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Artimagnella O, Maftei ES, Esposito M, Sanges R, Mallamaci A. Foxg1 regulates translation of neocortical neuronal genes, including the main NMDA receptor subunit gene, Grin1. BMC Biol 2024; 22:180. [PMID: 39183266 PMCID: PMC11346056 DOI: 10.1186/s12915-024-01979-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 08/12/2024] [Indexed: 08/27/2024] Open
Abstract
BACKGROUND Mainly known as a transcription factor patterning the rostral brain and governing its histogenesis, FOXG1 has been also detected outside the nucleus; however, biological meaning of that has been only partially clarified. RESULTS Prompted by FOXG1 expression in cytoplasm of pallial neurons, we investigated its implication in translational control. We documented the impact of FOXG1 on ribosomal recruitment of Grin1-mRNA, encoding for the main subunit of NMDA receptor. Next, we showed that FOXG1 increases GRIN1 protein level by enhancing the translation of its mRNA, while not increasing its stability. Molecular mechanisms underlying this activity included FOXG1 interaction with EIF4E and, possibly, Grin1-mRNA. Besides, we found that, within murine neocortical cultures, de novo synthesis of GRIN1 undergoes a prominent and reversible, homeostatic regulation and FOXG1 is instrumental to that. Finally, by integrated analysis of multiple omic data, we inferred that FOXG1 is implicated in translational control of hundreds of neuronal genes, modulating ribosome engagement and progression. In a few selected cases, we experimentally verified such inference. CONCLUSIONS These findings point to FOXG1 as a key effector, potentially crucial to multi-scale temporal tuning of neocortical pyramid activity, an issue with profound physiological and neuropathological implications.
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Affiliation(s)
- Osvaldo Artimagnella
- Laboratory of Cerebral Cortex Development, SISSA, Via Bonomea 265, 34136, Trieste, Italy
- Present Address: IRCCS Centro Neurolesi "Bonino-Pulejo", Messina, Italy
| | - Elena Sabina Maftei
- Laboratory of Cerebral Cortex Development, SISSA, Via Bonomea 265, 34136, Trieste, Italy
| | - Mauro Esposito
- Laboratory of Computational Genomics, SISSA, via Bonomea 265, 34136, Trieste, Italy
- Present Address: Neomatrix SRL, Rome, Italy
| | - Remo Sanges
- Laboratory of Computational Genomics, SISSA, via Bonomea 265, 34136, Trieste, Italy
| | - Antonello Mallamaci
- Laboratory of Cerebral Cortex Development, SISSA, Via Bonomea 265, 34136, Trieste, Italy.
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2
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Yuan S, Zhou G, Xu G. Translation machinery: the basis of translational control. J Genet Genomics 2024; 51:367-378. [PMID: 37536497 DOI: 10.1016/j.jgg.2023.07.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/23/2023] [Accepted: 07/23/2023] [Indexed: 08/05/2023]
Abstract
Messenger RNA (mRNA) translation consists of initiation, elongation, termination, and ribosome recycling, carried out by the translation machinery, primarily including tRNAs, ribosomes, and translation factors (TrFs). Translational regulators transduce signals of growth and development, as well as biotic and abiotic stresses, to the translation machinery, where global or selective translational control occurs to modulate mRNA translation efficiency (TrE). As the basis of translational control, the translation machinery directly determines the quality and quantity of newly synthesized peptides and, ultimately, the cellular adaption. Thus, regulating the availability of diverse machinery components is reviewed as the central strategy of translational control. We provide classical signaling pathways (e.g., integrated stress responses) and cellular behaviors (e.g., liquid-liquid phase separation) to exemplify this strategy within different physiological contexts, particularly during host-microbe interactions. With new technologies developed, further understanding this strategy will speed up translational medicine and translational agriculture.
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Affiliation(s)
- Shu Yuan
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, China
| | - Guilong Zhou
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, China
| | - Guoyong Xu
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, China; Hubei Hongshan Laboratory, Wuhan, Hubei 430070, China.
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3
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Glucocorticoid-Regulated Kinase CAMKIγ in the Central Amygdala Controls Anxiety-like Behavior in Mice. Int J Mol Sci 2022; 23:ijms232012328. [PMID: 36293185 PMCID: PMC9604347 DOI: 10.3390/ijms232012328] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 11/07/2022] Open
Abstract
The expression of the Calcium/Calmodulin-Dependent Protein Kinase I gamma (encoded by the Camk1g gene) depends on the activation of glucocorticoid receptors (GR) and is strongly regulated by stress. Since Camk1g is primarily expressed in neuronal cells of the limbic system in the brain, we hypothesized that it could be involved in signaling mechanisms that underlie the adaptive or maladaptive responses to stress. Here, we find that restraint-induced stress and the GR agonist dexamethasone robustly increase the expression of Camk1g in neurons of the amygdalar nuclei in the mouse brain. To assess the functional role of Camk1g expression, we performed a virally induced knock-down of the transcript. Mice with bilateral amygdala-specific Camk1g knock-down showed increased anxiety-like behaviors in the light-dark box, and an increase in freezing behavior after fear-conditioning, but normal spatial working memory during exploration of a Y-maze. Thus, we confirm that Camk1g is a neuron-specific GR-regulated transcript, and show that it is specifically involved in behaviors related to anxiety, as well as responses conditioned by aversive stimuli.
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4
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Molecular Mechanisms Underlying Ca2+/Calmodulin-Dependent Protein Kinase Kinase Signal Transduction. Int J Mol Sci 2022; 23:ijms231911025. [PMID: 36232320 PMCID: PMC9570080 DOI: 10.3390/ijms231911025] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/16/2022] [Accepted: 09/16/2022] [Indexed: 12/03/2022] Open
Abstract
Ca2+/calmodulin-dependent protein kinase kinase (CaMKK) is the activating kinase for multiple downstream kinases, including CaM-kinase I (CaMKI), CaM-kinase IV (CaMKIV), protein kinase B (PKB/Akt), and 5′AMP-kinase (AMPK), through the phosphorylation of their activation-loop Thr residues in response to increasing the intracellular Ca2+ concentration, as CaMKK itself is a Ca2+/CaM-dependent enzyme. The CaMKK-mediated kinase cascade plays important roles in a number of Ca2+-dependent pathways, such as neuronal morphogenesis and plasticity, transcriptional activation, autophagy, and metabolic regulation, as well as in pathophysiological pathways, including cancer progression, metabolic syndrome, and mental disorders. This review focuses on the molecular mechanism underlying CaMKK-mediated signal transduction in normal and pathophysiological conditions. We summarize the current knowledge of the structural, functional, and physiological properties of the regulatory kinase, CaMKK, and the development and application of its pharmacological inhibitors.
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5
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Meng E, Deng J, Jiang R, Wu H. CircRNA-Encoded Peptides or Proteins as New Players in Digestive System Neoplasms. Front Oncol 2022; 12:944159. [PMID: 35936754 PMCID: PMC9355255 DOI: 10.3389/fonc.2022.944159] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 06/15/2022] [Indexed: 11/13/2022] Open
Abstract
Circular RNAs (circRNAs) were considered non-coding RNAs. Nowadays, a large number of studies have found that these RNAs contain open reading frames that can be translated in a cap-independent manner, such as internal ribosome entry site (IRES) and N6-methyladenosine (m6A). The encoded peptides or proteins affect the occurrence and development of tumors by regulating the Yap-hippo and the Wnt/β-catenin signaling pathways, as well as the malignant progression of tumors through phosphorylation and ubiquitination of specific molecules. This review will summarize the regulation of circRNA translation and the functional roles and underlying mechanisms of circRNA-derived peptides or proteins in digestive tract tumors. Some circRNA-encoded peptides or proteins may be used as tumor biomarkers and prognostic factors for early screening and treatment of clinical gastrointestinal tumors.
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6
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TDP-43 aggregation induced by oxidative stress causes global mitochondrial imbalance in ALS. Nat Struct Mol Biol 2021; 28:132-142. [PMID: 33398173 DOI: 10.1038/s41594-020-00537-7] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 11/06/2020] [Indexed: 01/28/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) was initially thought to be associated with oxidative stress when it was first linked to mutant superoxide dismutase 1 (SOD1). The subsequent discovery of ALS-linked genes functioning in RNA processing and proteostasis raised the question of how different biological pathways converge to cause the disease. Both familial and sporadic ALS are characterized by the aggregation of the essential DNA- and RNA-binding protein TDP-43, suggesting a central role in ALS etiology. Here we report that TDP-43 aggregation in neuronal cells of mouse and human origin causes sensitivity to oxidative stress. Aggregated TDP-43 sequesters specific microRNAs (miRNAs) and proteins, leading to increased levels of some proteins while functionally depleting others. Many of those functionally perturbed gene products are nuclear-genome-encoded mitochondrial proteins, and their dysregulation causes a global mitochondrial imbalance that augments oxidative stress. We propose that this stress-aggregation cycle may underlie ALS onset and progression.
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7
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Locard‐Paulet M, Voisinne G, Froment C, Goncalves Menoita M, Ounoughene Y, Girard L, Gregoire C, Mori D, Martinez M, Luche H, Garin J, Malissen M, Burlet‐Schiltz O, Malissen B, Gonzalez de Peredo A, Roncagalli R. LymphoAtlas: a dynamic and integrated phosphoproteomic resource of TCR signaling in primary T cells reveals ITSN2 as a regulator of effector functions. Mol Syst Biol 2020; 16:e9524. [PMID: 32618424 PMCID: PMC7333348 DOI: 10.15252/msb.20209524] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 12/29/2022] Open
Abstract
T-cell receptor (TCR) ligation-mediated protein phosphorylation regulates the activation, cellular responses, and fates of T cells. Here, we used time-resolved high-resolution phosphoproteomics to identify, quantify, and characterize the phosphorylation dynamics of thousands of phosphorylation sites in primary T cells during the first 10 min after TCR stimulation. Bioinformatic analysis of the data revealed a coherent orchestration of biological processes underlying T-cell activation. In particular, functional modules associated with cytoskeletal remodeling, transcription, translation, and metabolic processes were mobilized within seconds after TCR engagement. Among proteins whose phosphorylation was regulated by TCR stimulation, we demonstrated, using a fast-track gene inactivation approach in primary lymphocytes, that the ITSN2 adaptor protein regulated T-cell effector functions. This resource, called LymphoAtlas, represents an integrated pipeline to further decipher the organization of the signaling network encoding T-cell activation. LymphoAtlas is accessible to the community at: https://bmm-lab.github.io/LymphoAtlas.
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Affiliation(s)
- Marie Locard‐Paulet
- Institut de Pharmacologie et de Biologie Structurale (IPBS)Université de Toulouse, CNRS, UPSToulouseFrance
- Present address:
Novo Nordisk Foundation Center for Protein ResearchUniversity of CopenhagenCopenhagenDenmark
| | - Guillaume Voisinne
- Centre d'Immunologie de Marseille‐LuminyINSERM, CNRSAix Marseille UniversitéMarseilleFrance
| | - Carine Froment
- Institut de Pharmacologie et de Biologie Structurale (IPBS)Université de Toulouse, CNRS, UPSToulouseFrance
| | | | - Youcef Ounoughene
- Centre d'Immunologie de Marseille‐LuminyINSERM, CNRSAix Marseille UniversitéMarseilleFrance
- Centre d'ImmunophénomiqueINSERM, CNRS UMRAix Marseille UniversitéMarseilleFrance
| | - Laura Girard
- Centre d'Immunologie de Marseille‐LuminyINSERM, CNRSAix Marseille UniversitéMarseilleFrance
- Centre d'ImmunophénomiqueINSERM, CNRS UMRAix Marseille UniversitéMarseilleFrance
| | - Claude Gregoire
- Centre d'Immunologie de Marseille‐LuminyINSERM, CNRSAix Marseille UniversitéMarseilleFrance
| | - Daiki Mori
- Centre d'Immunologie de Marseille‐LuminyINSERM, CNRSAix Marseille UniversitéMarseilleFrance
- Centre d'ImmunophénomiqueINSERM, CNRS UMRAix Marseille UniversitéMarseilleFrance
| | - Manuel Martinez
- Centre d'ImmunophénomiqueINSERM, CNRS UMRAix Marseille UniversitéMarseilleFrance
| | - Hervé Luche
- Centre d'ImmunophénomiqueINSERM, CNRS UMRAix Marseille UniversitéMarseilleFrance
| | - Jerôme Garin
- CEA, BIG, Biologie à Grande Echelle, INSERM, U1038Université Grenoble‐AlpesGrenobleFrance
| | - Marie Malissen
- Centre d'Immunologie de Marseille‐LuminyINSERM, CNRSAix Marseille UniversitéMarseilleFrance
- Centre d'ImmunophénomiqueINSERM, CNRS UMRAix Marseille UniversitéMarseilleFrance
| | - Odile Burlet‐Schiltz
- Institut de Pharmacologie et de Biologie Structurale (IPBS)Université de Toulouse, CNRS, UPSToulouseFrance
| | - Bernard Malissen
- Centre d'Immunologie de Marseille‐LuminyINSERM, CNRSAix Marseille UniversitéMarseilleFrance
- Centre d'ImmunophénomiqueINSERM, CNRS UMRAix Marseille UniversitéMarseilleFrance
| | - Anne Gonzalez de Peredo
- Institut de Pharmacologie et de Biologie Structurale (IPBS)Université de Toulouse, CNRS, UPSToulouseFrance
| | - Romain Roncagalli
- Centre d'Immunologie de Marseille‐LuminyINSERM, CNRSAix Marseille UniversitéMarseilleFrance
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8
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Sanlialp A, Schumacher D, Kiper L, Varma E, Riechert E, Ho TC, Hofmann C, Kmietczyk V, Zimmermann F, Dlugosz S, Wirth A, Gorska AA, Burghaus J, Camacho Londoño JE, Katus HA, Doroudgar S, Freichel M, Völkers M. Saraf-dependent activation of mTORC1 regulates cardiac growth. J Mol Cell Cardiol 2020; 141:30-42. [PMID: 32173353 DOI: 10.1016/j.yjmcc.2020.03.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 03/03/2020] [Accepted: 03/09/2020] [Indexed: 10/24/2022]
Abstract
Pathological cardiac hypertrophy is an independent risk for heart failure (HF) and sudden death. Deciphering signaling pathways regulating intracellular Ca2+ homeostasis that control adaptive and pathological cardiac growth may enable identification of novel therapeutic targets. The objective of the present study is to determine the role of the store-operated calcium entry-associated regulatory factor (Saraf), encoded by the Tmem66 gene, on cardiac growth control in vitro and in vivo. Saraf is a single-pass membrane protein located at the sarco/endoplasmic reticulum and regulates intracellular calcium homeostasis. We found that Saraf expression was upregulated in the hypertrophied myocardium and was sufficient for cell growth in response to neurohumoral stimulation. Increased Saraf expression caused cell growth, which was associated with dysregulation of calcium-dependent signaling and sarcoplasmic reticulum calcium content. In vivo, Saraf augmented cardiac myocyte growth in response to angiotensin II and resulted in increased cardiac remodeling together with worsened cardiac function. Mechanistically, Saraf activated mTORC1 (mechanistic target of rapamycin complex 1) and increased protein synthesis, while mTORC1 inhibition blunted Saraf-dependent cell growth. In contrast, the hearts of Saraf knockout mice and Saraf-deficient myocytes did not show any morphological or functional alterations after neurohumoral stimulation, but Saraf depletion resulted in worsened cardiac function after acute pressure overload. SARAF knockout blunted transverse aortic constriction cardiac myocyte hypertrophy and impaired cardiac function, demonstrating a role for SARAF in compensatory myocyte growth. Collectively, these results reveal a novel link between sarcoplasmic reticulum calcium homeostasis and mTORC1 activation that is regulated by Saraf.
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Affiliation(s)
- Ayse Sanlialp
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Dagmar Schumacher
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany; Institute of Pharmacology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Leon Kiper
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Eshita Varma
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Eva Riechert
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Thanh Cao Ho
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Christoph Hofmann
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Vivien Kmietczyk
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Frank Zimmermann
- Interfacultary Biomedical Faculty (IBF), University of Heidelberg, Im Neuenheimer Feld 347, 69120 Heidelberg, Germany
| | - Sascha Dlugosz
- Interfacultary Biomedical Faculty (IBF), University of Heidelberg, Im Neuenheimer Feld 347, 69120 Heidelberg, Germany
| | - Angela Wirth
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany; Institute of Pharmacology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Agnieszka A Gorska
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Jana Burghaus
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Juan E Camacho Londoño
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany; Institute of Pharmacology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Shirin Doroudgar
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Marc Freichel
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany; Institute of Pharmacology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Mirko Völkers
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany.
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9
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Kats IR, Klann E. Translating from cancer to the brain: regulation of protein synthesis by eIF4F. ACTA ACUST UNITED AC 2019; 26:332-342. [PMID: 31416906 PMCID: PMC6699409 DOI: 10.1101/lm.050047.119] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 07/03/2019] [Indexed: 12/27/2022]
Abstract
Formation of eukaryotic initiation factor 4F (eIF4F) is widely considered to be the rate-limiting step in cap-dependent translation initiation. Components of eIF4F are often up-regulated in various cancers, and much work has been done to elucidate the role of each of the translation initiation factors in cancer cell growth and survival. In fact, many of the basic mechanisms describing how eIF4F is assembled and how it functions to regulate translation initiation were first investigated in cancer cell lines. These same eIF4F translational control pathways also are relevant for neuronal signaling that underlies long-lasting synaptic plasticity and memory, and in neurological diseases where eIF4F and its upstream regulators are dysregulated. Although eIF4F is important in cancer and for brain function, there is not always a clear path to use the results of studies performed in cancer models to inform one of the roles that the same translation factors have in neuronal signaling. Issues arise when extrapolating from cell lines to tissue, and differences are likely to exist in how eIF4F and its upstream regulatory pathways are expressed in the diverse neuronal subtypes found in the brain. This review focuses on summarizing the role of eIF4F and its accessory proteins in cancer, and how this information has been utilized to investigate neuronal signaling, synaptic function, and animal behavior. Certain aspects of eIF4F regulation are consistent across cancer and neuroscience, whereas some results are more complicated to interpret, likely due to differences in the complexity of the brain, its billions of neurons and synapses, and its diverse cell types.
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Affiliation(s)
- Ilona R Kats
- Sackler Graduate Program, New York University School of Medicine, New York, New York 10016, USA.,Center for Neural Science, New York University, New York, New York 10003, USA
| | - Eric Klann
- Center for Neural Science, New York University, New York, New York 10003, USA.,NYU Neuroscience Institute, New York University School of Medicine, New York, New York 10016, USA
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10
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Penfold L, Woods A, Muckett P, Nikitin AY, Kent TR, Zhang S, Graham R, Pollard A, Carling D. CAMKK2 Promotes Prostate Cancer Independently of AMPK via Increased Lipogenesis. Cancer Res 2018; 78:6747-6761. [PMID: 30242113 DOI: 10.1158/0008-5472.can-18-0585] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 07/09/2018] [Accepted: 09/18/2018] [Indexed: 02/06/2023]
Abstract
: New targets are required for treating prostate cancer, particularly castrate-resistant disease. Previous studies reported that calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2) expression is increased in human prostate cancer. Here, we show that Camkk2 deletion or pharmacologic inhibition protects against prostate cancer development in a preclinical mouse model that lacks expression of prostate-specific Pten. In contrast, deletion of AMP-activated protein kinase (Ampk) β1 resulted in earlier onset of adenocarcinoma development. These findings suggest for the first time that Camkk2 and Ampk have opposing effects in prostate cancer progression. Loss of CAMKK2 in vivo or in human prostate cancer cells reduced the expression of two key lipogenic enzymes, acetyl-CoA carboxylase and fatty acid synthase. This reduction was mediated via a posttranscriptional mechanism, potentially involving a decrease in protein translation. Moreover, either deletion of CAMKK2 or activation of AMPK reduced cell growth in human prostate cancer cells by inhibiting de novo lipogenesis. Activation of AMPK in a panel of human prostate cancer cells inhibited cell proliferation, migration, and invasion as well as androgen-receptor signaling. These findings demonstrate that CAMKK2 and AMPK have opposing effects on lipogenesis, providing a potential mechanism for their contrasting effects on prostate cancer progression in vivo. They also suggest that inhibition of CAMKK2 combined with activation of AMPK would offer an efficacious therapeutic strategy in treatment of prostate cancer. SIGNIFICANCE: These findings show that CAMKK2 and its downstream target AMPK have opposing effects on prostate cancer development and raise the possibility of a new combined therapeutic approach that inhibits CAMKK2 and activates AMPK.
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Affiliation(s)
- Lucy Penfold
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Angela Woods
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Phillip Muckett
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Alexander Yu Nikitin
- Department of Biomedical Sciences and Cornell Stem Cell Program, Cornell University, Ithaca, New York
| | - Tera R Kent
- Department of Biomedical Sciences and Cornell Stem Cell Program, Cornell University, Ithaca, New York
| | - Shuai Zhang
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Rebecca Graham
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Alice Pollard
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - David Carling
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom. .,Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London, United Kingdom
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11
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Choi JH, Wang W, Park D, Kim SH, Kim KT, Min KT. IRES-mediated translation of cofilin regulates axonal growth cone extension and turning. EMBO J 2018; 37:embj.201695266. [PMID: 29440227 DOI: 10.15252/embj.201695266] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 12/19/2017] [Accepted: 01/05/2018] [Indexed: 11/09/2022] Open
Abstract
In neuronal development, dynamic rearrangement of actin promotes axonal growth cone extension, and spatiotemporal translation of local mRNAs in response to guidance cues directs axonal growth cone steering, where cofilin plays a critical role. While regulation of cofilin activity is well studied, regulatory mechanism for cofilin mRNA translation in neurons is unknown. In eukaryotic cells, proteins can be synthesized by cap-dependent or cap-independent mechanism via internal ribosome entry site (IRES)-mediated translation. IRES-mediated translation has been reported in various pathophysiological conditions, but its role in normal physiological environment is poorly understood. Here, we report that 5'UTR of cofilin mRNA contains an IRES element, and cofilin is predominantly translated by IRES-mediated mechanism in neurons. Furthermore, we show that IRES-mediated translation of cofilin is required for both axon extension and axonal growth cone steering. Our results provide new insights into the function of IRES-mediated translation in neuronal development.
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Affiliation(s)
- Jung-Hyun Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Wei Wang
- Department of Biological Sciences, School of Life Sciences, Ulsan, Korea.,National Creative Research Initiative Center for Proteostasis, Ulsan National Institute of Science and Technology, Ulsan, Korea
| | - Dongkeun Park
- Department of Biological Sciences, School of Life Sciences, Ulsan, Korea.,National Creative Research Initiative Center for Proteostasis, Ulsan National Institute of Science and Technology, Ulsan, Korea
| | - Sung-Hoon Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, Korea
| | - Kyong-Tai Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea .,Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, Korea
| | - Kyung-Tai Min
- Department of Biological Sciences, School of Life Sciences, Ulsan, Korea .,National Creative Research Initiative Center for Proteostasis, Ulsan National Institute of Science and Technology, Ulsan, Korea
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miR-139-5p controls translation in myeloid leukemia through EIF4G2. Oncogene 2015; 35:1822-31. [PMID: 26165837 DOI: 10.1038/onc.2015.247] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 05/21/2015] [Accepted: 05/22/2015] [Indexed: 12/15/2022]
Abstract
MicroRNAs (miRNAs) are crucial components of homeostatic and developmental gene regulation. In turn, dysregulation of miRNA expression is a common feature of different types of cancer, which can be harnessed therapeutically. Here we identify miR-139-5p suppression across several cytogenetically defined acute myeloid leukemia (AML) subgroups. The promoter of mir-139 was transcriptionally silenced and could be reactivated by histone deacetylase inhibitors in a dose-dependent manner. Restoration of mir-139 expression in cell lines representing the major AML subgroups (t[8;21], inv[16], mixed lineage leukemia-rearranged and complex karyotype AML) caused cell cycle arrest and apoptosis in vitro and in xenograft mouse models in vivo. During normal hematopoiesis, mir-139 is exclusively expressed in terminally differentiated neutrophils and macrophages. Ectopic expression of mir-139 repressed proliferation of normal CD34(+)-hematopoietic stem and progenitor cells and perturbed myelomonocytic in vitro differentiation. Mechanistically, mir-139 exerts its effects by repressing the translation initiation factor EIF4G2, thereby reducing overall protein synthesis while specifically inducing the translation of cell cycle inhibitor p27(Kip1). Knockdown of EIF4G2 recapitulated the effects of mir-139, whereas restoring EIF4G2 expression rescued the mir-139 phenotype. Moreover, elevated miR-139-5p expression is associated with a favorable outcome in a cohort of 165 pediatric patients with AML. Thus, mir-139 acts as a global tumor suppressor-miR in AML by controlling protein translation. As AML cells are dependent on high protein synthesis rates controlling the expression of mir-139 constitutes a novel path for the treatment of AML.
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Baucum AJ, Shonesy BC, Rose KL, Colbran RJ. Quantitative proteomics analysis of CaMKII phosphorylation and the CaMKII interactome in the mouse forebrain. ACS Chem Neurosci 2015; 6:615-31. [PMID: 25650780 PMCID: PMC4609176 DOI: 10.1021/cn500337u] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Ca(2+)/calmodulin-dependent protein kinase IIα (CaMKIIα) autophosphorylation at Thr286 and Thr305/Thr306 regulates kinase activity and modulates subcellular targeting and is critical for normal synaptic plasticity and learning and memory. Here, a mass spectrometry-based approach was used to identify Ca(2+)-dependent and -independent in vitro autophosphorylation sites in recombinant CaMKIIα and CaMKIIβ. CaMKII holoenzymes were then immunoprecipitated from subcellular fractions of forebrains isolated from either wild-type (WT) mice or mice with a Thr286 to Ala knock-in mutation of CaMKIIα (T286A-KI mice) and analyzed using the same approach in order to characterize in vivo phosphorylation sites in both CaMKII isoforms and identify CaMKII-associated proteins (CaMKAPs). A total of six and seven autophosphorylation sites in CaMKIIα and CaMKIIβ, respectively, were detected in WT mice. Thr286-phosphorylated CaMKIIα and Thr287-phosphorylated CaMKIIβ were selectively enriched in WT Triton-insoluble (synaptic) fractions compared to Triton-soluble (membrane) and cytosolic fractions. In contrast, Thr306-phosphorylated CaMKIIα and Ser315- and Thr320/Thr321-phosphorylated CaMKIIβ were selectively enriched in WT cytosolic fractions. The T286A-KI mutation significantly reduced levels of phosphorylation of CaMKIIα at Ser275 across all subcellular fractions and of cytosolic CaMKIIβ at Ser315 and Thr320/Thr321. Significantly more CaMKAPs coprecipitated with WT CaMKII holoenzymes in the synaptic fraction compared to that in the membrane fraction, with functions including scaffolding, microtubule organization, actin organization, ribosomal function, vesicle trafficking, and others. The T286A-KI mutation altered the interactions of multiple CaMKAPs with CaMKII, including several proteins linked to autism spectrum disorders. These data identify CaMKII isoform phosphorylation sites and a network of synaptic protein interactions that are sensitive to the abrogation of Thr286 autophosphorylation of CaMKIIα, likely contributing to the diverse synaptic and behavioral deficits of T286A-KI mice.
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Affiliation(s)
- Anthony J Baucum
- ⊥Department of Biology and Stark Neurosciences Research Institute, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, United States
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Dissociation of eIF4E-binding protein 2 (4E-BP2) from eIF4E independent of Thr37/Thr46 phosphorylation in the ischemic stress response. PLoS One 2015; 10:e0121958. [PMID: 25822952 PMCID: PMC4379021 DOI: 10.1371/journal.pone.0121958] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 02/10/2015] [Indexed: 12/22/2022] Open
Abstract
Eukaryotic initiation factor (eIF) 4E-binding proteins (4E-BPs) are translational repressors that bind specifically to eIF4E and are critical in the control of protein translation. 4E-BP2 is the predominant 4E-BP expressed in the brain, but their role is not well known. Here, we characterized four forms of 4E-BP2 detected by two-dimensional gel electrophoresis (2-DGE) in brain. The form with highest electrophoretic mobility was the main form susceptible to phosphorylation at Thr37/Thr46 sites, phosphorylation that was detected in acidic spots. Cerebral ischemia and subsequent reperfusion induced dephosphorylation and phosphorylation of 4E-BP2 at Thr37/Thr46, respectively. The induced phosphorylation was in parallel with the release of 4E-BP2 from eIF4E, although two of the phosphorylated 4E-BP2 forms were bound to eIF4E. Upon long-term reperfusion, there was a decrease in the binding of 4E-BP2 to eIF4E in cerebral cortex, demonstrated by cap binding assays and 4E-BP2-immunoprecipitation experiments. The release of 4E-BP2 from eIF4E was without changes in 4E-BP2 phosphorylation or other post-translational modification recognized by 2-DGE. These findings demonstrated specific changes in 4E-BP2/eIF4E association dependent and independent of 4E-BP2 phosphorylation. The last result supports the notion that phosphorylation may not be the uniquely regulation for the binding of 4E-BP2 to eIF4E under ischemic stress.
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Shatsky IN, Dmitriev SE, Andreev DE, Terenin IM. Transcriptome-wide studies uncover the diversity of modes of mRNA recruitment to eukaryotic ribosomes. Crit Rev Biochem Mol Biol 2014; 49:164-77. [PMID: 24520918 DOI: 10.3109/10409238.2014.887051] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The conventional paradigm of translation initiation in eukaryotes states that the cap-binding protein complex eIF4F (consisting of eIF4E, eIF4G and eIF4A) plays a central role in the recruitment of capped mRNAs to ribosomes. However, a growing body of evidence indicates that this paradigm should be revised. This review summarizes the data which have been mostly accumulated in a post-genomic era owing to revolutionary techniques of transcriptome-wide analysis. Unexpectedly, these techniques have uncovered remarkable diversity in the recruitment of cellular mRNAs to eukaryotic ribosomes. These data enable a preliminary classification of mRNAs into several groups based on their requirement for particular components of eIF4F. They challenge the widely accepted concept which relates eIF4E-dependence to the extent of secondary structure in the 5' untranslated regions of mRNAs. Moreover, some mRNA species presumably recruit ribosomes to their 5' ends without the involvement of either the 5' m(7)G-cap or eIF4F but instead utilize eIF4G or eIF4G-like auxiliary factors. The long-standing concept of internal ribosome entry site (IRES)-elements in cellular mRNAs is also discussed.
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Affiliation(s)
- Ivan N Shatsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University , Moscow , Russia and
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Riascos D, Nicholas A, Samaeekia R, Yukhananov R, Mesulam MM, Bigio EH, Weintraub S, Guo L, Geula C. Alterations of Ca²⁺-responsive proteins within cholinergic neurons in aging and Alzheimer's disease. Neurobiol Aging 2013; 35:1325-33. [PMID: 24461366 DOI: 10.1016/j.neurobiolaging.2013.12.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 12/07/2013] [Accepted: 12/19/2013] [Indexed: 01/05/2023]
Abstract
The molecular basis of selective neuronal vulnerability in Alzheimer's disease (AD) remains poorly understood. Using basal forebrain cholinergic neurons (BFCNs) as a model and immunohistochemistry, we have demonstrated significant age-related loss of the calcium-binding protein calbindin-D(28K) (CB) from BFCN, which was associated with tangle formation and degeneration in AD. Here, we determined alterations in RNA and protein for CB and the Ca(2+)-responsive proteins Ca(2+)/calmodulin-dependent protein kinase I (CaMKI), growth-associated protein-43 (GAP43), and calpain in the BF. We observed progressive downregulation of CB and CaMKI RNA in laser-captured BFCN in the normal-aged-AD continuum. We also detected progressive loss of CB, CaMKIδ, and GAP43 proteins in BF homogenates in aging and AD. Activated μ-calpain, a calcium-sensitive protease that degrades CaMKI and GAP43, was significantly increased in the normal aged BF and was 10 times higher in AD BF. Overactivation of μ-calpain was confirmed using proteolytic fragments of its substrate spectrin. Substantial age- and AD-related alterations in Ca(2+)-sensing proteins most likely contribute to selective vulnerability of BFCN to degeneration in AD.
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Affiliation(s)
- David Riascos
- Cognitive Neurology and Alzheimer's Disease Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Alexander Nicholas
- Department of Medicine, Harvard Medical School and Division of Gerontology, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Ravand Samaeekia
- Cognitive Neurology and Alzheimer's Disease Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | | | - M-Marsel Mesulam
- Cognitive Neurology and Alzheimer's Disease Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Eileen H Bigio
- Cognitive Neurology and Alzheimer's Disease Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Sandra Weintraub
- Cognitive Neurology and Alzheimer's Disease Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Ling Guo
- Cognitive Neurology and Alzheimer's Disease Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Changiz Geula
- Cognitive Neurology and Alzheimer's Disease Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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Gallo G. Mechanisms underlying the initiation and dynamics of neuronal filopodia: from neurite formation to synaptogenesis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 301:95-156. [PMID: 23317818 DOI: 10.1016/b978-0-12-407704-1.00003-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Filopodia are finger-like cellular protrusions found throughout the metazoan kingdom and perform fundamental cellular functions during development and cell migration. Neurons exhibit a wide variety of extremely complex morphologies. In the nervous system, filopodia underlie many major morphogenetic events. Filopodia have roles spanning the initiation and guidance of neuronal processes, axons and dendrites to the formation of synaptic connections. This chapter addresses the mechanisms of the formation and dynamics of neuronal filopodia. Some of the major lessons learned from the study of neuronal filopodia are (1) there are multiple mechanisms that can regulate filopodia in a context-dependent manner, (2) that filopodia are specialized subcellular domains, (3) that filopodia exhibit dynamic membrane recycling which also controls aspects of filopodial dynamics, (4) that neuronal filopodia contain machinery for the orchestration of the actin and microtubule cytoskeleton, and (5) localized protein synthesis contributes to neuronal filopodial dynamics.
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Affiliation(s)
- Gianluca Gallo
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair and Rehabilitation, Department of Anatomy and Cell Biology, Temple University, Philadelphia, PA, USA.
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