Patel ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Alport Syndrome ◽  
Discoidin Domain Receptor ◽  
Discoidin Domain Receptor 1

scholarly journals Design of Conditionally Active STATs: Insights into STAT Activation and Gene Regulatory Function

1999 ◽  
Vol 19 (4) ◽  
pp. 2913-2920 ◽  
Author(s):  
Lawrence H. Milocco ◽  
Jennifer A. Haslam ◽  
Jonathan Rosen ◽  
H. Martin Seidel
Keyword(s):  
Tyrosine Phosphorylation ◽  
Nuclear Translocation ◽  
Regulatory Function ◽  
Nuclear Localization Sequence ◽  
Wild Type ◽  
Localization Sequence ◽  
Gene Regulatory ◽  
First Time ◽  
Insight Into

ABSTRACT The STAT (signal transducer and activator of transcription) signaling pathway is activated by a large number of cytokines and growth factors. We sought to design a conditionally active STAT that could not only provide insight into basic questions about STAT function but also serve as a powerful tool to determine the precise biological role of STATs. To this end, we have developed a conditionally active STAT by fusing STATs with the ligand-binding domain of the estrogen receptor (ER). We have demonstrated that the resulting STAT-ER chimeras are estrogen-inducible transcription factors that retain the functional and biochemical characteristics of the cognate wild-type STATs. In addition, these tools have allowed us to evaluate separately the contribution of tyrosine phosphorylation and dimerization to STAT function. We have for the first time provided experimental data supporting the model that the only apparent role of STAT tyrosine phosphorylation is to drive dimerization, as dimerization alone is sufficient to unmask a latent STAT nuclear localization sequence and induce nuclear translocation, sequence-specific DNA binding, and transcriptional activity.

The Fanconi anemia proteins FANCA and FANCG stabilize each other and promote the nuclear accumulation of the Fanconi anemia complex

Blood ◽  
2000 ◽  
Vol 96 (9) ◽  
pp. 3224-3230 ◽  
Author(s):  
Irene Garcia-Higuera ◽  
Yanan Kuang ◽  
Jessica Denham ◽  
Alan D. D'Andrea
Keyword(s):  
Cell Line ◽  
Fanconi Anemia ◽  
Protein Complex ◽  
Half Life ◽  
Nuclear Translocation ◽  
Cancer Susceptibility ◽  
Nuclear Accumulation ◽  
Nuclear Localization Sequence ◽  
Amino Terminal ◽  
Mutant Forms

Fanconi anemia (FA) is an autosomal recessive cancer susceptibility syndrome with 8 complementation groups. Four of the FA genes have been cloned, and at least 3 of the encoded proteins, FANCA, FANCC, and FANCG/XRCC9, interact in a multisubunit protein complex. The FANCG protein binds directly to the amino terminal nuclear localization sequence (NLS) of FANCA, suggesting that FANCG plays a role in regulating FANCA nuclear accumulation. In the current study the functional consequences of FANCG/FANCA binding were examined. Correction of an FA-G cell line with the FANCG complementary DNA (cDNA) resulted in FANCA/FANCG binding, prolongation of the cellular half-life of FANCA, and an increase in the nuclear accumulation of the FA protein complex. Similar results were obtained upon correction of an FA-A cell line, with a reciprocal increase in the half-life of FANCG. Patient-derived mutant forms of FANCA, containing an intact NLS sequence but point mutations in the carboxy-terminal leucine zipper region, bound FANCG in the cytoplasm. The mutant forms failed to translocate to the nucleus of transduced cells, thereby suggesting a model of coordinated binding and nuclear translocation. These results demonstrate that the FANCA/FANCG interaction is required to maintain the cellular levels of both proteins. Moreover, at least one function of FANCG and FANCA is to regulate the nuclear accumulation of the FA protein complex. Failure to accumulate the nuclear FA protein complex results in the characteristic spectrum of clinical and cellular abnormalities observed in FA.

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