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Shi F. Understanding the roles of salt-inducible kinases in cardiometabolic disease. Front Physiol 2024; 15:1426244. [PMID: 39081779 PMCID: PMC11286596 DOI: 10.3389/fphys.2024.1426244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 06/26/2024] [Indexed: 08/02/2024] Open
Abstract
Salt-inducible kinases (SIKs) are serine/threonine kinases of the adenosine monophosphate-activated protein kinase family. Acting as mediators of a broad array of neuronal and hormonal signaling pathways, SIKs play diverse roles in many physiological and pathological processes. Phosphorylation by the upstream kinase liver kinase B1 is required for SIK activation, while phosphorylation by protein kinase A induces the binding of 14-3-3 protein and leads to SIK inhibition. SIKs are subjected to auto-phosphorylation regulation and their activity can also be modulated by Ca2+/calmodulin-dependent protein kinase in response to cellular calcium influx. SIKs regulate the physiological processes through direct phosphorylation on various substrates, which include class IIa histone deacetylases, cAMP-regulated transcriptional coactivators, phosphatase methylesterase-1, among others. Accumulative body of studies have demonstrated that SIKs are important regulators of the cardiovascular system, including early works establishing their roles in sodium sensing and vascular homeostasis and recent progress in pulmonary arterial hypertension and pathological cardiac remodeling. SIKs also regulate inflammation, fibrosis, and metabolic homeostasis, which are essential pathological underpinnings of cardiovascular disease. The development of small molecule SIK inhibitors provides the translational opportunity to explore their potential as therapeutic targets for treating cardiometabolic disease in the future.
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Affiliation(s)
- Fubiao Shi
- Department of Medicine, Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
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2
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Shahid NH, Rashid H, Kumar S, Archoo S, Umar SA, Nazir LA, Parvinder SP, Tasduq SA. Inhibition of melanogenesis by 3-(1'-methyltetrahydropyridinyl)-2,4-6-trihydroxy acetophenone via suppressing the activity of cAMP response element-binding protein (CREB) and nuclear exclusion of CREB-regulated transcription coactivator 1 (CRTC1). Eur J Pharmacol 2023:175734. [PMID: 37080332 DOI: 10.1016/j.ejphar.2023.175734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/03/2023] [Accepted: 04/17/2023] [Indexed: 04/22/2023]
Abstract
Exposure to Ultraviolet radiation or α-melanocyte-stimulating hormone (α-MSH) stimulates the Cyclic Adenosine Monophosphate/Protein Kinase A signalling pathway, which leads to the synthesis and deposition of melanin granules in the epidermis. Skin pigmentation is the major physiological defence against inimical effects of sunlight. However, excessive melanin production and accumulation can cause various skin hyperpigmentation disorders. The present study involved the identification of 3-(1'-methyltetrahydropyridinyl)-2,4-6-trihydroxy acetophenone (IIIM-8) as an inhibitor of melanogenesis, IIIM-8 significantly inhibited pigment production both invitro and invivowithout incurring any cytotoxicity in Human Adult Epidermal Melanocytes (HAEM). IIIM-8 repressed melanin synthesis and secretion both at basal levels and in α-MSH stimulated cultured HAEM cells by decreasing the levels of Cyclic Adenosine Monophosphate (cAMP) and inhibiting the phosphorylation of cAMP response element-binding (CREB) protein, coupled with restoring the phosphorylation of CREB-regulated transcription coactivator 1 (CRTC1) and its nuclear exclusion in HAEM cells. This impeding effect correlates with diminished expression of master melanogenic proteins including microphthalmia-associated transcription factor (MITF), Tyrosinase (TYR), Tyrosinase related protein 1 (TRP1), and Tyrosinase related protein 2 (TRP2). Additionally, topical application of IIIM-8 induced tail depigmentation in C57BL/6 J mice. Furthermore, IIIM-8 efficiently mitigated the effect of ultraviolet-B radiation on melanin synthesis in the auricles of C57BL/6 J mice. This study demonstrates that IIIM-8 is an active anti-melanogenic agent against ultraviolet radiation-induced melanogenesis and other hyperpigmentation disorders.
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Affiliation(s)
- Naikoo H Shahid
- Pharmacology Division, Council of Scientific and Industrial Research-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Haroon Rashid
- Sher-e-KashmirInstitute of Medical Sciences, Soura, Srinagar, 190011, Jammu and Kashmir, India
| | - Sanjay Kumar
- Natural Product and Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, Jammu and Kashmir, India
| | - Sajida Archoo
- Pharmacology Division, Council of Scientific and Industrial Research-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Sheikh A Umar
- Pharmacology Division, Council of Scientific and Industrial Research-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Lone A Nazir
- Pharmacology Division, Council of Scientific and Industrial Research-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Singh P Parvinder
- Natural Product and Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, Jammu and Kashmir, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Sheikh A Tasduq
- Pharmacology Division, Council of Scientific and Industrial Research-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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van Gijsel-Bonnello M, Darling NJ, Tanaka T, Di Carmine S, Marchesi F, Thomson S, Clark K, Kurowska-Stolarska M, McSorley HJ, Cohen P, Arthur JSC. Salt-inducible kinase 2 regulates fibrosis during bleomycin-induced lung injury. J Biol Chem 2022; 298:102644. [PMID: 36309093 PMCID: PMC9706632 DOI: 10.1016/j.jbc.2022.102644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/20/2022] [Accepted: 10/22/2022] [Indexed: 11/06/2022] Open
Abstract
Idiopathic pulmonary fibrosis is a progressive and normally fatal disease with limited treatment options. The tyrosine kinase inhibitor nintedanib has recently been approved for the treatment of idiopathic pulmonary fibrosis, and its effectiveness has been linked to its ability to inhibit a number of receptor tyrosine kinases including the platelet-derived growth factor, vascular endothelial growth factor, and fibroblast growth factor receptors. We show here that nintedanib also inhibits salt-inducible kinase 2 (SIK2), with a similar IC50 to its reported tyrosine kinase targets. Nintedanib also inhibited the related kinases SIK1 and SIK3, although with 12-fold and 72-fold higher IC50s, respectively. To investigate if the inhibition of SIK2 may contribute to the effectiveness of nintedanib in treating lung fibrosis, mice with kinase-inactive knockin mutations were tested using a model of bleomycin-induced lung fibrosis. We found that loss of SIK2 activity protects against bleomycin-induced fibrosis, as judged by collagen deposition and histological scoring. Loss of both SIK1 and SIK2 activity had a similar effect to loss of SIK2 activity. Total SIK3 knockout mice have a developmental phenotype making them unsuitable for analysis in this model; however, we determined that conditional knockout of SIK3 in the immune system did not affect bleomycin-induced lung fibrosis. Together, these results suggest that SIK2 is a potential drug target for the treatment of lung fibrosis.
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Affiliation(s)
- Manuel van Gijsel-Bonnello
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom; MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Nicola J Darling
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Takashi Tanaka
- Research Centre of Specialty, Ono Pharmaceutical Co Ltd, Osaka, Japan
| | - Samuele Di Carmine
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Francesco Marchesi
- School of Veterinary Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Sarah Thomson
- Biological Services, University of Dundee, Dundee, United Kingdom
| | - Kristopher Clark
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Mariola Kurowska-Stolarska
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Henry J McSorley
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Philip Cohen
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - J Simon C Arthur
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
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An Epilepsy-Associated Mutation of Salt-Inducible Kinase 1 Increases the Susceptibility to Epileptic Seizures and Interferes with Adrenocorticotropic Hormone Therapy for Infantile Spasms in Mice. Int J Mol Sci 2022; 23:ijms23147927. [PMID: 35887274 PMCID: PMC9319016 DOI: 10.3390/ijms23147927] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/14/2022] [Accepted: 07/16/2022] [Indexed: 12/10/2022] Open
Abstract
Six mutations in the salt-inducible kinase 1 (SIK1) have been identified in developmental and epileptic encephalopathy (DEE-30) patients, and two of the mutations are nonsense mutations that truncate the C-terminal region of SIK1. In a previous study, we generated SIK1 mutant (SIK1-MT) mice recapitulating the C-terminal truncated mutations using CRISPR/Cas9-mediated genome editing and found an increase in excitatory synaptic transmission and enhancement of neural excitability in neocortical neurons in SIK1-MT mice. NMDA was injected into SIK1-MT males to induce epileptic seizures in the mice. The severity of the NMDA-induced seizures was estimated by the latency and the number of tail flickering and hyperflexion. Activated brain regions were evaluated by immunohistochemistry against c-fos, Iba1, and GFAP. As another epilepsy model, pentylenetetrazol was injected into the adult SIK1 mutant mice. Seizure susceptibility induced by both NMDA and PTZ was enhanced in SIK1-MT mice. Brain regions including the thalamus and hypothalamus were strongly activated in NMDA-induced seizures. The epilepsy-associated mutation of SIK1 canceled the pharmacological effects of the ACTH treatment on NMDA-induced seizures. These results suggest that SIK1 may be involved in the neuropathological mechanisms of NMDA-induced spasms and the pharmacological mechanism of ACTH treatment.
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Mi Z, Song Y, Wang J, Liu Z, Cao X, Dang L, Lu Y, Sun Y, Xiong H, Zhang L, Chen Y. cAMP-Induced Nuclear Condensation of CRTC2 Promotes Transcription Elongation and Cystogenesis in Autosomal Dominant Polycystic Kidney Disease. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2104578. [PMID: 35037420 PMCID: PMC8981427 DOI: 10.1002/advs.202104578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Formation of biomolecular condensates by phase separation has recently emerged as a new principle for regulating gene expression in response to extracellular signaling. However, the molecular mechanisms underlying the coupling of signal transduction and gene activation through condensate formation, and how dysregulation of these mechanisms contributes to disease progression, remain elusive. Here, the authors report that CREB-regulated transcription coactivator 2 (CRTC2) translocates to the nucleus and forms phase-separated condensates upon activation of cAMP signaling. They show that intranuclear CRTC2 interacts with positive transcription elongation factor b (P-TEFb) and activates P-TEFb by disrupting the inhibitory 7SK snRNP complex. Aberrantly elevated cAMP signaling plays central roles in the development of autosomal dominant polycystic kidney disease (ADPKD). They find that CRTC2 localizes to the nucleus and forms condensates in cystic epithelial cells of both mouse and human ADPKD kidneys. Genetic depletion of CRTC2 suppresses cyst growth in an orthologous ADPKD mouse model. Using integrative transcriptomic and cistromic analyses, they identify CRTC2-regulated cystogenesis-associated genes, whose activation depends on CRTC2 condensate-facilitated P-TEFb recruitment and the release of paused RNA polymerase II. Together, their findings elucidate a mechanism by which CRTC2 nuclear condensation conveys cAMP signaling to transcription elongation activation and thereby promotes cystogenesis in ADPKD.
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Affiliation(s)
- Zeyun Mi
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Yandong Song
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Jiuchen Wang
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Zhiheng Liu
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Xinyi Cao
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Lin Dang
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Yumei Lu
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Yongzhan Sun
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Hui Xiong
- Department of UrologyShandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinanShandong250001China
| | - Lirong Zhang
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
| | - Yupeng Chen
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical EpigeneticsDepartment of Biochemistry and Molecular BiologySchool of Basic Medical SciencesTianjin Institute of UrologyThe Second Hospital of Tianjin Medical UniversityTianjin Medical UniversityTianjin300070China
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CREB Coactivator CRTC2 Plays a Crucial Role in Endothelial Function. J Neurosci 2020; 40:9533-9546. [PMID: 33127851 DOI: 10.1523/jneurosci.0407-20.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 10/20/2020] [Accepted: 10/22/2020] [Indexed: 11/21/2022] Open
Abstract
The cAMP pathway is known to stabilize endothelial barrier function and maintain vascular physiology. The family of cAMP-response element binding (CREB)-regulated transcription coactivators (CRTC)1-3 activate transcription by targeting the basic leucine zipper domain of CREB. CRTC2 is a master regulator of glucose metabolism in liver and adipose tissue. However, the role of CRTC2 in endothelium remains unknown. The aim of this study was to evaluate the effect of CRTC2 on endothelial function. We focused the effect of CRTC2 in endothelial cells and its relationship with p190RhoGAP-A. We examined the effect of CRTC2 on endothelial function using a mouse aorta ring assay ex vivo and with photothrombotic stroke in endothelial cell-specific CRTC2-knock-out male mice in vivo CRTC2 was highly expressed in endothelial cells and related to angiogenesis. Among CRTC1-3, only CRTC2 was activated under ischemic conditions at endothelial cells, and CRTC2 maintained endothelial barrier function through p190RhoGAP-A expression. Ser171 was a pivotal regulatory site for CRTC2 intracellular localization, and Ser307 functioned as a crucial phosphorylation site. Endothelial cell-specific CRTC2-knock-out mice showed reduced angiogenesis ex vivo, exacerbated stroke via endothelial dysfunction, and impaired neurologic recovery via reduced vascular beds in vivo These findings suggest that CRTC2 plays a crucial protective role in vascular integrity of the endothelium via p190RhoGAP-A under ischemic conditions.SIGNIFICANCE STATEMENT Previously, the role of CRTC2 in endothelial cells was unknown. In this study, we firstly clarified that CRTC2 was expressed in endothelial cells and among CRTC1-3, only CRTC2 was related to endothelial function. Most importantly, only CRTC2 was activated under ischemic conditions at endothelial cells and maintained endothelial barrier function through p190RhoGAP-A expression. Ser307 in CRTC2 functioned as a crucial phosphorylation site. Endothelial cell-specific CRTC2-knock-out mice showed reduced angiogenesis ex vivo, exacerbated stroke via endothelial dysfunction, and impaired neurologic recovery via reduced vascular beds in vivo These results suggested that CRTC2 maybe a potential therapeutic target for reducing blood-brain barrier (BBB) damage and improving recovery.
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Wang Y, Liu Q, Zhang H. Phosphorylation of CREB-Specific Coactivator CRTC2 at Ser238 Promotes Proliferation, Migration, and Invasion of Colorectal Cancer Cells. Technol Cancer Res Treat 2020; 19:1533033820962111. [PMID: 33000695 PMCID: PMC7533939 DOI: 10.1177/1533033820962111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
cAMP response element binding protein (CREB)-regulated transcription coactivator 2 (CRTC2), a member of the novel CRTC family of transcriptional coactivators that activates basic leucine zipper transcription factors, including CREB, is overexpressed in many carcinomas, including colon cancer. Phosphorylation of CRTC2 protein at different residues is important for its subcellular localization and activity. However, the functions of some of the serine phosphorylation sites have not been elucidated. This study aimed to investigate the effects of phosphorylation of Ser127, Ser238, and Ser245 sites of CRTC2 in colorectal cancer (CRC) cells. Recombinant lentiviral particles with a CRTC2-targeting small hairpin RNA (shRNA) sequence were transfected into CRC cells to obtained shCRTC2 cell lines. Site-directed mutagenesis of Ser127, Ser238, and Ser245 cells were constructed by transfecting CRTC2 cDNA containing S127A, S238A, and S245A mutations into shCRTC2. Cell proliferation was measured by cell counting kit-8. Cell migration and invasion were examined by transwell assay. mRNA expression was assayed by qRT-PCR, and protein expression was determined by Western blot. Our results indicate that CRTC2 is overexpressed in CRC cells. Knockdown of CRTC2 inhibits the proliferation, migration, and invasion of CRC cells. When the phosphorylation of CRTC2 Ser238 decreases due to the lack of ERK2, the phosphorylation of Ser171 site increases. The proliferation, migration and invasion of CRC cells were inhibited, the nuclear aggregation of CRTC2 in the nucleus was reduced, and the interaction between CRTC2 and CREB was weaken. It is shown that the phosphorylation of CRTC2 Ser238 is important for CREB transcriptional activity. These findings may help in the identification of potentially new targets for CRC therapy.
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Affiliation(s)
- Yi Wang
- Department of Colorectal Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Qian Liu
- Department of Colorectal Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Hanshuo Zhang
- GeneX health Life Co., Ltd, Beijing, People's Republic of China
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Salt inducible kinases as novel Notch interactors in the developing Drosophila retina. PLoS One 2020; 15:e0234744. [PMID: 32542037 PMCID: PMC7295197 DOI: 10.1371/journal.pone.0234744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 06/01/2020] [Indexed: 12/26/2022] Open
Abstract
Developmental processes require strict regulation of proliferation, differentiation and patterning for the generation of final organ size. Aberrations in these fundamental events are critically important in tumorigenesis and cancer progression. Salt inducible kinases (Siks) are evolutionarily conserved genes involved in diverse biological processes, including salt sensing, metabolism, muscle, cartilage and bone formation, but their role in development remains largely unknown. Recent findings implicate Siks in mitotic control, and in both tumor suppression and progression. Using a tumor model in the Drosophila eye, we show that perturbation of Sik function exacerbates tumor-like tissue overgrowth and metastasis. Furthermore, we show that both Drosophila Sik genes, Sik2 and Sik3, function in eye development processes. We propose that an important target of Siks may be the Notch signaling pathway, as we demonstrate genetic interaction between Siks and Notch pathway members. Finally, we investigate Sik expression in the developing retina and show that Sik2 is expressed in all photoreceptors, basal to cell junctions, while Sik3 appears to be expressed specifically in R3/R4 cells in the developing eye. Combined, our data suggest that Sik genes are important for eye tissue specification and growth, and that their dysregulation may contribute to tumor formation.
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Park M, Miyoshi C, Fujiyama T, Kakizaki M, Ikkyu A, Honda T, Choi J, Asano F, Mizuno S, Takahashi S, Yanagisawa M, Funato H. Loss of the conserved PKA sites of SIK1 and SIK2 increases sleep need. Sci Rep 2020; 10:8676. [PMID: 32457359 PMCID: PMC7250853 DOI: 10.1038/s41598-020-65647-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 05/05/2020] [Indexed: 11/25/2022] Open
Abstract
Although sleep is one of the most conserved behaviors, the intracellular mechanism regulating sleep/wakefulness remains unknown. We recently identified a protein kinase, SIK3, as a sleep-regulating molecule. Mice that lack a well-conserved protein kinase A (PKA) phosphorylation site, S551, showed longer non-rapid eye movement (NREM) sleep and increased NREMS delta density. S551 of SIK3 is conserved in other members of the SIK family, such as SIK1 (S577) and SIK2 (S587). Here, we examined whether the PKA phosphorylation sites of SIK1 and SIK2 are involved in sleep regulation by generating Sik1S577A and Sik2S587A mice. The homozygous Sik1S577A mice showed a shorter wake time, longer NREMS time, and higher NREMS delta density than the wild-type mice. The heterozygous and homozygous Sik2S587A mice showed increased NREMS delta density. Both the Sik1S577A and Sik2S587A mice exhibited proper homeostatic regulation of sleep need after sleep deprivation. Despite abundant expression of Sik1 in the suprachiasmatic nucleus, the Sik1S577A mice showed normal circadian behavior. Although Sik2 is highly expressed in brown adipose tissue, the male and female Sik2S587A mice that were fed either a chow or high-fat diet showed similar weight gain as the wild-type littermates. These results suggest that PKA-SIK signaling is involved in the regulation of sleep need.
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Affiliation(s)
- Minjeong Park
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Chika Miyoshi
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Tomoyuki Fujiyama
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Miyo Kakizaki
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Aya Ikkyu
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Takato Honda
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Jinhwan Choi
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Fuyuki Asano
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Seiya Mizuno
- Laboratory Animal Resource Center, University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Satoru Takahashi
- Laboratory Animal Resource Center, University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Masashi Yanagisawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, 305-8575, Japan. .,Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. .,Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, 305-8575, Ibaraki, Japan.
| | - Hiromasa Funato
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, 305-8575, Japan. .,Department of Anatomy, Faculty of Medicine, Toho University, Tokyo, 143-8540, Japan.
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Smith LIF, Huang V, Olah M, Trinh L, Liu Y, Hazell G, Conway-Campbell B, Zhao Z, Martinez A, Lefrançois-Martinez AM, Lightman S, Spiga F, Aguilera G. Involvement of CREB-regulated transcription coactivators (CRTC) in transcriptional activation of steroidogenic acute regulatory protein (Star) by ACTH. Mol Cell Endocrinol 2020; 499:110612. [PMID: 31604124 PMCID: PMC6899503 DOI: 10.1016/j.mce.2019.110612] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 09/06/2019] [Accepted: 10/04/2019] [Indexed: 12/20/2022]
Abstract
Studies in vivo have suggested the involvement of CREB-regulated transcription coactivator (CRTC)2 on ACTH-induced transcription of the key steroidogenic protein, Steroidogenic Acute Regulatory (StAR). The present study uses two ACTH-responsive adrenocortical cell lines, to examine the role of CRTC on Star transcription. Here we show that ACTH-induced Star primary transcript, or heteronuclear RNA (hnRNA), parallels rapid increases in nuclear levels of the 3 isoforms of CRTC; CRTC1, CRTC2 and CRTC3. Furthermore, ACTH promotes recruitment of CRTC2 and CRTC3 by the Star promoter and siRNA knockdown of either CRTC3 or CRTC2 attenuates the increases in ACTH-induced Star hnRNA. Using pharmacological inhibitors of PKA, MAP kinase and calcineurin, we show that the effects of ACTH on Star transcription and CRTC nuclear translocation depend predominantly on the PKA pathway. The data provides evidence that CRTC2 and CRTC3, contribute to activation of Star transcription by ACTH, and that PKA/CRTC-dependent pathways are part of the multifactorial mechanisms regulating Star transcription.
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Affiliation(s)
- Lorna I F Smith
- Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA; Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK.
| | - Victoria Huang
- Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Mark Olah
- Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Loc Trinh
- Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Ying Liu
- Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Georgina Hazell
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Becky Conway-Campbell
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Zidong Zhao
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Antoine Martinez
- Génétique Reproduction & Développement, CNRS UMR 6293, Inserm U1103, Université Clermont Auvergne, 63001, Clermont-Ferrand, France
| | - Anne-Marie Lefrançois-Martinez
- Génétique Reproduction & Développement, CNRS UMR 6293, Inserm U1103, Université Clermont Auvergne, 63001, Clermont-Ferrand, France
| | - Stafford Lightman
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Francesca Spiga
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Greti Aguilera
- Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
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11
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Berdeaux R, Hutchins C. Anabolic and Pro-metabolic Functions of CREB-CRTC in Skeletal Muscle: Advantages and Obstacles for Type 2 Diabetes and Cancer Cachexia. Front Endocrinol (Lausanne) 2019; 10:535. [PMID: 31428057 PMCID: PMC6688074 DOI: 10.3389/fendo.2019.00535] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/18/2019] [Indexed: 12/31/2022] Open
Abstract
cAMP is one of the earliest described mediators of hormone action in response to physiologic stress that allows acute stress responses and adaptation in every tissue. The classic role of cAMP signaling in metabolic tissues is to regulate nutrient partitioning. In response to acute stress, such as epinephrine released during strenuous exercise or fasting, intramuscular cAMP liberates glucose from glycogen and fatty acids from triglycerides. In the long-term, activation of Gs-coupled GPCRs stimulates muscle growth (hypertrophy) and metabolic adaptation through multiple pathways that culminate in a net increase of protein synthesis, mitochondrial biogenesis, and improved metabolic efficiency. This review focuses on regulation, function, and transcriptional targets of CREB (cAMP response element binding protein) and CRTCs (CREB regulated transcriptional coactivators) in skeletal muscle and the potential for targeting this pathway to sustain muscle mass and metabolic function in type 2 diabetes and cancer. Although the muscle-autonomous roles of these proteins might render them excellent targets for both conditions, pharmacologic targeting must be approached with caution. Gain of CREB-CRTC function is associated with excess liver glucose output in type 2 diabetes, and growing evidence implicates CREB-CRTC activation in proliferation and invasion of different types of cancer cells. We conclude that deeper investigation to identify skeletal muscle specific regulatory mechanisms that govern CREB-CRTC transcriptional activity is needed to safely take advantage of their potent effects to invigorate skeletal muscle to potentially improve health in people with type 2 diabetes and cancer.
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Affiliation(s)
- Rebecca Berdeaux
- Department of Integrative Biology and Pharmacology, Center for Metabolic and Degenerative Diseases, The Brown Foundation Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center Houston, Houston, TX, United States
- Graduate Program in Biochemistry and Cell Biology, The MD Anderson-UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States
- *Correspondence: Rebecca Berdeaux
| | - Chase Hutchins
- Department of Integrative Biology and Pharmacology, Center for Metabolic and Degenerative Diseases, The Brown Foundation Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center Houston, Houston, TX, United States
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12
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Abstract
The hypothalamic-pituitary-adrenal (HPA) axis is the major neuroendocrine axis regulating homeostasis in mammals. Glucocorticoid hormones are rapidly synthesized and secreted from the adrenal gland in response to stress. In addition, under basal conditions glucocorticoids are released rhythmically with both a circadian and an ultradian (pulsatile) pattern. These rhythms are important not only for normal function of glucocorticoid target organs, but also for the HPA axis responses to stress. Several studies have shown that disruption of glucocorticoid rhythms is associated with disease both in humans and in rodents. In this review, we will discuss our knowledge of the negative feedback mechanisms that regulate basal ultradian synthesis and secretion of glucocorticoids, including the role of glucocorticoid and mineralocorticoid receptors and their chaperone protein FKBP51. Moreover, in light of recent findings, we will also discuss the importance of intra-adrenal glucocorticoid receptor signaling in regulating glucocorticoid synthesis.
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Affiliation(s)
- Julia K Gjerstad
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Stafford L Lightman
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Francesca Spiga
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
- CONTACT Francesca SpigaUniversity of Bristol, Translational Health Sciences, Bristol Medical School, Dorothy Hodgkin Building, Whitson Street, BristolBS1 3NY, UK
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13
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Selvaraj V, Stocco DM, Clark BJ. Current knowledge on the acute regulation of steroidogenesis. Biol Reprod 2018; 99:13-26. [PMID: 29718098 PMCID: PMC6044331 DOI: 10.1093/biolre/ioy102] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/23/2018] [Accepted: 04/26/2018] [Indexed: 12/31/2022] Open
Abstract
How rapid induction of steroid hormone biosynthesis occurs in response to trophic hormone stimulation of steroidogenic cells has been a subject of intensive investigation for approximately six decades. A key observation made very early was that acute regulation of steroid biosynthesis required swift and timely synthesis of a new protein whose role appeared to be involved in the delivery of the substrate for all steroid hormones, cholesterol, from the outer to the inner mitochondrial membrane where the process of steroidogenesis begins. It was quickly learned that this transfer of cholesterol to the inner mitochondrial membrane was the regulated and rate-limiting step in steroidogenesis. Following this observation, the quest for this putative regulator protein(s) began in earnest in the late 1950s. This review provides a history of this quest, the candidate proteins that arose over the years and facts surrounding their rise or decline. Only two have persisted-translocator protein (TSPO) and the steroidogenic acute regulatory protein (StAR). We present a detailed summary of the work that has been published for each of these two proteins, the specific data that has appeared in support of their role in cholesterol transport and steroidogenesis, and the ensuing observations that have arisen in recent years that have refuted the role of TSPO in this process. We believe that the only viable candidate that has been shown to be indispensable is the StAR protein. Lastly, we provide our view on what may be the most important questions concerning the acute regulation of steroidogenesis that need to be asked in future.
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Affiliation(s)
- Vimal Selvaraj
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, USA
| | - Douglas M Stocco
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas, USA
| | - Barbara J Clark
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, Kentucky, USA
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14
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Yun CY, Mi Ko S, Pyo Choi Y, Kim BJ, Lee J, Mun Kim J, Kim JY, Song JY, Kim SH, Hwang BY, Tae Hong J, Han SB, Kim Y. α-Viniferin Improves Facial Hyperpigmentation via Accelerating Feedback Termination of cAMP/PKA-Signaled Phosphorylation Circuit in Facultative Melanogenesis. Theranostics 2018; 8:2031-2043. [PMID: 29556371 PMCID: PMC5858515 DOI: 10.7150/thno.24385] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Accepted: 01/24/2018] [Indexed: 12/14/2022] Open
Abstract
Rationale: cAMP up-regulates microphthalmia-associated transcription factor subtype M (MITF-M) and tyrosinase (Tyro) in the generation of heavily pigmented melanosomes. Here, we communicate a therapeutic mechanism of hyperpigmented disorder by α-viniferin, an active constituent of Caragana sinica. Methods: We used cAMP-elevated melanocyte cultures or facial hyperpigmented patches for pigmentation assays, and applied immunoprecipitation, immunobloting, RT-PCR or reporter gene for elucidation of the antimelanogenic mechanism. Results:C. sinica or α-viniferin inhibited melanin production in α-melanocyte-stimulating hormone (α-MSH)-, histamine- or cell-permeable cAMP-activated melanocyte cultures. Moreover, topical application with C. sinica containing α-viniferin, a standard in quality control, decreased melanin index on facial melasma and freckles in patients. As a molecular basis, α-viniferin accelerated protein kinase A (PKA) inactivation via the reassociation between catalytic and regulatory subunits in cAMP-elevated melanocytes, a feedback loop in the melanogenic process. α-Viniferin resultantly inhibited cAMP/PKA-signaled phosphorylation of cAMP-responsive element-binding protein (CREB) coupled with dephosphorylation of cAMP-regulated transcriptional co-activator 1 (CRTC1), thus down-regulating expression of MITF-M or Tyro gene with decreased melanin pigmentation. Conclusion: This study assigned PKA inactivation, a feedback termination in cAMP-induced facultative melanogenesis, as a putative target of α-viniferin in the treatment of melanocyte-specific hyperpigmented disorder. Finally, C. sinica containing α-viniferin was approved as an antimelanogenic agent with topical application in skin hyperpigmentation.
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15
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Sonntag T, Vaughan JM, Montminy M. 14-3-3 proteins mediate inhibitory effects of cAMP on salt-inducible kinases (SIKs). FEBS J 2018; 285:467-480. [PMID: 29211348 DOI: 10.1111/febs.14351] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 11/21/2017] [Accepted: 11/30/2017] [Indexed: 01/02/2023]
Abstract
The salt-inducible kinase (SIK) family regulates cellular gene expression via the phosphorylation of cAMP-regulated transcriptional coactivators (CRTCs) and class IIA histone deacetylases, which are sequestered in the cytoplasm by phosphorylation-dependent 14-3-3 interactions. SIK activity toward these substrates is inhibited by increases in cAMP signaling, although the underlying mechanism is unclear. Here, we show that the protein kinase A (PKA)-dependent phosphorylation of SIKs inhibits their catalytic activity by inducing 14-3-3 protein binding. SIK1 and SIK3 contain two functional PKA/14-3-3 sites, while SIK2 has four. In keeping with the dimeric nature of 14-3-3s, the presence of multiple binding sites within target proteins dramatically increases binding affinity. As a result, loss of a single 14-3-3-binding site in SIK1 and SIK3 abolished 14-3-3 association and rendered them insensitive to cAMP. In contrast, mutation of three sites in SIK2 was necessary to fully block cAMP regulation. Superimposed on the effects of PKA phosphorylation and 14-3-3 association, an evolutionary conserved domain in SIK1 and SIK2 (the so called RK-rich region; 595-624 in hSIK2) is also required for the inhibition of SIK2 activity. Collectively, these results point to a dual role for 14-3-3 proteins in repressing a family of Ser/Thr kinases as well as their substrates.
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Affiliation(s)
- Tim Sonntag
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Joan M Vaughan
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Marc Montminy
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA, USA
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16
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Novák J, Fabrik I, Linhartová I, Link M, Černý O, Stulík J, Šebo P. Phosphoproteomics of cAMP signaling of Bordetella adenylate cyclase toxin in mouse dendritic cells. Sci Rep 2017; 7:16298. [PMID: 29176673 PMCID: PMC5701129 DOI: 10.1038/s41598-017-14501-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 10/11/2017] [Indexed: 01/04/2023] Open
Abstract
The adenylate cyclase toxin (CyaA) of the whooping cough agent Bordetella pertussis subverts immune functions of host myeloid cells expressing the αMβ2 integrin (CD11b/CD18, CR3 or Mac-1). CyaA delivers into cytosol of cells an extremely catalytically active adenylyl cyclase enzyme, which disrupts the innate and adaptive immune functions of phagocytes through unregulated production of the key signaling molecule cAMP. We have used phosphoproteomics to analyze cAMP signaling of CyaA in murine bone marrow-derived dendritic cells. CyaA action resulted in alterations of phosphorylation state of a number of proteins that regulate actin cytoskeleton homeostasis, including Mena, Talin-1 and VASP. CyaA action repressed mTOR signaling through activation of mTORC1 inhibitors TSC2 and PRAS40 and altered phosphorylation of multiple chromatin remodelers, including the class II histone deacetylase HDAC5. CyaA toxin action further elicited inhibitory phosphorylation of SIK family kinases involved in modulation of immune response and provoked dephosphorylation of the transcriptional coactivator CRTC3, indicating that CyaA-promoted nuclear translocation of CRTC3 may account for CyaA-induced IL-10 production. These findings document the complexity of subversive physiological manipulation of myeloid phagocytes by the CyaA toxin, serving in immune evasion of the pertussis agent.
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Affiliation(s)
- Jakub Novák
- Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prague, Czech Republic
| | - Ivo Fabrik
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Irena Linhartová
- Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prague, Czech Republic
| | - Marek Link
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Ondřej Černý
- Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prague, Czech Republic
| | - Jiří Stulík
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Peter Šebo
- Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prague, Czech Republic.
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17
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Li Y, Wang L, Zhou L, Song Y, Ma S, Yu C, Zhao J, Xu C, Gao L. Thyroid stimulating hormone increases hepatic gluconeogenesis via CRTC2. Mol Cell Endocrinol 2017; 446:70-80. [PMID: 28212844 DOI: 10.1016/j.mce.2017.02.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 02/09/2017] [Accepted: 02/10/2017] [Indexed: 10/20/2022]
Abstract
Epidemiological evidence indicates that thyroid stimulating hormone (TSH) is positively correlated with abnormal glucose levels. We previously reported that TSH has direct effects on gluconeogenesis. However, the underlying molecular mechanism remains unclear. In this study, we observed increased fasting blood glucose and glucose production in a mouse model of subclinical hypothyroidism (only elevated TSH levels). TSH acts via the classical cAMP/PKA pathway and CRTC2 regulates glucose homeostasis. Thus, we explore whether CRTC2 is involved in the process of TSH-induced gluconeogenesis. We show that TSH increases CRTC2 expression via the TSHR/cAMP/PKA pathway, which in turn upregulates hepatic gluconeogenic genes. Furthermore, TSH stimulates CRTC2 dephosphorylation and upregulates p-CREB (Ser133) in HepG2 cells. Silencing CRTC2 and CREB decreases the effect of TSH on PEPCK-luciferase, the rate-limiting enzyme of gluconeogenesis. Finally, the deletion of TSHR reduces the levels of the CRTC2:CREB complex in mouse livers. This study demonstrates that TSH activates CRTC2 via the TSHR/cAMP/PKA pathway, leading to the formation of a CRTC2:CREB complex and increases hepatic gluconeogenesis.
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Affiliation(s)
- Yujie Li
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China
| | - Laicheng Wang
- Scientific Center, Shandong Provincial Hospital Affiliated to Shandong University, 544 Jing 4 Rd Jinan, Shangdong 250021, PR China
| | - Lingyan Zhou
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China
| | - Yongfeng Song
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China
| | - Shizhan Ma
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China
| | - Chunxiao Yu
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China
| | - Jiajun Zhao
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China
| | - Chao Xu
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong Clinical Medical Center of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jing 5 Rd Jinan, Shandong 250021, PR China.
| | - Ling Gao
- Institute of Endocrinology, Shandong Academy of Clinical Medicine, Scientific Center, Shandong Provincial Hospital Affiliated to Shandong University, 544 Jing 4 Rd Jinan, Shangdong 250021, PR China.
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18
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Sonntag T, Moresco JJ, Vaughan JM, Matsumura S, Yates JR, Montminy M. Analysis of a cAMP regulated coactivator family reveals an alternative phosphorylation motif for AMPK family members. PLoS One 2017; 12:e0173013. [PMID: 28235073 PMCID: PMC5325614 DOI: 10.1371/journal.pone.0173013] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 02/13/2017] [Indexed: 11/24/2022] Open
Abstract
The second messenger cAMP stimulates cellular gene expression via the PKA-mediated phosphorylation of the transcription factor CREB and through dephosphorylation of the cAMP-responsive transcriptional coactivators (CRTCs). Under basal conditions, CRTCs are phosphorylated by members of the AMPK family of Ser/Thr kinases and sequestered in the cytoplasm via a phosphorylation-dependent association with 14-3-3 proteins. Increases in cAMP promote the dephosphorylation and nuclear translocation of CRTCs, where they bind to CREB and stimulate relevant target genes. Although they share considerable sequence homology, members of the CRTC family exert non-overlapping effects on cellular gene expression through as yet unidentified mechanisms. Here we show that the three CRTCs exhibit distinct patterns of 14-3-3 binding at three conserved sites corresponding to S70, S171, and S275 (in CRTC2). S171 functions as the gatekeeper site for 14-3-3 binding; it acts cooperatively with S275 in stabilizing this interaction following its phosphorylation by the cAMP-responsive SIK and the cAMP-nonresponsive MARK kinases. Although S171 contains a consensus recognition site for phosphorylation by AMPK family members, S70 and S275 carry variant motifs (MNTGGS275LPDL), lacking basic residues that are otherwise critical for SIK/MARK recognition as well as 14-3-3 binding. Correspondingly, the activity of these motifs differs between CRTC family members. As the variant (SLPDL) motif is present and apparently phosphorylated in other mammalian proteins, our studies suggest that the regulation of cellular targets by AMPK family members is more extensive than previously appreciated.
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Affiliation(s)
- Tim Sonntag
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - James J. Moresco
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Joan M. Vaughan
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Shigenobu Matsumura
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto, Japan
| | - John R. Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Marc Montminy
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California, United States of America
- * E-mail:
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Epilepsy-causing sequence variations in SIK1 disrupt synaptic activity response gene expression and affect neuronal morphology. Eur J Hum Genet 2016; 25:216-221. [PMID: 27966542 DOI: 10.1038/ejhg.2016.145] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 09/20/2016] [Accepted: 09/27/2016] [Indexed: 12/30/2022] Open
Abstract
SIK1 syndrome is a newly described developmental epilepsy disorder caused by heterozygous mutations in the salt-inducible kinase SIK1. To better understand the pathophysiology of SIK1 syndrome, we studied the effects of SIK1 pathogenic sequence variations in human neurons. Primary human fetal cortical neurons were transfected with a lentiviral vector to overexpress wild-type and mutant SIK1 protein. We evaluated the transcriptional activity of known downstream gene targets in neurons expressing mutant SIK1 compared with wild type. We then assayed neuronal morphology by measuring neurite length, number and branching. Truncating SIK1 sequence variations were associated with abnormal MEF2C transcriptional activity and decreased MEF2C protein levels. Epilepsy-causing SIK1 sequence variations were associated with significantly decreased expression of ARC (activity-regulated cytoskeletal-associated) and other synaptic activity response element genes. Assay of mRNA levels for other MEF2C target genes NR4A1 (Nur77) and NRG1, found significantly, decreased the expression of these genes as well. The missense p.(Pro287Thr) SIK1 sequence variation was associated with abnormal neuronal morphology, with significant decreases in mean neurite length, mean number of neurites and a significant increase in proximal branches compared with wild type. Epilepsy-causing SIK1 sequence variations resulted in abnormalities in the MEF2C-ARC pathway of neuronal development and synapse activity response. This work provides the first insights into the mechanisms of pathogenesis in SIK1 syndrome, and extends the ARX-MEF2C pathway in the pathogenesis of developmental epilepsy.
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20
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Pterosin B has multiple targets in gluconeogenic programs, including coenzyme Q in RORα–SRC2 signaling. Biochem Biophys Res Commun 2016; 473:415-20. [DOI: 10.1016/j.bbrc.2016.03.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 03/06/2016] [Indexed: 11/21/2022]
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21
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Henriksson E, Säll J, Gormand A, Wasserstrom S, Morrice NA, Fritzen AM, Foretz M, Campbell DG, Sakamoto K, Ekelund M, Degerman E, Stenkula KG, Göransson O. SIK2 regulates CRTCs, HDAC4 and glucose uptake in adipocytes. J Cell Sci 2016; 128:472-86. [PMID: 25472719 DOI: 10.1242/jcs.153932] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Salt-inducible kinase 2 (SIK2) is an AMP-activated protein kinase (AMPK) related kinase abundantly expressed in adipose tissue. Our aim was to identify molecular targets and functions of SIK2 in adipocytes, and to address the role of PKA-mediated phosphorylation of SIK2 on Ser358. Modulation of SIK2 in adipocytes resulted in altered phosphorylation of CREB-regulated transcription co-activator 2 (CRTC2), CRTC3 and class IIa histone deacetylase 4 (HDAC4). Furthermore, CRTC2, CRTC3, HDAC4 and protein phosphatase 2A (PP2A) interacted with SIK2, and the binding of CRTCs and PP2A to wild-type but not Ser358Ala SIK2, was reduced by cAMP elevation. Silencing of SIK2 resulted in reduced GLUT4 (also known as SLC2A4) protein levels, whereas cells treated with CRTC2 or HDAC4 siRNA displayed increased levels of GLUT4. Overexpression or pharmacological inhibition of SIK2 resulted in increased and decreased glucose uptake, respectively. We also describe a SIK2–CRTC2–HDAC4 pathway and its regulation in human adipocytes, strengthening the physiological relevance of our findings. Collectively, we demonstrate that SIK2 acts directly on CRTC2, CRTC3 and HDAC4, and that the cAMP–PKA pathway reduces the interaction of SIK2 with CRTCs and PP2A. Downstream, SIK2 increases GLUT4 levels and glucose uptake in adipocytes.
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22
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Yahara Y, Takemori H, Okada M, Kosai A, Yamashita A, Kobayashi T, Fujita K, Itoh Y, Nakamura M, Fuchino H, Kawahara N, Fukui N, Watanabe A, Kimura T, Tsumaki N. Pterosin B prevents chondrocyte hypertrophy and osteoarthritis in mice by inhibiting Sik3. Nat Commun 2016; 7:10959. [PMID: 27009967 PMCID: PMC4820810 DOI: 10.1038/ncomms10959] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 02/05/2016] [Indexed: 01/09/2023] Open
Abstract
Osteoarthritis is a common debilitating joint disorder. Risk factors for osteoarthritis include age, which is associated with thinning of articular cartilage. Here we generate chondrocyte-specific salt-inducible kinase 3 (Sik3) conditional knockout mice that are resistant to osteoarthritis with thickened articular cartilage owing to a larger chondrocyte population. We also identify an edible Pteridium aquilinum compound, pterosin B, as a Sik3 pathway inhibitor. We show that either Sik3 deletion or intraarticular injection of mice with pterosin B inhibits chondrocyte hypertrophy and protects cartilage from osteoarthritis. Collectively, our results suggest Sik3 regulates the homeostasis of articular cartilage and is a target for the treatment of osteoarthritis, with pterosin B as a candidate therapeutic.
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Affiliation(s)
- Yasuhito Yahara
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.,Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, 2630, Sugitani, Toyama 930-0194, Japan
| | - Hiroshi Takemori
- Laboratory of Cell Signaling and Metabolic Disease, National Institutes of Biomedical Innovation, Health and Nutrition, 7-6-8, Asagi, Saito, Ibaraki, Osaka 567-0085, Japan
| | - Minoru Okada
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Azuma Kosai
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Akihiro Yamashita
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Tomohito Kobayashi
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Kaori Fujita
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Yumi Itoh
- Laboratory of Cell Signaling and Metabolic Disease, National Institutes of Biomedical Innovation, Health and Nutrition, 7-6-8, Asagi, Saito, Ibaraki, Osaka 567-0085, Japan
| | - Masahiro Nakamura
- Genome/Epigenome Analysis Core Facility, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Hiroyuki Fuchino
- Research Center for Medicinal Plant Resources, Tsukuba Division, National Institutes of Biomedical Innovation, Health and Nutrition, 1-2, Hachimandai, Tsukuba, Ibaraki 305-0843, Japan
| | - Nobuo Kawahara
- Research Center for Medicinal Plant Resources, Tsukuba Division, National Institutes of Biomedical Innovation, Health and Nutrition, 1-2, Hachimandai, Tsukuba, Ibaraki 305-0843, Japan
| | - Naoshi Fukui
- Graduate School of Arts and Sciences, Department of Life Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan
| | - Akira Watanabe
- Genome/Epigenome Analysis Core Facility, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Tomoatsu Kimura
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, 2630, Sugitani, Toyama 930-0194, Japan
| | - Noriyuki Tsumaki
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
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Taub M, Garimella S, Kim D, Rajkhowa T, Cutuli F. Renal proximal tubule Na,K-ATPase is controlled by CREB-regulated transcriptional coactivators as well as salt-inducible kinase 1. Cell Signal 2015; 27:2568-78. [PMID: 26432356 PMCID: PMC4696386 DOI: 10.1016/j.cellsig.2015.09.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 09/17/2015] [Accepted: 09/28/2015] [Indexed: 01/11/2023]
Abstract
Sodium reabsorption by the kidney is regulated by locally produced natriuretic and anti-natriuretic factors, including dopamine and norepinephrine, respectively. Previous studies indicated that signaling events initiated by these natriuretic and anti-natriuretic factors achieve their effects by altering the phosphorylation of Na,K-ATPase in the renal proximal tubule, and that protein kinase A (PKA) and calcium-mediated signaling pathways are involved. The same signaling pathways also control the transcription of the Na,K-ATPase β subunit gene atp1b1 in renal proximal tubule cells. In this report, evidence is presented that (1) both the recently discovered cAMP-regulated transcriptional coactivators (CRTCs) and salt-inducible kinase 1 (SIK1) contribute to the transcriptional regulation of atp1b1 in renal proximal tubule (RPT) cells and (2) renal effectors, including norepinephrine, dopamine, prostaglandins, and sodium, play a role. Exogenously expressed CRTCs stimulate atp1b1 transcription. Evidence for a role of endogenous CRTCs includes the loss of transcriptional regulation of atp1b1 by a dominant-negative CRTC, as well as by a CREB mutant, with an altered CRTC binding site. In a number of experimental systems, SIK phosphorylates CRTCs, which are then sequestered in the cytoplasm, preventing their nuclear effects. Consistent with such a role of SIK in primary RPT cells, atp1b1 transcription increased in the presence of a dominant-negative SIK1, and in addition, regulation by dopamine, norepinephrine, and monensin was disrupted by a dominant-negative SIK1. These latter observations can be explained if SIK1 is phosphorylated and inactivated in the presence of these renal effectors. Our results support the hypothesis that Na,K-ATPase in the renal proximal tubule is regulated at the transcriptional level via SIK1 and CRTCs by renal effectors, in addition to the previously reported control of the phosphorylation of Na,K-ATPase.
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Affiliation(s)
- Mary Taub
- Biochemistry Department,School of Medicine and Biomedical SciencesUniversity at Buffalo,140 Farber Hall, 3435 Main Street,Buffalo, NY 14214, USA.
| | - Sudha Garimella
- Biochemistry Department,School of Medicine and Biomedical SciencesUniversity at Buffalo,140 Farber Hall, 3435 Main Street,Buffalo, NY 14214, USA
| | - Dongwook Kim
- Biochemistry Department,School of Medicine and Biomedical SciencesUniversity at Buffalo,140 Farber Hall, 3435 Main Street,Buffalo, NY 14214, USA
| | - Trivikram Rajkhowa
- Biochemistry Department,School of Medicine and Biomedical SciencesUniversity at Buffalo,140 Farber Hall, 3435 Main Street,Buffalo, NY 14214, USA
| | - Facundo Cutuli
- Biochemistry Department,School of Medicine and Biomedical SciencesUniversity at Buffalo,140 Farber Hall, 3435 Main Street,Buffalo, NY 14214, USA
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24
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Hu Z, Hu J, Shen WJ, Kraemer FB, Azhar S. A Novel Role of Salt-Inducible Kinase 1 (SIK1) in the Post-Translational Regulation of Scavenger Receptor Class B Type 1 Activity. Biochemistry 2015; 54:6917-30. [PMID: 26567857 DOI: 10.1021/acs.biochem.5b00147] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Salt-inducible kinase 1 (SIK1) is a serine/threonine kinase that belongs to the stress- and energy-sensing AMPK family of kinases. SIK1 expression is rapidly induced in Y1 adrenal cells in response to ACTH via the cAMP-PKA signaling cascade, and it has been suggested that an increased level of SIK1 expression inhibits adrenal steroidogenesis by repressing the cAMP-dependent transcription of steroidogenic proteins, CYP11A1 and StAR, by attenuating CREB transcriptional activity. Here we show that SIK1 stimulates adrenal steroidogenesis by modulating the selective HDL-CE transport activity of SR-B1. Overexpression of SIK1 increases cAMP-stimulated and SR-B1-mediated selective HDL-BODIPY-CE uptake in cell lines without impacting SR-B1 protein levels, whereas knockdown of SIK1 attenuated cAMP-stimulated selective HDL-BODIPY-CE uptake. SIK1 forms a complex with SR-B1 by interacting with its cytoplasmic C-terminal domain, and in vitro kinase activity measurements indicate that SIK1 can phosphorylate the C-terminal domain of SR-B1. Among potential phosphorylation sites, SIK1-catalyzed phosphorylation of Ser496 is critical for SIK1 stimulation of the selective CE transport activity of SR-B1. Mutational studies further demonstrated that both the intact catalytic activity of SIK1 and its PKA-catalyzed phosphorylation are essential for SIK1 stimulation of SR-B1 activity. Finally, overexpression of SIK1 caused time-dependent increases in SR-B1-mediated and HDL-supported steroid production in Y1 cells; however, these effects were lost with knockdown of SR-B1. Taken together, these studies establish a role for SIK1 in the positive regulation of selective HDL-CE transport function of SR-B1 and steroidogenesis and suggest a potential mechanism for SIK1 signaling in modulating SR-B1-mediated selective CE uptake and associated steroidogenesis.
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Affiliation(s)
- Zhigang Hu
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System , Palo Alto, California 94304, United States
| | - Jie Hu
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System , Palo Alto, California 94304, United States
| | - Wen-Jun Shen
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System , Palo Alto, California 94304, United States
| | - Fredric B Kraemer
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System , Palo Alto, California 94304, United States
| | - Salman Azhar
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System , Palo Alto, California 94304, United States
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25
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Lee J, Tong T, Takemori H, Jefcoate C. Stimulation of StAR expression by cAMP is controlled by inhibition of highly inducible SIK1 via CRTC2, a co-activator of CREB. Mol Cell Endocrinol 2015; 408:80-9. [PMID: 25662274 PMCID: PMC4417451 DOI: 10.1016/j.mce.2015.01.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 01/15/2015] [Accepted: 01/15/2015] [Indexed: 12/21/2022]
Abstract
In mouse steroidogenic cells the activation of cholesterol metabolism is mediated by steroidogenic acute regulatory protein (StAR). Here, we visualized a coordinated regulation of StAR transcription, splicing and post-transcriptional processing, which are synchronized by salt inducible kinase (SIK1) and CREB-regulated transcription coactivator (CRTC2). To detect primary RNA (pRNA), spliced primary RNA (Sp-RNA) and mRNA in single cells, we generated probe sets by using fluorescence in situ hybridization (FISH). These methods allowed us to address the nature of StAR gene expression and to visualize protein-nucleic acid interactions through direct detection. We show that SIK1 represses StAR expression in Y1 adrenal and MA10 testis cells through inhibition of processing mediated by CRTC2. Digital image analysis matches qPCR analyses of the total cell culture. Evidence is presented for spatially separate accumulation of StAR pRNA and Sp-RNA at the gene loci in the nucleus. These findings establish that cAMP, SIK and CRTC mediate StAR expression through activation of individual StAR gene loci.
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Affiliation(s)
- Jinwoo Lee
- Department of Cell and Regenerative Biology, University of Wisconsin, Madison, WI, USA; Endocrinology and Reproductive Physiology Program, University of Wisconsin, Madison, WI, USA
| | - Tiegang Tong
- Department of Cell and Regenerative Biology, University of Wisconsin, Madison, WI, USA
| | | | - Colin Jefcoate
- Department of Cell and Regenerative Biology, University of Wisconsin, Madison, WI, USA; Endocrinology and Reproductive Physiology Program, University of Wisconsin, Madison, WI, USA; University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
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26
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Itoh Y, Sanosaka M, Fuchino H, Yahara Y, Kumagai A, Takemoto D, Kagawa M, Doi J, Ohta M, Tsumaki N, Kawahara N, Takemori H. Salt-inducible Kinase 3 Signaling Is Important for the Gluconeogenic Programs in Mouse Hepatocytes. J Biol Chem 2015; 290:17879-17893. [PMID: 26048985 DOI: 10.1074/jbc.m115.640821] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Indexed: 01/24/2023] Open
Abstract
Salt-inducible kinases (SIKs), members of the 5'-AMP-activated protein kinase (AMPK) family, are proposed to be important suppressors of gluconeogenic programs in the liver via the phosphorylation-dependent inactivation of the CREB-specific coactivator CRTC2. Although a dramatic phenotype for glucose metabolism has been found in SIK3-KO mice, additional complex phenotypes, dysregulation of bile acids, cholesterol, and fat homeostasis can render it difficult to discuss the hepatic functions of SIK3. The aim of this study was to examine the cell autonomous actions of SIK3 in hepatocytes. To eliminate systemic effects, we prepared primary hepatocytes and screened the small compounds suppressing SIK3 signaling cascades. SIK3-KO primary hepatocytes produced glucose more quickly after treatment with the cAMP agonist forskolin than the WT hepatocytes, which was accompanied by enhanced gluconeogenic gene expression and CRTC2 dephosphorylation. Reporter-based screening identified pterosin B as a SIK3 signaling-specific inhibitor. Pterosin B suppressed SIK3 downstream cascades by up-regulating the phosphorylation levels in the SIK3 C-terminal regulatory domain. When pterosin B promoted glucose production by up-regulating gluconeogenic gene expression in mouse hepatoma AML-12 cells, it decreased the glycogen content and stimulated an association between the glycogen phosphorylase kinase gamma subunit (PHKG2) and SIK3. PHKG2 phosphorylated the peptides with sequences of the C-terminal domain of SIK3. Here we found that the levels of active AMPK were higher both in the SIK3-KO hepatocytes and in pterosin B-treated AML-12 cells than in their controls. These results suggest that SIK3, rather than SIK1, SIK2, or AMPKs, acts as the predominant suppressor in gluconeogenic gene expression in the hepatocytes.
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Affiliation(s)
- Yumi Itoh
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Osaka, 567-0085, Japan
| | - Masato Sanosaka
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Osaka, 567-0085, Japan
| | - Hiroyuki Fuchino
- Research Center for Medicinal Plant Resources, Tsukuba Division, Ibaraki, 305-0843, Japan
| | - Yasuhito Yahara
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan
| | - Ayako Kumagai
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Osaka, 567-0085, Japan
| | - Daisaku Takemoto
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Osaka, 567-0085, Japan; Department of Life Science and Biotechnology, Kansai University, Osaka 564-8680, Japan
| | - Mai Kagawa
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Osaka, 567-0085, Japan
| | - Junko Doi
- Department of Food and Nutrition, Senri Kinran University, Osaka, 565-0873 Japan
| | - Miho Ohta
- Department of Nutrition and Health, Faculty of Human Development, Soai University, Osaka, 559-0033, Japan
| | - Noriyuki Tsumaki
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan
| | - Nobuo Kawahara
- Research Center for Medicinal Plant Resources, Tsukuba Division, Ibaraki, 305-0843, Japan
| | - Hiroshi Takemori
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Osaka, 567-0085, Japan.
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Venkatesan A, Tripathi S, Sanz de Galdeano A, Blondé W, Lægreid A, Mironov V, Kuiper M. Finding gene regulatory network candidates using the gene expression knowledge base. BMC Bioinformatics 2014; 15:386. [PMID: 25490885 PMCID: PMC4279962 DOI: 10.1186/s12859-014-0386-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 11/14/2014] [Indexed: 12/17/2022] Open
Abstract
Background Network-based approaches for the analysis of large-scale genomics data have become well established. Biological networks provide a knowledge scaffold against which the patterns and dynamics of ‘omics’ data can be interpreted. The background information required for the construction of such networks is often dispersed across a multitude of knowledge bases in a variety of formats. The seamless integration of this information is one of the main challenges in bioinformatics. The Semantic Web offers powerful technologies for the assembly of integrated knowledge bases that are computationally comprehensible, thereby providing a potentially powerful resource for constructing biological networks and network-based analysis. Results We have developed the Gene eXpression Knowledge Base (GeXKB), a semantic web technology based resource that contains integrated knowledge about gene expression regulation. To affirm the utility of GeXKB we demonstrate how this resource can be exploited for the identification of candidate regulatory network proteins. We present four use cases that were designed from a biological perspective in order to find candidate members relevant for the gastrin hormone signaling network model. We show how a combination of specific query definitions and additional selection criteria derived from gene expression data and prior knowledge concerning candidate proteins can be used to retrieve a set of proteins that constitute valid candidates for regulatory network extensions. Conclusions Semantic web technologies provide the means for processing and integrating various heterogeneous information sources. The GeXKB offers biologists such an integrated knowledge resource, allowing them to address complex biological questions pertaining to gene expression. This work illustrates how GeXKB can be used in combination with gene expression results and literature information to identify new potential candidates that may be considered for extending a gene regulatory network. Electronic supplementary material The online version of this article (doi:10.1186/s12859-014-0386-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Aravind Venkatesan
- Department of Biology, Norwegian University of Science and Technology (NTNU), N-7491, Trondheim, Norway.
| | - Sushil Tripathi
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7489, Trondheim, Norway.
| | | | - Ward Blondé
- Department of Biology, Norwegian University of Science and Technology (NTNU), N-7491, Trondheim, Norway.
| | - Astrid Lægreid
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7489, Trondheim, Norway.
| | - Vladimir Mironov
- Department of Biology, Norwegian University of Science and Technology (NTNU), N-7491, Trondheim, Norway.
| | - Martin Kuiper
- Department of Biology, Norwegian University of Science and Technology (NTNU), N-7491, Trondheim, Norway.
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28
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Selvik LKM, Rao S, Steigedal TS, Haltbakk I, Misund K, Bruland T, Prestvik WS, Lægreid A, Thommesen L. Salt-inducible kinase 1 (SIK1) is induced by gastrin and inhibits migration of gastric adenocarcinoma cells. PLoS One 2014; 9:e112485. [PMID: 25384047 PMCID: PMC4226541 DOI: 10.1371/journal.pone.0112485] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 10/06/2014] [Indexed: 12/21/2022] Open
Abstract
Salt-inducible kinase 1 (SIK1/Snf1lk) belongs to the AMP-activated protein kinase (AMPK) family of kinases, all of which play major roles in regulating metabolism and cell growth. Recent studies have shown that reduced levels of SIK1 are associated with poor outcome in cancers, and that this involves an invasive cellular phenotype with increased metastatic potential. However, the molecular mechanism(s) regulated by SIK1 in cancer cells is not well explored. The peptide hormone gastrin regulates cellular processes involved in oncogenesis, including proliferation, apoptosis, migration and invasion. The aim of this study was to examine the role of SIK1 in gastrin responsive adenocarcinoma cell lines AR42J, AGS-GR and MKN45. We show that gastrin, known to signal through the Gq/G11-coupled CCK2 receptor, induces SIK1 expression in adenocarcinoma cells, and that transcriptional activation of SIK1 is negatively regulated by the Inducible cAMP early repressor (ICER). We demonstrate that gastrin-mediated signalling induces phosphorylation of Liver Kinase 1B (LKB1) Ser-428 and SIK1 Thr-182. Ectopic expression of SIK1 increases gastrin-induced phosphorylation of histone deacetylase 4 (HDAC4) and enhances gastrin-induced transcription of c-fos and CRE-, SRE-, AP1- and NF-κB-driven luciferase reporter plasmids. We also show that gastrin induces phosphorylation and nuclear export of HDACs. Next we find that siRNA mediated knockdown of SIK1 increases migration of the gastric adenocarcinoma cell line AGS-GR. Evidence provided here demonstrates that SIK1 is regulated by gastrin and influences gastrin elicited signalling in gastric adenocarcinoma cells. The results from the present study are relevant for the understanding of molecular mechanisms involved in gastric adenocarcinomas.
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Affiliation(s)
- Linn-Karina M. Selvik
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Department of Technology, Sør-Trøndelag University College, Trondheim, Norway
| | - Shalini Rao
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Department of Technology, Sør-Trøndelag University College, Trondheim, Norway
| | - Tonje S. Steigedal
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Ildri Haltbakk
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Kristine Misund
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Torunn Bruland
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Wenche S. Prestvik
- Department of Technology, Sør-Trøndelag University College, Trondheim, Norway
| | - Astrid Lægreid
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Liv Thommesen
- Department of Technology, Sør-Trøndelag University College, Trondheim, Norway
- * E-mail:
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29
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Jain P, Bhalla US. Transcription control pathways decode patterned synaptic inputs into diverse mRNA expression profiles. PLoS One 2014; 9:e95154. [PMID: 24787753 PMCID: PMC4006808 DOI: 10.1371/journal.pone.0095154] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 03/24/2014] [Indexed: 12/22/2022] Open
Abstract
Synaptic plasticity requires transcription and translation to establish long-term changes that form the basis for long term memory. Diverse stimuli, such as synaptic activity and growth factors, trigger synthesis of mRNA to regulate changes at the synapse. The palette of possible mRNAs is vast, and a key question is how the cell selects which mRNAs to synthesize. To address this molecular decision-making, we have developed a biochemically detailed model of synaptic-activity triggered mRNA synthesis. We find that there are distinct time-courses and amplitudes of different branches of the mRNA regulatory signaling pathways, which carry out pattern-selective combinatorial decoding of stimulus patterns into distinct mRNA subtypes. Distinct, simultaneously arriving input patterns that impinge on the transcriptional control network interact nonlinearly to generate novel mRNA combinations. Our model combines major regulatory pathways and their interactions connecting synaptic input to mRNA synthesis. We parameterized and validated the model by incorporating data from multiple published experiments. The model replicates outcomes of knockout experiments. We suggest that the pattern-selectivity mechanisms analyzed in this model may act in many cell types to confer the capability to decode temporal patterns into combinatorial mRNA expression.
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Affiliation(s)
- Pragati Jain
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
- Manipal University, Manipal, India
| | - Upinder S. Bhalla
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
- * E-mail:
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30
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Liu Y, Smith LI, Huang V, Poon V, Coello A, Olah M, Spiga F, Lightman S, Aguilera G. Transcriptional regulation of episodic glucocorticoid secretion. Mol Cell Endocrinol 2013; 371:62-70. [PMID: 23138111 PMCID: PMC3582781 DOI: 10.1016/j.mce.2012.10.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 10/02/2012] [Accepted: 10/03/2012] [Indexed: 01/13/2023]
Abstract
Circadian and ultradian variations of basal glucocorticoid secretion and transient elevations during stress are essential for homeostasis. Using intronic qRT-PCR to measure changes in primary transcript (hnRNA) we have shown that secretory events induced by stress or ACTH injection are followed by episodic increases in transcription of rate limiting steroidogenic proteins, such as steroidogenic acute regulatory protein (StAR), cytochrome P450 side chain cleavage and melanocortin receptor associated protein. These transcriptional episodes imply rapid turnover of steroidogenic proteins and the need of de novo synthesis following each secretory event. In addition to episodic ACTH secretion, it is likely that intracellular feedback mechanisms at the adrenal fasciculata level contribute to the generation of episodes of transcription. The time relationship between activation and translocation of the CREB co-activator, transducer of regulated CREB activity (TORC) to the nucleus preceding transcriptional episodes suggest the involvement of TORC in the transcriptional activation of StAR and other steroidogenic proteins.
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Affiliation(s)
- Ying Liu
- Section on Endocrine Physiology, National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Lorna I Smith
- Section on Endocrine Physiology, National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Victoria Huang
- Section on Endocrine Physiology, National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Victoria Poon
- Section on Endocrine Physiology, National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Ana Coello
- Section on Endocrine Physiology, National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Mark Olah
- Section on Endocrine Physiology, National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Francesca Spiga
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Stafford Lightman
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Greti Aguilera
- Section on Endocrine Physiology, National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
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31
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Finsterwald C, Carrard A, Martin JL. Role of salt-inducible kinase 1 in the activation of MEF2-dependent transcription by BDNF. PLoS One 2013; 8:e54545. [PMID: 23349925 PMCID: PMC3551851 DOI: 10.1371/journal.pone.0054545] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 12/14/2012] [Indexed: 01/02/2023] Open
Abstract
Substantial evidence supports a role for myocyte enhancer factor 2 (MEF2)-mediated transcription in neuronal survival, differentiation and synaptic function. In developing neurons, it has been shown that MEF2-dependent transcription is regulated by neurotrophins. Despite these observations, little is known about the cellular mechanisms by which neurotrophins activate MEF2 transcriptional activity. In this study, we examined the role of salt-inducible kinase 1 (SIK1), a member of the AMP-activated protein kinase (AMPK) family, in the regulation of MEF2-mediated transcription by the neurotrophin brain-derived neurotrophic factor (BDNF). We show that BDNF increases the expression of SIK1 in primary cultures of rat cortical neurons through the extracellular signal-regulated kinase 1/2 (ERK1/2)-signaling pathway. In addition to inducing SIK1 expression, BDNF triggers the phosphorylation of SIK1 at Thr182 and its translocation from the cytoplasm to the nucleus of cortical neurons. The effects of BDNF on the expression, phosphorylation and, translocation of SIK1 are followed by the phosphorylation and nuclear export of histone deacetylase 5 (HDAC5). Blockade of SIK activity with a low concentration of staurosporine abolished BDNF-induced phosphorylation and nuclear export of HDAC5 in cortical neurons. Importantly, stimulation of HDAC5 phosphorylation and nuclear export by BDNF is accompanied by the activation of MEF2-mediated transcription, an effect that is suppressed by staurosporine. Consistent with these data, BDNF induces the expression of the MEF2 target genes Arc and Nur77, in a staurosporine-sensitive manner. In further support of the role of SIK1 in the regulation of MEF2-dependent transcription by BDNF, we found that expression of wild-type SIK1 or S577A SIK1, a mutated form of SIK1 which is retained in the nucleus of transfected cells, is sufficient to enhance MEF2 transcriptional activity in cortical neurons. Together, these data identify a previously unrecognized mechanism by which SIK1 mediates the activation of MEF2-dependent transcription by BDNF.
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Affiliation(s)
- Charles Finsterwald
- Center for Psychiatric Neuroscience, Department of Psychiatry-CHUV, Prilly-Lausanne, Switzerland
| | - Anthony Carrard
- Center for Psychiatric Neuroscience, Department of Psychiatry-CHUV, Prilly-Lausanne, Switzerland
| | - Jean-Luc Martin
- Center for Psychiatric Neuroscience, Department of Psychiatry-CHUV, Prilly-Lausanne, Switzerland
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MacKenzie KF, Clark K, Naqvi S, McGuire VA, Nöehren G, Kristariyanto Y, van den Bosch M, Mudaliar M, McCarthy PC, Pattison MJ, Pedrioli PGA, Barton GJ, Toth R, Prescott A, Arthur JSC. PGE(2) induces macrophage IL-10 production and a regulatory-like phenotype via a protein kinase A-SIK-CRTC3 pathway. THE JOURNAL OF IMMUNOLOGY 2012; 190:565-77. [PMID: 23241891 DOI: 10.4049/jimmunol.1202462] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The polarization of macrophages into a regulatory-like phenotype and the production of IL-10 plays an important role in the resolution of inflammation. We show in this study that PGE(2), in combination with LPS, is able to promote an anti-inflammatory phenotype in macrophages characterized by high expression of IL-10 and the regulatory markers SPHK1 and LIGHT via a protein kinase A-dependent pathway. Both TLR agonists and PGE(2) promote the phosphorylation of the transcription factor CREB on Ser(133). However, although CREB regulates IL-10 transcription, the mutation of Ser(133) to Ala in the endogenous CREB gene did not prevent the ability of PGE(2) to promote IL-10 transcription. Instead, we demonstrate that protein kinase A regulates the phosphorylation of salt-inducible kinase 2 on Ser(343), inhibiting its ability to phosphorylate CREB-regulated transcription coactivator 3 in cells. This in turn allows CREB-regulated transcription coactivator 3 to translocate to the nucleus where it serves as a coactivator with the transcription factor CREB to induce IL-10 transcription. In line with this, we find that either genetic or pharmacological inhibition of salt-inducible kinases mimics the effect of PGE(2) on IL-10 production.
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Affiliation(s)
- Kirsty F MacKenzie
- Medical Research Council Protein Phosphorylation Unit, Sir James Black Centre, College of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kingdom
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Feng Y, Wang Y, Wang Z, Fang Z, Li F, Gao Y, Liu H, Xiao T, Li F, Zhou Y, Zhai Q, Liu X, Sun Y, Bardeesy N, Wong KK, Chen H, Xiong ZQ, Ji H. The CRTC1-NEDD9 signaling axis mediates lung cancer progression caused by LKB1 loss. Cancer Res 2012; 72:6502-11. [PMID: 23074285 DOI: 10.1158/0008-5472.can-12-1909] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Somatic mutation of the tumor suppressor gene LKB1 occurs frequently in lung cancer where it causes tumor progression and metastasis, but the underlying mechanisms remain mainly unknown. Here, we show that the oncogene NEDD9 is an important downstream mediator of lung cancer progression evoked by LKB1 loss. In de novo mouse models, RNAi-mediated silencing of Nedd9 inhibited lung tumor progression, whereas ectopic NEDD9 expression accelerated this process. Mechanistically, LKB1 negatively regulated NEDD9 transcription by promoting cytosolic translocation of CRTC1 from the nucleus. Notably, ectopic expression of either NEDD9 or CRTC1 partially reversed the inhibitory function of LKB1 on metastasis of lung cancer cells. In clinical specimens, elevated expression of NEDD9 was associated with malignant progression and metastasis. Collectively, our results decipher the mechanism through which LKB1 deficiency promotes lung cancer progression and metastasis, and provide a mechanistic rationale for therapeutic attack of these processes.
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Affiliation(s)
- Yan Feng
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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Ch'ng TH, Uzgil B, Lin P, Avliyakulov NK, O'Dell TJ, Martin KC. Activity-dependent transport of the transcriptional coactivator CRTC1 from synapse to nucleus. Cell 2012; 150:207-21. [PMID: 22770221 DOI: 10.1016/j.cell.2012.05.027] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 04/05/2012] [Accepted: 05/02/2012] [Indexed: 12/30/2022]
Abstract
Long-lasting changes in synaptic efficacy, such as those underlying long-term memory, require transcription. Activity-dependent transport of synaptically localized transcriptional regulators provides a direct means of coupling synaptic stimulation with changes in transcription. The CREB-regulated transcriptional coactivator (CRTC1), which is required for long-term hippocampal plasticity, binds CREB to potently promote transcription. We show that CRTC1 localizes to synapses in silenced hippocampal neurons but translocates to the nucleus in response to localized synaptic stimulation. Regulated nuclear translocation occurs only in excitatory neurons and requires calcium influx and calcineurin activation. CRTC1 is controlled in a dual fashion with activity regulating CRTC1 nuclear translocation and cAMP modulating its persistence in the nucleus. Neuronal activity triggers a complex change in CRTC1 phosphorylation, suggesting that CRTC1 may link specific types of stimuli to specific changes in gene expression. Together, our results indicate that synapse-to-nuclear transport of CRTC1 dynamically informs the nucleus about synaptic activity.
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Affiliation(s)
- Toh Hean Ch'ng
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA 90095-1737, USA
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Abstract
SIK2 (salt-inducible kinase 2) is a member of the AMPK (AMP-activated protein kinase) family of kinases and is highly expressed in adipocytes. We investigated the regulation of SIK2 in adipocytes in response to cellular stimuli with relevance for adipocyte function and/or AMPK signalling. None of the treatments, including insulin, cAMP inducers or AICAR (5-amino-4-imidazolecarboxamide riboside), affected SIK2 activity towards peptide or protein substrates in vitro. However, stimulation with the cAMP-elevating agent forskolin and the β-adrenergic receptor agonist CL 316,243 resulted in a PKA (protein kinase A)-dependent phosphorylation and 14-3-3 binding of SIK2. Phosphopeptide mapping of SIK2 revealed several sites phosphorylated in response to cAMP induction, including Ser358. Site-directed mutagenesis demonstrated that phosphorylation of Ser358, but not the previously reported PKA site Ser587, was required for 14-3-3 binding. Immunocytochemistry illustrated that the localization of exogenously expressed SIK2 in HEK (human embryonic kidney)-293 cells was exclusively cytosolic and remained unchanged after cAMP elevation. Fractionation of adipocytes, however, revealed a significant increase of wild-type, but not Ser358Ala, HA (haemagglutinin)–SIK2 in the cytosol and a concomitant decrease in a particulate fraction after CL 316,243 treatment. This supports a phosphorylation-dependent relocalization in adipocytes. We hypothesize that regulation of SIK2 by cAMP could play a role for the critical effects of this second messenger on lipid metabolism in adipocytes.
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Uebi T, Itoh Y, Hatano O, Kumagai A, Sanosaka M, Sasaki T, Sasagawa S, Doi J, Tatsumi K, Mitamura K, Morii E, Aozasa K, Kawamura T, Okumura M, Nakae J, Takikawa H, Fukusato T, Koura M, Nish M, Hamsten A, Silveira A, Bertorello AM, Kitagawa K, Nagaoka Y, Kawahara H, Tomonaga T, Naka T, Ikegawa S, Tsumaki N, Matsuda J, Takemori H. Involvement of SIK3 in glucose and lipid homeostasis in mice. PLoS One 2012; 7:e37803. [PMID: 22662228 PMCID: PMC3360605 DOI: 10.1371/journal.pone.0037803] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 04/24/2012] [Indexed: 01/20/2023] Open
Abstract
Salt-inducible kinase 3 (SIK3), an AMP-activated protein kinase-related kinase, is induced in the murine liver after the consumption of a diet rich in fat, sucrose, and cholesterol. To examine whether SIK3 can modulate glucose and lipid metabolism in the liver, we analyzed phenotypes of SIK3-deficent mice. Sik3(-/-) mice have a malnourished the phenotype (i.e., lipodystrophy, hypolipidemia, hypoglycemia, and hyper-insulin sensitivity) accompanied by cholestasis and cholelithiasis. The hypoglycemic and hyper-insulin-sensitive phenotypes may be due to reduced energy storage, which is represented by the low expression levels of mRNA for components of the fatty acid synthesis pathways in the liver. The biliary disorders in Sik3(-/-) mice are associated with the dysregulation of gene expression programs that respond to nutritional stresses and are probably regulated by nuclear receptors. Retinoic acid plays a role in cholesterol and bile acid homeostasis, wheras ALDH1a which produces retinoic acid, is expressed at low levels in Sik3(-/-) mice. Lipid metabolism disorders in Sik3(-/-) mice are ameliorated by the treatment with 9-cis-retinoic acid. In conclusion, SIK3 is a novel energy regulator that modulates cholesterol and bile acid metabolism by coupling with retinoid metabolism, and may alter the size of energy storage in mice.
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Affiliation(s)
- Tatsuya Uebi
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Yumi Itoh
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Osamu Hatano
- Department of Anatomy, Nara Medical University, Nara, Japan
| | - Ayako Kumagai
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
- Department of Life Science and Biotechnology, Kansai University, Suita, Osaka, Japan
| | - Masato Sanosaka
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Tsutomu Sasaki
- Department of Neurology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Satoru Sasagawa
- Department of Bone and Cartilage Biology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Junko Doi
- Food and Nutrition, Senri Kinran University, Osaka, Japan
| | - Keita Tatsumi
- Department of Laboratory Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Kuniko Mitamura
- Faculty of Pharmaceutical Sciences, Kinki University, Osaka, Japan
| | - Eiichi Morii
- Department of Pathology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Katsuyuki Aozasa
- Department of Pathology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Tomohiro Kawamura
- Department of General Thoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Meinoshin Okumura
- Department of General Thoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Jun Nakae
- Frontier Medicine on Metabolic Syndrome, Keio University School of Medicine, Tokyo, Japan
| | - Hajime Takikawa
- Department of Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Toshio Fukusato
- Department of Pathology, Teikyo University School of Medicine, Tokyo, Japan
| | - Minako Koura
- Animal Models for Human Diseases, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Mayumi Nish
- Department of Anatomy, Nara Medical University, Nara, Japan
| | - Anders Hamsten
- Cardiovascular Genetics and Genomics, Atherosclerosis Research Unit, Karolinska Institutet, CMM, Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Angela Silveira
- Cardiovascular Genetics and Genomics, Atherosclerosis Research Unit, Karolinska Institutet, CMM, Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Alejandro M. Bertorello
- Membrane Signaling Networks, Atherosclerosis Research Unit, Karolinska Institutet, CMM, Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Kazuo Kitagawa
- Department of Neurology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yasuo Nagaoka
- Department of Life Science and Biotechnology, Kansai University, Suita, Osaka, Japan
| | - Hidehisa Kawahara
- Department of Life Science and Biotechnology, Kansai University, Suita, Osaka, Japan
| | - Takeshi Tomonaga
- Laboratory of Proteome Research, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Tetsuji Naka
- Laboratory for Immune Signal, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Shigeo Ikegawa
- Faculty of Pharmaceutical Sciences, Kinki University, Osaka, Japan
| | - Noriyuki Tsumaki
- Department of Bone and Cartilage Biology, Osaka University Graduate School of Medicine, Osaka, Japan
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, Kyoto, Japan
| | - Junichiro Matsuda
- Animal Models for Human Diseases, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Hiroshi Takemori
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
- * E-mail:
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Liu Y, Poon V, Sanchez-Watts G, Watts AG, Takemori H, Aguilera G. Salt-inducible kinase is involved in the regulation of corticotropin-releasing hormone transcription in hypothalamic neurons in rats. Endocrinology 2012; 153:223-33. [PMID: 22109884 PMCID: PMC3249682 DOI: 10.1210/en.2011-1404] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Activation of CRH transcription requires phosphorylation of cAMP response element-binding protein (CREB) and translocation of the CREB coactivator, transducer of regulated CREB activity (TORC) from cytoplasm to nucleus. In basal conditions, transcription is low because TORC remains in the cytoplasm, inactivated by phosphorylation through Ser/Thr protein kinases of the AMP-dependent protein kinases (AMPK) family, including salt-inducible kinase (SIK). To determine which kinase is responsible for TORC phosphorylation in CRH neurons, we measured SIK1 and SIK2 mRNA in the hypothalamic paraventricular nucleus of rats by in situ hybridization. In basal conditions, low mRNA levels of the two kinases were found in the dorsomedial paraventricular nucleus, consistent with location in CRH neurons. One hour of restraint stress increased SIK1 mRNA levels, whereas SIK2 mRNA showed only minor increases. In 4B hypothalamic neurons, or primary cultures, SIK1 mRNA (but not SIK2 mRNA) was inducible by the cAMP stimulator, forskolin. Overexpression of either SIK1 or SIK2 in 4B cells reduced nuclear TORC2 levels (Western blot) and inhibited forskolin-stimulated CRH transcription (luciferase assay). Conversely, the nonselective SIK inhibitor, staurosporine, increased nuclear TORC2 content and stimulated CRH transcription in 4Bcells and primary neuronal cultures (heteronuclear RNA). Unexpectedly, in 4B cells specific short hairpin RNA knockdown of endogenous SIK2 but not SIK1 induced nuclear translocation of TORC2 and CRH transcription, suggesting that SIK2 mediates TORC inactivation in basal conditions, whereas induction of SIK1 limits transcriptional activation. The study provides evidence that SIK represses CRH transcription by inactivating TORC, providing a potential mechanism for rapid on/off control of CRH transcription.
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Affiliation(s)
- Ying Liu
- Section on Endocrine Physiology, Developmental Endocrinology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 10 Center Drive, Bethesda, Maryland 20892, USA
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Kumar V, Fahey PG, Jong YJI, Ramanan N, O'Malley KL. Activation of intracellular metabotropic glutamate receptor 5 in striatal neurons leads to up-regulation of genes associated with sustained synaptic transmission including Arc/Arg3.1 protein. J Biol Chem 2011; 287:5412-25. [PMID: 22179607 DOI: 10.1074/jbc.m111.301366] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The G-protein coupled receptor, metabotropic glutamate receptor 5 (mGluR5), is expressed on both cell surface and intracellular membranes in striatal neurons. Using pharmacological tools to differentiate membrane responses, we previously demonstrated that cell surface mGluR5 triggers rapid, transient cytoplasmic Ca(2+) rises, resulting in c-Jun N-terminal kinase, Ca(2+)/calmodulin-dependent protein kinase, and cyclic adenosine 3',5'-monophosphate-responsive element-binding protein (CREB) phosphorylation, whereas stimulation of intracellular mGluR5 induces long, sustained Ca(2+) responses leading to the phosphorylation of extracellular signal-regulated kinase (ERK1/2) and Elk-1 (Jong, Y. J., Kumar, V., and O'Malley, K. L. (2009) J. Biol. Chem. 284, 35827-35838). Using pharmacological, genetic, and bioinformatics approaches, the current findings show that both receptor populations up-regulate many immediate early genes involved in growth and differentiation. Activation of intracellular mGluR5 also up-regulates genes involved in synaptic plasticity including activity-regulated cytoskeletal-associated protein (Arc/Arg3.1). Mechanistically, intracellular mGluR5-mediated Arc induction is dependent upon extracellular and intracellular Ca(2+) and ERK1/2 as well as calmodulin-dependent kinases as known chelators, inhibitors, and a dominant negative Ca(2+)/calmodulin-dependent protein kinase II construct block Arc increases. Moreover, intracellular mGluR5-induced Arc expression requires the serum response transcription factor (SRF) as wild type but not SRF-deficient neurons show this response. Finally, increased Arc levels due to high K(+) depolarization is significantly reduced in response to a permeable but not an impermeable mGluR5 antagonist. Taken together, these data highlight the importance of intracellular mGluR5 in the cascade of events associated with sustained synaptic transmission.
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Affiliation(s)
- Vikas Kumar
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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A potent inhibitor of SIK2, 3, 3', 7-trihydroxy-4'-methoxyflavon (4'-O-methylfisetin), promotes melanogenesis in B16F10 melanoma cells. PLoS One 2011; 6:e26148. [PMID: 22022544 PMCID: PMC3192784 DOI: 10.1371/journal.pone.0026148] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 09/20/2011] [Indexed: 11/24/2022] Open
Abstract
Flavonoids, which are plant polyphenols, are now widely used in supplements and cosmetics. Here, we report that 4′-methylflavonoids are potent inducers of melanogenesis in B16F10 melanoma cells and in mice. We recently identified salt inducible kinase 2 (SIK2) as an inhibitor of melanogenesis via the suppression of the cAMP-response element binding protein (CREB)-specific coactivator 1 (TORC1). Using an in vitro kinase assay targeting SIK2, we identified fisetin as a candidate inhibitor, possibly being capable of promoting melanogenesis. However, fisetin neither inhibited the CREB-inhibitory activity of SIK2 nor promoted melanogenesis in B16F10 melanoma cells. Conversely, mono-methyl-flavonoids, such as diosmetin (4′-O-metlylluteolin), efficiently inhibited SIK2 and promoted melanogenesis in this cell line. The cAMP-CREB system is impaired in Ay/a mice and these mice have yellow hair as a result of pheomelanogenesis, while Sik2+/−; Ay/a mice also have yellow hair, but activate eumelanogenesis when they are exposed to CREB stimulators. Feeding Sik2+/−; Ay/a mice with diets supplemented with fisetin resulted in their hair color changing to brown, and metabolite analysis suggested the presence of mono-methylfisetin in their feces. Thus, we decided to synthesize 4′-O-methylfisetin (4′MF) and found that 4′MF strongly induced melanogenesis in B16F10 melanoma cells, which was accompanied by the nuclear translocation of TORC1, and the 4′-O-methylfisetin-induced melanogenic programs were inhibited by the overexpression of dominant negative TORC1. In conclusion, compounds that modulate SIK2 cascades are helpful to regulate melanogenesis via TORC1 without affecting cAMP levels, and the combined analysis of Sik2+/− mice and metabolites from these mice is an effective strategy to identify beneficial compounds to regulate CREB activity in vivo.
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Thompson CL, Wisor JP, Lee CK, Pathak SD, Gerashchenko D, Smith KA, Fischer SR, Kuan CL, Sunkin SM, Ng LL, Lau C, Hawrylycz M, Jones AR, Kilduff TS, Lein ES. Molecular and anatomical signatures of sleep deprivation in the mouse brain. Front Neurosci 2010; 4:165. [PMID: 21088695 PMCID: PMC2981377 DOI: 10.3389/fnins.2010.00165] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2010] [Accepted: 08/23/2010] [Indexed: 11/13/2022] Open
Abstract
Sleep deprivation (SD) leads to a suite of cognitive and behavioral impairments, and yet the molecular consequences of SD in the brain are poorly understood. Using a systematic immediate-early gene (IEG) mapping to detect neuronal activation, the consequences of SD were mapped primarily to forebrain regions. SD was found to both induce and suppress IEG expression (and thus neuronal activity) in subregions of neocortex, striatum, and other brain regions. Laser microdissection and cDNA microarrays were used to identify the molecular consequences of SD in seven brain regions. In situ hybridization (ISH) for 222 genes selected from the microarray data and other sources confirmed that robust molecular changes were largely restricted to the forebrain. Analysis of the ISH data for 222 genes (publicly accessible at http://sleep.alleninstitute.org) provided a molecular and anatomic signature of the effects of SD on the brain. The suprachiasmatic nucleus (SCN) and the neocortex exhibited differential regulation of the same genes, such that in the SCN genes exhibited time-of-day effects while in the neocortex, genes exhibited only SD and waking (W) effects. In the neocortex, SD activated gene expression in areal-, layer-, and cell type-specific manner. In the forebrain, SD preferentially activated excitatory neurons, as demonstrated by double-labeling, except for striatum which consists primarily of inhibitory neurons. These data provide a characterization of the anatomical and cell type-specific signatures of SD on neuronal activity and gene expression that may account for the associated cognitive and behavioral effects.
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Uebi T, Tamura M, Horike N, Hashimoto YK, Takemori H. Phosphorylation of the CREB-specific coactivator TORC2 at Ser(307) regulates its intracellular localization in COS-7 cells and in the mouse liver. Am J Physiol Endocrinol Metab 2010; 299:E413-25. [PMID: 20551288 DOI: 10.1152/ajpendo.00525.2009] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The CREB-specific coactivator TORC2 (also known as CRTC2) upregulates gluconeogenic gene expression in the liver. Salt-inducible kinase (SIK) family enzymes inactivate TORC2 through phosphorylation and localize it in the cytoplasm. Ser(171) and Ser(275) were found to be phosphorylated in pancreatic beta-cells. Calcineurin (Cn) is proposed as the Ser(275) phosphatase, because its inhibitor cyclosporin A (CsA) stabilizes phospho-Ser(275) and retains TORC2 in the cytoplasm. Because the regulation of dephosphorylation at Ser(171) has not been fully clarified, we performed experiments with a range of doses of okadaic acid (OA), an inhibitor of PP2A/PP1, and with overexpression of various phosphatases and found that PP1 functions as an activator for TORC2, whereas PP2A acts as an inhibitor. In further studies using TORC2 mutants, we detected a disassociation between the intracellular distribution and the transcription activity of TORC2. Additional mutant analyses suggested the presence of a third phosphorylation site, Ser(307). The Ser(307)-disrupted TORC2 was constitutively localized in the nucleus, but its coactivator activity was normally suppressed by SIK1 in COS-7 cells. CsA, but not OA, stabilized the phosphogroup at Ser(307), suggesting that differential dephosphorylation at Ser(171) and Ser(307) cooperatively regulate TORC2 activity and that the nuclear localization of TORC2 is insufficient to function as a coactivator. Because the COS-7 cell line may not possess signaling cascades for gluconeogenic programs, we next examined the importance of Ser(307) and Ser(171) for TORC2's function in mouse liver. Levels of phosphorylation at Ser(171) and Ser(307) changed in response to fasting or fed conditions and insulin resistance of the mouse liver, which were modified by treatment with CsA/OA and by overexpression of PP1/PP2A/Cn. These results suggest that multiple phosphorylation sites and their phosphatases may play important roles in regulating TORC2/CREB-mediated gluconeogenic programs in the liver.
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Affiliation(s)
- Tatsuya Uebi
- National Institute of Biomedical Innovation, Osaka, Japan
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Horike N, Kumagai A, Shimono Y, Onishi T, Itoh Y, Sasaki T, Kitagawa K, Hatano O, Takagi H, Susumu T, Teraoka H, Kusano KI, Nagaoka Y, Kawahara H, Takemori H. Downregulation of SIK2 expression promotes the melanogenic program in mice. Pigment Cell Melanoma Res 2010; 23:809-19. [PMID: 20819186 DOI: 10.1111/j.1755-148x.2010.00760.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
cAMP response element-binding protein (CREB) promotes melanogenesis by inducing microphthalmia-associated transcription factor (Mitf ) gene expression. We report here that the CREB-specific coactivator TORC and its repressor, salt-inducible kinase 2 (SIK2), are fundamental determinants of the melanogenic program in mice. Exposure of B16 melanoma cells to ultraviolet (UV) light results in the immediate nuclear translocation of TORC1, which is inhibited by SIK2. Overexpression of dominant-negative TORC1 also inhibits UV-induced Mitf gene expression and melanogenesis. α-MSH signaling regulates hair pigmentation, and the decrease in α-MSH activity in hair follicle melanocytes switches the melanin synthesis from eumelanin (black) to pheomelanin (yellow). Mice with the lethal yellow allele of agouti (A(y)) have yellow hair because of impaired activation of the α-MSH receptor. To examine the involvement of SIK2 in the regulation of the melanogenesis switch in vivo, we prepared SIK2-knockout mice, and the Sik2(-/-) genotype was introduced into A(y)/a mice. The resultant Sik2(-/-); A(y)/a mice had brown hair, indicating that SIK2 represses eumelanogenesis in mice.
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Affiliation(s)
- Nanao Horike
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Saito, Ibaraki, Osaka, Japan
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Lee JM, Seo WY, Song KH, Chanda D, Kim YD, Kim DK, Lee MW, Ryu D, Kim YH, Noh JR, Lee CH, Chiang JYL, Koo SH, Choi HS. AMPK-dependent repression of hepatic gluconeogenesis via disruption of CREB.CRTC2 complex by orphan nuclear receptor small heterodimer partner. J Biol Chem 2010; 285:32182-91. [PMID: 20688914 DOI: 10.1074/jbc.m110.134890] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Orphan nuclear receptor small heterodimer partner (SHP) plays a key role in transcriptional repression of gluconeogenic enzyme gene expression. Here, we show that SHP inhibited protein kinase A-mediated transcriptional activity of cAMP-response element-binding protein (CREB), a major regulator of glucose metabolism, to modulate hepatic gluconeogenic gene expression. Deletion analysis of phosphoenolpyruvate carboxykinase (PEPCK) promoter demonstrated that SHP inhibited forskolin-mediated induction of PEPCK gene transcription via inhibition of CREB transcriptional activity. In vivo imaging demonstrated that SHP inhibited CREB-regulated transcription coactivator 2 (CRTC2)-mediated cAMP-response element-driven promoter activity. Furthermore, overexpression of SHP using adenovirus SHP decreased CRTC2-dependent elevations in blood glucose levels and PEPCK or glucose-6-phosphatase (G6Pase) expression in mice. SHP and CREB physically interacted and were co-localized in vivo. Importantly, SHP inhibited both wild type CRTC2 and S171A (constitutively active form of CRTC2) coactivator activity and disrupted CRTC2 recruitment on the PEPCK gene promoter. In addition, metformin or overexpression of a constitutively active form of AMPK (Ad-CA-AMPK) inhibited S171A-mediated PEPCK and G6Pase gene expression, and hepatic glucose production and knockdown of SHP partially relieved the metformin- and Ad-CA-AMPK-mediated repression of hepatic gluconeogenic enzyme gene expression in primary rat hepatocytes. In conclusion, our results suggest that a delayed effect of metformin-mediated induction of SHP gene expression inhibits CREB-dependent hepatic gluconeogenesis.
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Affiliation(s)
- Ji-Min Lee
- Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea
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Yuan J, Liu X, Wu AW, McGonagill PW, Keller MJ, Galle CS, Meier JL. Breaking human cytomegalovirus major immediate-early gene silence by vasoactive intestinal peptide stimulation of the protein kinase A-CREB-TORC2 signaling cascade in human pluripotent embryonal NTera2 cells. J Virol 2009; 83:6391-403. [PMID: 19369332 PMCID: PMC2698552 DOI: 10.1128/jvi.00061-09] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2009] [Accepted: 04/07/2009] [Indexed: 12/31/2022] Open
Abstract
The triggering mechanisms underlying reactivation of human cytomegalovirus (HCMV) in latently infected persons are unclear. During latency, HCMV major immediate-early (MIE) gene expression breaks silence to initiate viral reactivation. Using quiescently HCMV-infected human pluripotent embryonal NTera2 cells (NT2) to model HCMV reactivation, we show that vasoactive intestinal peptide (VIP), an immunomodulatory neuropeptide, immediately and dose-dependently (1 to 500 nM) activates HCMV MIE gene expression. This response requires the MIE enhancer cyclic AMP response elements (CRE). VIP quickly elevates CREB Ser133 and ATF-1 Ser63 phosphorylation levels, although the CREB Ser133 phosphorylation level is substantial at baseline. VIP does not change the level of HCMV genomes in nuclei, Oct4 (pluripotent cell marker), or hDaxx (cellular repressor of HCMV gene expression). VIP-activated MIE gene expression is mediated by cellular protein kinase A (PKA), CREB, and TORC2. VIP induces PKA-dependent TORC2 Ser171 dephosphorylation and nuclear entry, which likely enables MIE gene activation, as TORC2 S171A (devoid of Ser171 phosphorylation) exhibits enhanced nuclear entry and desilences the MIE genes in the absence of VIP stimulation. In conclusion, VIP stimulation of the PKA-CREB-TORC2 signaling cascade activates HCMV CRE-dependent MIE gene expression in quiescently infected NT2 cells. We speculate that neurohormonal stimulation via this signaling cascade is a possible means for reversing HCMV silence in vivo.
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Affiliation(s)
- Jinxiang Yuan
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
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47
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Muraoka M, Fukushima A, Viengchareun S, Lombès M, Kishi F, Miyauchi A, Kanematsu M, Doi J, Kajimura J, Nakai R, Uebi T, Okamoto M, Takemori H. Involvement of SIK2/TORC2 signaling cascade in the regulation of insulin-induced PGC-1alpha and UCP-1 gene expression in brown adipocytes. Am J Physiol Endocrinol Metab 2009; 296:E1430-9. [PMID: 19351809 DOI: 10.1152/ajpendo.00024.2009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Salt-inducible kinase 2 (SIK2) is expressed abundantly in adipose tissues and represses cAMP-response element-binding protein (CREB)-mediated gene expression by phosphorylating the coactivator transducer of regulated CREB activity (TORC2). Phosphorylation at Ser(587) of SIK2 diminishes its TORC2 phosphorylation activity. In 3T3-L1 white adipocytes, SIK2 downregulates lipogenic gene in response to nutritional stresses. To investigate the impact of SIK2 on the function of brown adipose tissue (BAT), we used T37i brown adipocytes, mice with diet-induced obesity, and SIK2 mutant (S587A) transgenic mice. When T37i adipocytes were treated with insulin, the levels of peroxisome proliferator-activated receptor-coactivator-1alpha (PGC-1alpha) and uncoupling protein-1 (UCP-1) mRNA were increased, and the induction was inhibited by overexpression of SIK2 (S587A) mutant or dominant-negative CREB. Insulin enhanced SIK2 phosphorylation at Ser(587), which was accompanied by decrease in phospho-TORC2. Similarly, the decrease in the level of SIK2 phosphorylation at Ser(587) was observed in the BAT of mice with diet-induced obesity, which was negatively correlated with TORC2 phosphorylation. To confirm the negative correlation between SIK2 phosphorylation at Ser(587) and TORC2 phosphorylation in BAT, SIK2 mutant (S587A) was overexpressed in adipose tissues by using the adipocyte fatty acid-binding protein 2 promoter. The expression of recombinant SIK2 (S587A) was restricted to BAT, and the levels of phospho-TORC2 were elevated in BAT of transgenic mice. Male transgenic mice developed high-fat diet-induced obesity, and their BAT expressed low levels of PGC-1alpha and UCP-1 mRNA, suggesting that SIK2-TORC2 cascade may be important for the regulation of PGC-1alpha and UCP-1 gene expression in insulin signaling in BAT.
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Affiliation(s)
- Masaaki Muraoka
- Laboratory of Cell Signaling and Metabolism, National Institute of Biomedical Innovation, 7-6-8, Asagi, Saito, Ibaraki, Osaka 567-0085, Japan
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48
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TORC1 regulates activity-dependent CREB-target gene transcription and dendritic growth of developing cortical neurons. J Neurosci 2009; 29:2334-43. [PMID: 19244510 DOI: 10.1523/jneurosci.2296-08.2009] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
CREB-target gene transcription during neuronal excitation is important for many aspects of neuronal development and function, including dendrite morphogenesis. However, the signaling events that regulate cAMP response element-binding protein (CREB)-mediated gene transcription during dendritic development are not well understood. Herein we report that the CREB coactivator TORC1 (transducer of regulated CREB 1) is required for activity-dependent CREB-target gene expression and dendrite growth in developing cortical neurons. Ca(2+) influx via voltage-gated calcium channels induced TORC1 dephosphorylation and translocation into the nucleus in a calcineurin-dependent manner. Nuclear accumulation of TORC1 initiated the expression of CREB-target genes, including salt-inducible kinase 1 (SIK1). In response of persistent depolarization, de novo SIK1 protein in turn promoted TORC1 phosphorylation and consequent depletion of nucleus-localized TORC1. SIK1 induction thus appears to act as a negative feedback signal that prevents persistent CREB/TORC1-dependent transcription in the face of long-lasting neuronal activity. Overexpressing wild type TORC1 promoted basal as well as activity-induced dendritic growth, whereas expressing a dominant-negative form of TORC1 or downregulating TORC1 inhibited activity-dependent dendritic growth in vitro and in vivo. Together, these results suggest that neuronal activity-dependent dendritic growth in developing cortical neurons relies on transient TORC1-mediated CREB-target gene transcription.
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Takemori H, Katoh Hashimoto Y, Nakae J, Olson EN, Okamoto M. Inactivation of HDAC5 by SIK1 in AICAR-treated C2C12 myoblasts. Endocr J 2009; 56:121-30. [PMID: 18946175 DOI: 10.1507/endocrj.k08e-173] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Salt inducible kinase (SIK) 1, a member of the AMP-activated kinase (AMPK) family, is activated by the AMPK-activator LKB1 which phosphorylates SIK1 at Thr182. The activated SIK1 then auto-phosphorylates its Ser186 located at the +4 position of Thr182. The phospho-Ser186 is essential for sustained activity of SIK1, which is maintained by sequential phosphorylation at Ser186-Thr182 by glycogen synthase kinase (GSK)-3beta. Meanwhile, SIK1 represses the transcription factor cAMP-response element binding protein (CREB) by phosphorylating its co-activator transducer of regulated CREB activity (TORC). Recently, histone deacetylase (HDAC) 5 was identified as a new substrate of SIK1. Inhibition of SIK1 or AMPK results in the stimulation of glyconeogensis in the liver by enhancing dephosphorylation of TORC2 followed by up-regulation of peroxisome proliferator-activated receptor coactivator (PGC)-1alpha gene expression. However, expression of the PGC-1alpha gene has been found to be repressed in LKB1-defective muscle cells. Our findings show that the AMPK agonist 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside (AICAR)-dependent expression of PGC-1alpha is diminished by inhibitors of GSK-3beta or SIKs in C2C12 myoblasts. Treatment with AICAR or the overexpression of SIK1 induces nuclear export of HDAC5 followed by the activation of myogenic transcription factor (MEF)-2C. The levels of phosphorylation at Thr182 and Ser186 of SIK1 in AICAR-treated C2C12 cells are elevated, and GSK-3beta enzyme purified from AICAR-treated cells shows enhanced phosphorylation activity of SIK1 in vitro. These observations suggest that GSK-3 beta and SIK1 may play important roles in the regulation of PGC-1alpha gene expression by inactivating HDAC5 followed by activation of MEF2C.
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Affiliation(s)
- Hiroshi Takemori
- Laboratory of Cell Signaling and Metabolism, National Institute of Biomedical Innovation, Osaka, Japan
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50
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Hashimoto YK, Satoh T, Okamoto M, Takemori H. Importance of autophosphorylation at Ser186 in the A-loop of salt inducible kinase 1 for its sustained kinase activity. J Cell Biochem 2008; 104:1724-39. [PMID: 18348280 DOI: 10.1002/jcb.21737] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Autophosphorylation is an important mechanism by which protein kinases regulate their own biological activities. Salt inducible kinase 1 (SIK1) is a regulator in the feedback cascades of cAMP-mediated gene expression, while its kinase domain also features autophosphorylation activity. We provide evidence that Ser186 in the activation loop is the site of autophosphorylation and essential for the kinase activity. Ser186 is located at the +4 position of the critical Thr residue Thr182, which is phosphorylated by upstream kinases such as LKB1. The relationship between phosphorylation at Ser186 and at Thr182 in COS-7 cells indicates that the former is a prerequisite for the latter. Glycogen synthase kinase-3beta (GSK-3beta) phosphorylates Ser/Thr residues located at the fourth position ahead of the pre-phosphorylated Ser/Thr residues, and inhibitors of GSK-3beta reduce the phosphorylation at Thr182. The results of an in vitro reconstitution assay also indicate that GSK-3beta could be the SIK1 kinase. However, overexpression and knockdown of GSK-3beta in LKB1-defective HeLa cells suggests that GSK-3beta alone may not be able to phosphorylate or activate SIK1, indicating that LKB1 may play a crucial role by phosphorylating SIK1 at Thr182, possibly as an initiator of the autophosphorylation cascade, and GSK-3beta may phosphorylate SIK1 at Thr182 by recognizing the priming-autophosphorylation at Ser186 in cultured cells. This may also be the case for the other isoform SIK2, but not for SIK3.
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Affiliation(s)
- Yoshiko Katoh Hashimoto
- Laboratory of Cell Signaling and Metabolism, National Institute of Biomedical Innovation, Osaka 567-0085, Japan
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