The distal arthrogryposis‐linked p.R63C variant promotes the stability and nuclear accumulation of TNNT3

Down-regulation of the Kpm/Lats2 tumor suppressor is observed in various malignancies and associated with poor prognosis in acute lymphoblastic leukemia. We documented that Kpm/Lats2 was markedly decreased in several leukemias that were highly resistant to conventional chemotherapy. Silencing of Kpm/Lats2 expression in leukemic cells did not change the rate of cell growth but rendered the cells more resistant to DNA damage–inducing agents. Expression of p21 and PUMA was strongly induced by these agents in control cells, despite defective p53, but was only slightly induced in Kpm/Lats2-knockdown cells. DNA damage–induced nuclear accumulation of p73 was clearly observed in control cells but hardly detected in Kpm/Lats2-knockdown cells. Chromatin immunoprecipitation (ChIP) assay showed that p73 was recruited to the PUMA gene promoter in control cells but not in Kpm/Lats2-knockdown cells after DNA damage. The analyses with transient coexpression of Kpm/Lats2, YAP2, and p73 showed that Kpm/Lats2 contributed the stability of YAP2 and p73, which was dependent on the kinase function of Kpm/Lats2 and YAP2 phosphorylation at serine 127. Our results suggest that Kpm/Lats2 is involved in the fate of p73 through the phosphorylation of YAP2 by Kpm/Lats2 and the induction of p73 target genes that underlie chemosensitivity of leukemic cells.

Download Full-text

Phospho-Ser727 triggers a multistep inactivation of STAT3 by rapid dissociation of pY705–SH2 through C-terminal tail modulation

International Immunology ◽

10.1093/intimm/dxz061 ◽

2019 ◽

Author(s):

Junhao Yang ◽

Hiroyuki Kunimoto ◽

Bumpei Katayama ◽

Hong Zhao ◽

Takashi Shiromizu ◽

...

Keyword(s):

Conformational Changes ◽

Nuclear Export ◽

Chromosome Region ◽

Intramolecular Interactions ◽

Nuclear Accumulation ◽

Proper Function ◽

Functional Studies ◽

Reciprocal Interactions ◽

The Stability ◽

Transcription 3

Abstract Signal transducer and activator of transcription 3 (STAT3) is involved in many biological processes, including immunity and cancer. STAT3 becomes phosphorylated at Tyr705 and Ser727 on IL-6 stimulation. Phospho-Tyr705 (pY705) stabilizes the STAT3 dimer with reciprocal interactions between pY705 and the SH2 of the other molecule and phospho-Ser727 (pS727) accelerates pY705 dephosphorylation. We study how pS727 regulates STAT3 in both structural and biological perspectives. Using STAT3 reconstituted in HepG2-stat3-knockout cells, we show that pS727, together with a handshake N-terminal domain (NTD) interaction, causes rapid inactivation of STAT3 for pY705 dephosphorylation and a chromosome region maintenance 1 (CRM1)-independent nuclear export, which is critical for faithful STAT3 response to the cellular signals. The various N-terminal tags, GFP-related Ruby and FLAG, rendered the export CRM1-dependent and especially FLAG-tag caused nuclear accumulation of STAT3, indicating the presence of conformational changes in inactivation. Impaired reactivation of STAT3 by S727A or FLAG-tag delayed or inhibited the IL-6-induced saa1 mRNA expression, respectively. The detailed analysis of the pY705–SH2 structure identified the C-terminal tail (CTT) from L706 to P715 as a key regulator of the CTT–CTT intermolecular and the CTT–SH2 intramolecular interactions that support pY705–SH2 association. The functional studies using multiple STAT3 mutants indicated that the degree of the two interactions determines the stability of pY705–SH2 interaction. Importantly, Pro715 was critical for the pS727's destabilizing activity and the known phosphorylation and acetylation at the CTT structurally inhibited the pY705–SH2 interaction. Thus, pS727 triggers pY705–SH2 dissociation by weakening the supportive interactions likely through CTT modulation, inducing rapid cycles of STAT3 activation–inactivation for proper function of STAT3.

Download Full-text

Ubc9 promotes the stability of Smad4 and the nuclear accumulation of Smad1 in osteoblast-like Saos-2 cells

Bone ◽

10.1016/j.bone.2008.01.009 ◽

2008 ◽

Vol 42 (5) ◽

pp. 886-893 ◽

Cited By ~ 22

Author(s):

Koichi Shimada ◽

Naoto Suzuki ◽

Yoichi Ono ◽

Koji Tanaka ◽

Masao Maeno ◽

...

Keyword(s):

Nuclear Accumulation ◽

The Stability

Download Full-text

Role of the CXCR4-LASP1 Axis in the Stabilization of Snail1 in Triple-Negative Breast Cancer

Cancers ◽

10.3390/cancers12092372 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2372 ◽

Cited By ~ 1

Author(s):

Boopathi Subramaniyan ◽

Sangita Sridharan ◽

Cory M. Howard ◽

Augustus M.C. Tilley ◽

Tupa Basuroy ◽

...

Keyword(s):

Breast Cancer ◽

Triple Negative Breast Cancer ◽

Molecular Mechanisms ◽

Cancer Metastasis ◽

Triple Negative ◽

Breast Cancer Metastasis ◽

Nuclear Accumulation ◽

Genetic Ablation ◽

Gsk 3Β ◽

The Stability

The CXCL12-CXCR4 axis plays a vital role in many steps of breast cancer metastasis, but the molecular mechanisms have not been fully elucidated. We previously reported that activation of CXCR4 by CXCL12 promotes the nuclear localization of LASP1 (LIM and SH3 protein 1). The nuclear LASP1 then interacts with Snail1 in triple-negative breast cancer (TNBC) cell lines. In this study, we report that the nuclear accumulation and retention of Snail1 was dependent on an increase in nuclear LASP1 levels driven by active CXCR4. The CXCR4-LASP1 axis may directly regulate the stabilization of nuclear Snail1, by upregulating nuclear levels of pS473-Akt, pS9-GSK-3β, A20, and LSD1. Furthermore, the activation of CXCR4 induced association of LASP1 with Snail1, A20, GSK-3β, and LSD1 endogenously. Thus, nuclear LASP1 may also regulate protein-protein interactions that facilitate the stability of Snail1. Genetic ablation of LASP1 resulted in the mislocalization of nuclear Snail1, loss of the ability of TNBC cells to invade Matrigel and a dysregulated expression of both epithelial and mesenchymal markers, including an increased expression of ALDH1A1, a marker for epithelial breast cancer stem-like cells. Our findings reveal a novel role for the CXCR4-LASP1 axis in facilitating the stability of nuclear localized Snail1.

Download Full-text

Albumin nanoparticles improved the stability, nuclear accumulation and anticytomegaloviral activity of a phosphodiester oligonucleotide

Journal of Controlled Release ◽

10.1016/j.jconrel.2003.10.009 ◽

2004 ◽

Vol 94 (1) ◽

pp. 217-227 ◽

Cited By ~ 47

Author(s):

A. Arnedo ◽

J.M. Irache ◽

M. Merodio ◽

M.S. Espuelas Millán

Keyword(s):

Nuclear Accumulation ◽

Albumin Nanoparticles ◽

The Stability

Download Full-text

Impaired p53 Expression, Function, and Nuclear Localization in Calreticulin-deficient Cells

Molecular Biology of the Cell ◽

10.1091/mbc.e03-04-0251 ◽

2004 ◽

Vol 15 (4) ◽

pp. 1862-1870 ◽

Cited By ~ 52

Author(s):

Nasrin Mesaeli ◽

Clark Phillipson

Keyword(s):

Dna Damage ◽

Binding Site ◽

Nuclear Localization ◽

P53 Protein ◽

Nuclear Accumulation ◽

P53 Expression ◽

Cycle Arrest ◽

Expression Of Genes ◽

The Stability

The tumor suppressor protein, p53 is a transcription factor that not only activates expression of genes containing the p53 binding site but also can repress the expression of some genes lacking this binding site. Previous studies have shown that overexpression of wild-type p53 leads to apoptosis and cell cycle arrest. DNA damage, such as that caused by UV irradiation, results in p53 stabilization and nuclear localization that subsequently induces apoptosis. Recently, the level of calreticulin (CRT) has been correlated with the rate of apoptosis. Therefore, the aim of this study was to investigate the role of CRT in the regulation of apoptosis via modulating p53 function and expression. Here we show a significant decrease in both basal and DNA damage induced p53 functions in the CRT-deficient cells (crt-/-). This study is the first to demonstrate that CRT function is required for the stability and localization of the p53 protein. By using immuonocytochemical techniques, we showed that observed changes in p53 in the crt-/- cells are due to the nuclear accumulation of Mdm2 (murine double minute gene). These results, lead us to conclude that CRT regulates p53 function by affecting its rate of degradation and nuclear localization.

Download Full-text

DIX Domains of Dvl and Axin Are Necessary for Protein Interactions and Their Ability To Regulate β-Catenin Stability

Molecular and Cellular Biology ◽

10.1128/mcb.19.6.4414 ◽

1999 ◽

Vol 19 (6) ◽

pp. 4414-4422 ◽

Cited By ~ 249

Author(s):

Shosei Kishida ◽

Hideki Yamamoto ◽

Shin-ichiro Hino ◽

Satoshi Ikeda ◽

Michiko Kishida ◽

...

Keyword(s):

Growth Rate ◽

Protein Interactions ◽

Glycogen Synthase ◽

Terminal Region ◽

Nuclear Accumulation ◽

Protein Protein Interactions ◽

Sw480 Cells ◽

The Stability ◽

Two Hybrid ◽

Hybrid Screening

ABSTRACT The N-terminal region of Dvl-1 (a mammalian Dishevelled homolog) shares 37% identity with the C-terminal region of Axin, and this related region is named the DIX domain. The functions of the DIX domains of Dvl-1 and Axin were investigated. By yeast two-hybrid screening, the DIX domain of Dvl-1 was found to interact with Dvl-3, a second mammalian Dishevelled relative. The DIX domains of Dvl-1 and Dvl-3 directly bound one another. Furthermore, Dvl-1 formed a homo-oligomer. Axin also formed a homo-oligomer, and its DIX domain was necessary. The N-terminal region of Dvl-1, including its DIX domain, bound to Axin directly. Dvl-1 inhibited Axin-promoted glycogen synthase kinase 3β-dependent phosphorylation of β-catenin, and the DIX domain of Dvl-1 was required for this inhibitory activity. Expression of Dvl-1 in L cells induced the nuclear accumulation of β-catenin, and deletion of the DIX domain abolished this activity. Although expression of Axin in SW480 cells caused the degradation of β-catenin and reduced the cell growth rate, expression of an Axin mutant that lacks the DIX domain did not affect the level of β-catenin or the growth rate. These results indicate that the DIX domains of Dvl-1 and Axin are important for protein-protein interactions and that they are necessary for the ability of Dvl-1 and Axin to regulate the stability of β-catenin.

Download Full-text

Open discussion

Symposium - International Astronomical Union ◽

10.1017/s0074180900029533 ◽

1982 ◽

Vol 99 ◽

pp. 605-613

Author(s):

P. S. Conti

Keyword(s):

Buenos Aires ◽

Large Mass ◽

List Type ◽

Common Phenomenon ◽

Open Discussion ◽

The Stability ◽

Ring Nebulae

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.

Download Full-text

Symmetric Multistep Methods Revisited: II. Numerical Experiments

International Astronomical Union Colloquium ◽

10.1017/s0252921100031602 ◽

1999 ◽

Vol 173 ◽

pp. 309-314 ◽

Cited By ~ 3

Author(s):

T. Fukushima

Keyword(s):

Multistep Methods ◽

Computational Time ◽

Integration Time ◽

Implicit Methods ◽

Symmetric Methods ◽

Celestial Bodies ◽

The Stability ◽

Predictor Corrector ◽

Symmetric Multistep Methods ◽

Integration Errors

AbstractBy using the stability condition and general formulas developed by Fukushima (1998 = Paper I) we discovered that, just as in the case of the explicit symmetric multistep methods (Quinlan and Tremaine, 1990), when integrating orbital motions of celestial bodies, the implicit symmetric multistep methods used in the predictor-corrector manner lead to integration errors in position which grow linearly with the integration time if the stepsizes adopted are sufficiently small and if the number of corrections is sufficiently large, say two or three. We confirmed also that the symmetric methods (explicit or implicit) would produce the stepsize-dependent instabilities/resonances, which was discovered by A. Toomre in 1991 and confirmed by G.D. Quinlan for some high order explicit methods. Although the implicit methods require twice or more computational time for the same stepsize than the explicit symmetric ones do, they seem to be preferable since they reduce these undesirable features significantly.

Download Full-text

Uniformity of Magnification from Different Electron Microscopes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100060179 ◽

1967 ◽

Vol 25 ◽

pp. 32-33

Author(s):

Godfrey C. Hoskins ◽

V. Williams ◽

V. Allison

Keyword(s):

Diffraction Grating ◽

The Other ◽

Carbon Replica ◽

Electron Microscopes ◽

The Stability

The method demonstrated is an adaptation of a proven procedure for accurately determining the magnification of light photomicrographs. Because of the stability of modern electrical lenses, the method is shown to be directly applicable for providing precise reproducibility of magnification in various models of electron microscopes.A readily recognizable area of a carbon replica of a crossed-line diffraction grating is used as a standard. The same area of the standard was photographed in Phillips EM 200, Hitachi HU-11B2, and RCA EMU 3F electron microscopes at taps representative of the range of magnification of each. Negatives from one microscope were selected as guides and printed at convenient magnifications; then negatives from each of the other microscopes were projected to register with these prints. By deferring measurement to the print rather than comparing negatives, correspondence of magnification of the specimen in the three microscopes could be brought to within 2%.

Download Full-text