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Tian R, Li Y, Gao M. Shikonin causes cell-cycle arrest and induces apoptosis by regulating the EGFR-NF-κB signalling pathway in human epidermoid carcinoma A431 cells. Biosci Rep 2015; 35:e00189. [PMID: 25720435 PMCID: PMC4413019 DOI: 10.1042/bsr20150002] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 02/02/2015] [Accepted: 02/09/2015] [Indexed: 01/21/2023] Open
Abstract
Shikonin, a naphthoquinone pigment isolated from the Chinese herbal Zicao, has been shown to exhibit antioxidant and anticancer effects. In the present study, we investigated the antiproliferative and pro-apoptotic effects of shikonin on A431 cells and explored the underlying molecular mechanisms. In the present study, our results showed that shikonin significantly inhibited the growth of A431 cells in a concentration- and time-dependent manner, and caused cell cycle arrest by upregulation of p21 and p27, and downregulation of cyclins and cyclin-dependent kinases. In addition, shikonin evidently induced apoptosis due to decreasing Bcl-2 expression, increasing Bax expression, activating caspase and inactivating NF-κB, while pretreatment with a pan-caspase inhibitor Z-Asp-CH2-DCB abrogated shikonin-induced apoptosis. Moreover, EGF could significantly increase the NF-κB DNA-binding activity and reversed the shikonin-induced inactivation of NF-κB. As anticipated AG1478 (EGFR inhibitor) and Bay11-7082 (NF-κB inhibitor) blocked EGF-reversed the inactivation of NF-κB induced by shikonin. Our data also showed that EGF could evidently reverse the shikonin-induced decreases in cell viability and increases in apoptosis. Then, the NF-κB inhibitors such as Bay11-7082, SN50, Helenalin and the EGFR inhibitor AG1478 and its downstream inhibitor such as PI3K inhibitor LY294002 and STAT3 inhibitor Stattic dramatically blocked EGF-reversed decreases in cell viability and increases in apoptosis induced by shikonin. Collectively, our findings indicated that shikonin inhibited cell growth and caused cell cycle arrest of the A431 cells through the regulation of apoptosis. Moreover, these effects were mediated at least partially by suppressing the activation of the EGFR-NF-κB signaling pathways.
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Key Words
- apoptosis
- cell cycle
- epidermal growth factor receptor–nuclear factor-kappa b signalling pathway
- human epidermoid carcinoma cells
- shikonin
- skin cancer
- akt, protein kinase b
- bcl-2, b-cell lymphoma 2
- cdk, cyclin-dependent kinase
- dmem, dulbecco's modified eagle's medium
- egf, epidermal growth factor
- egfr, epidermal growth factor receptor
- erk, extracellular signal-regulated kinase
- gapdh, glyceraldehyde-3-phosphate dehydrogenase
- jak, janus kinase
- jnk, c-jun n-terminal kinase
- mapk, mitogen-activated protein kinase
- nf-κb, nuclear factor kappa-light-chain-enhancer of activated b-cells
- pi, propidium iodide
- pi3k, phosphoinositide 3-kinase
- scc, squamous cell carcinoma
- stat3, signal transducer and activator of transcription 3
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Affiliation(s)
- Rong Tian
- *Department of Dermatology, Air Force General Hospital of PLA, Beijing 100142, China
| | - You Li
- *Department of Dermatology, Air Force General Hospital of PLA, Beijing 100142, China
| | - Mei Gao
- *Department of Dermatology, Air Force General Hospital of PLA, Beijing 100142, China
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Zhang L, Ngo JA, Wetzel MD, Marchetti D. Heparanase mediates a novel mechanism in lapatinib-resistant brain metastatic breast cancer. Neoplasia 2015; 17:101-13. [PMID: 25622903 PMCID: PMC4309682 DOI: 10.1016/j.neo.2014.11.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 11/18/2014] [Accepted: 11/26/2014] [Indexed: 11/04/2022]
Abstract
Heparanase (HPSE) is the dominant mammalian endoglycosidase and important tumorigenic, angiogenic, and pro-metastatic molecule. Highest levels of HPSE activity have been consistently detected in cells possessing highest propensities to colonize the brain, emphasizing the therapeutic potential for targeting HPSE in brain metastatic breast cancer (BMBC). Lapatinib (Tykerb) is a small-molecule and dual inhibitor of human epidermal growth factor receptor1 and 2 (EGFR and HER2, respectively) which are both high-risk predictors of BMBC. It was approved by the US Food and Drug Administration for treatment of patients with advanced or metastatic breast cancer. However, its role is limited in BMBC whose response rates to lapatinib are significantly lower than those for extracranial metastasis. Because HPSE can affect EGFR phosphorylation, we examined Roneparstat, a non-anticoagulant heparin with potent anti-HPSE activity, to inhibit EGFR signaling pathways and BMBC onset using lapatinib-resistant clones generated from HER2-transfected, EGFR-expressing MDA-MB-231BR cells. Cell growth, EGFR pathways, and HPSE targets were assessed among selected clones in the absence or presence of Roneparstat and/or lapatinib. Roneparstat overcame lapatinib resistance by inhibiting pathways associated with EGFR tyrosine residues that are not targeted by lapatinib. Roneparstat inhibited the growth and BMBC abilities of lapatinib-resistant clones. A molecular mechanism was identified by which HPSE mediates an alternative survival pathway in lapatinib-resistant clones and is modulated by Roneparstat. These results demonstrate that the inhibition of HPSE-mediated signaling plays important roles in lapatinib resistance, and provide mechanistic insights to validate the use of Roneparstat for novel BMBC therapeutic strategies.
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Key Words
- anova, analysis of variance
- br, her2-transfected mda-mb-231br
- bmbc, brain metastatic breast cancer
- cox-2, cyclooxygenase-2
- dme/f-12, dulbecco’s modified eagle’s/f-12 medium
- erk, extracellular signal-regulated kinase
- egfr, human epidermal growth factor receptor1
- facs, fluorescence activated cell sorting
- fak, focal adhesion kinase
- fbs, fetal bovine serum
- her2, human epidermal growth factor receptor2
- hpse, heparanase
- hs, heparan sulfate
- ls/lr br clones, lapatinib-sensitive/lapatinib-resistant br clones
- mapk, mitogen-activated protein kinase
- mmp-9, matrix metalloprotease-9
- pbs, phosphate-buffered saline
- pi3k, phosphoinositide 3-kinase
- str, short tandem repeat.
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Affiliation(s)
- Lixin Zhang
- Department of Pathology & Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030
| | - Jason A Ngo
- Department of Pathology & Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030
| | - Michael D Wetzel
- Department of Pathology & Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030
| | - Dario Marchetti
- Department of Pathology & Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030; Department of Molecular & Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030.
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Hawley S, Ross F, Gowans G, Tibarewal P, Leslie N, Hardie DG. Phosphorylation by Akt within the ST loop of AMPK-α1 down-regulates its activation in tumour cells. Biochem J 2014; 459:275-87. [PMID: 24467442 PMCID: PMC4052680 DOI: 10.1042/bj20131344] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 01/16/2014] [Accepted: 01/27/2014] [Indexed: 12/18/2022]
Abstract
The insulin/IGF-1 (insulin-like growth factor 1)-activated protein kinase Akt (also known as protein kinase B) phosphorylates Ser487 in the 'ST loop' (serine/threonine-rich loop) within the C-terminal domain of AMPK-α1 (AMP-activated protein kinase-α1), leading to inhibition of phosphorylation by upstream kinases at the activating site, Thr172. Surprisingly, the equivalent site on AMPK-α2, Ser491, is not an Akt target and is modified instead by autophosphorylation. Stimulation of HEK (human embryonic kidney)-293 cells with IGF-1 caused reduced subsequent Thr172 phosphorylation and activation of AMPK-α1 in response to the activator A769662 and the Ca2+ ionophore A23187, effects we show to be dependent on Akt activation and Ser487 phosphorylation. Consistent with this, in three PTEN (phosphatase and tensin homologue deleted on chromosome 10)-null tumour cell lines (in which the lipid phosphatase PTEN that normally restrains the Akt pathway is absent and Akt is thus hyperactivated), AMPK was resistant to activation by A769662. However, full AMPK activation could be restored by pharmacological inhibition of Akt, or by re-expression of active PTEN. We also show that inhibition of Thr172 phosphorylation is due to interaction of the phosphorylated ST loop with basic side chains within the αC-helix of the kinase domain. Our findings reveal that a previously unrecognized effect of hyperactivation of Akt in tumour cells is to restrain activation of the LKB1 (liver kinase B1)-AMPK pathway, which would otherwise inhibit cell growth and proliferation.
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Key Words
- akt
- amp-activated protein kinase (ampk)
- cancer
- cross-talk
- tumour suppressor
- acc, acetyl-coa carboxylase
- aicar, 5-amino-4-imidazolecarboxamide riboside
- ampk, amp-activated protein kinase
- brsk, brain-specific kinase
- camkk, calmodulin-dependent kinase kinase β
- dmem, dulbecco’s modified eagle’s medium
- gsk3, glycogen synthase kinase 3
- hek, human embryonic kidney
- igf-1, insulin-like growth factor 1
- lkb1, liver kinase b1
- mef, mouse embryonic fibroblast
- mo25α, mouse protein-25α
- mtorc1, mammalian (or mechanistic) target of rapamycin complex 1
- neaa, non-essential amino acid
- pi3k, phosphoinositide 3-kinase
- pka, protein kinase a (camp-dependent protein kinase)
- pten, phosphatase and tensin homologue deleted on chromosome 10
- s6k1, s6 kinase 1
- st loop, serine/threonine-rich loop
- stradα, ste20-related adapter protein-α
- wt, wild-type
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Affiliation(s)
- Simon A. Hawley
- *Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, U.K
| | - Fiona A. Ross
- *Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, U.K
| | - Graeme J. Gowans
- *Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, U.K
| | - Priyanka Tibarewal
- *Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, U.K
| | - Nicholas R. Leslie
- *Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, U.K
| | - D. Grahame Hardie
- *Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, U.K
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Abstract
COPD (chronic obstructive pulmonary disease) is a major incurable global health burden and will become the third largest cause of death in the world by 2020. It is currently believed that an exaggerated inflammatory response to inhaled irritants, in particular cigarette smoke, causes progressive airflow limitation. This inflammation, where macrophages, neutrophils and T-cells are prominent, leads to oxidative stress, emphysema, small airways fibrosis and mucus hypersecretion. The mechanisms and mediators that drive the induction and progression of chronic inflammation, emphysema and altered lung function are poorly understood. Current treatments have limited efficacy in inhibiting chronic inflammation, do not reverse the pathology of disease and fail to modify the factors that initiate and drive the long-term progression of disease. Therefore there is a clear need for new therapies that can prevent the induction and progression of COPD. Animal modelling systems that accurately reflect disease pathophysiology continue to be essential to the development of new therapies. The present review highlights some of the mouse models used to define the cellular, molecular and pathological consequences of cigarette smoke exposure and whether they can be used to predict the efficacy of new therapeutics for COPD.
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Key Words
- acute exacerbations of chronic obstructive pulmonary disease (aecopd)
- chronic obstructive pulmonary disease (copd)
- emphysema
- inflammation
- skeletal muscle wasting
- smoking
- aecopd, acute exacerbations of copd
- bal, bronchoalveolar lavage
- balf, bal fluid
- copd, chronic obstructive pulmonary disease
- gm-csf, granulocyte/macrophage colony-stimulating factor
- gold, global initiative on chronic obstructive lung disease
- gpx, glutathione peroxidase
- hdac, histone deacetylation
- il, interleukin
- ltb4, leukotriene b4
- mapk, mitogen-activated protein kinase
- mcp-1, monocyte chemotactic protein-1
- mmp, matrix metalloproteinase
- ne, neutrophil elastase
- nf-κb, nuclear factor κb
- nrf2, nuclear erythroid-related factor 2
- o2•−, superoxide radical
- onoo−, peroxynitrite
- pde, phosphodiesterase
- pi3k, phosphoinositide 3-kinase
- ros, reactive oxygen species
- rv, rhinovirus
- slpi, secretory leucocyte protease inhibitor
- sod, superoxide dismutase
- tgf-β, transforming growth factor-β
- timp, tissue inhibitor of metalloproteinases
- tnf-α, tumour necrosis factor-α
- v/q, ventilation/perfusion
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Affiliation(s)
- Ross Vlahos
- *Lung Health Research Centre, Department of Pharmacology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Steven Bozinovski
- *Lung Health Research Centre, Department of Pharmacology, University of Melbourne, Parkville, VIC 3010, Australia
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Kreft M, Bak LK, Waagepetersen HS, Schousboe A. Aspects of astrocyte energy metabolism, amino acid neurotransmitter homoeostasis and metabolic compartmentation. ASN Neuro 2012; 4:e00086. [PMID: 22435484 PMCID: PMC3338196 DOI: 10.1042/an20120007] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 03/06/2012] [Accepted: 03/21/2012] [Indexed: 02/08/2023] Open
Abstract
Astrocytes are key players in brain function; they are intimately involved in neuronal signalling processes and their metabolism is tightly coupled to that of neurons. In the present review, we will be concerned with a discussion of aspects of astrocyte metabolism, including energy-generating pathways and amino acid homoeostasis. A discussion of the impact that uptake of neurotransmitter glutamate may have on these pathways is included along with a section on metabolic compartmentation.
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Key Words
- amino acid
- astrocyte
- compartmentation
- energy
- metabolism
- α-kg, α-ketoglutarate
- aat, aspartate aminotransferase
- cfp, cyan fluorescence protein
- dab, diaminobenzidine
- fret, fluorescence resonance energy transfer
- [glc]i, intracellular glucose concentration
- gaba, γ-aminobutyric acid
- gaba-t, gaba aminotransferase
- gdh, glutamate dehydrogenase
- glut, glucose transporter
- gp, glycogen phosphorylase
- gs, glutamine synthetase
- gsk3, gs kinase 3
- pag, phosphate-activated glutaminase
- pi3k, phosphoinositide 3-kinase
- pkc, protein kinase c
- tca, tricarboxylic acid
- yfp, yellow fluorescence protein
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Affiliation(s)
- Marko Kreft
- *LNMCP, Institute of Pathophysiology, Faculty of Medicine and CPAE, Department of Biology, Biotechnical Faculty, University of Ljubljana and Celica Biomedical Center, Slovenia
| | - Lasse K Bak
- †Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Helle S Waagepetersen
- †Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Arne Schousboe
- †Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
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Jung S, Ha Y, Shim E, Choi S, Jin J, Yun-Choi H, Lee J. Insulin-mimetic and insulin-sensitizing activities of a pentacyclic triterpenoid insulin receptor activator. Biochem J 2007; 403:243-50. [PMID: 17201692 PMCID: PMC1874232 DOI: 10.1042/bj20061123] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2006] [Revised: 12/19/2006] [Accepted: 01/04/2007] [Indexed: 01/18/2023]
Abstract
Five pentacyclic triterpenoids isolated from Campsis grandiflora were tested for insulin-mimetic and insulin-sensitizing activity. The compounds enhanced the activity of insulin on tyrosine phosphorylation of the IR (insulin receptor) beta-subunit in CHO/IR (Chinese-hamster ovary cells expressing human IR). Among the compounds tested, CG7 (ursolic acid) showed the greatest enhancement and CG11 (myrianthic acid) the least. We characterized the effect of CG7 further, and showed that it acted as an effective insulin-mimetic agent at doses above 50 mug/ml and as an insulin-sensitizer at doses as low as 1 mug/ml. Additional experiments showed that CG7 increased the number of IRs that were activated by insulin. This indicates that a major mechanism by which CG7 enhances total IR auto-phosphorylation is by promoting the tyrosine phosphorylation of additional IRs. CG7 not only potentiated insulin-mediated signalling (tyrosine phosphorylation of the IR beta-subunit, phosphorylation of Akt and glycogen synthase kinase-3beta), but also enhanced the effect of insulin on translocation of glucose transporter 4 in a classical insulin-sensitive cell line, 3T3-L1 adipocytes. The results of the present study demonstrate that a specific pentacyclic triterpenoid, CG7, exerts an insulin-sensitizing effect as an IR activator in CHO/IR cells and adipocytes. The enhancement of insulin activity by CG7 may be useful for developing a new class of specific IR activators for treatment of Type 1 and Type 2 diabetes.
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Key Words
- adipocyte
- glucose transporter 4 (glut4)
- insulin signal transduction
- pentacyclic triterpenoids
- receptor tyrosine phosphorylation
- ursolic acid
- ab, antibody
- cho/ir, chinese-hamster ovary cells expressing human insulin receptor
- cg6, oleanolic acid
- cg7, ursolic acid
- cg9, hederagenin acid
- cg10, tormentic acid
- cg11, myrianthic acid
- dmem, dulbecco's modified eagle's medium
- erk, extracellular-signal-regulated kinase
- fbs, foetal bovine serum
- glut4, glucose transporter 4
- gsk3β, glycogen synthase kinase 3β
- hrp, horseradish peroxidase
- ibmx, isobutylmethylxanthine
- ip, immunoprecipitation
- ir, insulin receptor
- irβ, ir β-subunit
- irs, ir substrate
- αmem, α-minimal eagle's medium
- pi3k, phosphoinositide 3-kinase
- ptyr, phosphotyrosine
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Affiliation(s)
- Seung H. Jung
- *Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul 120-750, Korea
| | - Yun J. Ha
- *Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul 120-750, Korea
| | - Eun K. Shim
- *Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul 120-750, Korea
| | - Soo Y. Choi
- *Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul 120-750, Korea
| | - Jing L. Jin
- †Natural Product Research Institute, Seoul National University, Seoul 110-460, Korea
| | - Hye S. Yun-Choi
- †Natural Product Research Institute, Seoul National University, Seoul 110-460, Korea
| | - Jong R. Lee
- *Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul 120-750, Korea
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Barbat C, Trucy M, Sorice M, Garofalo T, Manganelli V, Fischer A, Mazerolles F. p56lck, LFA-1 and PI3K but not SHP-2 interact with GM1- or GM3-enriched microdomains in a CD4-p56lck association-dependent manner. Biochem J 2007; 402:471-81. [PMID: 17123354 PMCID: PMC1863576 DOI: 10.1042/bj20061061] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 11/14/2006] [Accepted: 11/24/2006] [Indexed: 11/17/2022]
Abstract
We previously showed that the association of CD4 and G(M3) ganglioside induced by CD4 ligand binding was required for the down-regulation of adhesion and that aggregation of ganglioside-enriched domains was accompanied by transient co-localization of LFA-1 (lymphocyte function-associated antigen-1), PI3K (phosphoinositide 3-kinase) and CD4. We also showed that these proteins co-localized with the G(M1) ganglioside that partially co-localized with G(M3) in these domains. In the present study, we show that CD4-p56(lck) association in CD4 signalling is required for the redistribution of p56(lck), PI3K and LFA-1 in ganglioside-enriched domains, since ganglioside aggregation and recruitment of these proteins were not observed in a T-cell line (A201) expressing the mutant form of CD4 that does not bind p56(lck). In addition, we show that although these proteins associated in different ways with G(M1) and G(M3), all of the associations were dependent on CD4-p56(lck) association. Gangliosides could associate with these proteins that differ in affinity binding and could be modified following CD4 signalling. Our results suggest that through these associations, gangliosides transiently sequestrate these proteins and consequently inhibit LFA-1-dependent adhesion. Furthermore, while structural diversity of gangliosides may allow association with distinct proteins, we show that the tyrosine phosphatase SHP-2 (Src homology 2 domain-containing protein tyrosine phosphatase 2), also required for the down-regulation of LFA-1-dependent adhesion, transiently and partially co-localized with PI3K and p56(lck) in detergent-insoluble membranes without association with G(M1) or G(M3). We propose that CD4 ligation and binding with p56(lck) and their interaction with G(M3) and/or G(M1) gangliosides induce recruitment of distinct proteins important for CD4 signalling to form a multimolecular signalling complex.
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Key Words
- adhesion molecule
- cd4 t-cell
- ganglioside
- lymphocyte function-associated antigen-1 (lfa-1)
- phosphoinositide 3-kinase (pi3k)
- raft
- ab, antibody
- au, arbitrary units
- ctxb, cholera toxin
- drm, detergent-resistant membrane
- gamig, goat anti-mouse ig
- hla, human leucocyte antigen
- hptlc, high-performance tlc
- hrp, horseradish peroxidase
- lfa-1, lymphocyte function-associated antigen-1
- mab, monoclonal ab
- pi3k, phosphoinositide 3-kinase
- pdk1, phosphoinositide-dependent kinase-1
- pns, post-nuclear supernatant
- rn, relative number
- shp-2, src homology 2 domain-containing protein tyrosine phosphatase 2
- tcr, t-cell receptor
- tritc, tetramethylrhodamine β-isothiocyanate
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Affiliation(s)
- Christiane Barbat
- *Inserm, U768, Paris, F-75015, France
- †Université Paris Descartes, Faculté de Médecine René Descartes, Hôpital Necker-Enfants-Malades, 149 rue de Sèvres, Paris, F-75015, France
| | - Maylis Trucy
- *Inserm, U768, Paris, F-75015, France
- †Université Paris Descartes, Faculté de Médecine René Descartes, Hôpital Necker-Enfants-Malades, 149 rue de Sèvres, Paris, F-75015, France
| | - Maurizio Sorice
- ‡Dipartimento di Medicina Sperimentale, Università ‘La Sapienza’, Viale Regina Elena 324, 00161 Rome, Italy
| | - Tina Garofalo
- ‡Dipartimento di Medicina Sperimentale, Università ‘La Sapienza’, Viale Regina Elena 324, 00161 Rome, Italy
| | - Valeria Manganelli
- ‡Dipartimento di Medicina Sperimentale, Università ‘La Sapienza’, Viale Regina Elena 324, 00161 Rome, Italy
| | - Alain Fischer
- *Inserm, U768, Paris, F-75015, France
- †Université Paris Descartes, Faculté de Médecine René Descartes, Hôpital Necker-Enfants-Malades, 149 rue de Sèvres, Paris, F-75015, France
- §Assistance Publique Hôpitaux de Paris (AP-HP), Hôpital Necker-Enfants-Malades, Paris, F-75015, France
| | - Fabienne Mazerolles
- *Inserm, U768, Paris, F-75015, France
- †Université Paris Descartes, Faculté de Médecine René Descartes, Hôpital Necker-Enfants-Malades, 149 rue de Sèvres, Paris, F-75015, France
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Soundararajan M, Yang X, Elkins J, Sobott F, Doyle D. The centaurin gamma-1 GTPase-like domain functions as an NTPase. Biochem J 2007; 401:679-88. [PMID: 17037982 PMCID: PMC1770848 DOI: 10.1042/bj20060555] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2006] [Revised: 09/19/2006] [Accepted: 10/12/2006] [Indexed: 01/04/2023]
Abstract
Centaurins are a family of proteins that contain GTPase-activating protein domains, with the gamma family members containing in addition a GTPase-like domain. Centaurins reside mainly in the nucleus and are known to activate phosphoinositide 3-kinase, a key regulator of cell proliferation, motility and vesicular trafficking. In the present study, using X-ray structural analysis, enzymatic assays and nucleotide-binding studies, we show that, for CENTG1 (centaurin gamma-1) the GTPase-like domain has broader trinucleotide specificity. Alterations within the G4 motif of CENTG1 from the highly conserved NKXD found in typical GTPases to TQDR result in the loss of specificity, a lower affinity for the nucleotides and higher turnover rates. These results indicate that the centaurins could be more accurately classified as NTPases and point to alternative mechanisms of cell signalling control.
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Key Words
- centaurin γ-1 (centg1)
- gtpase-activating domain
- ntpase
- phosphoinositide 3-kinase (pi3k)
- phosphoinositide 3-kinase enhancer (pike)
- atp[s], adenosine 5′-[γ-thio]triphosphate
- centg, centaurin γ
- dtt, dithiothreitol
- gap, gtpase-activating protein
- gef, guanine-nucleotide-exchange factor
- gi, geninfo identifier
- gld, gtpase-like domain
- gtp[s], guanosine 5′-[γ-thio]triphosphate
- itc, isothermal calorimetry
- ni-nta, ni2+-nitrilotriacetate
- peg1000, poly(ethylene glycol) 1000
- ph, pleckstrin homology
- pi3k, phosphoinositide 3-kinase
- (r)pike, (rat) pi3k enhancer
- rmsd, root mean square deviation
- tev, tobacco etch virus
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Affiliation(s)
- Meera Soundararajan
- The Structural Genomics Consortium, University of Oxford, Botnar Research Centre, Oxford OX3 7LD, U.K
| | - Xiaowen Yang
- The Structural Genomics Consortium, University of Oxford, Botnar Research Centre, Oxford OX3 7LD, U.K
| | - Jonathan M. Elkins
- The Structural Genomics Consortium, University of Oxford, Botnar Research Centre, Oxford OX3 7LD, U.K
| | - Frank Sobott
- The Structural Genomics Consortium, University of Oxford, Botnar Research Centre, Oxford OX3 7LD, U.K
| | - Declan A. Doyle
- The Structural Genomics Consortium, University of Oxford, Botnar Research Centre, Oxford OX3 7LD, U.K
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Fernández-Martínez A, Mollá B, Mayoral R, Boscá L, Casado M, Martín-Sanz P. Cyclo-oxygenase 2 expression impairs serum-withdrawal-induced apoptosis in liver cells. Biochem J 2006; 398:371-80. [PMID: 16800815 PMCID: PMC1559469 DOI: 10.1042/bj20060780] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have investigated the mechanism of COX-2 (cyclo-oxygenase 2)-dependent inhibition of apoptosis in liver, a key pathway underlying proliferative actions of COX-2 in liver cancers, cirrhosis, chronic hepatitis C infection and regeneration after partial hepatectomy. Stable expression of COX-2 in CHL (Chang liver) cells induced proliferation, with an increase in the proportion of cells in S-phase, but no other significant changes in cell-cycle distribution. This was associated with a marked inhibition of the apoptotic response to serum deprivation, an effect mimicked by treating empty-vector-transfected control cells (CHL-V cells) with prostaglandin E2 and prevented in COX-2-expressing cells (CHL-C cells) treated with selective inhibitors of COX-2. Serum-deprived CHL-V cells displayed several indicators of activation of intrinsic apoptosis: caspases 9 and 3 activated within 6 h and caspase 8 within 18 h, Bax expression was induced, cytochrome c was released to the cytosol, and PARP-1 [poly(ADP-ribose) polymerase 1] cleavage was evident in nuclei. COX-2 expression blocked these events, concomitant with reduced expression of p53 and promotion of Akt phosphorylation, the latter indicating activation of survival pathways. CHL cells were resistant to stimulation of the extrinsic pathway with anti-Fas antibody. Moreover, in vivo expression of GFP (green fluorescent protein)-labelled COX-2 in mice by hydrodynamics-based transient transfection conferred resistance to caspase 3 activation and apoptosis induced by stimulation of Fas.
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Key Words
- apoptosis
- cyclo-oxygenase (cox)
- hepatocyte
- hydrodynamic transfection
- liver
- prostaglandin
- aa, arachidonic acid
- alt, alanine aminotransferase
- chl, chang liver
- chl-c cell, cyclo-oxygenase-2-expressing chl cell
- chl-v cell, empty-vector-transfected control chl cell
- cox, cyclo-oxygenase
- coxib, selective cox-2 inhibitor
- dfu, 5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulfonyl)phenyl-2(5h)-furanone
- dmem, dulbecco's modified eagle's medium
- fbs, foetal bovine serum
- gfp, green fluorescent protein
- hcc, hepatocellular carcinoma
- iap, inhibitor of apoptosis
- nf-κb, nuclear factor κb
- parp-1, poly(adp-ribose) polymerase 1
- pg, prostaglandin
- pi, propidium iodide
- pi3k, phosphoinositide 3-kinase
- rt, reverse transcription
- sp1, specificity protein 1
- tnf, tumour necrosis factor
- tunel, terminal deoxynucleotidyl transferase-mediated dutp nick-end labelling
- xiap, x-linked iap
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Affiliation(s)
- Amalia Fernández-Martínez
- *Centro de Investigaciones Biológicas (CSIC), Centro Nacional de Investigaciones Cardiovasculares, Melchor Fernández Almagro 3, 28029 Madrid, Spain
| | - Belén Mollá
- †Instituto de Biomedicina de Valencia (CSIC), Jaume Roig 11, 46010 Valencia, Spain
| | - Rafael Mayoral
- *Centro de Investigaciones Biológicas (CSIC), Centro Nacional de Investigaciones Cardiovasculares, Melchor Fernández Almagro 3, 28029 Madrid, Spain
| | - Lisardo Boscá
- *Centro de Investigaciones Biológicas (CSIC), Centro Nacional de Investigaciones Cardiovasculares, Melchor Fernández Almagro 3, 28029 Madrid, Spain
| | - Marta Casado
- †Instituto de Biomedicina de Valencia (CSIC), Jaume Roig 11, 46010 Valencia, Spain
| | - Paloma Martín-Sanz
- *Centro de Investigaciones Biológicas (CSIC), Centro Nacional de Investigaciones Cardiovasculares, Melchor Fernández Almagro 3, 28029 Madrid, Spain
- To whom correspondence should be addressed (email )
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Sánchez-Molina S, Oliva J, García-Vargas S, Valls E, Rojas J, Martínez-Balbás M. The histone acetyltransferases CBP/p300 are degraded in NIH 3T3 cells by activation of Ras signalling pathway. Biochem J 2006; 398:215-24. [PMID: 16704373 PMCID: PMC1550303 DOI: 10.1042/bj20060052] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Revised: 04/07/2006] [Accepted: 05/17/2006] [Indexed: 11/17/2022]
Abstract
The CBP [CREB (cAMP-response-element-binding protein)-binding protein]/p300 acetyltransferases function as transcriptional co-activators and play critical roles in cell differentiation and proliferation. Accumulating evidence shows that alterations of the CBP/p300 protein levels are linked to human tumours. In the present study, we show that the levels of the CBP/p300 co-activators are decreased dramatically by continuous PDGF (platelet-derived growth factor) and Ras signalling pathway activation in NIH 3T3 fibroblasts. This effect occurs by reducing the expression levels of the CBP/p300 genes. In addition, CBP and p300 are degraded by the 26 S proteasome pathway leading to an overall decrease in the levels of the CBP/p300 proteins. Furthermore, we provide evidence that Mdm2 (murine double minute 2), in the presence of active H-Ras or N-Ras, induces CBP/p300 degradation in NIH 3T3 cells. These findings support a novel mechanism for modulating other signalling transduction pathways that require these common co-activators.
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Key Words
- acetylation
- camp-response-element-binding-protein-binding protein/p300 (cbp/p300)
- histone acetyltransferase activity (hat activity)
- murine double minute 2 (mdm2)
- nih 3t3 cell
- ras pathway
- alln, n-acetyl-l-leucyl-l-leucylnorleucinal
- creb, camp-response-element-binding protein
- cbp, creb-binding protein
- cs, calf serum
- dapi, 4′,6-diamidino-2-phenylindole
- erk, extracellular-signal-regulated kinase
- gds, guanine nucleotide dissociation stimulator
- gst, glutathione s-transferase
- ha, haemagglutinin
- hat, histone acetyltransferase
- hdac, histone deacetylase
- mapk, mitogen-activated protein kinase
- mdm2, murine double minute 2
- mek, mapk/erk kinase
- p/caf, p300/cbp-associated factor
- pdgf, platelet-derived growth factor
- pi3k, phosphoinositide 3-kinase
- ra, retinoic acid
- ral-bd, ral-binding domain
- rts, rubinstein–taybi syndrome
- sirna, small interfering rna
- tafii, tata-box-binding-protein-associated factor
- tgase, transglutaminase
- tk, thymidine kinase
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Affiliation(s)
- Sara Sánchez-Molina
- *Instituto de Biología Molecular de Barcelona, CID, Consejo Superior de Investigaciones Científicas (CSIC), Parc Cientific de Barcelona (PCB), Josep Samitier 1–5, 08028 Barcelona, Spain
| | - José Luis Oliva
- †Unidad de Biología Celular, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
| | - Susana García-Vargas
- †Unidad de Biología Celular, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
| | - Ester Valls
- *Instituto de Biología Molecular de Barcelona, CID, Consejo Superior de Investigaciones Científicas (CSIC), Parc Cientific de Barcelona (PCB), Josep Samitier 1–5, 08028 Barcelona, Spain
| | - José M. Rojas
- †Unidad de Biología Celular, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
| | - Marian A. Martínez-Balbás
- *Instituto de Biología Molecular de Barcelona, CID, Consejo Superior de Investigaciones Científicas (CSIC), Parc Cientific de Barcelona (PCB), Josep Samitier 1–5, 08028 Barcelona, Spain
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11
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Blenn C, Althaus F, Malanga M. Poly(ADP-ribose) glycohydrolase silencing protects against H2O2-induced cell death. Biochem J 2006; 396:419-29. [PMID: 16526943 PMCID: PMC1482814 DOI: 10.1042/bj20051696] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2005] [Revised: 02/28/2006] [Accepted: 03/09/2006] [Indexed: 11/17/2022]
Abstract
PAR [poly(ADP-ribose)] is a structural and regulatory component of multiprotein complexes in eukaryotic cells. PAR catabolism is accelerated under genotoxic stress conditions and this is largely attributable to the activity of a PARG (PAR glycohydrolase). To overcome the early embryonic lethality of parg-knockout mice and gain more insights into the biological functions of PARG, we used an RNA interference approach. We found that as little as 10% of PARG protein is sufficient to ensure basic cellular functions: PARG-silenced murine and human cells proliferated normally through several subculturing rounds and they were able to repair DNA damage induced by sublethal doses of H2O2. However, cell survival following treatment with higher concentrations of H2O2 (0.05-1 mM) was increased. In fact, PARG-silenced cells were more resistant than their wild-type counterparts to oxidant-induced apoptosis while exhibiting delayed PAR degradation and transient accumulation of ADP-ribose polymers longer than 15-mers at early stages of drug treatment. No difference was observed in response to the DNA alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine, suggesting a specific involvement of PARG in the cellular response to oxidative DNA damage.
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Key Words
- dna damage response
- h2o2
- n-methyl-n′-nitro-n-nitrosoguanidine (mnng)
- poly(adp-ribose) glycohydrolase (parg)
- silencing
- rna interference
- 3-ab, 3-aminobenzamide
- adp-hpd, adp (hydroxymethyl)pyrrolidinediol
- arh3, adp-ribosyl-(arginine)-hydrolase 3
- dtnb, 5,5′-dithiobis-(2-nitrobenzoic acid)
- dtt, dithiothreitol
- dmem, dulbecco's modified eagle's medium
- fbs, fetal bovine serum
- gapdh, glyceraldehyde-3-phosphate dehydrogenase
- mef, mouse embryonic fibroblast
- mnng, n-methyl-n′-nitro-n-nitrosoguanidine
- nls, nuclear localization signal
- par, poly(adp-ribose)
- parg, par glycohydrolase
- parp, par polymerase
- pcna, proliferating-cell nuclear antigen
- pi3k, phosphoinositide 3-kinase
- rnai, rna interference
- sirna, small interfering rna
- svpde, snake venom phosphodiesterase
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Affiliation(s)
- Christian Blenn
- Institute of Pharmacology and Toxicology, University of Zurich-Tierspital, Winterthurerstrasse 260, CH-8057 Zurich, Switzerland
| | - Felix R. Althaus
- Institute of Pharmacology and Toxicology, University of Zurich-Tierspital, Winterthurerstrasse 260, CH-8057 Zurich, Switzerland
| | - Maria Malanga
- Institute of Pharmacology and Toxicology, University of Zurich-Tierspital, Winterthurerstrasse 260, CH-8057 Zurich, Switzerland
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Abstract
Leptin is a versatile 16 kDa peptide hormone, with a tertiary structure resembling that of members of the long-chain helical cytokine family. It is mainly produced by adipocytes in proportion to fat size stores, and was originally thought to act only as a satiety factor. However, the ubiquitous distribution of OB-R leptin receptors in almost all tissues underlies the pleiotropism of leptin. OB-Rs belong to the class I cytokine receptor family, which is known to act through JAKs (Janus kinases) and STATs (signal transducers and activators of transcription). The OB-R gene is alternatively spliced to produce at least five isoforms. The full-length isoform, OB-Rb, contains intracellular motifs required for activation of the JAK/STAT signal transduction pathway, and is considered to be the functional receptor. Considerable evidence for systemic effects of leptin on body mass control, reproduction, angiogenesis, immunity, wound healing, bone remodelling and cardiovascular function, as well as on specific metabolic pathways, indicates that leptin operates both directly and indirectly to orchestrate complex pathophysiological processes. Consistent with leptin's pleiotropic role, its participation in and crosstalk with some of the main signalling pathways, including those involving insulin receptor substrates, phosphoinositide 3-kinase, protein kinase B, protein kinase C, extracellular-signal-regulated kinase, mitogen-activated protein kinases, phosphodiesterase, phospholipase C and nitric oxide, has been observed. The impact of leptin on several equally relevant signalling pathways extends also to Rho family GTPases in relation to the actin cytoskeleton, production of reactive oxygen species, stimulation of prostaglandins, binding to diacylglycerol kinase and catecholamine secretion, among others.
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Key Words
- adipocyte
- cytokine
- janus kinase/signal transducer and activator of transcription pathway (jak/stat pathway)
- leptin receptor
- obesity
- signalling cascade
- acc, acetyl-coa carboxylase
- ampk, 5′-amp-activated protein kinase
- cntf, ciliary neurotrophic factor
- ct-1, cardiotrophin-1
- erk, extracellular-signal-regulated kinase
- hif-1α, hypoxia-inducible factor 1α
- il, interleukin
- irs, insulin receptor substrate
- jak, janus kinase
- jnk, c-jun n-terminal kinase
- lif, leukaemia inhibitory factor
- mapk, mitogen-activated protein kinase
- nf-κb, nuclear factor κb
- npy, neuropeptide y
- osm, oncostatin-m
- pde, phosphodiesterase
- pi3k, phosphoinositide 3-kinase
- pka, protein kinase a
- pkc, protein kinase c
- ptp1b, protein tyrosine phosphatase 1b
- sh2, src-like homology 2
- shp-2, sh2 domain-containing protein tyrosine phosphatase
- socs, suppressor of cytokine signalling
- stat, signal transducer and activator of transcription
- tnfα, tumour necrosis factor α
- tyk2, tyrosine kinase 2
- vegf, vascular endothelial growth factor
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Affiliation(s)
- Gema Frühbeck
- Department of Endocrinology, Clínica Universitaria de Navarra and Metabolic Research Laboratory, University of Navarra, 36 Avda. Pío XII, 31008 Pamplona, Spain.
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van der Heide L, Jacobs F, Burbach J, Hoekman M, Smidt M. FoxO6 transcriptional activity is regulated by Thr26 and Ser184, independent of nucleo-cytoplasmic shuttling. Biochem J 2005; 391:623-9. [PMID: 15987244 PMCID: PMC1276963 DOI: 10.1042/bj20050525] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2005] [Revised: 06/24/2005] [Accepted: 06/29/2005] [Indexed: 11/17/2022]
Abstract
Forkhead members of the 'O' class (FoxO) are transcription factors crucial for the regulation of metabolism, cell cycle, cell death and cell survival. FoxO factors are regulated by insulin-mediated activation of PI3K (phosphoinositide 3-kinase)-PKB (protein kinase B) signalling. Activation of PI3K-PKB signalling results in the phosphorylation of FoxO factors on three conserved phosphorylation motifs, which are essential for the translocation of FoxO factors from the nucleus to the cytosol. FoxO6, however, remains mostly nuclear due to the fact that its shuttling ability is dramatically impaired. FoxO1, FoxO3 and FoxO4 all contain an N- and C-terminal PKB motif and a motif located in the forkhead domain. FoxO6 lacks the conserved C-terminal PKB motif, which is the cause of the shuttling impairment. Since FoxO6 can be considered constitutively nuclear, we investigated whether it is also a constitutively active transcription factor. Our results show that FoxO6 transcriptional activity is inhibited by growth factors, independent of shuttling, indicating that it is not constitutively active. The PKB site in the forkhead domain (Ser184) regulated the DNA binding characteristics and the N-terminal PKB site acted as a growth factor sensor. In summary, FoxO6 is not a constitutively active transcription factor and can be regulated by growth factors in a Thr26- and Ser184-dependent manner, independent of shuttling to the cytosol.
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Key Words
- cytosol
- foxo6
- growth factor
- nucleo-cytoplasmic shuttling
- transcriptional activity
- translocation
- dbe, daf-16 binding element
- dmem, dulbecco's modified eagle's medium
- fcs, fetal calf serum
- foxo, forkhead members of the ‘o’ class
- g-6-pase, glucose-6-phosphatase
- gfp, green fluorescent protein
- hek-293 cells, human embryonic kidney 293 cells
- hifcs, heat-inactivated fcs
- iru, insulin response unit
- nes, nuclear export sequence
- nls, nuclear localization sequence
- pbs-t, pbs containing 0.05% tween 20
- pi3k, phosphoinositide 3-kinase
- pkb, protein kinase b
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Affiliation(s)
- Lars P. van der Heide
- Rudolf Magnus Institute of Neuroscience, Department of Pharmacology and Anatomy, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Frank M. J. Jacobs
- Rudolf Magnus Institute of Neuroscience, Department of Pharmacology and Anatomy, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - J. Peter H. Burbach
- Rudolf Magnus Institute of Neuroscience, Department of Pharmacology and Anatomy, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Marco F. M. Hoekman
- Rudolf Magnus Institute of Neuroscience, Department of Pharmacology and Anatomy, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Marten P. Smidt
- Rudolf Magnus Institute of Neuroscience, Department of Pharmacology and Anatomy, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
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Johnson J, Ellis B, Noack D, Seabra M, Catz S. The Rab27a-binding protein, JFC1, regulates androgen-dependent secretion of prostate-specific antigen and prostatic-specific acid phosphatase. Biochem J 2005; 391:699-710. [PMID: 16004602 PMCID: PMC1276972 DOI: 10.1042/bj20050380] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2005] [Revised: 06/29/2005] [Accepted: 07/08/2005] [Indexed: 11/17/2022]
Abstract
Two of the major proteins secreted by the prostate epithelium secretory cells are PSA (prostate-specific antigen) and PSAP (prostatic-specific acid phosphatase). The molecules involved in the secretory machinery of PSA and PSAP, and the regulation of this machinery, remain unknown. In the present paper, we provide evidence that JFC1 [synaptotagmin-like protein (slp1)], a Rab27a- and PtdIns(3,4,5)P3-binding protein, regulates the androgen-dependent secretion of PSAP and PSA in human LNCaP prostate carcinoma cells. Androgen-dependent PSAP secretion was significantly inhibited in cells that expressed the C2A domain of JFC1 [PtdIns(3,4,5)P3-binding-domain], but was unaffected by JFC1 overexpression. Conversely, PSA secretion was not inhibited by the C2A domain of JFC1. We show, using immunofluorescence analysis, that JFC1 co-localizes with PSAP, but rarely with PSA, in prostate granules, suggesting that JFC1 is part of the PSAP secretory machinery. However, PSA secretion was significantly increased in LNCaP cells that overexpressed JFC1, indicating that the secretion of PSA is susceptible to variations in the intracellular concentration of JFC1. Both PSAP and PSA secretion was increased by overexpression of wild-type Rab27a or the constitutively active Rab27aQ78L. The secretion of PSA was partially inhibited in the presence of LY294002, while the secretion of PSAP was completely abolished by the PI3K (phosphoinositide 3-kinase) inhibitor. This supports the view that PI3K plays a differential role in the secretion of prostate secretory markers. In conclusion, we present evidence that JFC1 differentially regulates the secretion of PSAP and PSA, and that Rab27a and PI3K play a central role in the exocytosis of prostate-specific markers.
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Key Words
- exocytosis
- phosphoinositide 3-kinase (pi3k)
- prostate-specific antigen (psa)
- prostatic-specific acid phosphatase (psap)
- synaptotagmin-like protein
- vesicular trafficking
- dsred, red fluorescent protein from discosoma sp.
- eea1, early endosome antigen 1
- egfp, enhanced green fluorescent protein
- nf-κb, nuclear factor κb
- pi3k, phosphoinositide 3-kinase
- pip3, ptdins(3,4,5)p3
- psa, prostate-specific antigen
- psap, prostate-specific acid phosphatase
- slp, synaptotagmin-like protein
- syt, synaptotagmin
- t-snare, target-associated soluble n-ethylmaleimide-sensitive fusion protein attachment protein receptor
- vamp-2, vesicle-associated membrane protein-2
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Affiliation(s)
- Jennifer L. Johnson
- *Division of Biochemistry, Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, U.S.A
| | - Beverly A. Ellis
- *Division of Biochemistry, Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, U.S.A
| | - Deborah Noack
- *Division of Biochemistry, Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, U.S.A
| | - Miguel C. Seabra
- †Cell and Molecular Biology Section, Division of Biomedical Sciences, Faculty of Medicine, Imperial College London, London SW7 2AZ, U.K
| | - Sergio D. Catz
- *Division of Biochemistry, Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, U.S.A
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Gokoh M, Kishimoto S, Oka S, Mori M, Waku K, Ishima Y, Sugiura T. 2-arachidonoylglycerol, an endogenous cannabinoid receptor ligand, induces rapid actin polymerization in HL-60 cells differentiated into macrophage-like cells. Biochem J 2005; 386:583-9. [PMID: 15456404 PMCID: PMC1134878 DOI: 10.1042/bj20041163] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2004] [Revised: 09/07/2004] [Accepted: 09/30/2004] [Indexed: 02/03/2023]
Abstract
Delta9-Tetrahydrocannabinol, a major psychoactive constituent of marijuana, interacts with specific receptors, i.e. the cannabinoid receptors, thereby eliciting a variety of pharmacological responses. To date, two types of cannabinoid receptors have been identified: the CB1 receptor, which is abundantly expressed in the nervous system, and the CB2 receptor, which is predominantly expressed in the immune system. Previously, we investigated in detail the structure-activity relationship of various cannabinoid receptor ligands and found that 2-AG (2-arachidonoylglycerol) is the most efficacious agonist. We have proposed that 2-AG is the true natural ligand for both the CB1 and CB2 receptors. Despite the potential physiological importance of 2-AG, not much information is available concerning its biological activities towards mammalian tissues and cells. In the present study, we examined the effect of 2-AG on morphology as well as the actin filament system in differentiated HL-60 cells, which express the CB2 receptor. We found that 2-AG induces rapid morphological changes such as the extension of pseudopods. We also found that it provokes a rapid actin polymerization in these cells. Actin polymerization induced by 2-AG was abolished when cells were treated with SR144528, a CB2 receptor antagonist, and pertussis toxin, suggesting that the response was mediated by the CB2 receptor and G(i/o). A phosphoinositide 3-kinase, Rho family small G-proteins and a tyrosine kinase were also suggested to be involved. Reorganization of the actin filament system is known to be indispensable for a variety of cellular events; it is possible that 2-AG plays physiologically essential roles in various inflammatory cells and immune-competent cells by inducing a rapid actin rearrangement.
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Key Words
- actin polymerization
- anandamide
- 2-arachidonoylglycerol
- cannabinoid
- macrophage
- morphological change
- 2-ag, 2-arachidonoylglycerol
- δ9-thc, δ9-tetrahydrocannabinol
- f-actin, filamentous actin
- il, interleukin
- mapk, mitogen-activated protein kinase
- nbd-phallacidin, 7-nitrobenz-2-oxa-1,3-phallacidin
- 1,25(oh)2d3, 1α, 25-dihydroxyvitamin d3
- pi3k, phosphoinositide 3-kinase
- ptx, pertussis toxin
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Affiliation(s)
- Maiko Gokoh
- *Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa 199-0195, Japan
| | - Seishi Kishimoto
- *Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa 199-0195, Japan
| | - Saori Oka
- *Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa 199-0195, Japan
| | - Masahiro Mori
- *Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa 199-0195, Japan
| | - Keizo Waku
- *Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa 199-0195, Japan
| | - Yoshio Ishima
- †Ishima Institute for Neurosciences, Kunitachi, Tokyo 186-0002, Japan
| | - Takayuki Sugiura
- *Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa 199-0195, Japan
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Lindgren E, Nielsen R, Petrovic N, Jacobsson A, Mandrup S, Cannon B, Nedergaard J. Noradrenaline represses PPAR (peroxisome-proliferator-activated receptor) gamma2 gene expression in brown adipocytes: intracellular signalling and effects on PPARgamma2 and PPARgamma1 protein levels. Biochem J 2004; 382:597-606. [PMID: 15193150 PMCID: PMC1133817 DOI: 10.1042/bj20031622] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2003] [Revised: 06/04/2004] [Accepted: 06/14/2004] [Indexed: 11/17/2022]
Abstract
PPAR (peroxisome-proliferator-activated receptor) gamma is expressed in brown and white adipose tissues and is involved in the control of differentiation and proliferation. Noradrenaline stimulates brown pre-adipocyte proliferation and brown adipocyte differentiation. The aim of the present study was thus to investigate the influence of noradrenaline on PPARgamma gene expression in brown adipocytes. In primary cultures of brown adipocytes, PPARgamma2 mRNA levels were 20-fold higher than PPARgamma1 mRNA levels. PPARgamma expression occurred during both the proliferation and the differentiation phases, with the highest mRNA levels being found at the time of transition between the phases. PPARgamma2 mRNA levels were downregulated by noradrenaline treatment (EC50, 0.1 microM) in both proliferative and differentiating cells, with a lagtime of 1 h and lasting up to 4 h, after which expression gradually recovered. The down-regulation was beta-adrenoceptor-induced and intracellularly mediated via cAMP and protein kinase A; the signalling pathway did not involve phosphoinositide 3-kinase, Src, p38 mitogen-activated protein kinase or extracellular-signal-regulated kinases 1 and 2. Treatment of the cells with the protein synthesis inhibitor cycloheximide not only abolished the noradrenaline-induced down-regulation of PPARgamma2 mRNA, but also in itself induced PPARgamma2 hyperexpression. The down-regulation was probably the result of suppression of transcription. The down-regulation of PPARgamma2 mRNA resulted in similar down-regulation of PPARgamma2 and phosphoPPARgamma2 protein levels. Remarkably, the level of PPARgamma1 protein was similar to that of PPARgamma2 (despite almost no PPARgamma1 mRNA), and the down-regulation by noradrenaline demonstrated similar kinetics to that of PPARgamma2; thus PPARgamma1 was apparently translated from the PPARgamma2 template. It is suggested that beta-adrenergic stimulation via cAMP and protein kinase A represses PPARgamma gene expression, leading to reduction of PPARgamma2 mRNA levels, which is then reflected in down-regulated levels of PPARgamma2, phosphoPPARgamma2 and PPARgamma1.
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Key Words
- brown adipocyte
- camp
- cycloheximide
- noradrenaline
- peroxisome-proliferator-activated receptor γ2 (pparγ2)
- protein kinase a
- creb, camp-response-element-binding protein
- dmem, dulbecco's modified eagle's medium
- erk, extracellular-signal-regulated kinase
- mapk, mitogen-activated protein kinase
- mek, mapk/erk kinase
- pi3k, phosphoinositide 3-kinase
- pka, protein kinase a
- ppar, peroxisome-proliferator-activated receptor
- ppre, ppar-response element
- tfiib, transcription factor iib
- ucp1, uncoupling protein 1
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Affiliation(s)
- Eva M. Lindgren
- *The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Ronni Nielsen
- †Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Natasa Petrovic
- *The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Anders Jacobsson
- *The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Susanne Mandrup
- †Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Barbara Cannon
- *The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Jan Nedergaard
- *The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, SE-106 91 Stockholm, Sweden
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Arnaud M, Mzali R, Gesbert F, Crouin C, Guenzi C, Vermot-Desroches C, Wijdenes J, Courtois G, Bernard O, Bertoglio J. Interaction of the tyrosine phosphatase SHP-2 with Gab2 regulates Rho-dependent activation of the c-fos serum response element by interleukin-2. Biochem J 2004; 382:545-56. [PMID: 15170389 PMCID: PMC1133811 DOI: 10.1042/bj20040103] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2004] [Revised: 05/17/2004] [Accepted: 06/01/2004] [Indexed: 12/27/2022]
Abstract
Gab2 (Grb2-associated binder-2), a member of the IRS (insulin receptor substrate)/Gab family of adapter proteins, undergoes tyrosine phosphorylation in response to cytokine or growth factor stimulation and serves as a docking platform for many signal transduction effectors, including the tyrosine phosphatase SHP-2 [SH2 (Src homology 2)-domain-containing tyrosine phosphatase]. Here, we report that, following IL-2 (interleukin-2) stimulation of human T lymphocytes, SHP-2 binds tyrosine residues 614 and 643 of human Gab2 through its N- and C-terminal SH2 domains respectively. However, the sole mutation of Tyr-614 into phenylalanine is sufficient to prevent Gab2 from recruiting SHP-2. Expression of the Gab2 Tyr-614-->Phe (Y614F) mutant, defective in SHP-2 association, prevents ERK (extracellular-signal-regulated kinase) activation and expression of a luciferase reporter plasmid driven by the c-fos SRE (serum response element), indicating that interaction of SHP-2 with Gab2 is required for ERK activation in response to IL-2. Further investigation of IL-2-dependent induction of SRE showed that expression of a constitutively active mutant of the RhoA GTPase synergizes with IL-2 for SRE-driven transcription, whereas a dominant-negative mutant reduces the IL-2 response. Thus, in response to IL-2, full induction of the SRE requires ERK-dependent as well as Rho-dependent signals that target the Ets-box and the CArG-box respectively. We also report that the synergy between Gab2/SHP-2 and RhoA for IL-2-dependent CArG-box-driven transcription depends upon MEK (mitogen-activated protein kinase/ERK kinase) activation, and is likely to involve regulation of the serum response factor co-activator MAL. Our studies thus provide new insights into the role of Gab2 and SHP-2 in IL-2 signal transduction.
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Key Words
- c-fos
- grb2-associated binder 2 (gab2)
- interleukin 2 (il-2)
- mitogen-activated protein (map) kinase
- rho gtpase
- serum response element (sre)
- sh2-domain-containing tyrosine phosphatase (shp-2)
- ecl, enhanced chemiluminescence
- erk, extracellular-signal-regulated kinase
- gab2, grb2-associated binder-2
- gst, glutathione s-transferase
- ha, haemagglutinin
- il, interleukin
- iptg, isopropyl β-d-thiogalactoside
- irs, insulin receptor substrate
- jak, janus kinase
- mapk, mitogen-activated protein kinase
- mek, mapk/erk kinase
- pdgf-r, platelet-derived growth factor receptor
- pi3k, phosphoinositide 3-kinase
- sre, serum response element
- srf, serum response factor
- sh2, src homology 2
- shp-2, sh2-domain-containing tyrosine phosphatase
- stat, signal transduction and activators of transcription
- tcf, ternary complex factor
- y614f, etc., a mutant bearing a replacement of tyr-614 with phenylalanine, etc
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Affiliation(s)
- Mary Arnaud
- *Inserm U461, Faculté de Pharmacie Paris-XI, 5 rue Jean-Baptiste Clément, 92290 Chatenay-Malabry, France
| | - Rym Mzali
- *Inserm U461, Faculté de Pharmacie Paris-XI, 5 rue Jean-Baptiste Clément, 92290 Chatenay-Malabry, France
| | - Franck Gesbert
- †Unité de Biologie des Interactions Cellulaires, Institut Pasteur, 25 rue du docteur Roux, 75015 Paris, France
| | - Catherine Crouin
- *Inserm U461, Faculté de Pharmacie Paris-XI, 5 rue Jean-Baptiste Clément, 92290 Chatenay-Malabry, France
| | - Christine Guenzi
- *Inserm U461, Faculté de Pharmacie Paris-XI, 5 rue Jean-Baptiste Clément, 92290 Chatenay-Malabry, France
| | | | - John Wijdenes
- ‡Diaclone, 1 Boulevard A. Fleming, 25020 Besançon, France
| | - Geneviève Courtois
- §Inserm EMI0210, Faculté de Médecine Necker-Enfants Malades, 156 rue de Vaugirard, 75015 Paris, France
| | - Olivier Bernard
- §Inserm EMI0210, Faculté de Médecine Necker-Enfants Malades, 156 rue de Vaugirard, 75015 Paris, France
| | - Jacques Bertoglio
- *Inserm U461, Faculté de Pharmacie Paris-XI, 5 rue Jean-Baptiste Clément, 92290 Chatenay-Malabry, France
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