1
|
Lu H, Jiang J, Min J, Huang X, McLeod P, Liu W, Haig A, Gunaratnam L, Jevnikar AM, Zhang ZX. The CaMK Family Differentially Promotes Necroptosis and Mouse Cardiac Graft Injury and Rejection. Int J Mol Sci 2024; 25:4428. [PMID: 38674016 DOI: 10.3390/ijms25084428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 03/27/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
Organ transplantation is associated with various forms of programmed cell death which can accelerate transplant injury and rejection. Targeting cell death in donor organs may represent a novel strategy for preventing allograft injury. We have previously demonstrated that necroptosis plays a key role in promoting transplant injury. Recently, we have found that mitochondria function is linked to necroptosis. However, it remains unknown how necroptosis signaling pathways regulate mitochondrial function during necroptosis. In this study, we investigated the receptor-interacting protein kinase 3 (RIPK3) mediated mitochondrial dysfunction and necroptosis. We demonstrate that the calmodulin-dependent protein kinase (CaMK) family members CaMK1, 2, and 4 form a complex with RIPK3 in mouse cardiac endothelial cells, to promote trans-phosphorylation during necroptosis. CaMK1 and 4 directly activated the dynamin-related protein-1 (Drp1), while CaMK2 indirectly activated Drp1 via the phosphoglycerate mutase 5 (PGAM5). The inhibition of CaMKs restored mitochondrial function and effectively prevented endothelial cell death. CaMKs inhibition inhibited activation of CaMKs and Drp1, and cell death and heart tissue injury (n = 6/group, p < 0.01) in a murine model of cardiac transplantation. Importantly, the inhibition of CaMKs greatly prolonged heart graft survival (n = 8/group, p < 0.01). In conclusion, CaMK family members orchestrate cell death in two different pathways and may be potential therapeutic targets in preventing cell death and transplant injury.
Collapse
Affiliation(s)
- Haitao Lu
- Matthew Mailing Centre for Translational Transplantation Studies, London Health Sciences Centre, London, ON N6A 5A5, Canada
- Department of Pathology, Western University, London, ON N6A 3K7, Canada
| | - Jifu Jiang
- Matthew Mailing Centre for Translational Transplantation Studies, London Health Sciences Centre, London, ON N6A 5A5, Canada
| | - Jeffery Min
- Matthew Mailing Centre for Translational Transplantation Studies, London Health Sciences Centre, London, ON N6A 5A5, Canada
| | - Xuyan Huang
- Matthew Mailing Centre for Translational Transplantation Studies, London Health Sciences Centre, London, ON N6A 5A5, Canada
| | - Patrick McLeod
- Matthew Mailing Centre for Translational Transplantation Studies, London Health Sciences Centre, London, ON N6A 5A5, Canada
| | - Weihua Liu
- Department of Pathology, Western University, London, ON N6A 3K7, Canada
| | - Aaron Haig
- Department of Pathology, Western University, London, ON N6A 3K7, Canada
| | - Lakshman Gunaratnam
- Matthew Mailing Centre for Translational Transplantation Studies, London Health Sciences Centre, London, ON N6A 5A5, Canada
- Department of Microbiology and Immunology, Western University, London, ON N6A 3K7, Canada
- Multi-Organ Transplant Program, London Health Sciences Centre, London, ON N6A 5A5, Canada
- Division of Nephrology, Department of Medicine, Western University, London, ON N6A 3K7, Canada
| | - Anthony M Jevnikar
- Matthew Mailing Centre for Translational Transplantation Studies, London Health Sciences Centre, London, ON N6A 5A5, Canada
- Department of Microbiology and Immunology, Western University, London, ON N6A 3K7, Canada
- Multi-Organ Transplant Program, London Health Sciences Centre, London, ON N6A 5A5, Canada
- Division of Nephrology, Department of Medicine, Western University, London, ON N6A 3K7, Canada
| | - Zhu-Xu Zhang
- Matthew Mailing Centre for Translational Transplantation Studies, London Health Sciences Centre, London, ON N6A 5A5, Canada
- Department of Pathology, Western University, London, ON N6A 3K7, Canada
- Multi-Organ Transplant Program, London Health Sciences Centre, London, ON N6A 5A5, Canada
- Division of Nephrology, Department of Medicine, Western University, London, ON N6A 3K7, Canada
| |
Collapse
|
2
|
Gurd BJ, Menezes ES, Arhen BB, Islam H. Impacts of altered exercise volume, intensity, and duration on the activation of AMPK and CaMKII and increases in PGC-1α mRNA. Semin Cell Dev Biol 2023; 143:17-27. [PMID: 35680515 DOI: 10.1016/j.semcdb.2022.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 04/11/2022] [Accepted: 05/18/2022] [Indexed: 10/18/2022]
Abstract
The purpose of this review is to explore and discuss the impacts of augmented training volume, intensity, and duration on the phosphorylation/activation of key signaling protein - AMPK, CaMKII and PGC-1α - involved in the initiation of mitochondrial biogenesis. Specifically, we explore the impacts of augmented exercise protocols on AMP/ADP and Ca2+ signaling and changes in post exercise PGC - 1α gene expression. Although AMP/ADP concentrations appear to increase with increasing intensity and during extended durations of higher intensity exercise AMPK activation results are varied with some results supporting and intensity/duration effect and others not. Similarly, CaMKII activation and signaling results following exercise of different intensities and durations are inconsistent. The PGC-1α literature is equally inconsistent with only some studies demonstrating an effect of intensity on post exercise mRNA expression. We present a novel meta-analysis that suggests that the inconsistency in the PGC-1α literature may be due to sample size and statistical power limitations owing to the effect of intensity on PGC-1α expression being small. There is little data available regarding the impact of exercise duration on PGC-1α expression. We highlight the need for future well designed, adequately statistically powered, studies to clarify our understanding of the effects of volume, intensity, and duration on the induction of mitochondrial biogenesis by exercise.
Collapse
Affiliation(s)
- Brendon J Gurd
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada.
| | | | - Benjamin B Arhen
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Hashim Islam
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada
| |
Collapse
|
3
|
Ventura E, Iannuzzi CA, Pentimalli F, Giordano A, Morrione A. RBL1/p107 Expression Levels Are Modulated by Multiple Signaling Pathways. Cancers (Basel) 2021; 13:cancers13195025. [PMID: 34638509 PMCID: PMC8507926 DOI: 10.3390/cancers13195025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/29/2021] [Accepted: 10/02/2021] [Indexed: 11/16/2022] Open
Abstract
The members of the retinoblastoma (RB) protein family, RB1/p105, retinoblastoma-like (RBL)1/p107 and RBL2/p130 are critical modulators of the cell cycle and their dysregulation has been associated with tumor initiation and progression. The activity of RB proteins is regulated by numerous pathways including oncogenic signaling, but the molecular mechanisms of these functional interactions are not fully defined. We previously demonstrated that RBL2/p130 is a direct target of AKT and it is a key mediator of the apoptotic process induced by AKT inhibition. Here we demonstrated that RBL1/p107 levels are only minorly modulated by the AKT signaling pathway. In contrast, we discovered that RBL1/p107 levels are regulated by multiple pathways linked directly or indirectly to Ca2+-dependent signaling. Inhibition of the multifunctional calcium/calmodulin-dependent kinases (CaMKs) significantly reduced RBL1/p107 expression levels and phosphorylation, increased RBL1/p107 nuclear localization and led to cell cycle arrest in G0/G1. Targeting the Ca2+-dependent endopeptidase calpain stabilized RBL1/p107 levels and counteracted the reduction of RBL1/p107 levels associated with CaMKs inhibition. Thus, these novel observations suggest a complex regulation of RBL1/p107 expression involving different components of signaling pathways controlled by Ca2+ levels, including CaMKs and calpain, pointing out a significant difference with the mechanisms modulating the close family member RBL2/p130.
Collapse
Affiliation(s)
- Elisa Ventura
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA 19122, USA; (E.V.); (A.G.)
| | - Carmelina Antonella Iannuzzi
- Cell Biology and Biotherapy Unit, Istituto Nazionale Tumori, IRCCS, Fondazione G. Pascale, I-80131 Napoli, Italy; (C.A.I.); (F.P.)
| | - Francesca Pentimalli
- Cell Biology and Biotherapy Unit, Istituto Nazionale Tumori, IRCCS, Fondazione G. Pascale, I-80131 Napoli, Italy; (C.A.I.); (F.P.)
| | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA 19122, USA; (E.V.); (A.G.)
- Department of Medical Biotechnologies, University of Siena, I-53100 Siena, Italy
| | - Andrea Morrione
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA 19122, USA; (E.V.); (A.G.)
- Correspondence: ; Tel.: +215-204-2450
| |
Collapse
|
4
|
Nawaratna SSK, McManus DP, Gasser RB, Brindley PJ, Boyle GM, Rivera V, Ranasinghe SL, Jones MK, You H, Gobert GN. Use of kinase inhibitors against schistosomes to improve and broaden praziquantel efficacy. Parasitology 2020; 147:1488-98. [PMID: 32741402 DOI: 10.1017/S0031182020001250] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Praziquantel (PZQ) is the drug of choice for schistosomiasis. The potential drug resistance necessitates the search for adjunct or alternative therapies to PZQ. Previous functional genomics has shown that RNAi inhibition of Ca2+/calmodulin-dependent protein kinase II (CaMKII) gene in Schistosoma adult worms significantly improved the effectiveness of PZQ. Here we tested the in vitro efficacy of 15 selective and non-selective CaMK inhibitors against Schistosoma mansoni and showed that PZQ efficacy was improved against refractory juvenile parasites when combined with these CaMK inhibitors. By measuring CaMK activity and the mobility of adult S. mansoni, we identified two non-selective CaMK inhibitors, Staurosporine (STSP) and 1Naphthyl PP1 (1NAPP1), as promising candidates for further study. The impact of STSP and 1NAPP1 was investigated in mice infected with S. mansoni in the presence or absence of a sub-lethal dose of PZQ against 2- and 7-day-old schistosomula and adults. Treatment with STSP/PZQ induced a significant (47-68%) liver egg burden reduction compared with mice treated with PZQ alone. The findings indicate that the combination of STSP and PZQ dosages significantly improved anti-schistosomal activity compared to PZQ alone, demonstrating the potential of selective and non-selective CaMK/kinase inhibitors as a combination therapy with PZQ in treating schistosomiasis.
Collapse
|
5
|
Sorrentino S, Barbiera A, Proietti G, Sica G, Adamo S, Scicchitano BM. Inhibition of Phosphoinositide 3-Kinase/Protein Kinase B Signaling Hampers the Vasopressin-dependent Stimulation of Myogenic Differentiation. Int J Mol Sci 2019; 20:ijms20174188. [PMID: 31461843 PMCID: PMC6747374 DOI: 10.3390/ijms20174188] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/18/2019] [Accepted: 08/24/2019] [Indexed: 01/09/2023] Open
Abstract
Arginine-vasopressin (AVP) promotes muscle differentiation, hypertrophy, and regeneration through the combined activation of the calcineurin and Calcium/Calmodulin-dependent Protein Kinase (CaMK) pathways. The AVP system is impaired in several neuromuscular diseases, suggesting that AVP may act as a physiological factor in skeletal muscle. Since the Phosphoinositide 3-kinases/Protein Kinase B/mammalian Target Of Rapamycin (PI3K/Akt/mTOR) signaling plays a significant role in regulating muscle mass, we evaluated its role in the AVP myogenic effect. In L6 cells AKT1 expression was knocked down, and the AVP-dependent expression of mTOR and Forkhead box O3 (FoxO) was analyzed by Western blotting. The effect of the PI3K inhibitor LY294002 was evaluated by cellular and molecular techniques. Akt knockdown hampered the AVP-dependent mTOR expression while increased the levels of FoxO transcription factor. LY294002 treatment inhibited the AVP-dependent expression of Myocyte Enhancer Factor-2 (MEF2) and myogenin and prevented the nuclear translocation of MEF2. LY294002 also repressed the AVP-dependent nuclear export of histone deacetylase 4 (HDAC4) interfering with the formation of multifactorial complexes on the myogenin promoter. We demonstrate that the PI3K/Akt pathway is essential for the full myogenic effect of AVP and that, by targeting this pathway, one may highlight novel strategies to counteract muscle wasting in aging or neuromuscular disorders.
Collapse
Affiliation(s)
- Silvia Sorrentino
- Istituto di Istologia ed Embriologia, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Roma, Italy
| | - Alessandra Barbiera
- Istituto di Istologia ed Embriologia, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Roma, Italy
| | - Gabriella Proietti
- Istituto di Istologia ed Embriologia, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Roma, Italy
| | - Gigliola Sica
- Istituto di Istologia ed Embriologia, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Roma, Italy
| | - Sergio Adamo
- Dipartimento di Scienze Anatomiche, Istologiche, Medico-legali e dell'Apparato Locomotore (SAIMLAL), Sezione di Istologia ed Embriologia Medica, Sapienza Università, via A. Scarpa 16, 00161 Roma, Italy.
| | - Bianca Maria Scicchitano
- Istituto di Istologia ed Embriologia, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Roma, Italy
| |
Collapse
|
6
|
Dumon C, Pisella L, Diabira D, Belaidouni Y, Wayman GA, Gaiarsa JL. Developmental Switch of Leptin Action on Network Driven Activity in the Neonatal Rat Hippocampus. Front Cell Neurosci 2019; 13:254. [PMID: 31213989 PMCID: PMC6558146 DOI: 10.3389/fncel.2019.00254] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 05/21/2019] [Indexed: 12/31/2022] Open
Abstract
The adipose-derived circulating hormone leptin plays a pivotal role in the control of energy balance and body weight. Sound data indicate that this hormone also acts as an important developmental signal impacting a number of brain regions during fetal and postnatal stages. Leptin levels surge during the two first postnatal weeks of life in rodents. This period is characterized by the presence of early network driven activity in the immature hippocampus, the so-called Giant Depolarizing Potentials (GDPs). GDPs are thought to contribute to the wiring of the hippocampal network. We therefore tested the effect of leptin on GDPs. Leptin increased GDPs frequency between the postnatal days (P) 1 and 3 via a calcium/Calmodulin-dependent kinase (CaMK) and extracellular signal-related kinase (ERK) dependent pathways. Between P6 and P7, leptin inhibited the frequency of GDPs through the activation of large conductance Ca2+ activated K+ (BK) channels driven by a phosphoinositol-3 kinase (PI3K) dependent pathway. These results show that leptin exerts a bi-directional and age-dependent control of GDPs and extends the scope of leptin’s action in the developing brain.
Collapse
Affiliation(s)
- Camille Dumon
- INSERM (Institut National de la Santé et de la Recherche Médicale) Unité 1249, UMR 1249, INMED (Institut de Neurobiologie de la Méditerranée), Aix-Marseille University, Marseille, France
| | - Lucie Pisella
- INSERM (Institut National de la Santé et de la Recherche Médicale) Unité 1249, UMR 1249, INMED (Institut de Neurobiologie de la Méditerranée), Aix-Marseille University, Marseille, France
| | - Diabe Diabira
- INSERM (Institut National de la Santé et de la Recherche Médicale) Unité 1249, UMR 1249, INMED (Institut de Neurobiologie de la Méditerranée), Aix-Marseille University, Marseille, France
| | - Yasmine Belaidouni
- INSERM (Institut National de la Santé et de la Recherche Médicale) Unité 1249, UMR 1249, INMED (Institut de Neurobiologie de la Méditerranée), Aix-Marseille University, Marseille, France
| | - Gary A Wayman
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, United States
| | - Jean-Luc Gaiarsa
- INSERM (Institut National de la Santé et de la Recherche Médicale) Unité 1249, UMR 1249, INMED (Institut de Neurobiologie de la Méditerranée), Aix-Marseille University, Marseille, France
| |
Collapse
|
7
|
Abstract
BACKGROUND The divalent cation Calcium (Ca2+) regulates a wide range of processes in disparate cell types. Within insulin-producing β-cells, increases in cytosolic Ca2+ directly stimulate insulin vesicle exocytosis, but also initiate multiple signaling pathways. Mediated through activation of downstream kinases and transcription factors, Ca2+-regulated signaling pathways leverage substantial influence on a number of critical cellular processes within the β-cell. Additionally, there is evidence that prolonged activation of these same pathways is detrimental to β-cell health and may contribute to Type 2 Diabetes pathogenesis. SCOPE OF REVIEW This review aims to briefly highlight canonical Ca2+ signaling pathways in β-cells and how β-cells regulate the movement of Ca2+ across numerous organelles and microdomains. As a main focus, this review synthesizes experimental data from in vitro and in vivo models on both the beneficial and detrimental effects of Ca2+ signaling pathways for β-cell function and health. MAJOR CONCLUSIONS Acute increases in intracellular Ca2+ stimulate a number of signaling cascades, resulting in (de-)phosphorylation events and activation of downstream transcription factors. The short-term stimulation of these Ca2+ signaling pathways promotes numerous cellular processes critical to β-cell function, including increased viability, replication, and insulin production and secretion. Conversely, chronic stimulation of Ca2+ signaling pathways increases β-cell ER stress and results in the loss of β-cell differentiation status. Together, decades of study demonstrate that Ca2+ movement is tightly regulated within the β-cell, which is at least partially due to its dual roles as a potent signaling molecule.
Collapse
Affiliation(s)
- Paul V Sabatini
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada; Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Thilo Speckmann
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Francis C Lynn
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
| |
Collapse
|
8
|
Ramamoorthy P, Xu G, Shi H. Expression of Hypoxia Inducible Factor 1alpha Is Protein Kinase A-dependent in Primary Cortical Astrocytes Exposed to Severe Hypoxia. Neurochem Res 2018; 44:258-268. [PMID: 29589179 DOI: 10.1007/s11064-018-2516-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/20/2018] [Accepted: 03/22/2018] [Indexed: 11/29/2022]
Abstract
The hypoxia inducible factor 1 (HIF-1) and the cyclic AMP-responsive element binding protein (CREB) are two transcription factors that have been studied in the context of neuronal survival and neurodegeneration. HIF-1 upregulation and CREB activation have been observed not only in neurons but also in astrocytes under conditions of hypoxia. We hypothesized that activation of CREB regulate HIF-1α expression in the nucleus of cortical astrocytes under in vitro ischemic condition. To test the hypothesis, we determined the effects of inhibiting the CREB activation pathway on the expression of HIF-1α protein in astrocytes exposed to CoCl2 and severe hypoxia (near anoxia, 0.1% O2). The results demonstrated that inhibition of CaMKII and CaMKIV had no effect on both HIF-1α and pCREB expression in cortical astrocytes exposed to CoCl2 and anoxia. In contrast, PKA inhibition lowered the expression of HIF-1α and pCREB expression. Furthermore, the inhibition of PKA but not CaMKII or CaMKIV increased cell death of astrocytes exposed to near anoxia. The results suggest that PKA plays an important role in the cell survival signaling pathways in astrocytes.
Collapse
Affiliation(s)
- Prabhu Ramamoorthy
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, 66045, USA
| | - Grace Xu
- Department of Anesthesiology, School of Medicine, University of Kansas, Kansas City, KS, 66160, USA
| | - Honglian Shi
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, 66045, USA.
| |
Collapse
|
9
|
Mauger O, Lemoine F, Scheiffele P. Targeted Intron Retention and Excision for Rapid Gene Regulation in Response to Neuronal Activity. Neuron 2017; 92:1266-1278. [PMID: 28009274 DOI: 10.1016/j.neuron.2016.11.032] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 10/14/2016] [Accepted: 11/18/2016] [Indexed: 01/03/2023]
Abstract
Activity-dependent transcription has emerged as a major source of gene products that regulate neuronal excitability, connectivity, and synaptic properties. However, the elongation rate of RNA polymerases imposes a significant temporal constraint for transcript synthesis, in particular for long genes where new synthesis requires hours. Here we reveal a novel, transcription-independent mechanism that releases transcripts within minutes of neuronal stimulation. We found that, in the mouse neocortex, polyadenylated transcripts retain select introns and are stably accumulated in the cell nucleus. A subset of these intron retention transcripts undergoes activity-dependent splicing, cytoplasmic export, and ribosome loading, thus acutely releasing mRNAs in response to stimulation. This process requires NMDA receptor- and calmodulin-dependent kinase pathways, and it is particularly prevalent for long transcripts. We conclude that regulated intron retention in fully transcribed RNAs represents a mechanism to rapidly mobilize a pool of mRNAs in response to neuronal activity.
Collapse
Affiliation(s)
- Oriane Mauger
- Biozentrum of the University of Basel, Klingelbergstrasse 50-70, 4056 Basel, Switzerland
| | - Frédéric Lemoine
- GenoSplice Technology, iPEPS-ICM, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Peter Scheiffele
- Biozentrum of the University of Basel, Klingelbergstrasse 50-70, 4056 Basel, Switzerland.
| |
Collapse
|
10
|
Takemoto-Kimura S, Suzuki K, Horigane SI, Kamijo S, Inoue M, Sakamoto M, Fujii H, Bito H. Calmodulin kinases: essential regulators in health and disease. J Neurochem 2017; 141:808-818. [PMID: 28295333 DOI: 10.1111/jnc.14020] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 02/24/2017] [Accepted: 03/08/2017] [Indexed: 01/22/2023]
Abstract
Neuronal activity induces intracellular Ca2+ increase, which triggers activation of a series of Ca2+ -dependent signaling cascades. Among these, the multifunctional Ca2+ /calmodulin-dependent protein kinases (CaMKs, or calmodulin kinases) play key roles in neuronal transmission, synaptic plasticity, circuit development and cognition. The most investigated CaMKs for these roles in neuronal functions are CaMKI, CaMKII, CaMKIV and we will shed light on these neuronal CaMKs' functions in this review. Catalytically active members of CaMKs currently are CaMKI, CaMKII, CaMKIV and CaMKK. Although they all necessitate the binding of Ca2+ and calmodulin complex (Ca2+ /CaM) for releasing autoinhibition, each member of CaMK has distinct activation mechanisms-autophosphorylation mediated autonomy of multimeric CaMKII and CaMKK-dependent phosphoswitch-induced activation of CaMKI or CaMKIV. Furthermore, each CaMK shows distinct subcellular localization that underlies specific compartmentalized function in each activated neuron. In this review, we first summarize these molecular characteristics of each CaMK as to regulation and subcellular localization, and then describe each biological function. In the last section, we also focus on the emerging role of CaMKs in pathophysiological conditions by introducing the recent studies, especially focusing on drug addiction and depression, and discuss how dysfunctional CaMKs may contribute to the pathology of the neuropsychological disorders. This article is part of the mini review series "60th Anniversary of the Japanese Society for Neurochemistry".
Collapse
Affiliation(s)
- Sayaka Takemoto-Kimura
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Department of Neuroscience I, Research Institute of Environmental Medicine, Nagoya University, Chikusa-ku, Nagoya, Japan.,PRESTO-Japan Science and Technology Agency, Chiyoda-ku, Tokyo, Japan
| | - Kanzo Suzuki
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shin-Ichiro Horigane
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Department of Neuroscience I, Research Institute of Environmental Medicine, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Satoshi Kamijo
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masatoshi Inoue
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masayuki Sakamoto
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hajime Fujii
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Haruhiko Bito
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
11
|
Abstract
In contrast to cell type-specific pre-mRNA alternative splicing, mechanisms controlling activity-dependent alternative splicing is under-studied and not well understood. In a recent study, we conducted a comprehensive analysis of calcium-mediated mechanism that regulates alternative exon skipping in mouse cardiomyocytes. Our results reveal a strong link between histone hyperacetylation and skipping of cassette exons, and provide support to the kinetic coupling model of the epigenetic regulation of alternative splicing at the chromatin level.
Collapse
Affiliation(s)
- Alok Sharma
- a Department of Genetics and Genome Sciences ; Case Western Reserve University ; Cleveland , OH USA
| | | | | | | |
Collapse
|
12
|
Monaco S, Rusciano MR, Maione AS, Soprano M, Gomathinayagam R, Todd LR, Campiglia P, Salzano S, Pastore L, Leggiero E, Wilkerson DC, Rocco M, Selleri C, Iaccarino G, Sankar U, Illario M. A novel crosstalk between calcium/calmodulin kinases II and IV regulates cell proliferation in myeloid leukemia cells. Cell Signal 2014; 27:204-14. [PMID: 25446257 DOI: 10.1016/j.cellsig.2014.11.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/24/2014] [Accepted: 11/08/2014] [Indexed: 12/26/2022]
Abstract
CaMKs link transient increases in intracellular Ca(2+) with biological processes. In myeloid leukemia cells, CaMKII, activated by the bcr-abl oncogene, promotes cell proliferation. Inhibition of CaMKII activity restricts cell proliferation, and correlates with growth arrest and differentiation. The mechanism by which the inhibition of CaMKII results in growth arrest and differentiation in myeloid leukemia cells is still unknown. We report that inhibition of CaMKII activity results in an upregulation of CaMKIV mRNA and protein in leukemia cell lines. Conversely, expression of CaMKIV inhibits autophosphorylation and activation of CaMKII, and elicits G0/G1cell cycle arrest,impairing cell proliferation. Furthermore, U937 cells expressing CaMKIV show elevated levels of Cdk inhibitors p27(kip1) and p16(ink4a) and reduced levels of cyclins A, B1 and D1. These findings were also confirmed in the K562 leukemic cell line. The relationship between CaMKII and CaMKIV is also observed in primary acute myeloid leukemia (AML) cells, and it correlates with their immunophenotypic profile. Indeed, immature MO/M1 AML showed increased CaMKIV expression and decreased pCaMKII, whereas highly differentiated M4/M5 AML showed decreased CaMKIV expression and increased pCaMKII levels. Our data reveal a novel cross-talk between CaMKII and CaMKIV and suggest that CaMKII suppresses the expression of CaMKIV to promote leukemia cell proliferation.
Collapse
Affiliation(s)
- Sara Monaco
- Dipartimento di Scienze Mediche Traslazionali, Federico II University, Naples, Italy
| | | | - Angela S Maione
- Dipartimento di Scienze Mediche Traslazionali, Federico II University, Naples, Italy
| | - Maria Soprano
- Dipartimento di Scienze Mediche Traslazionali, Federico II University, Naples, Italy
| | - Rohini Gomathinayagam
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Lance R Todd
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Pietro Campiglia
- Dipartimento di Scienze Farmaceutiche, Università di Salerno, Fisciano, Salerno,Italy
| | - Salvatore Salzano
- Instituto di Endocrinologia ed Oncologia Sperimentale, CNR, Naples, Italy
| | - Lucio Pastore
- CEINGE-Biotecnologie Avanzate, Italy; Dipartimento di Biochimica e Biotecnologie Mediche, Federico II University, Naples, Italy
| | | | - Donald C Wilkerson
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Monia Rocco
- Experimental Pharmacology Unit, Department of Research, National Cancer Institute "Fondazione G. Pascale", Napoli, Italy
| | - Carmine Selleri
- Hematology Unit, Azienda Ospedaliera Universitaria "S. Giovanni di Dio e Ruggi d'Aragona", Salerno, Italy
| | - Guido Iaccarino
- Department of Medicine, University of Salerno, Italy; IRCCS "Multimedica", Milan, Italy
| | - Uma Sankar
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Maddalena Illario
- Dipartimento di Scienze Mediche Traslazionali, Federico II University, Naples, Italy.
| |
Collapse
|
13
|
Nakamura MT, Yudell BE, Loor JJ. Regulation of energy metabolism by long-chain fatty acids. Prog Lipid Res 2013; 53:124-44. [PMID: 24362249 DOI: 10.1016/j.plipres.2013.12.001] [Citation(s) in RCA: 467] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 12/03/2013] [Accepted: 12/04/2013] [Indexed: 12/12/2022]
Abstract
In mammals, excess energy is stored primarily as triglycerides, which are mobilized when energy demands arise. This review mainly focuses on the role of long chain fatty acids (LCFAs) in regulating energy metabolism as ligands of peroxisome proliferator-activated receptors (PPARs). PPAR-alpha expressed primarily in liver is essential for metabolic adaptation to starvation by inducing genes for beta-oxidation and ketogenesis and by downregulating energy expenditure through fibroblast growth factor 21. PPAR-delta is highly expressed in skeletal muscle and induces genes for LCFA oxidation during fasting and endurance exercise. PPAR-delta also regulates glucose metabolism and mitochondrial biogenesis by inducing FOXO1 and PGC1-alpha. Genes targeted by PPAR-gamma in adipocytes suggest that PPAR-gamma senses incoming non-esterified LCFAs and induces the pathways to store LCFAs as triglycerides. Adiponectin, another important target of PPAR-gamma may act as a spacer between adipocytes to maintain their metabolic activity and insulin sensitivity. Another topic of this review is effects of skin LCFAs on energy metabolism. Specific LCFAs are required for the synthesis of skin lipids, which are essential for water barrier and thermal insulation functions of the skin. Disturbance of skin lipid metabolism often causes apparent resistance to developing obesity at the expense of normal skin function.
Collapse
Affiliation(s)
- Manabu T Nakamura
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, 905 South Goodwin Avenue, Urbana, IL 61801, USA.
| | - Barbara E Yudell
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, 905 South Goodwin Avenue, Urbana, IL 61801, USA
| | - Juan J Loor
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, 905 South Goodwin Avenue, Urbana, IL 61801, USA
| |
Collapse
|
14
|
Aoi W, Naito Y, Yoshikawa T. Role of oxidative stress in impaired insulin signaling associated with exercise-induced muscle damage. Free Radic Biol Med 2013; 65:1265-1272. [PMID: 24075894 DOI: 10.1016/j.freeradbiomed.2013.09.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 09/18/2013] [Accepted: 09/19/2013] [Indexed: 10/26/2022]
Abstract
Skeletal muscle is a major tissue that utilizes blood glucose. A single bout of exercise improves glucose uptake in skeletal muscle through insulin-dependent and insulin-independent signal transduction mechanisms. However, glucose utilization is decreased in muscle damage induced by acute, unaccustomed, or eccentric exercise. The decrease in glucose utilization is caused by decreased insulin-stimulated glucose uptake in damaged muscles with inhibition of the membrane translocation of glucose transporter 4 through phosphatidyl 3-kinase/Akt signaling. In addition to inflammatory cytokines, reactive oxygen species including 4-hydroxy-2-nonenal and peroxynitrate can induce degradation or inactivation of signaling proteins through posttranslational modification, thereby resulting in a disturbance in insulin signal transduction. In contrast, treatment with factors that attenuate oxidative stress in damaged muscle suppresses the impairment of insulin sensitivity. Muscle-damaging exercise may thus lead to decreased endurance capacity and muscle fatigue in exercise, and it may decrease the efficiency of exercise therapy for metabolic improvement.
Collapse
Affiliation(s)
- Wataru Aoi
- Laboratory of Health Science, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto 606-8522, Japan.
| | - Yuji Naito
- Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Toshikazu Yoshikawa
- Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| |
Collapse
|
15
|
Tokuoka H, Hatanaka T, Metzger D, Ichinose H. Nurr1 expression is regulated by voltage-dependent calcium channels and calcineurin in cultured hippocampal neurons. Neurosci Lett 2013; 559:50-5. [PMID: 24291696 DOI: 10.1016/j.neulet.2013.11.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 11/19/2013] [Indexed: 12/01/2022]
Abstract
Nurr1 is an orphan nuclear transcription factor expressed in the brain. While Nurr1 is assumed to be an immediate early gene, it is not fully understood how Nurr1 expression is regulated in an activity-dependent manner in the central nervous system. Here, we investigated the molecular mechanisms underlying the regulation of Nurr1 expression in cultured hippocampal and cortical neurons. We found that upregulation of neural activity by high KCl and bicuculline enhances Nurr1 levels, while blockade of its activity by tetrodotoxin reduces Nurr1 levels. The induction of Nurr1 expression was mediated by voltage-dependent calcium channels (VDCCs), as shown by cadmium and VDCC-specific inhibitors. Furthermore, calcineurin, but not calcium/calmodulin-dependent protein kinase (CaMK) was critical for the induction. Thus, Nurr1 expression is regulated by VDCC and calcineurin in a cell-autonomous, neural activity-dependent manner.
Collapse
Affiliation(s)
- Hirofumi Tokuoka
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan
| | - Takayuki Hatanaka
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan
| | - Daniel Metzger
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch F-67400, France; CNRS UMR7104, Illkirch, France; INSERM U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Hiroshi Ichinose
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
| |
Collapse
|
16
|
Abstract
The neuroactive steroids 17β-estradiol and progesterone control a broad spectrum of neural functions. Besides their roles in the regulation of classical neuroendocrine loops, they strongly influence motor and cognitive systems, behavior, and modulate brain performance at almost every level. Such a statement is underpinned by the widespread and lifelong expression pattern of all types of classical and non-classical estrogen and progesterone receptors in the CNS. The life-sustaining power of neurosteroids for tattered or seriously damaged neurons aroused interest in the scientific community in the past years to study their ability for therapeutic use under neuropathological challenges. Documented by excellent studies either performed in vitro or in adequate animal models mimicking acute toxic or chronic neurodegenerative brain disorders, both hormones revealed a high potency to protect neurons from damage and saved neural systems from collapse. Unfortunately, neurons, astroglia, microglia, and oligodendrocytes are comparably target cells for both steroid hormones. This hampers the precise assignment and understanding of neuroprotective cellular mechanisms activated by both steroids. In this article, we strive for a better comprehension of the mutual reaction between these steroid hormones and the two major glial cell types involved in the maintenance of brain homeostasis, astroglia and microglia, during acute traumatic brain injuries such as stroke and hypoxia. In particular, we attempt to summarize steroid-activated cellular signaling pathways and molecular responses in these cells and their contribution to dampening neuroinflammation and neural destruction. This article is part of a Special Issue entitled 'CSR 2013'.
Collapse
Affiliation(s)
- Sonja Johann
- Institute of Neuroanatomy, RWTH Aachen University, D-52074 Aachen, Germany
| | | |
Collapse
|
17
|
Jeon JP, Roh SE, Wie J, Kim J, Kim H, Lee KP, Yang D, Jeon JH, Cho NH, Kim IG, Kang DE, Kim HJ, So I. Activation of TRPC4β by Gαi subunit increases Ca2+ selectivity and controls neurite morphogenesis in cultured hippocampal neuron. Cell Calcium 2013; 54:307-19. [PMID: 24011658 DOI: 10.1016/j.ceca.2013.07.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 07/27/2013] [Accepted: 07/29/2013] [Indexed: 11/16/2022]
Abstract
The ubiquitous transient receptor potential canonical (TRPC) channels function as non-selective, Ca(2+)-permeable channels. TRPC channels are activated by stimulation of Gαq-PLC-coupled receptors. Here, we report that TRPC4/TRPC5 can be activated by Gαi. We studied the essential role of Gαi subunits in TRPC4 activation and investigated changes in ion selectivity and pore dilation of the TRPC4 channel elicited by the Gαi2 subunit. Activation of TRPC4 by Gαi2 increased Ca2+ permeability and Ca2+ influx through TRPC4 channels. Co-expression of the muscarinic receptor (M2) and TRPC4 in HEK293 cells induced TRPC4-mediated Ca2+ influx. Moreover, both TRPC4β and the TRPC4β-Gαi2 signaling complex induced inhibition of neurite growth and arborization in cultured hippocampal neurons. Cells treated with KN-93, a CaMKII inhibitor, prevented TRPC4- and TRPC4-Gαi2(Q205L)-mediated inhibition of neurite branching and growth. These findings indicate an essential role of Gαi proteins in TRPC4 activation and extend our knowledge of the functional role of TRPC4 in hippocampal neurons.
Collapse
Affiliation(s)
- Jae-Pyo Jeon
- Department of Physiology and Institute of Dermatological Science, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Kajiwara A, Tsuchiya Y, Takata T, Nyunoya M, Nozaki N, Ihara H, Watanabe Y. Nitric oxide enhances increase in cytosolic Ca(2+) and promotes nicotine-triggered MAPK pathway in PC12 cells. Nitric Oxide 2013; 34:3-9. [PMID: 23624270 DOI: 10.1016/j.niox.2013.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 03/06/2013] [Accepted: 04/12/2013] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to investigate the roles of neuronal nitric oxide synthase (nNOS), Ca(2+)/calmodulin (CaM)-dependent protein kinases (CaMKs), and protein kinase C (PKC) in nicotine-induced extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) activation. Treatment with nicotine stimulated ERK1/2 and p38 MAPK phosphorylation in the PC12 cells expressing nNOS (NPC12 cells) as compared with that in control PC12 cells. An inhibitor of L-type voltage-sensitive Ca(2+) channel suppressed the nicotine-induced phosphorylation of p38 MAPK. The inhibition of CaMK-kinase, the upstream activator of CaMKI and CaMKIV, did not inhibit the enhanced their phosphorylation. ERK1/2 phosphorylation was attenuated by inhibitors of p38 MAPK, PKC, and MAPK-kinase 1/2, indicating the involvement of these protein kinases upstream of ERK1/2. Furthermore, we found that nNOS expression enhances the nicotine-induced increase in the intracellular concentration of Ca(2+), using the Ca(2+)-sensitive fluorescent probe Fura2. These data suggest that NO promotes nicotine-triggered Ca(2+) transient in PC12 cells to activate possibly CaMKII, leading to sequential phosphorylation of p38 MAPK and ERK1/2.
Collapse
|
19
|
Abstract
BACKGROUND Although the pathophysiology and treatment of adult heart failure (HF) are well studied, HF in children remains poorly understood. In adults, adrenergic receptor (AR)-mediated adaptation plays a central role in cardiac abnormalities in HF, and these patients respond well to β-blocker (BB) therapy. However, in children with HF, there is a growing body of literature suggesting a lack of efficacy of adult HF therapies. Due to these unanticipated differences in response to therapy and the paucity of data regarding the molecular adaptation of the paediatric heart, we investigated the molecular characteristics of HF in children. METHODS AND RESULTS Explanted hearts from adults and children with idiopathic dilated cardiomyopathy and non-failing controls were used in the study. Our results show that the molecular characteristics of paediatric HF are strikingly different from their adult counterparts. These differences include: (i) down-regulation of β1- and β2-AR in children, whereas β2-AR expression is maintained in adults; (ii) up-regulation of connexin43 in children, whereas down-regulation is observed in adults; (iii) no differences in phosphatase expression, whereas up-regulation is observed in adults; (iv) no decrease in the phosphorylation of phospholamban at the Ser16 or Thr17 sites in children, which are known characteristics of adult HF. CONCLUSION There is a different adaptation of β-AR and adrenergic signalling pathways in children with HF compared with adults. Our results begin to address the disparities in cardiovascular research specific to children and suggest that age-related differences in adaptation could influence the response to therapy. These findings could lead to a paradigm shift in the contemporary management of children with HF.
Collapse
Affiliation(s)
- Shelley D Miyamoto
- Department of Pediatrics, University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, CO, USA
| | | | | | | | | | | | | |
Collapse
|
20
|
Inoue M, Yagishita-Kyo N, Nonaka M, Kawashima T, Okuno H, Bito H. Synaptic activity-responsive element (SARE): A unique genomic structure with an unusual sensitivity to neuronal activity. Commun Integr Biol 2011; 3:443-6. [PMID: 21057636 DOI: 10.4161/cib.3.5.12287] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Accepted: 05/06/2010] [Indexed: 11/19/2022] Open
Abstract
Formation of a new memory requires plasticity at the synaptic level. However, it has also been shown that the consolidation and the maintenance of such a new memory involve processes that necessitate active mRNA at the nucleus of the cell. How can robust changes in synaptic efficacy specifically drive new transcription and translation of new gene transcripts, and thus transform an otherwise transient plasticity into a long-lasting and stable one? In this article, we highlight the conceptual advance that was gained by the discovery of a potent Synaptic Activity-Responsive Element (SARE) found ∼7 kb upstream of the transcription initiation site of the neuronal immediate early gene Arc. The unique genomic structure of SARE, which contained adjacent and cooperative binding sites for three major activity-dependent transcription factors within a 100-bp locus, was associated with an unusual responsiveness to neuronal stimuli. Taken together, these findings shed light on a new class of transcriptional sensor with enhanced sensitivity to synaptic activity.
Collapse
Affiliation(s)
- Masatoshi Inoue
- Department of Neurochemistry; University of Tokyo Graduate School of Medicine; Bunkyo-ku, Tokyo Japan
| | | | | | | | | | | |
Collapse
|
21
|
Abstract
The CDPK superfamily consists of six types of protein kinases, which differ in the regulatory domains they contain. CDPKs (calcium-dependent protein kinases or calmodulin-like domain protein kinases) are activated by the binding of calcium to their calmodulin-like regulatory domains. The carboxyl terminal domains of CRKs (CDPK-related kinases) have sequence similarity to the regulatory domains of CDPKs, but do not bind calcium. PPCKs (PEP carboxylase kinases) contain only a catalytic domain. PRKs (PPCK-related kinases) have a carboxyl-terminal domain that has no similarity to that of any other member of the superfamily. CCaMKs (calcium and calmodulin regulated kinases) bind both calcium ions and the calcium/calmodulin complex, whereas CaMKs (calmodulin-dependent protein kinases) bind the calcium/calmodulin complex, but not calcium. Phylogenetic trees constructed from amino acid sequences of catalytic or regulatory domains show that CDPKs and CRKs are closely related and might share a common ancestor. Plant CCaMKs and CaMK form a group more closely related to protozoan, than to plant, CDPKs. Intron analysis of the 42 CDPK, CRK, PPCK, and PRK genes from Arabidopsis supports the structure of the gene trees, the possibility that PPCKs/PRKs belong to the CDPK superfamily, and suggests that several introns have been added during evolution of the family.
Collapse
Affiliation(s)
- Alice C Harmon
- Department of Botany, PO Box 118526, University of Florida, Gainesville, Florida 32611-8526, USA
- Plant Molecular and Cellular Biology Program, PO Box 118526, University of Florida, Gainesville, Florida 32611-8526, USA
| | - Michael Gribskov
- San Diego Supercomputer Center, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093-0537, USA
| | - Erika Gubrium
- Department of Botany, PO Box 118526, University of Florida, Gainesville, Florida 32611-8526, USA
| | - Jeffrey F Harper
- Department of Cell Biology, The Scripps Research Institute, 10550 N. Torrey Pines Rd. La Jolla, California 92037, USA
| |
Collapse
|