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1.
Urology ; 185: 100-108, 2024 03.
Article in English | MEDLINE | ID: mdl-38309596

ABSTRACT

To synthesise the evidence comparing the incidence rates of UAS post-RARC vs Open Radical cystectomy (ORC) in adults undergoing cystectomy and to compare differential stricture rates between Extracorporeal and Intracorporeal urinary diversion (ECUD vs ICUD). The primary outcome was incidence rate of UAS post RARC vs ORC and the secondary outcome was incidence rate of UAS in RARC post ECUD vs ICUD. Review authors conducted comprehensive search for studies comparing RARC with ORC in terms of incidence of UAS. Furthermore, we conducted a secondary search for studies which compared UAS incidence comparing ECUD and ICUD. We found that RARC may have higher incidence of UAS [OR: 1.39; 95% CI 1.11-1.75; p < 0.0001]. ECUD may result in lower rate of UAS as compared to ICUD [OR: 0.74; 95% CI 0.56 to 0.98; p= 0.04].


Subject(s)
Robotic Surgical Procedures , Urinary Bladder Neoplasms , Urinary Diversion , Adult , Humans , Cystectomy/adverse effects , Incidence , Robotic Surgical Procedures/adverse effects , Constriction, Pathologic/surgery , Urinary Bladder Neoplasms/surgery , Treatment Outcome , Postoperative Complications/epidemiology , Urinary Diversion/adverse effects , Retrospective Studies
2.
Adv Sci (Weinh) ; 11(13): e2305277, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38279508

ABSTRACT

The availability of an ever-expanding portfolio of 2D materials with rich internal degrees of freedom (spin, excitonic, valley, sublattice, and layer pseudospin) together with the unique ability to tailor heterostructures made layer by layer in a precisely chosen stacking sequence and relative crystallographic alignments, offers an unprecedented platform for realizing materials by design. However, the breadth of multi-dimensional parameter space and massive data sets involved is emblematic of complex, resource-intensive experimentation, which not only challenges the current state of the art but also renders exhaustive sampling untenable. To this end, machine learning, a very powerful data-driven approach and subset of artificial intelligence, is a potential game-changer, enabling a cheaper - yet more efficient - alternative to traditional computational strategies. It is also a new paradigm for autonomous experimentation for accelerated discovery and machine-assisted design of functional 2D materials and heterostructures. Here, the study reviews the recent progress and challenges of such endeavors, and highlight various emerging opportunities in this frontier research area.

3.
BJU Int ; 127(1): 4-11, 2021 01.
Article in English | MEDLINE | ID: mdl-32981191

ABSTRACT

OBJECTIVE: To provide an update on the literature regarding the management of complications secondary to synthetic mesh placed to treat stress urinary incontinence (SUI). METHODS: We performed a systematic review of the literature using a multi-database structured search within OVID, the Medical Literature Analysis and Retrieval System Online (MEDLINE), the Excerpta Medica dataBASE (EMBASE) and Cochrane library databases; using the keywords: urology, incontinence, mesh and surgery. RESULTS: Several million synthetic polypropylene meshes have been inserted into women worldwide to manage SUI. Unfortunately, a significant number of women have now reported life-changing complications. We found a paucity of studies, heterogeneity of cohorts, poor long-term follow-up, and lack of evidence on the effective management of mesh-related complications. CONCLUSIONS: The contemporary evidence is low-level and often contradictory, which prevents robust recommendations regarding treatment. A prospective registry will be required to generate meaningful outcome data and help in the complex management of patients who have mesh-related complications.


Subject(s)
Suburethral Slings/adverse effects , Surgical Mesh/adverse effects , Urinary Incontinence, Stress/surgery , Urologic Diseases/etiology , Vaginal Diseases/etiology , Autoimmunity , Female , Humans , Polypropylenes/immunology
4.
J Synchrotron Radiat ; 27(Pt 5): 1131-1140, 2020 Sep 01.
Article in English | MEDLINE | ID: mdl-32876587

ABSTRACT

This paper presents a novel cantilevered liquid-nitrogen-cooled silicon mirror design for the first optic in a new soft X-ray beamline that is being developed as part of the Advanced Light Source Upgrade (ALS-U) (Lawrence Berkeley National Laboratory, USA). The beamline is optimized for photon energies between 400 and 1400 eV with full polarization control. Calculations indicate that, without correction, this design will achieve a Strehl ratio greater than 0.85 for the entire energy and polarization ranges of the beamline. With a correction achieved by moving the focus 7.5 mm upstream, the minimum Strehl ratio is 0.99. This design is currently the baseline plan for all new ALS-U insertion device beamlines.

5.
Natl Sci Rev ; 7(4): 745-754, 2020 Apr.
Article in English | MEDLINE | ID: mdl-34692093

ABSTRACT

Mechanically exfoliated two-dimensional ferromagnetic materials (2D FMs) possess long-range ferromagnetic order and topologically nontrivial skyrmions in few layers. However, because of the dimensionality effect, such few-layer systems usually exhibit much lower Curie temperature (T C) compared to their bulk counterparts. It is therefore of great interest to explore effective approaches to enhance their T C, particularly in wafer-scale for practical applications. Here, we report an interfacial proximity-induced high-T C 2D FM Fe3GeTe2 (FGT) via A-type antiferromagnetic material CrSb (CS) which strongly couples to FGT. A superlattice structure of (FGT/CS)n, where n stands for the period of FGT/CS heterostructure, has been successfully produced with sharp interfaces by molecular-beam epitaxy on 2-inch wafers. By performing elemental specific X-ray magnetic circular dichroism (XMCD) measurements, we have unequivocally discovered that T C of 4-layer Fe3GeTe2 can be significantly enhanced from 140 K to 230 K because of the interfacial ferromagnetic coupling. Meanwhile, an inverse proximity effect occurs in the FGT/CS interface, driving the interfacial antiferromagnetic CrSb into a ferrimagnetic state as evidenced by double-switching behavior in hysteresis loops and the XMCD spectra. Density functional theory calculations show that the Fe-Te/Cr-Sb interface is strongly FM coupled and doping of the spin-polarized electrons by the interfacial Cr layer gives rise to the T C enhancement of the Fe3GeTe2 films, in accordance with our XMCD measurements. Strikingly, by introducing rich Fe in a 4-layer FGT/CS superlattice, T C can be further enhanced to near room temperature. Our results provide a feasible approach for enhancing the magnetic order of few-layer 2D FMs in wafer-scale and render opportunities for realizing realistic ultra-thin spintronic devices.

7.
ACS Nano ; 13(11): 12894-12900, 2019 Nov 26.
Article in English | MEDLINE | ID: mdl-31693338

ABSTRACT

We present a combined experimental and theoretical study of monolayer vanadium ditelluride, VTe2, grown on highly oriented pyrolytic graphite by molecular-beam epitaxy. Using various in situ microscopic and spectroscopic techniques, including scanning tunneling microscopy/spectroscopy, synchrotron X-ray and angle-resolved photoemission, and X-ray absorption, together with theoretical analysis by density functional theory calculations, we demonstrate direct evidence of the metallic 1T phase and 3d1 electronic configuration in monolayer VTe2 that also features a (4 × 4) charge density wave order at low temperatures. In contrast to previous theoretical predictions, our element-specific characterization by X-ray magnetic circular dichroism rules out a ferromagnetic order intrinsic to the monolayer. Our findings provide essential knowledge necessary for understanding this interesting yet less explored metallic monolayer in the emerging family of van der Waals magnets.

8.
Adv Mater ; 31(23): e1901185, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30997712

ABSTRACT

Monolayer VSe2 , featuring both charge density wave and magnetism phenomena, represents a unique van der Waals magnet in the family of metallic 2D transition-metal dichalcogenides (2D-TMDs). Herein, by means of in situ microscopy and spectroscopic techniques, including scanning tunneling microscopy/spectroscopy, synchrotron X-ray and angle-resolved photoemission, and X-ray absorption, direct spectroscopic signatures are established, that identify the metallic 1T-phase and vanadium 3d1 electronic configuration in monolayer VSe2 grown on graphite by molecular-beam epitaxy. Element-specific X-ray magnetic circular dichroism, complemented with magnetic susceptibility measurements, further reveals monolayer VSe2 as a frustrated magnet, with its spins exhibiting subtle correlations, albeit in the absence of a long-range magnetic order down to 2 K and up to a 7 T magnetic field. This observation is attributed to the relative stability of the ferromagnetic and antiferromagnetic ground states, arising from its atomic-scale structural features, such as rotational disorders and edges. The results of this study extend the current understanding of metallic 2D-TMDs in the search for exotic low-dimensional quantum phenomena, and stimulate further theoretical and experimental studies on van der Waals monolayer magnets.

9.
ACS Nano ; 13(2): 2253-2261, 2019 Feb 26.
Article in English | MEDLINE | ID: mdl-30775909

ABSTRACT

Ferromagnet/two-dimensional transition-metal dichalcogenide (FM/2D TMD) interfaces provide attractive opportunities to push magnetic information storage to the atomically thin limit. Existing work has focused on FMs contacted with mechanically exfoliated or chemically vapor-deposition-grown TMDs, where clean interfaces cannot be guaranteed. Here, we report a reliable way to achieve contamination-free interfaces between ferromagnetic CoFeB and molecular-beam epitaxial MoSe2. We show a spin reorientation arising from the interface, leading to a perpendicular magnetic anisotropy (PMA), and reveal the CoFeB/2D MoSe2 interface allowing for the PMA development in a broader CoFeB thickness-range than common systems such as CoFeB/MgO. Using X-ray magnetic circular dichroism analysis, we attribute generation of this PMA to interfacial d-d hybridization and deduce a general rule to enhance its magnitude. We also demonstrate favorable magnetic softness and considerable magnetic moment preserved at the interface and theoretically predict the interfacial band matching for spin filtering. Our work highlights the CoFeB/2D MoSe2 interface as a promising platform for examination of TMD-based spintronic applications and might stimulate further development with other combinations of FM/2D TMD interfaces.

10.
Protein Pept Lett ; 26(1): 70-75, 2019.
Article in English | MEDLINE | ID: mdl-30484401

ABSTRACT

BACKGROUND: Synchrotron hydroxyl radical footprinting is a relatively new structural method used to investigate structural features and conformational changes of nucleic acids and proteins in the solution state. It was originally developed at the National Synchrotron Light Source at Brookhaven National Laboratory in the late nineties, and more recently, has been established at the Advanced Light Source at Lawrence Berkeley National Laboratory. The instrumentation for this method is an active area of development, and includes methods to increase dose to the samples while implementing high-throughput sample delivery methods. CONCLUSION: Improving instrumentation to irradiate biological samples in real time using a sample droplet generator and inline fluorescence monitoring to rapidly determine dose response curves for samples will significantly increase the range of biological problems that can be investigated using synchrotron hydroxyl radical footprinting.


Subject(s)
Crystallography, X-Ray , Hydroxyl Radical , Synchrotrons , Crystallography, X-Ray/instrumentation , Crystallography, X-Ray/methods , Crystallography, X-Ray/trends , Fluorescent Dyes/chemistry , Hydroxyl Radical/analysis , Hydroxyl Radical/chemistry , Microfluidic Analytical Techniques , Protein Conformation , Proteins/chemistry
11.
Scott Med J ; 59(4): 204-8, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25314954

ABSTRACT

BACKGROUND: Transperineal prostatic biopsy is firmly established as an important tool in the diagnosis of prostate cancer. The benefit of additional imaging (magnetic resonance imaging) to target biopsy remains to be fully addressed. METHODS: Using a cohort of consecutive patients undergoing transperineal template mapping biopsies, we studied positive biopsies in the context of magnetic resonance imaging findings and examined the accuracy of magnetic resonance imaging in predicting the location of transperineal template mapping biopsies-detected prostate cancer. RESULTS: Forty-four patients (mean age: 65 years, range 53-78) underwent transperineal template mapping biopsies. Thirty-four patients had 1-2 and 10 patients had ≥3 previous transrectal ultrasound scan-guided biopsies. The mean prostate-specific antigen was 15 ng/mL (range 2.5-79 ng/mL). High-grade prostatic intraepithelial neoplasia was found in 12 (27%) patients and prostate cancer with Gleason <7, 7 and >7 in 13, 10 and 8 patients, respectively. Suspicious lesions on magnetic resonance imaging scans were scored from 1 to 5. In 28 patients, magnetic resonance imaging detected lesions with score ≥3. Magnetic resonance imaging correctly localised transperineal template mapping biopsies-detected prostate cancer in a hemi-gland approach, particularly in a right to left manner (79% positive prediction rate), but not in a quadrant approach (33% positive prediction rate). CONCLUSION: Our findings support the notion of magnetic resonance imaging-based selection of patients for transperineal template mapping biopsies and that lesions revealed by magnetic resonance imaging are likely useful for targeted biopsies.


Subject(s)
Biopsy, Needle , Image-Guided Biopsy , Magnetic Resonance Imaging , Prostate/pathology , Prostatic Neoplasms/diagnosis , Ultrasonography, Interventional , Aged , Biopsy, Needle/methods , Humans , Male , Middle Aged , Perineum , Prospective Studies , Prostatic Neoplasms/epidemiology , Prostatic Neoplasms/pathology , Reproducibility of Results , Scotland/epidemiology
12.
Biochem J ; 434(3): 537-48, 2011 Mar 15.
Article in English | MEDLINE | ID: mdl-21204785

ABSTRACT

Mammalian Pellino isoforms are phosphorylated by IRAK (interleukin receptor associated kinase) 1/IRAK4 in vitro, converting them into active E3 ubiquitin ligases. In the present paper we report a striking enhancement in both transcription of the gene encoding Pellino 1 and Pellino 1 protein expression when murine BMDMs (bone-marrow-derived macrophages) are stimulated with LPS (lipopolysaccharide) or poly(I:C). This induction occurs via a TRIF [TIR (Toll/interleukin-1 receptor)-domain-containing adaptor-inducing interferon-ß]-dependent IRAK-independent pathway and is prevented by inhibition of the IKK [IκB (inhibitor of nuclear factor κB) kinase]-related protein kinases, TBK1 {TANK [TRAF (tumour-necrosis-factor-receptor-associated factor)-associated nuclear factor κB activator]-binding kinase 1} and IKKε. Pellino 1 is not induced in IRF3 (interferon regulatory factor 3)-/- BMDMs, and its induction is only reduced slightly in type 1 interferon receptor-/- BMDMs, identifying Pellino 1 as a new IRF3-dependent gene. We also identify Pellino 1 in a two-hybrid screen using IKKε as bait, and show that IKKε/TBK1 activate Pellino 1 in vitro by phosphorylating Ser76, Thr288 and Ser293. Moreover, we show that the E3 ligase activity of endogenous Pellino 1 is activated in LPS- or poly(I:C)-stimulated macrophages. This occurs more rapidly than the increase in Pellino 1 mRNA and protein expression, is prevented by the inhibition of IKKε/TBK1 and is reversed by phosphatase treatment. Thus IKKε/TBK1 mediate the activation of Pellino 1's E3 ligase activity, as well as inducing the transcription of its gene and protein expression in response to TLR3 and TLR4 agonists.


Subject(s)
I-kappa B Kinase/physiology , Nuclear Proteins/biosynthesis , Protein Serine-Threonine Kinases/physiology , Adaptor Proteins, Vesicular Transport/genetics , Adaptor Proteins, Vesicular Transport/physiology , Animals , Cells, Cultured , Enzyme Activation , Humans , Interferon Regulatory Factor-3/physiology , Lipopolysaccharides/pharmacology , Macrophages/drug effects , Macrophages/metabolism , Mice , Mice, Knockout , Myeloid Differentiation Factor 88/genetics , Phosphorylation , Poly I-C/pharmacology , Receptor, Interferon alpha-beta/physiology , Signal Transduction , Toll-Like Receptor 3/agonists , Toll-Like Receptor 4/agonists , Ubiquitin-Protein Ligases/metabolism
13.
Biochem J ; 418(3): 625-34, 2009 Mar 15.
Article in English | MEDLINE | ID: mdl-19076070

ABSTRACT

In Ewing's sarcomas, chromosomal translocations cause the N-terminal domain of the EWS (Ewing's sarcoma protein) to fuse with the DNA-binding domains of the Ets (E26 transformation-specific) family of transcription factors. Here we show that EWS and EWS-Fli1 (Friend leukaemia virus integration 1), the fusion most frequently found in Ewing's sarcomas, become phosphorylated at Thr(79) in response to either mitogens or DNA-damaging agents. The much weaker mitogen-induced phosphorylation of EWS is catalysed by the MAPKs (mitogen-activated protein kinases) ERK1 (extracellular signal-regulated kinase 1) and ERK2, whereas the much stronger phosphorylation of EWS induced by the DNA alkylating agent MMS (methyl methanesulphonate) can be catalysed by JNK (c-Jun N-terminal kinase) and at least one other protein kinase distinct from ERK1/ERK2. In contrast, the phosphorylation of EWS-Fli1 induced by MMS was largely mediated by p38alpha/p38beta MAPKs. MMS induced a much stronger phosphorylation of EWS-Fli1 than EWS in heterodimers comprising both proteins.


Subject(s)
DNA Damage/physiology , Oncogene Proteins, Fusion/metabolism , Proto-Oncogene Protein c-fli-1/metabolism , RNA-Binding Protein EWS/metabolism , Sarcoma, Ewing/metabolism , Amino Acid Sequence , Ataxia Telangiectasia Mutated Proteins , Cell Cycle Proteins/metabolism , Cell Line, Tumor , DNA-Binding Proteins/metabolism , Humans , MAP Kinase Signaling System/physiology , Methyl Methanesulfonate/pharmacology , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Naphthalenes/pharmacology , Peptide Fragments/metabolism , Phosphorylation , Protein Serine-Threonine Kinases/metabolism , Pyrazoles/pharmacology , Tumor Suppressor Proteins/metabolism , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors
14.
FEBS Lett ; 582(6): 997-1002, 2008 Mar 19.
Article in English | MEDLINE | ID: mdl-18307994

ABSTRACT

TANK-binding kinase 1 (TBK1) was identified as a binding partner for Optineurin (OPTN) in two-hybrid screens, an interaction confirmed by overexpression/immunoprecipitation experiments in HEK293 cells and by coimmunoprecipitation of endogenous OPTN and TBK1 from cell extracts. A TBK1 binding site was located between residues 1-127 of OPTN, residues 78-121 displaying striking homology to the TBK1-binding domain of TANK. The OPTN-binding domain was localised to residues 601-729 of TBK1, while TBK1[1-688] which cannot bind to TANK, did not interact with OPTN. The OPTN[E50K] mutant associated with Primary Open Angle Glaucoma (POAG) displayed strikingly enhanced binding to TBK1, suggesting that this interaction may contribute to familial POAG caused by this mutation.


Subject(s)
Glaucoma, Open-Angle/genetics , Protein Serine-Threonine Kinases/metabolism , Transcription Factor TFIIIA/genetics , Transcription Factor TFIIIA/metabolism , Amino Acid Sequence , Amino Acid Substitution , Binding Sites , Cell Cycle Proteins , Chromatin Immunoprecipitation , Glaucoma, Open-Angle/metabolism , Glutamic Acid/chemistry , Glutamic Acid/genetics , Humans , Lysine/chemistry , Lysine/genetics , Membrane Transport Proteins , Molecular Sequence Data , Mutation , Two-Hybrid System Techniques
15.
Biochem J ; 399(2): 265-73, 2006 Oct 15.
Article in English | MEDLINE | ID: mdl-16848763

ABSTRACT

A protein in RAW 264.7 macrophages, which became phosphorylated in response to LPS (lipopolysaccharide), was identified as the RNA-binding protein called DAZAP1 [DAZ (deleted in azoospermia)-associated protein 1]. The phosphorylation of this protein was prevented by specific inhibition of MKK1 [MAPK (mitogen-activated protein kinase) kinase 1], indicating that it was phosphorylated via the classical MAPK cascade. Further experiments showed that DAZAP1 was phosphorylated stoichiometrically in vitro by ERK2 (extracellular-signal-regulated protein kinase 2) at two Thr-Pro sequences (Thr269 and Thr315), and that both sites became phosphorylated in HEK-293 (human embryonic kidney 293) cells in response to PMA or EGF (epidermal growth factor), or RAW 264.7 macrophages in response to LPS. Phosphorylation induced by each stimulus was prevented by two structurally distinct inhibitors of MKK1 (PD184352 and U0126), demonstrating that DAZAP1 is a physiological substrate for ERK1/ERK2. The mutation of Thr269 and Thr315 to aspartate or the phosphorylation of these residues caused DAZAP1 to dissociate from its binding partner DAZ. DAZ interacts with PABP [poly(A)-binding protein] and thereby stimulates the translation of mRNAs containing short poly(A) tails [Collier, Gorgoni, Loveridge, Cooke and Gray (2005) EMBO J. 24, 2656-2666]. In the present study we have shown that DAZ cannot bind simultaneously to DAZAP1 and PABP, and suggest that the phosphorylation-induced dissociation of DAZ and DAZAP1 may allow the former to stimulate translation by interacting with PABP.


Subject(s)
Mitogen-Activated Protein Kinase 1/metabolism , RNA-Binding Proteins/metabolism , Amino Acid Sequence , Animals , Cells, Cultured , Deleted in Azoospermia 1 Protein , Gene Expression Regulation/drug effects , Heterogeneous-Nuclear Ribonucleoprotein K/chemistry , Humans , Lipopolysaccharides/pharmacology , Macrophages/drug effects , Mice , Mitogen-Activated Protein Kinase 3/metabolism , Molecular Sequence Data , Phosphorylation/drug effects , Phosphothreonine/metabolism , Poly(A)-Binding Protein I/metabolism , Protein Binding/drug effects , RNA, Messenger/genetics , RNA-Binding Proteins/chemistry , Regulatory Sequences, Ribonucleic Acid/genetics , Tumor Necrosis Factor-alpha/genetics
16.
Biochem J ; 394(Pt 1): 365-73, 2006 Feb 15.
Article in English | MEDLINE | ID: mdl-16336213

ABSTRACT

ERK8 (extracellular-signal-regulated protein kinase 8) expressed in Escherichia coli or insect cells was catalytically active and phosphorylated at both residues of the Thr-Glu-Tyr motif. Dephosphorylation of the threonine residue by PP2A (protein serine/threonine phosphatase 2A) decreased ERK8 activity by over 95% in vitro, whereas complete dephosphorylation of the tyrosine residue by PTP1B (protein tyrosine phosphatase 1B) decreased activity by only 15-20%. Wild-type ERK8 expressed in HEK-293 cells was over 100-fold less active than the enzyme expressed in bacteria or insect cells, but activity could be increased by exposure to hydrogen peroxide, by incubation with the protein serine/threonine phosphatase inhibitor okadaic acid, or more weakly by osmotic shock. In unstimulated cells, ERK8 was monophosphorylated at Tyr-177, and exposure to hydrogen peroxide induced the appearance of ERK8 that was dually phosphorylated at both Thr-175 and Tyr-177. IGF-1 (insulin-like growth factor 1), EGF (epidermal growth factor), PMA or anisomycin had little effect on activity. In HEK-293 cells, phosphorylation of the Thr-Glu-Tyr motif of ERK8 was prevented by Ro 318220, a potent inhibitor of ERK8 in vitro. The catalytically inactive mutants ERK8[D154A] and ERK8[K42A] were not phosphorylated in HEK-293 cells or E. coli, whether or not the cells had been incubated with protein phosphatase inhibitors or exposed to hydrogen peroxide. Our results suggest that the activity of ERK8 in transfected HEK-293 cells depends on the relative rates of ERK8 autophosphorylation and dephosphorylation by one or more members of the PPP family of protein serine/threonine phosphatases. The major residue in myelin basic protein phosphorylated by ERK8 (Ser-126) was distinct from that phosphorylated by ERK2 (Thr-97), demonstrating that, although ERK8 is a proline-directed protein kinase, its specificity is distinct from ERK1/ERK2.


Subject(s)
Extracellular Signal-Regulated MAP Kinases/metabolism , Binding Sites , Cell Line , Enzyme Activation , Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors , Extracellular Signal-Regulated MAP Kinases/genetics , Humans , Phosphoprotein Phosphatases/metabolism , Phosphorylation , Protein Phosphatase 2 , Recombinant Proteins , Substrate Specificity
17.
FEBS Lett ; 572(1-3): 177-83, 2004 Aug 13.
Article in English | MEDLINE | ID: mdl-15304344

ABSTRACT

The multisite phosphorylation of the transcription factor ATF-2 was investigated using transformed embryonic fibroblasts from wild-type mice and mice deficient in c-Jun N-terminal kinases (JNK)1 and 2, and in the presence and absence of inhibitors of p38 mitogen-activated protein kinase (p38 MAPK) and the classical MAP kinase cascade. In wild-type cells, p38 MAPK and extracellular signal-regulated protein kinase (ERK)1/2 were not rate limiting for the phosphorylation of Thr69, Thr71 or Ser90. In JNK-deficient cells, p38 MAPK substituted for JNK partially in the phosphorylation of Thr69 and p38 MAPK or ERK1/2 in the phosphorylation of Thr71. JNK was the only MAP kinase that phosphorylated Ser90 under the conditions examined.


Subject(s)
Cyclic AMP Response Element-Binding Protein/metabolism , MAP Kinase Signaling System/physiology , Signal Transduction/physiology , Transcription Factors/metabolism , Activating Transcription Factor 2 , Animals , Anisomycin/pharmacology , Embryo, Mammalian , Enzyme Inhibitors/pharmacology , Fibroblasts/drug effects , Fibroblasts/physiology , MAP Kinase Kinase 7 , MAP Kinase Signaling System/drug effects , Mice , Mice, Knockout , Mitogen-Activated Protein Kinase 8 , Mitogen-Activated Protein Kinase Kinases/deficiency , Mitogen-Activated Protein Kinase Kinases/genetics , Mitogen-Activated Protein Kinase Kinases/metabolism , Mitogen-Activated Protein Kinases/deficiency , Mitogen-Activated Protein Kinases/genetics , Mitogen-Activated Protein Kinases/metabolism , Peptide Fragments/chemistry , Peptide Fragments/metabolism , Phosphopeptides/chemistry , Phosphopeptides/metabolism , Phosphorylation , Signal Transduction/drug effects , Tetradecanoylphorbol Acetate/pharmacology , Tumor Necrosis Factor-alpha/pharmacology , p38 Mitogen-Activated Protein Kinases
18.
Org Biomol Chem ; 2(1): 142-9, 2004 Jan 07.
Article in English | MEDLINE | ID: mdl-14737674

ABSTRACT

The synthesis of C(4)H and C(4)Me analogues of the JNK/p38 pathway activator anisomycin, based upon an aldol or Claisen construction of the C(3)-C(4) bond, has been demonstrated. The relative activation of the JNK/SAPK1 and p38/SAPK2 pathways in RAW macrophages by these analogues, and their synthetic precursors, has been assessed using immunoblot assays against phosphorylated c-Jun and MAPKAP-K2. These studies demonstrate that some of the synthetic C(4) analogues are also potent activators of these stress kinase pathways.


Subject(s)
Anisomycin/analogs & derivatives , Mitogen-Activated Protein Kinases/metabolism , Animals , Anisomycin/chemical synthesis , Anisomycin/chemistry , Cell Line , Enzyme Activation , MAP Kinase Signaling System , Macrophages/drug effects , Macrophages/enzymology , Mice , Mitogen-Activated Protein Kinase 8 , p38 Mitogen-Activated Protein Kinases
19.
EMBO J ; 22(15): 3876-86, 2003 Aug 01.
Article in English | MEDLINE | ID: mdl-12881422

ABSTRACT

We have used phospho-specific antibodies to re-examine the multisite phosphorylation of c-Jun in murine RAW macrophages and embryonic fibroblasts. Our results indicate that JNK isoforms are required and sufficient for the phosphorylation of Thr91 and Thr93, as well as the phosphorylation of Ser63 and Ser73, in response to LPS or anisomycin in macrophages and TNFalpha or anisomycin in fibroblasts. However, the phorbol ester (TPA) and EGF-induced phosphorylation of Ser63 and Ser73 is mediated by ERK1/ERK2, as well as JNK1/JNK2, in fibroblasts from wild-type mice and by ERK1/ERK2 alone in fibroblasts from JNK-deficient mice. The phosphorylation of Thr239 is catalysed by GSK3 and the phosphorylation of Ser243 by an as yet unidentified protein kinase. The inhibition of GSK3 is not required for the dephosphorylation of Thr239 in response to LPS, and nor is the phosphorylation of Thr91 and Thr93 required for the TPA- or EGF-induced dephosphorylation of Thr239 in fibroblasts. The agonist-induced dephosphorylation of Thr239 may involve a conformational change that exposes Thr239 to dephosphorylation and/or the activation of a Thr239 phosphatase.


Subject(s)
Proto-Oncogene Proteins c-jun/metabolism , Amino Acid Sequence , Animals , Anisomycin/pharmacology , Antibodies/immunology , Cell Line , Mice , Mitogen-Activated Protein Kinases/metabolism , Molecular Sequence Data , Phosphorylation , Proto-Oncogene Proteins c-jun/chemistry , Proto-Oncogene Proteins c-jun/immunology , Serine/metabolism , Threonine/metabolism
20.
J Am Chem Soc ; 124(33): 9894-8, 2002 Aug 21.
Article in English | MEDLINE | ID: mdl-12175250

ABSTRACT

X-ray magnetic circular dichroism (XMCD) measurements on Yb14MnSb11 provide experimental evidence of a moment of 5 microB on Mn, with partial cancellation by an opposing moment on the Sb4 cage surrounding each Mn ion. The compound is isostructural to Ca14AlSb11, with Mn occupying the Al site in the AlSb4(9-) discrete tetrahedral, anionic unit. Bulk magnetization measurements indicate a saturation moment of 3.90 +/- 0.02 microB/formula unit consistent with four unpaired spins and implying a Mn3+, high-spin d4 state. XMCD measurements reveal that there is strong dichroism in the Mn L23 edge, the Sb M45 edge shows a weak dichroism indicating antialignment to the Mn, and the Yb N45 edge shows no dichroism. Comparisons of the Mn spectra with theoretical models for Mn2+ show excellent agreement. The bulk magnetization can be understood as Mn with a moment of 5 microB and a 2+ configuration, with cancellation of one spin by an antialigned moment from the Sb 5p band of the Sb4 cage surrounding the Mn.

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