1
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Mars JC, Culjkovic-Kraljacic B, Borden KL. eIF4E orchestrates mRNA processing, RNA export and translation to modify specific protein production. Nucleus 2024; 15:2360196. [PMID: 38880976 PMCID: PMC11185188 DOI: 10.1080/19491034.2024.2360196] [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: 02/12/2024] [Accepted: 05/22/2024] [Indexed: 06/18/2024] Open
Abstract
The eukaryotic translation initiation factor eIF4E acts as a multifunctional factor that simultaneously influences mRNA processing, export, and translation in many organisms. Its multifactorial effects are derived from its capacity to bind to the methyl-7-guanosine cap on the 5'end of mRNAs and thus can act as a cap chaperone for transcripts in the nucleus and cytoplasm. In this review, we describe the multifactorial roles of eIF4E in major mRNA-processing events including capping, splicing, cleavage and polyadenylation, nuclear export and translation. We discuss the evidence that eIF4E acts at two levels to generate widescale changes to processing, export and ultimately the protein produced. First, eIF4E alters the production of components of the mRNA processing machinery, supporting a widescale reprogramming of multiple mRNA processing events. In this way, eIF4E can modulate mRNA processing without physically interacting with target transcripts. Second, eIF4E also physically interacts with both capped mRNAs and components of the RNA processing or translation machineries. Further, specific mRNAs are sensitive to eIF4E only in particular mRNA processing events. This selectivity is governed by the presence of cis-acting elements within mRNAs known as USER codes that recruit relevant co-factors engaging the appropriate machinery. In all, we describe the molecular bases for eIF4E's multifactorial function and relevant regulatory pathways, discuss the basis for selectivity, present a compendium of ~80 eIF4E-interacting factors which play roles in these activities and provide an overview of the relevance of its functions to its oncogenic potential. Finally, we summarize early-stage clinical studies targeting eIF4E in cancer.
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Affiliation(s)
- Jean-Clément Mars
- Institute of Research in Immunology and Cancer, Department of Pathology and Cell Biology, Université de Montréal, Montréal, QC, Canada
| | - Biljana Culjkovic-Kraljacic
- Institute of Research in Immunology and Cancer, Department of Pathology and Cell Biology, Université de Montréal, Montréal, QC, Canada
| | - Katherine L.B. Borden
- Institute of Research in Immunology and Cancer, Department of Pathology and Cell Biology, Université de Montréal, Montréal, QC, Canada
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2
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Mir DA, Ma Z, Horrocks J, Rogers AN. Stress-induced Eukaryotic Translational Regulatory Mechanisms. ARXIV 2024:arXiv:2405.01664v1. [PMID: 38745702 PMCID: PMC11092689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The eukaryotic protein synthesis process entails intricate stages governed by diverse mechanisms to tightly regulate translation. Translational regulation during stress is pivotal for maintaining cellular homeostasis, ensuring the accurate expression of essential proteins crucial for survival. This selective translational control mechanism is integral to cellular adaptation and resilience under adverse conditions. This review manuscript explores various mechanisms involved in selective translational regulation, focusing on mRNA-specific and global regulatory processes. Key aspects of translational control include translation initiation, which is often a rate-limiting step, and involves the formation of the eIF4F complex and recruitment of mRNA to ribosomes. Regulation of translation initiation factors, such as eIF4E, eIF4E2, and eIF2, through phosphorylation and interactions with binding proteins, modulates translation efficiency under stress conditions. This review also highlights the control of translation initiation through factors like the eIF4F complex and the ternary complex and also underscores the importance of eIF2α phosphorylation in stress granule formation and cellular stress responses. Additionally, the impact of amino acid deprivation, mTOR signaling, and ribosome biogenesis on translation regulation and cellular adaptation to stress is also discussed. Understanding the intricate mechanisms of translational regulation during stress provides insights into cellular adaptation mechanisms and potential therapeutic targets for various diseases, offering valuable avenues for addressing conditions associated with dysregulated protein synthesis.
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Affiliation(s)
- Dilawar Ahmad Mir
- Kathryn W. Davis Center for Regenerative Biology and Aging, Mount Desert Island Biological Laboratory, Bar Harbor, ME
| | - Zhengxin Ma
- Kathryn W. Davis Center for Regenerative Biology and Aging, Mount Desert Island Biological Laboratory, Bar Harbor, ME
| | - Jordan Horrocks
- Kathryn W. Davis Center for Regenerative Biology and Aging, Mount Desert Island Biological Laboratory, Bar Harbor, ME
| | - Aric N Rogers
- Kathryn W. Davis Center for Regenerative Biology and Aging, Mount Desert Island Biological Laboratory, Bar Harbor, ME
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3
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Borden KLB. The eukaryotic translation initiation factor eIF4E unexpectedly acts in splicing thereby coupling mRNA processing with translation: eIF4E induces widescale splicing reprogramming providing system-wide connectivity between splicing, nuclear mRNA export and translation. Bioessays 2024; 46:e2300145. [PMID: 37926700 PMCID: PMC11021180 DOI: 10.1002/bies.202300145] [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: 08/02/2023] [Revised: 10/17/2023] [Accepted: 10/24/2023] [Indexed: 11/07/2023]
Abstract
Recent findings position the eukaryotic translation initiation factor eIF4E as a novel modulator of mRNA splicing, a process that impacts the form and function of resultant proteins. eIF4E physically interacts with the spliceosome and with some intron-containing transcripts implying a direct role in some splicing events. Moreover, eIF4E drives the production of key components of the splicing machinery underpinning larger scale impacts on splicing. These drive eIF4E-dependent reprogramming of the splicing signature. This work completes a series of studies demonstrating eIF4E acts in all the major mRNA maturation steps whereby eIF4E drives production of the RNA processing machinery and escorts some transcripts through various maturation steps. In this way, eIF4E couples the mRNA processing-export-translation axis linking nuclear mRNA processing to cytoplasmic translation. eIF4E elevation is linked to worse outcomes in acute myeloid leukemia patients where these activities are dysregulated. Understanding these effects provides new insight into post-transcriptional control and eIF4E-driven cancers.
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Affiliation(s)
- Katherine L. B. Borden
- Institute for Research in Immunology and Cancer and Department of Pathology and Cell BiologyUniversity of MontrealMontrealQuebecCanada
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4
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Hernández G, Vazquez-Pianzola P. eIF4E as a molecular wildcard in metazoans RNA metabolism. Biol Rev Camb Philos Soc 2023; 98:2284-2306. [PMID: 37553111 DOI: 10.1111/brv.13005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 07/01/2023] [Accepted: 07/25/2023] [Indexed: 08/10/2023]
Abstract
The evolutionary origin of eukaryotes spurred the transition from prokaryotic-like translation to a more sophisticated, eukaryotic translation. During this process, successive gene duplication of a single, primordial eIF4E gene encoding the mRNA cap-binding protein eukaryotic translation initiation factor 4E (eIF4E) gave rise to a plethora of paralog genes across eukaryotes that underwent further functional diversification in RNA metabolism. The ability to take different roles is due to eIF4E promiscuity in binding many partner proteins, rendering eIF4E a highly versatile and multifunctional player that functions as a molecular wildcard. Thus, in metazoans, eIF4E paralogs are involved in various processes, including messenger RNA (mRNA) processing, export, translation, storage, and decay. Moreover, some paralogs display differential expression in tissues and developmental stages and show variable biochemical properties. In this review, we discuss recent advances shedding light on the functional diversification of eIF4E in metazoans. We emphasise humans and two phylogenetically distant species which have become paradigms for studies on development, namely the fruit fly Drosophila melanogaster and the roundworm Caenorhabditis elegans.
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Affiliation(s)
- Greco Hernández
- mRNA and Cancer Laboratory, Unit of Biomedical Research on Cancer, National Institute of Cancer (Instituto Nacional de Cancerología, INCan), 22 San Fernando Ave., Tlalpan, Mexico City, 14080, Mexico
| | - Paula Vazquez-Pianzola
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, Berne, 3012, Switzerland
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5
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Mghezzi-Habellah M, Prochasson L, Jalinot P, Mocquet V. Viral Subversion of the Chromosome Region Maintenance 1 Export Pathway and Its Consequences for the Cell Host. Viruses 2023; 15:2218. [PMID: 38005895 PMCID: PMC10674744 DOI: 10.3390/v15112218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/28/2023] [Accepted: 11/01/2023] [Indexed: 11/26/2023] Open
Abstract
In eukaryotic cells, the spatial distribution between cytoplasm and nucleus is essential for cell homeostasis. This dynamic distribution is selectively regulated by the nuclear pore complex (NPC), which allows the passive or energy-dependent transport of proteins between these two compartments. Viruses possess many strategies to hijack nucleocytoplasmic shuttling for the benefit of their viral replication. Here, we review how viruses interfere with the karyopherin CRM1 that controls the nuclear export of protein cargoes. We analyze the fact that the viral hijacking of CRM1 provokes are-localization of numerous cellular factors in a suitable place for specific steps of viral replication. While CRM1 emerges as a critical partner for viruses, it also takes part in antiviral and inflammatory response regulation. This review also addresses how CRM1 hijacking affects it and the benefits of CRM1 inhibitors as antiviral treatments.
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Affiliation(s)
| | | | | | - Vincent Mocquet
- Laboratoire de Biologie et Modélisation de la Cellule, Ecole Normale Supérieure-Lyon, Université Claude Bernard Lyon, U1293, UMR5239, 69364 Lyon, France; (M.M.-H.); (L.P.); (P.J.)
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6
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Zuberek J, Warzecha M, Dobrowolski M, Modrak-Wojcik A. An intramolecular disulphide bond in human 4E-T affects its binding to eIF4E1a protein. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2023; 52:497-510. [PMID: 37798395 PMCID: PMC10618305 DOI: 10.1007/s00249-023-01684-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 09/14/2023] [Accepted: 09/16/2023] [Indexed: 10/07/2023]
Abstract
The cap at the 5'terminus of mRNA is a key determinant of gene expression in eukaryotic cells, which among others is required for cap dependent translation and protects mRNA from degradation. These properties of cap are mediated by several proteins. One of them is 4E-Transporter (4E-T), which plays an important role in translational repression, mRNA decay and P-bodies formation. 4E-T is also one of several proteins that interact with eukaryotic initiation factor 4E (eIF4E), a cap binding protein which is a key component of the translation initiation machinery. The molecular mechanisms underlying the interactions of these two proteins are crucial for mRNA processing. Studying the interactions between human eIF4E1a and the N-terminal fragment of 4E-T that possesses unstructured 4E-binding motifs under non-reducing conditions, we observed that 4E-T preferentially forms an intramolecular disulphide bond. This "disulphide loop" reduces affinity of 4E-T for eIF4E1a by about 300-fold. Considering that only human 4E-T possesses two cysteines located between the 4E binding motifs, we proposed that the disulphide bond may act as a switch to regulate interactions between the two proteins.
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Affiliation(s)
- Joanna Zuberek
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland.
| | - Marek Warzecha
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
| | - Mateusz Dobrowolski
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
| | - Anna Modrak-Wojcik
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
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7
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Cárdenas EL, O'Rourke RL, Menon A, Meagher J, Stuckey J, Garner AL. Design of Cell-Permeable Inhibitors of Eukaryotic Translation Initiation Factor 4E (eIF4E) for Inhibiting Aberrant Cap-Dependent Translation in Cancer. J Med Chem 2023; 66:10734-10745. [PMID: 37471629 DOI: 10.1021/acs.jmedchem.3c00917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Eukaryotic translation initiation factor 4E (eIF4E) is an RNA-binding protein that binds to the m7GpppX-cap at the 5' terminus of coding mRNAs to initiate cap-dependent translation. While all cells require cap-dependent translation, cancer cells become addicted to enhanced translational capacity, driving the production of oncogenic proteins involved in proliferation, evasion of apoptosis, metastasis, and angiogenesis, among other cancerous phenotypes. eIF4E is the rate-limiting translation factor, and its activation has been shown to drive cancer initiation, progression, metastasis, and drug resistance. These findings have established eIF4E as a translational oncogene and promising, albeit challenging, anti-cancer therapeutic target. Although significant effort has been put forth toward inhibiting eIF4E, the design of cell-permeable, cap-competitive inhibitors remains a challenge. Herein, we describe our work toward solving this long-standing challenge. By employing an acyclic nucleoside phosphonate prodrug strategy, we report the synthesis of cell-permeable inhibitors of eIF4E binding to capped mRNA to inhibit cap-dependent translation.
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Affiliation(s)
- Emilio L Cárdenas
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Rachel L O'Rourke
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Arya Menon
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jennifer Meagher
- Life Science Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jeanne Stuckey
- Life Science Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Amanda L Garner
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
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8
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Solodushko V, Fouty B. Terminal hairpins improve protein expression in IRES-initiated mRNA in the absence of a cap and polyadenylated tail. Gene Ther 2023; 30:620-627. [PMID: 36828937 PMCID: PMC9951143 DOI: 10.1038/s41434-023-00391-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 01/31/2023] [Accepted: 02/08/2023] [Indexed: 02/26/2023]
Abstract
Synthesizing mRNA in vitro is a standard and simple procedure. Adding the 5' cap and 3' polyadenylated (poly(A)) tail to make this mRNA functional for use as a vaccine or therapy increases the time and cost of production and usually decreases the yield, however. We designed mRNA that lacked a cap and poly(A) tail but included an internal ribosomal entry site (IRES) to initiate protein translation. To protect the 5' and 3' ends of mRNA from exonucleases, we added stable terminal hairpins. When compared against typical mRNA (i.e., mRNA that contained a cap and poly(A) tail but lacked hairpins), expression of the delivered reporter protein in HEK293 cells was similar. Using a triple instead of a single hairpin at each end increased protein expression even more. This method has the potential to simplify the production and reduce the cost of synthesizing exogenous mRNA for use as biologics or vaccines.
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Affiliation(s)
- Victor Solodushko
- Department of Pharmacology, University of South Alabama School of Medicine, Mobile, AL, 36688, USA.
- The Center for Lung Biology, University of South Alabama School of Medicine, Mobile, AL, 36688, USA.
| | - Brian Fouty
- Department of Pharmacology, University of South Alabama School of Medicine, Mobile, AL, 36688, USA.
- The Center for Lung Biology, University of South Alabama School of Medicine, Mobile, AL, 36688, USA.
- Department of Internal Medicine, University of South Alabama School of Medicine, Mobile, AL, 36688, USA.
- The Division of Pulmonary and Critical Care Medicine, University of South Alabama School of Medicine, Mobile, AL, 36688, USA.
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9
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Jin L, Kashyap MP, Chen Y, Khan J, Guo Y, Chen JQ, Lee MB, Weng Z, Oak A, Patcha P, Mayo T, Sinha R, Atigadda V, Mukhtar SM, Deshane JS, Raman C, Elston C, Elewski BE, Elmets CA, Athar M. Mechanism underlying follicular hyperproliferation and oncogenesis in hidradenitis suppurativa. iScience 2023; 26:106896. [PMID: 37332597 PMCID: PMC10275975 DOI: 10.1016/j.isci.2023.106896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 04/23/2023] [Accepted: 05/12/2023] [Indexed: 06/20/2023] Open
Abstract
Hidradenitis suppurativa (HS) is a skin disorder that causes chronic painful inflammation and hyperproliferation, often with the comorbidity of invasive keratoacanthoma (KA). Our research, employing high-resolution immunofluorescence and data science approaches together with confirmatory molecular analysis, has identified that the 5'-cap-dependent protein translation regulatory complex eIF4F is a key factor in the development of HS and is responsible for regulating follicular hyperproliferation. Specifically, eIF4F translational targets, Cyclin D1 and c-MYC, orchestrate the development of HS-associated KA. Although eIF4F and p-eIF4E are contiguous throughout HS lesions, Cyclin D1 and c-MYC have unique spatial localization and functions. The keratin-filled crater of KA is formed by nuclear c-MYC-induced differentiation of epithelial cells, whereas the co-localization of c-MYC and Cyclin D1 provides oncogenic transformation by activating RAS, PI3K, and ERK pathways. In sum, we have revealed a novel mechanism underlying HS pathogenesis of follicular hyperproliferation and the development of HS-associated invasive KA.
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Affiliation(s)
- Lin Jin
- Center for Epigenomics and Translational Research in Inflammatory Skin Diseases, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- UAB Research Center of Excellence in Arsenicals, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Mahendra P. Kashyap
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- UAB Research Center of Excellence in Arsenicals, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Yunjia Chen
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jasim Khan
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- UAB Research Center of Excellence in Arsenicals, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Yuanyuan Guo
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- UAB Research Center of Excellence in Arsenicals, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jari Q. Chen
- Hoover High School, Hoover, Birmingham, AL 35244, USA
| | - Madison B. Lee
- School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Zhiping Weng
- Center for Epigenomics and Translational Research in Inflammatory Skin Diseases, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- UAB Research Center of Excellence in Arsenicals, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Allen Oak
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Prasanth Patcha
- Division of Plastic Surgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Tiffany Mayo
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Rajesh Sinha
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- UAB Research Center of Excellence in Arsenicals, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Venkatram Atigadda
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Shahid M. Mukhtar
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jessy S. Deshane
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Chander Raman
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Carly Elston
- Department of Dermatology and Dermatopathology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Boni E. Elewski
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Craig A. Elmets
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Mohammad Athar
- Center for Epigenomics and Translational Research in Inflammatory Skin Diseases, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- UAB Research Center of Excellence in Arsenicals, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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10
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Khan M, Hou S, Chen M, Lei H. Mechanisms of RNA export and nuclear retention. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1755. [PMID: 35978483 DOI: 10.1002/wrna.1755] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 06/21/2022] [Accepted: 07/06/2022] [Indexed: 05/13/2023]
Abstract
With the identification of huge amount of noncoding RNAs in recent years, the concept of RNA localization has extended from traditional mRNA export to RNA export of mRNA and ncRNA as well as nuclear retention of ncRNA. This review aims to summarize the recent findings from studies on the mechanisms of export of different RNAs and nuclear retention of some lncRNAs in higher eukaryotes, with a focus on splicing-dependent TREX recruitment for the export of spliced mRNA and the sequence-dependent mechanism of mRNA export in the absence of splicing. In addition, evidence to support the involvement of m6 A modification in RNA export with the coordination between the methylase complex and TREX complex as well as sequence-dependent nuclear retention of lncRNA is recapitulated. Finally, a model of sequence-dependent RNA localization is proposed along with the many questions that remain to be answered. This article is categorized under: RNA Export and Localization > RNA Localization RNA Export and Localization > Nuclear Export/Import.
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Affiliation(s)
- Misbah Khan
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, China
| | - Shuai Hou
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, China
| | - Mo Chen
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, China
| | - Haixin Lei
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, China
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11
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Yang G, Xin Q, Feng I, Wu D, Dean J. Germ cell-specific eIF4E1b regulates maternal mRNA translation to ensure zygotic genome activation. Genes Dev 2023; 37:418-431. [PMID: 37257918 PMCID: PMC10270193 DOI: 10.1101/gad.350400.123] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 05/11/2023] [Indexed: 06/02/2023]
Abstract
Translation of maternal mRNAs is detected before transcription of zygotic genes and is essential for mammalian embryo development. How certain maternal mRNAs are selected for translation instead of degradation and how this burst of translation affects zygotic genome activation remain unknown. Using gene-edited mice, we document that the oocyte-specific eukaryotic translation initiation factor 4E family member 1b (eIF4E1b) is the regulator of maternal mRNA expression that ensures subsequent reprogramming of the zygotic genome. In oocytes, eIF4E1b binds to transcripts encoding translation machinery proteins, chromatin remodelers, and reprogramming factors to promote their translation in zygotes and protect them from degradation. The protein products are thought to establish an open chromatin landscape in one-cell zygotes to enable transcription of genes required for cleavage stage development. Our results define a program for rapid resetting of the zygotic epigenome that is regulated by maternal mRNA expression and provide new insights into the mammalian maternal-to-zygotic transition.
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Affiliation(s)
- Guanghui Yang
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Qiliang Xin
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Iris Feng
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Di Wu
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Jurrien Dean
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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12
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Xu R, Li X, Huang X, Lin Z, Xiong Y, Chen X, Chu C, Han J, Wang F. Translation-Dependent Skin Hyperplasia Is Promoted by Type 1/17 Inflammation in Psoriasis. J Dermatol Sci 2023; 110:10-18. [PMID: 37024314 DOI: 10.1016/j.jdermsci.2023.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 02/21/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023]
Abstract
BACKGROUND Psoriasis vulgaris (PV) is a chronic skin inflammatory disease and characterized by aberrant epidermal hyperplasia. The molecule eukaryotic initiation factor (eIF) 4E controls translation initiation of certain protein synthesis and determines cell cycle or differentiation fate. OBJECTIVE To determine the role of eIF4E in keratinocytes abnormal differentiation in the context of psoriasis. METHODS The expression of eIF4E in psoriatic skin lesions and normal skin from human subjects was examined by western blot and immunohistochemistry. In a murine model of psoriasis-like dermatitis that is induced by topical imiquimod, 4EGI-1 was used to inhibit eIF4E activities. To measure murine skin eIF4E and keratinocytes differentiation, immunofluorescence and western blot assays were conducted. Normal human epidermal keratinocytes (NHEK) were isolated, cultured, and stimulated with cytokines including TNF-α, IFN-γ, and IL-17A, respectively. Immunofluorescence and western blot were performed to test eIF4E and effect of 4EGI-1 in a co-culture system. RESULTS Compared with healthy controls, skin lesions from patients with PV exhibited a higher expression of eIF4E, which was positively correlated with the epidermal thickness. This expression pattern of eIF4E was replicated by the imiquimod-induced murine model. Skin hyperplasia and eIF4E activities in the murine model were attenuated by the administration of 4EGI-1. Both IFN-γ and IL-17A, rather than TNF-α, are sufficient to induce NHEK abnormal differentiation. This effect can be disrupted by 4EGI-1. CONCLUSION eIF4E plays a crucial role in keratinocytes abnormal differentiation driven by type 1/17 inflammation in the context of psoriasis. The initiation of abnormal translation provides an alternative treatment target for psoriasis.
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13
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Ghram M, Morris G, Culjkovic-Kraljacic B, Mars JC, Gendron P, Skrabanek L, Revuelta MV, Cerchietti L, Guzman ML, Borden KLB. The eukaryotic translation initiation factor eIF4E reprograms alternative splicing. EMBO J 2023; 42:e110496. [PMID: 36843541 PMCID: PMC10068332 DOI: 10.15252/embj.2021110496] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 02/28/2023] Open
Abstract
Aberrant splicing is typically attributed to splice-factor (SF) mutation and contributes to malignancies including acute myeloid leukemia (AML). Here, we discovered a mutation-independent means to extensively reprogram alternative splicing (AS). We showed that the dysregulated expression of eukaryotic translation initiation factor eIF4E elevated selective splice-factor production, thereby impacting multiple spliceosome complexes, including factors mutated in AML such as SF3B1 and U2AF1. These changes generated a splicing landscape that predominantly supported altered splice-site selection for ~800 transcripts in cell lines and ~4,600 transcripts in specimens from high-eIF4E AML patients otherwise harboring no known SF mutations. Nuclear RNA immunoprecipitations, export assays, polysome analyses, and mutational studies together revealed that eIF4E primarily increased SF production via its nuclear RNA export activity. By contrast, eIF4E dysregulation did not induce known SF mutations or alter spliceosome number. eIF4E interacted with the spliceosome and some pre-mRNAs, suggesting its direct involvement in specific splicing events. eIF4E induced simultaneous effects on numerous SF proteins, resulting in a much larger range of splicing alterations than in the case of mutation or dysregulation of individual SFs and providing a novel paradigm for splicing control and dysregulation.
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Affiliation(s)
- Mehdi Ghram
- Department of Pathology and Cell Biology, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, QC, Canada.,Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC, Canada
| | - Gavin Morris
- Department of Pathology and Cell Biology, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, QC, Canada.,Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC, Canada
| | - Biljana Culjkovic-Kraljacic
- Department of Pathology and Cell Biology, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, QC, Canada.,Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC, Canada
| | - Jean-Clement Mars
- Department of Pathology and Cell Biology, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, QC, Canada.,Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC, Canada
| | - Patrick Gendron
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC, Canada
| | - Lucy Skrabanek
- Department of Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA.,Applied Bioinformatics Core, Weill Cornell Medicine, New York, NY, USA
| | - Maria Victoria Revuelta
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Leandro Cerchietti
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Monica L Guzman
- Division of Hematology/Oncology, Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Katherine L B Borden
- Department of Pathology and Cell Biology, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, QC, Canada.,Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC, Canada
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14
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Song Z, Lin J, Su R, Ji Y, Jia R, Li S, Shan G, Huang C. eIF3j inhibits translation of a subset of circular RNAs in eukaryotic cells. Nucleic Acids Res 2022; 50:11529-11549. [PMID: 36330957 PMCID: PMC9723666 DOI: 10.1093/nar/gkac980] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/04/2022] [Accepted: 10/17/2022] [Indexed: 11/06/2022] Open
Abstract
Increasing studies have revealed that a subset of circular RNAs (circRNAs) harbor an open reading frame and can act as protein-coding templates to generate functional proteins that are closely associated with multiple physiological and disease-relevant processes, and thus proper regulation of synthesis of these circRNA-derived proteins is a fundamental cellular process required for homeostasis maintenance. However, how circRNA translation initiation is coordinated by different trans-acting factors remains poorly understood. In particular, the impact of different eukaryotic translation initiation factors (eIFs) on circRNA translation and the physiological relevance of this distinct regulation have not yet been characterized. In this study, we screened all 43 Drosophila eIFs and revealed the conflicting functions of eIF3 subunits in the translational control of the translatable circRNA circSfl: eIF3 is indispensable for circSfl translation, while the eIF3-associated factor eIF3j is the most potent inhibitor. Mechanistically, the binding of eIF3j to circSfl promotes the disassociation of eIF3. The C-terminus of eIF3j and an RNA regulon within the circSfl untranslated region (UTR) are essential for the inhibitory effect of eIF3j. Moreover, we revealed the physiological relevance of eIF3j-mediated circSfl translation repression in response to heat shock. Finally, additional translatable circRNAs were identified to be similarly regulated in an eIF3j-dependent manner. Altogether, our study provides a significant insight into the field of cap-independent translational regulation and undiscovered functions of eIF3.
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Affiliation(s)
| | | | - Rui Su
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Yu Ji
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Ruirui Jia
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Shi Li
- School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Ge Shan
- School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Chuan Huang
- To whom correspondence should be addressed. Tel: +86 19956025374;
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15
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Zhang S, Yang X, Jiang M, Ma L, Hu J, Zhang HH. Post-transcriptional control by RNA-binding proteins in diabetes and its related complications. Front Physiol 2022; 13:953880. [PMID: 36277184 PMCID: PMC9582753 DOI: 10.3389/fphys.2022.953880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 09/20/2022] [Indexed: 11/25/2022] Open
Abstract
Diabetes mellitus (DM) is a fast-growing chronic metabolic disorder that leads to significant health, social, and economic problems worldwide. Chronic hyperglycemia caused by DM leads to multiple devastating complications, including macrovascular complications and microvascular complications, such as diabetic cardiovascular disease, diabetic nephropathy, diabetic neuropathy, and diabetic retinopathy. Numerous studies provide growing evidence that aberrant expression of and mutations in RNA-binding proteins (RBPs) genes are linked to the pathogenesis of diabetes and associated complications. RBPs are involved in RNA processing and metabolism by directing a variety of post-transcriptional events, such as alternative splicing, stability, localization, and translation, all of which have a significant impact on RNA fate, altering their function. Here, we purposed to summarize the current progression and underlying regulatory mechanisms of RBPs in the progression of diabetes and its complications. We expected that this review will open the door for RBPs and their RNA networks as novel therapeutic targets for diabetes and its related complications.
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Affiliation(s)
- Shiyu Zhang
- Department of Endocrinology, The Second Affiliated Hospital, Soochow University, Suzhou, China
| | - Xiaohua Yang
- The Affiliated Haian Hospital of Nantong University, Nantong, China
| | - Miao Jiang
- Department of Endocrinology, The Second Affiliated Hospital, Soochow University, Suzhou, China
| | - Lianhua Ma
- Department of Endocrinology, The Second Affiliated Hospital, Soochow University, Suzhou, China
| | - Ji Hu
- Department of Endocrinology, The Second Affiliated Hospital, Soochow University, Suzhou, China,*Correspondence: Ji Hu, ; Hong-Hong Zhang,
| | - Hong-Hong Zhang
- Department of Endocrinology, The Second Affiliated Hospital, Soochow University, Suzhou, China,*Correspondence: Ji Hu, ; Hong-Hong Zhang,
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16
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Dimitriou ID, Meiri D, Jitkova Y, Elford AR, Koritzinsky M, Schimmer AD, Ohashi PS, Sonenberg N, Rottapel R. Translational Control by 4E-BP1/2 Suppressor Proteins Regulates Mitochondrial Biosynthesis and Function during CD8 + T Cell Proliferation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:2702-2712. [PMID: 35667842 DOI: 10.4049/jimmunol.2101090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 04/03/2022] [Indexed: 06/15/2023]
Abstract
CD8+ T cell proliferation and differentiation into effector and memory states are high-energy processes associated with changes in cellular metabolism. CD28-mediated costimulation of T cells activates the PI3K/AKT/mammalian target of rapamycin signaling pathway and induces eukaryotic translation initiation factor 4E-dependent translation through the derepression by 4E-BP1 and 4E-BP2. In this study, we demonstrate that 4E-BP1/2 proteins are required for optimum proliferation of mouse CD8+ T cells and the development of an antiviral effector function. We show that translation of genes encoding mitochondrial biogenesis is impaired in T cells derived from 4E-BP1/2-deficient mice. Our findings demonstrate an unanticipated role for 4E-BPs in regulating a metabolic program that is required for cell growth and biosynthesis during the early stages of CD8+ T cell expansion.
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Affiliation(s)
- Ioannis D Dimitriou
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - David Meiri
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Yulia Jitkova
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Alisha R Elford
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Marianne Koritzinsky
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Aaron D Schimmer
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Pamela S Ohashi
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
- Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada
| | - Robert Rottapel
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada;
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada; and
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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17
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Das S. Analysis of domain organization and functional signatures of trypanosomatid keIF4Gs. Mol Cell Biochem 2022; 477:2415-2431. [PMID: 35585276 DOI: 10.1007/s11010-022-04464-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 05/02/2022] [Indexed: 11/25/2022]
Abstract
Translation initiation is the first step in three essential processes leading to protein synthesis. It is carried out by proteins called translation initiation factors and ribosomes on the mRNA. One of the critical translation initiation factors in eukaryotes is eIF4G which is a scaffold protein that helps assemble translation initiation complexes that carry out translation initiation which ultimately leads to polypeptide synthesis. Trypanosomatids are a large family of kinetoplastids, some of which are protozoan parasites that cause diseases in humans through transmission by vectors. While the protein translation mechanisms in eukaryotes and prokaryotes are well understood, the protein translation factors and mechanisms in trypanosomatids are poorly understood necessitating further studies. Unlike other eukaryotes, trypanosomatids contain five eIF4G orthologues with diversity in length and sequences. Here, I have used bioinformatics tools to look at trypanosomatid keIF4G orthologue sequences and report that there are similarities and considerable differences in their domains/motifs organization and signature amino acid sequences that are required for different functions as compared to human eIF4G. My analysis suggests that there is likely to be considerable diversity and complexity in trypanosomatid keIF4G functions as compared to other eukaryotes.
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Affiliation(s)
- Supratik Das
- Infection and Immunology, Translational Health Science and Technology Institute, Faridabad, Haryana, 121001, India.
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, PO Box #04, Faridabad, Haryana, 121001, India.
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18
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Hernández G. The versatile relationships between eIF4E and eIF4E-interacting proteins. Trends Genet 2022; 38:801-804. [PMID: 35568601 DOI: 10.1016/j.tig.2022.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 04/10/2022] [Accepted: 04/11/2022] [Indexed: 11/18/2022]
Abstract
RNA metabolism and gene expression lie at the core of cellular life. eIF4E has emerged as a central interface in both processes as it plays critical roles in mRNA processing, transport, translation, and storage. Crucially, eIF4E depends on its association with a universe of proteins to form biologically meaningful complexes.
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Affiliation(s)
- Greco Hernández
- Translation and Cancer Laboratory, Unit of Biomedical Research on Cancer, National Institute of Cancer (Instituto Nacional de Cancerología, INCan). 22 San Fernando Avenue, Tlalpan, 14080-Mexico City, Mexico.
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19
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Advances in the Treatment of Relapsed and Refractory Multiple Myeloma in Patients with Renal Insufficiency: Novel Agents, Immunotherapies and Beyond. Cancers (Basel) 2021; 13:cancers13205036. [PMID: 34680184 PMCID: PMC8533858 DOI: 10.3390/cancers13205036] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/19/2021] [Accepted: 09/29/2021] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Renal insufficiency is one of the most frequent complications in multiple myeloma. The incidence of renal insufficiency in patients with multiple myeloma ranges from 20% to 50%. Renal impairment in patients with multiple myeloma results primarily from the toxic effects of monoclonal light chains on the kidneys. Dehydration, hypercalcemia, hyperuricemia, the application of nephrotoxic NSARs, antibiotics, contrast agents, etc., all play a major role in the deterioration of renal function in patients with multiple myeloma. The diagnosis and treatment of these patients use an interdisciplinary approach in consultation with hematologist-oncologists, radiologists, nephrologists and intensive care specialists. Using new drugs in the treatment of patients with refractory/relapsed multiple myeloma and renal insufficiency markedly improves progression-free survival and overall survival in these patients. CONCLUSIONS New drugs have helped to widen the treatment options available for patients with renal impairment and refractory/relapsed multiple myeloma, since dose adjustments are unnecessary with carfilzomib as well as with panobinostat, elotuzumab, pomalidomide or daratumumab in patients with renal impairment. Several new substances for the treatment of refractory/relapsed multiple myeloma have been approved in the meantime, including belantamab mafodotin, selinexor, melflufen, venetoclax, CAR T-cell therapy and checkpoint inhibitors. Ongoing studies are investigating their administration in patients with renal impairment.
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20
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Lang YD, Jou YS. PSPC1 is a new contextual determinant of aberrant subcellular translocation of oncogenes in tumor progression. J Biomed Sci 2021; 28:57. [PMID: 34340703 PMCID: PMC8327449 DOI: 10.1186/s12929-021-00753-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 07/24/2021] [Indexed: 12/30/2022] Open
Abstract
Dysregulation of nucleocytoplasmic shuttling is commonly observed in cancers and emerging as a cancer hallmark for the development of anticancer therapeutic strategies. Despite its severe adverse effects, selinexor, a selective first-in-class inhibitor of the common nuclear export receptor XPO1, was developed to target nucleocytoplasmic protein shuttling and received accelerated FDA approval in 2019 in combination with dexamethasone as a fifth-line therapeutic option for adults with relapsed refractory multiple myeloma (RRMM). To explore innovative targets in nucleocytoplasmic shuttling, we propose that the aberrant contextual determinants of nucleocytoplasmic shuttling, such as PSPC1 (Paraspeckle component 1), TGIF1 (TGF-β Induced Factor Homeobox 1), NPM1 (Nucleophosmin), Mortalin and EBP50, that modulate shuttling (or cargo) proteins with opposite tumorigenic functions in different subcellular locations could be theranostic targets for developing anticancer strategies. For instance, PSPC1 was recently shown to be the contextual determinant of the TGF-β prometastatic switch and PTK6/β-catenin reciprocal oncogenic nucleocytoplasmic shuttling during hepatocellular carcinoma (HCC) progression. The innovative nucleocytoplasmic shuttling inhibitor PSPC1 C-terminal 131 polypeptide (PSPC1-CT131), which was developed to target both the shuttling determinant PSPC1 and the shuttling protein PTK6, maintained their tumor-suppressive characteristics and exhibited synergistic effects on tumor suppression in HCC cells and mouse models. In summary, targeting the contextual determinants of nucleocytoplasmic shuttling with cargo proteins having opposite tumorigenic functions in different subcellular locations could be an innovative strategy for developing new therapeutic biomarkers and agents to improve cancer therapy.
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Affiliation(s)
- Yaw-Dong Lang
- Institute of Biomedical Sciences, Academia Sinica, 11529, Taipei, Taiwan
| | - Yuh-Shan Jou
- Institute of Biomedical Sciences, Academia Sinica, 11529, Taipei, Taiwan.
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21
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Li Y, Tang J, Ji X, Hua MM, Liu M, Chang L, Gu Y, Shi C, Ni W, Liu J, Shi HJ, Huang X, O'Neill C, Jin X. Regulation of the mammalian maternal-to-embryonic transition by eukaryotic translation initiation factor 4E. Development 2021; 148:268308. [PMID: 34013332 PMCID: PMC8254863 DOI: 10.1242/dev.190793] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 05/12/2021] [Indexed: 12/24/2022]
Abstract
Eukaryotic translation initiation factor 4E (eIF4E) mediates cap-dependent translation. Genetic and inhibitor studies show that eIF4E expression is required for the successful transition from maternal to embryonic control of mouse embryo development. eIF4E was present in the oocyte and in the cytoplasm soon after fertilization and during each stage of early development. Functional knockout (Eif4e−/−) by PiggyBac [Act-RFP] transposition resulted in peri-implantation embryonic lethality because of the failure of normal epiblast formation. Maternal stores of eIF4E supported development up to the two- to four-cell stage, after which new expression occurred from both maternal and paternal inherited alleles. Inhibition of the maternally acquired stores of eIF4E (using the inhibitor 4EGI-1) resulted in a block at the two-cell stage. eIF4E activity was required for new protein synthesis in the two-cell embryo and Eif4e−/− embryos had lower translational activity compared with wild-type embryos. eIF4E-binding protein 1 (4E-BP1) is a hypophosphorylation-dependent negative regulator of eIF4E. mTOR activity was required for 4E-BP1 phosphorylation and inhibiting mTOR retarded embryo development. Thus, this study shows that eIF4E activity is regulated at key embryonic transitions in the mammalian embryo and is essential for the successful transition from maternal to embryonic control of development. Summary: Combined use of a PB [Act-RFP] transgenesis model, selective pharmacological inhibition and expression analyses verified the essential role of eIF4E in the transition from maternal to embryonic control of mouse development.
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Affiliation(s)
- Yan Li
- Reproductive Medicine Center, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, 325000, China
| | - Jianan Tang
- NHC Key Lab of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, Fudan University, Shanghai, 200032, China
| | - Xu Ji
- Department of Pharmacology, School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, Jiangsu Province, 211816, China
| | - Min-Min Hua
- NHC Key Lab of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, Fudan University, Shanghai, 200032, China
| | - Miao Liu
- Reproductive Medical Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Lu Chang
- Department of Pharmacology, School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, Jiangsu Province, 211816, China
| | - Yihua Gu
- NHC Key Lab of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, Fudan University, Shanghai, 200032, China
| | - Changgen Shi
- NHC Key Lab of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, Fudan University, Shanghai, 200032, China
| | - Wuhua Ni
- Reproductive Medicine Center, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, 325000, China
| | - Jing Liu
- Department of Pharmacology, School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, Jiangsu Province, 211816, China
| | - Hui-Juan Shi
- NHC Key Lab of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, Fudan University, Shanghai, 200032, China
| | - Xuefeng Huang
- Reproductive Medicine Center, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, 325000, China
| | - Christopher O'Neill
- Human Reproduction Unit, Sydney Center for Regenerative and Developmental Medicine, Kolling Institute for Medical Research, Sydney Medical School, University of Sydney, St. Leonards, New South Wales, 2065, Australia
| | - Xingliang Jin
- Reproductive Medicine Center, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, 325000, China.,Human Reproduction Unit, Sydney Center for Regenerative and Developmental Medicine, Kolling Institute for Medical Research, Sydney Medical School, University of Sydney, St. Leonards, New South Wales, 2065, Australia
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22
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Venetoclax response is enhanced by selective inhibitor of nuclear export compounds in hematologic malignancies. Blood Adv 2021; 4:586-598. [PMID: 32045477 DOI: 10.1182/bloodadvances.2019000359] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 01/17/2020] [Indexed: 12/18/2022] Open
Abstract
The selective inhibitor of nuclear export (SINE) compounds selinexor (KPT-330) and eltanexor (KPT-8602) are from a novel class of small molecules that target exportin-1 (XPO1 [CRM1]), an essential nucleo-cytoplasmic transport protein responsible for the nuclear export of major tumor suppressor proteins and growth regulators such as p53, p21, and p27. XPO1 also affects the translation of messenger RNAs for critical oncogenes, including MYC, BCL2, MCL1, and BCL6, by blocking the export of the translation initiation factor eIF4E. Early trials with venetoclax (ABT-199), a potent, selective inhibitor of BCL2, have revealed responses across a variety of hematologic malignancies. However, many tumors are not responsive to venetoclax. We used models of acute myeloid leukemia (AML) and diffuse large B-cell lymphoma (DLBCL) to determine in vitro and in vivo responses to treatment with venetoclax and SINE compounds combined. Cotreatment with venetoclax and SINE compounds demonstrated loss of viability in multiple cell lines. Further in vitro analyses showed that this enhanced cell death was the result of an increase in apoptosis that led to a loss of clonogenicity in methylcellulose assays, coinciding with activation of p53 and loss of MCL1. Treatment with SINE compounds and venetoclax combined led to a reduction in tumor growth in both AML and DLBCL xenografts. Immunohistochemical analysis of tissue sections revealed that the reduction in tumor cells was partly the result of an induction of apoptosis. The enhanced effects of this combination were validated in primary AML and DLBCL patient cells. Our studies reveal synergy with SINE compounds and venetoclax in aggressive hematologic malignancies and provide a rationale for pursuing this approach in a clinical trial.
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23
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Longo F, Klann E. Reciprocal control of translation and transcription in autism spectrum disorder. EMBO Rep 2021; 22:e52110. [PMID: 33977633 DOI: 10.15252/embr.202052110] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/20/2021] [Accepted: 04/19/2021] [Indexed: 12/11/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication and the presence of restricted patterns of interest and repetitive behaviors. ASD is genetically heterogeneous and is believed to be caused by both inheritable and de novo gene variations. Studies have revealed an extremely complex genetic landscape of ASD, favoring the idea that mutations in different clusters of genes interfere with interconnected downstream signaling pathways and circuitry, resulting in aberrant behavior. In this review, we describe a select group of candidate genes that represent both syndromic and non-syndromic forms of ASD and encode proteins that are important in transcriptional and translational regulation. We focus on the interplay between dysregulated translation and transcription in ASD with the hypothesis that dysregulation of each synthetic process triggers a feedback loop to act on the other, which ultimately exacerbates ASD pathophysiology. Finally, we summarize findings from interdisciplinary studies that pave the way for the investigation of the cooperative impact of different genes and pathways underlying the development of ASD.
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Affiliation(s)
- Francesco Longo
- Center for Neural Science, New York University, New York, NY, USA
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY, USA
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24
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Batool W, Shabbir A, Lin L, Chen X, An Q, He X, Pan S, Chen S, Chen Q, Wang Z, Norvienyeku J. Translation Initiation Factor eIF4E Positively Modulates Conidiogenesis, Appressorium Formation, Host Invasion and Stress Homeostasis in the Filamentous Fungi Magnaporthe oryzae. FRONTIERS IN PLANT SCIENCE 2021; 12:646343. [PMID: 34220879 PMCID: PMC8244596 DOI: 10.3389/fpls.2021.646343] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 05/21/2021] [Indexed: 05/14/2023]
Abstract
Translation initiation factor eIF4E generally mediates the recognition of the 5'cap structure of mRNA during the recruitment of the ribosomes to capped mRNA. Although the eIF4E has been shown to regulate stress response in Schizosaccharomyces pombe positively, there is no direct experimental evidence for the contributions of eIF4E to both physiological and pathogenic development of filamentous fungi. We generated Magnaporthe oryzae eIF4E (MoeIF4E3) gene deletion strains using homologous recombination strategies. Phenotypic and biochemical analyses of MoeIF4E3 defective strains showed that the deletion of MoeIF4E3 triggered a significant reduction in growth and conidiogenesis. We also showed that disruption of MoeIF4E3 partially impaired conidia germination, appressorium integrity and attenuated the pathogenicity of ΔMoeif4e3 strains. In summary, this study provides experimental insights into the contributions of the eIF4E3 to the development of filamentous fungi. Additionally, these observations underscored the need for a comprehensive evaluation of the translational regulatory machinery in phytopathogenic fungi during pathogen-host interaction progression.
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Affiliation(s)
- Wajjiha Batool
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, The School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ammarah Shabbir
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, The School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Lili Lin
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, The School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaomin Chen
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, The School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qiuli An
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, The School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiongjie He
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, The School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Shu Pan
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, The School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Shuzun Chen
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, The School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qinghe Chen
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, The School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection, Hainan University, Haikou, China
| | - Zonghua Wang
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection, Hainan University, Haikou, China
- Institute of Oceanography, Minjiang University, Fuzhou, China
- *Correspondence: Zonghua Wang,
| | - Justice Norvienyeku
- Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, The School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection, Hainan University, Haikou, China
- Justice Norvienyeku, ;
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25
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Das S. Taking a re-look at cap-binding signatures of the mRNA cap-binding protein eIF4E orthologues in trypanosomatids. Mol Cell Biochem 2020; 476:1037-1049. [PMID: 33169189 DOI: 10.1007/s11010-020-03970-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 10/31/2020] [Indexed: 01/04/2023]
Abstract
Protein translation leading to polypeptide synthesis involves three distinct events, namely, initiation, elongation, and termination. Translation initiation is a multi-step process that is carried out by ribosomes on the mRNA with the assistance of a large number of proteins called translation initiation factors. Trypanosomatids are kinetoplastidas (flagellated protozoans), some of which cause acute disease syndromes in humans. Vector-borne transmission of protozoan parasites like Leishmania and Trypanosoma causes diseases that affect a large section of the world population and lead to significant morbidity and mortality. The mechanisms of translation initiation in higher eukaryotes are relatively well understood. However, structural and functional conservation of initiation factors in trypanosomatids are only beginning to be understood. Studies carried out so far suggests that at least in Leishmania and Trypanosoma eIF4E function may not be restricted to canonical translation initiation and some of the homologues may have alternate/non-canonical functions. Nonetheless, all of them bind the cap analogs, albeit with different efficiencies, indicating that this property may play an important role in the functionality of eIF4Es. Here, I give a brief background of trypanosomatid eIF4Es and revisit the cap-binding signatures of eIF4E orthologues in trypanosomatids, whose genome sequences are available, in detail, in comparison to human eIF4E1 and Trypanosoma cruzi eIF4E5, with an expanded list of members of this group in light of newer findings. The group 1 and 2 eIF4Es may use either a variation of heIF4E1 or T. cruzi eIF4E5 cap-4-binding signatures, while eIF4E5 and eIF4E6 use distinct amino acid contacts.
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Affiliation(s)
- Supratik Das
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, PO Box #04, Faridabad, Haryana, 121001, India.
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26
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Gallagher EE, Menon A, Chmiel AF, Deprey K, Kritzer JA, Garner AL. A cell-penetrant lactam-stapled peptide for targeting eIF4E protein-protein interactions. Eur J Med Chem 2020; 205:112655. [PMID: 32739551 DOI: 10.1016/j.ejmech.2020.112655] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/01/2020] [Accepted: 07/08/2020] [Indexed: 11/30/2022]
Abstract
Eukaryotic translation initiation factor 4E (eIF4E) has emerged as a promising cancer therapeutic target due to its role in the initiation of cap-dependent translation, a process that is accelerated during tumorigenesis. To regulate the initiation of cap-dependent translation, eIF4E participates in protein-protein interactions (PPI) with binding partners, 4E-BP1 and eIF4G, which act as an inhibitor and stimulator of translation, respectively. As both of these proteins interact with eIF4E by utilizing a short, α-helical stretch of amino acids, our laboratory has been working to develop helical mimetics of these proteins, in particular 4E-BP1, to inhibit eIF4E PPIs. Herein, we describe our continued efforts in this area and report the development and characterization of a cell-penetrant lactam stapled peptide for targeting cellular eIF4E.
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Affiliation(s)
- Erin E Gallagher
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 1600 Huron Parkway, NCRC B520, Ann Arbor, MI, 48109, USA
| | - Arya Menon
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 1600 Huron Parkway, NCRC B520, Ann Arbor, MI, 48109, USA
| | - Alyah F Chmiel
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 1600 Huron Parkway, NCRC B520, Ann Arbor, MI, 48109, USA
| | - Kirsten Deprey
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, MA, 02155, USA
| | - Joshua A Kritzer
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, MA, 02155, USA
| | - Amanda L Garner
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 1600 Huron Parkway, NCRC B520, Ann Arbor, MI, 48109, USA.
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27
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Polinski JM, Kron N, Smith DR, Bodnar AG. Unique age-related transcriptional signature in the nervous system of the long-lived red sea urchin Mesocentrotus franciscanus. Sci Rep 2020; 10:9182. [PMID: 32514014 PMCID: PMC7280269 DOI: 10.1038/s41598-020-66052-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 05/12/2020] [Indexed: 11/23/2022] Open
Abstract
The red sea urchin, Mesocentrotus franciscanus, is one the earth’s longest-lived animals, reported to live more than 100 years with indeterminate growth, life-long reproduction and no increase in mortality rate with age. To gain insight into mechanisms associated with longevity and negligible senescence, age-related transcriptional profiles were examined in tissues of the red sea urchin. Genome-wide transcriptional profiling using RNA-Seq revealed few age-related changes in gene expression in muscle and esophagus tissue. In contrast, radial nerve showed an unexpected level of complexity with the expression of 3,370 genes significantly altered more than two-fold with age, including genes involved in nerve function, signaling, metabolism, transcriptional regulation and chromatin modification. There was an age-related upregulation in expression of genes involved in synaptogenesis, axonogenesis and neuroprotection suggesting preservation of neuronal processes with age. There was also an upregulation in expression of positive regulators and key components of the AMPK pathway, autophagy, proteasome function, and the unfolded protein response. This unique age-related gene expression profile in the red sea urchin nervous system may play a role in mitigating the detrimental effects of aging in this long-lived animal.
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Affiliation(s)
- Jennifer M Polinski
- Gloucester Marine Genomics Institute, 417 Main Street, Gloucester, MA, 01930, USA
| | - Nicholas Kron
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL, 33149, United States
| | - Douglas R Smith
- Gloucester Marine Genomics Institute, 417 Main Street, Gloucester, MA, 01930, USA
| | - Andrea G Bodnar
- Gloucester Marine Genomics Institute, 417 Main Street, Gloucester, MA, 01930, USA.
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28
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Borden KLB, Volpon L. The diversity, plasticity, and adaptability of cap-dependent translation initiation and the associated machinery. RNA Biol 2020; 17:1239-1251. [PMID: 32496897 PMCID: PMC7549709 DOI: 10.1080/15476286.2020.1766179] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Translation initiation is a critical facet of gene expression with important impacts that underlie cellular responses to stresses and environmental cues. Its dysregulation in many diseases position this process as an important area for the development of new therapeutics. The gateway translation factor eIF4E is typically considered responsible for ‘global’ or ‘canonical’ m7G cap-dependent translation. However, eIF4E impacts translation of specific transcripts rather than the entire translatome. There are many alternative cap-dependent translation mechanisms that also contribute to the translation capacity of the cell. We review the diversity of these, juxtaposing more recently identified mechanisms with eIF4E-dependent modalities. We also explore the multiplicity of functions played by translation factors, both within and outside protein synthesis, and discuss how these differentially contribute to their ultimate physiological impacts. For comparison, we discuss some modalities for cap-independent translation. In all, this review highlights the diverse mechanisms that engage and control translation in eukaryotes.
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Affiliation(s)
- Katherine L B Borden
- Institute of Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Université de Montréal , Montreal, Québec, Canada
| | - Laurent Volpon
- Institute of Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Université de Montréal , Montreal, Québec, Canada
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29
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Choi SH, Kim S, Jones KA. Gene expression regulation by CDK12: a versatile kinase in cancer with functions beyond CTD phosphorylation. Exp Mol Med 2020; 52:762-771. [PMID: 32451425 PMCID: PMC7272620 DOI: 10.1038/s12276-020-0442-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 04/08/2020] [Accepted: 04/13/2020] [Indexed: 12/21/2022] Open
Abstract
Cyclin-dependent kinases (CDKs) play critical roles in cell cycle progression and gene expression regulation. In human cancer, transcription-associated CDKs can activate oncogenic gene expression programs, whereas cell cycle-regulatory CDKs mainly induce uncontrolled proliferation. Cyclin-dependent kinase 12 (CDK12) belongs to the CDK family of serine/threonine kinases and has been recently found to have multiple roles in gene expression regulation and tumorigenesis. Originally, CDK12 was thought to be one of the transcription-associated CDKs, acting with its cyclin partner Cyclin K to promote the phosphorylation of the C-terminal domain (CTD) of RNA polymerase II and induce transcription elongation. However, recent studies have demonstrated that CDK12 also controls multiple gene expression processes, including transcription termination, mRNA splicing, and translation. Most importantly, CDK12 mutations are frequently found in human tumors. Loss of CDK12 function causes defective expression of DNA damage response (DDR) genes, which eventually results in genome instability, a hallmark of human cancer. Here, we discuss the diverse roles of CDK12 in gene expression regulation and human cancer, focusing on newly identified CDK12 kinase functions in cellular processes and highlighting CDK12 as a promising therapeutic target for human cancer treatment. Better understanding of the roles played by a protein kinase, an enzyme that adds phosphate groups to other molecules, in healthy and diseased states may help scientists identify novel cancer treatments. Cyclin-dependent kinases (CDKs) are a family of protein kinases crucial to cell cycling and gene expression. CDK12 can activate and modulate cancer-related gene expression, but, according to a review by Seung Hyuk Choi and colleagues at the Salk Institute for Biological Studies in La Jolla, USA, further investigations into its exact functioning and control mechanisms are required. CDK12 mutations are frequently found in aggressive breast and ovarian cancers, while loss of CDK12 function results in abnormal expression of DNA damage response genes and genome instability. CDK12 may also regulate drug resistance in cancer cells. The team suggests that therapies targeting CDK12 are worth exploring.
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Affiliation(s)
- Seung Hyuk Choi
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.
| | - Seongjae Kim
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Katherine A Jones
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
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30
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eIF4E and Interactors from Unicellular Eukaryotes. Int J Mol Sci 2020; 21:ijms21062170. [PMID: 32245232 PMCID: PMC7139794 DOI: 10.3390/ijms21062170] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/12/2020] [Accepted: 03/18/2020] [Indexed: 12/22/2022] Open
Abstract
eIF4E, the mRNA cap-binding protein, is well known as a general initiation factor allowing for mRNA-ribosome interaction and cap-dependent translation in eukaryotic cells. In this review we focus on eIF4E and its interactors in unicellular organisms such as yeasts and protozoan eukaryotes. In a first part, we describe eIF4Es from yeast species such as Saccharomyces cerevisiae, Candida albicans, and Schizosaccharomyces pombe. In the second part, we will address eIF4E and interactors from parasite unicellular species—trypanosomatids and marine microorganisms—dinoflagellates. We propose that different strategies have evolved during evolution to accommodate cap-dependent translation to differing requirements. These evolutive “adjustments” involve various forms of eIF4E that are not encountered in all microorganismic species. In yeasts, eIF4E interactors, particularly p20 and Eap1 are found exclusively in Saccharomycotina species such as S. cerevisiae and C. albicans. For protozoan parasites of the Trypanosomatidae family beside a unique cap4-structure located at the 5′UTR of all mRNAs, different eIF4Es and eIF4Gs are active depending on the life cycle stage of the parasite. Additionally, an eIF4E-interacting protein has been identified in Leishmania major which is important for switching from promastigote to amastigote stages. For dinoflagellates, little is known about the structure and function of the multiple and diverse eIF4Es that have been identified thanks to widespread sequencing in recent years.
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31
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Taylor J, Yeomans AM, Packham G. Targeted inhibition of mRNA translation initiation factors as a novel therapeutic strategy for mature B-cell neoplasms. EXPLORATION OF TARGETED ANTI-TUMOR THERAPY 2020; 1:3-25. [PMID: 32924027 PMCID: PMC7116065 DOI: 10.37349/etat.2020.00002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 01/31/2020] [Indexed: 12/17/2022] Open
Abstract
Cancer development is frequently associated with dysregulation of mRNA translation to enhance both increased global protein synthesis and translation of specific mRNAs encoding oncoproteins. Thus, targeted inhibition of mRNA translation is viewed as a promising new approach for cancer therapy. In this article we review current progress in investigating dysregulation of mRNA translation initiation in mature B-cell neoplasms, focusing on chronic lymphocytic leukemia, follicular lymphoma and diffuse large B-cell lymphoma. We discuss mechanisms and regulation of mRNA translation, potential pathways by which genetic alterations and the tumor microenvironment alters mRNA translation in malignant B cells, preclinical evaluation of drugs targeted against specific eukaryotic initiation factors and current progress towards clinical development. Overall, inhibition of mRNA translation initiation factors is an exciting and promising area for development of novel targeted anti-tumor drugs.
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Affiliation(s)
- Joe Taylor
- Cancer Research UK Centre, Cancer Sciences, Faculty of Medicine, University of Southampton, SO16 6YD Southampton, United Kingdom
| | - Alison M Yeomans
- Cancer Research UK Centre, Cancer Sciences, Faculty of Medicine, University of Southampton, SO16 6YD Southampton, United Kingdom
| | - Graham Packham
- Cancer Research UK Centre, Cancer Sciences, Faculty of Medicine, University of Southampton, SO16 6YD Southampton, United Kingdom
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32
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Vergote IB, Lund B, Peen U, Umajuridze Z, Mau-Sorensen M, Kranich A, Van Nieuwenhuysen E, Haslund C, Nottrup T, Han SN, Concin N, Unger TJ, Chai Y, Au N, Rashal T, Joshi A, Crochiere M, Landesman Y, Shah J, Shacham S, Kauffman M, Mirza MR. Phase 2 study of the Exportin 1 inhibitor selinexor in patients with recurrent gynecological malignancies. Gynecol Oncol 2020; 156:308-314. [PMID: 31822399 DOI: 10.1016/j.ygyno.2019.11.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 10/24/2019] [Accepted: 11/08/2019] [Indexed: 12/18/2022]
Abstract
BACKGROUND Selinexor is an oral inhibitor of the nuclear export protein Exportin 1 (XPO1) with demonstrated antitumor activity in solid and hematological malignancies. We evaluated the efficacy and safety of selinexor in heavily pretreated, recurrent gynecological malignancies. METHODS In this phase 2 trial, patients received selinexor (35 or 50 mg/m2 twice-weekly [BIW] or 50 mg/m2 once-weekly [QW]) in 4-week cycles. Primary endpoint was disease control rate (DCR) including complete response (CR), partial response (PR) or stable disease (SD) ≥12 weeks. Secondary endpoints were progression-free survival (PFS), overall survival (OS) and safety. RESULTS 114 patients with ovarian (N = 66), endometrial (N = 23) or cervical (N = 25) cancer were enrolled. Median number of prior regimens for ovarian, endometrial and cervical cancer was 6 (1-11), 2 (1-5), and 3 (1-6) respectively. DCR was 30% (ovarian 30%; endometrial 35%; cervical 24%), which included confirmed PRs in 8%, 9%, and 4% of patients with ovarian, endometrial, and cervical cancer respectively. Median PFS and OS for patients with ovarian, endometrial and cervical cancer were 2.6, 2.8 and 1.4 months, and 7.3, 7.0, and 5.0 months, respectively. Common Grade 3/4 adverse events (AEs) were thrombocytopenia (17%), fatigue (14%), anemia (10%), nausea (9%) and hyponatremia (9%). Patients with ovarian cancer receiving 50 mg/m2 QW had fewer high-grade AEs with similar efficacy as BIW treatment. CONCLUSIONS Selinexor demonstrated single-agent activity and disease control in patients with heavily pretreated ovarian and endometrial cancers. Side effects were a function of dose level and treatment frequency, similar to previous reports, reversible and mitigated with supportive care.
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Affiliation(s)
- I B Vergote
- Department of Obstetrics and Gynaecology, Division of Gynecologic Oncology, University Hospital Leuven, Leuven Cancer Institute, Leuven, Belgium, European Union.
| | - B Lund
- Aalborg University Hospital, Aalborg, Denmark
| | - U Peen
- Herlev University Hospital, Herlev, Denmark
| | - Z Umajuridze
- Department of Oncology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - M Mau-Sorensen
- Department of Oncology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | | | - E Van Nieuwenhuysen
- Department of Obstetrics and Gynaecology, Division of Gynecologic Oncology, University Hospital Leuven, Leuven Cancer Institute, Leuven, Belgium, European Union
| | - C Haslund
- Aalborg University Hospital, Aalborg, Denmark
| | - T Nottrup
- Department of Oncology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - S N Han
- Department of Obstetrics and Gynaecology, Division of Gynecologic Oncology, University Hospital Leuven, Leuven Cancer Institute, Leuven, Belgium, European Union
| | - N Concin
- Department of Obstetrics and Gynaecology, Division of Gynecologic Oncology, University Hospital Leuven, Leuven Cancer Institute, Leuven, Belgium, European Union
| | - T J Unger
- Karyopharm Therapeutics Newton, MA, USA
| | - Y Chai
- Karyopharm Therapeutics Newton, MA, USA
| | - N Au
- Karyopharm Therapeutics Newton, MA, USA
| | - T Rashal
- Karyopharm Therapeutics Newton, MA, USA
| | - A Joshi
- Karyopharm Therapeutics Newton, MA, USA
| | | | | | - J Shah
- Karyopharm Therapeutics Newton, MA, USA
| | - S Shacham
- Karyopharm Therapeutics Newton, MA, USA
| | | | - M R Mirza
- Karyopharm Therapeutics Newton, MA, USA
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Ala-Poikela M, Rajamäki ML, Valkonen JP. A Novel Interaction Network Used by Potyviruses in Virus-Host Interactions at the Protein Level. Viruses 2019; 11:E1158. [PMID: 31847316 PMCID: PMC6950583 DOI: 10.3390/v11121158] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 12/30/2022] Open
Abstract
Host proteins that are central to infection of potyviruses (genus Potyvirus; family Potyviridae) include the eukaryotic translation initiation factors eIF4E and eIF(iso)4E. The potyviral genome-linked protein (VPg) and the helper component proteinase (HCpro) interact with each other and with eIF4E and eIF(iso)4E and proteins are involved in the same functions during viral infection. VPg interacts with eIF4E/eIF(iso)4E via the 7-methylguanosine cap-binding region, whereas HCpro interacts with eIF4E/eIF(iso)4E via the 4E-binding motif YXXXXLΦ, similar to the motif in eIF4G. In this study, HCpro and VPg were found to interact in the nucleus, nucleolus, and cytoplasm in cells infected with the potyvirus potato virus A (PVA). In the cytoplasm, interactions between HCpro and VPg occurred in punctate bodies not associated with viral replication vesicles. In addition to HCpro, the 4E-binding motif was recognized in VPg of PVA. Mutations in the 4E-binding motif of VPg from PVA weakened interactions with eIF4E and heavily reduced PVA virulence. Furthermore, mutations in the 4G-binding domain of eIF4E reduced interactions with VPg and abolished interactions with HCpro. Thus, HCpro and VPg can both interact with eIF4E using the 4E-binding motif. Our results suggest a novel interaction network used by potyviruses to interact with host plants via translation initiation factors.
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Affiliation(s)
| | - Minna-Liisa Rajamäki
- Department of Agricultural Sciences, University of Helsinki, P.O. Box 27, FI-00014 Helsinki, Finland;
| | - Jari P.T. Valkonen
- Department of Agricultural Sciences, University of Helsinki, P.O. Box 27, FI-00014 Helsinki, Finland;
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Scott DD, Aguilar LC, Kramar M, Oeffinger M. It's Not the Destination, It's the Journey: Heterogeneity in mRNA Export Mechanisms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:33-81. [PMID: 31811630 DOI: 10.1007/978-3-030-31434-7_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The process of creating a translation-competent mRNA is highly complex and involves numerous steps including transcription, splicing, addition of modifications, and, finally, export to the cytoplasm. Historically, much of the research on regulation of gene expression at the level of the mRNA has been focused on either the regulation of mRNA synthesis (transcription and splicing) or metabolism (translation and degradation). However, in recent years, the advent of new experimental techniques has revealed the export of mRNA to be a major node in the regulation of gene expression, and numerous large-scale and specific mRNA export pathways have been defined. In this chapter, we will begin by outlining the mechanism by which most mRNAs are homeostatically exported ("bulk mRNA export"), involving the recruitment of the NXF1/TAP export receptor by the Aly/REF and THOC5 components of the TREX complex. We will then examine various mechanisms by which this pathway may be controlled, modified, or bypassed in order to promote the export of subset(s) of cellular mRNAs, which include the use of metazoan-specific orthologs of bulk mRNA export factors, specific cis RNA motifs which recruit mRNA export machinery via specific trans-acting-binding factors, posttranscriptional mRNA modifications that act as "inducible" export cis elements, the use of the atypical mRNA export receptor, CRM1, and the manipulation or bypass of the nuclear pore itself. Finally, we will discuss major outstanding questions in the field of mRNA export heterogeneity and outline how cutting-edge experimental techniques are providing new insights into and tools for investigating the intriguing field of mRNA export heterogeneity.
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Affiliation(s)
- Daniel D Scott
- Institut de recherches cliniques de Montréal, Montréal, QC, Canada.,Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC, Canada
| | | | - Mathew Kramar
- Institut de recherches cliniques de Montréal, Montréal, QC, Canada.,Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC, Canada
| | - Marlene Oeffinger
- Institut de recherches cliniques de Montréal, Montréal, QC, Canada. .,Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC, Canada. .,Faculté de Médecine, Département de Biochimie, Université de Montréal, Montréal, QC, Canada.
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35
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G3BP1 and G3BP2 regulate translation of interferon-stimulated genes: IFITM1, IFITM2 and IFITM3 in the cancer cell line MCF7. Mol Cell Biochem 2019; 459:189-204. [PMID: 31172368 DOI: 10.1007/s11010-019-03562-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 05/27/2019] [Indexed: 12/13/2022]
Abstract
G3BPs are members of an RNA-binding protein family and their aberrant expression is common in various cancers and there is growing evidence that G3BPs possess antiviral activities and are targeted by various viruses. G3BPs have also been implicated in both stabilization and degradation of specific mRNAs as well as translational control of mRNA targets. G3BPs have been shown to control translation of interferon-stimulated genes (ISGs), implying that G3BPs are involved in the regulation of the interferon system in response to viral infections and/or cellular stress. The interferon induced transmembrane (IFITM1, IFITM2 and IFITM3) proteins are antiviral proteins, and are also involved in cancer progression and metastasis. Therefore, these genes were selected in the studies reported here as potential transcript targets of G3BPs. Furthermore, G3BPs are involved in the regulation of the MEK pathway which also impacts on the translation of ISGs. Therefore, the role of this pathway was also analysed in regulation of IFITM1-3 proteins. Overall, this research study suggests that G3BPs are essential for the accumulation of IFITM1-3 proteins and intersect twice in the regulation of IFITM1-3 expression, first through MEK pathway and then through an interaction with the 3'-UTRs of its target transcripts. However, it is still to be determined whether the two apparent functions are part of a single control mechanism or the two functions are mutually exclusive.
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36
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Hu J, Sun F, Handel MA. Nuclear localization of EIF4G3 suggests a role for the XY body in translational regulation during spermatogenesis in mice. Biol Reprod 2019; 98:102-114. [PMID: 29161344 DOI: 10.1093/biolre/iox150] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 11/16/2017] [Indexed: 12/28/2022] Open
Abstract
Eukaryotic translation initiation factor 4G (EIF4G) is an important scaffold protein in the translation initiation complex. In mice, mutation of the Eif4g3 gene causes male infertility, with arrest of meiosis at the end of meiotic prophase. This study documents features of the developmental expression and subcellular localization of EIF4G3 that might contribute to its highly specific role in meiosis and spermatogenesis. Quite unexpectedly, EIF4G3 is located in the nucleus of spermatocytes, where it is highly enriched in the XY body, the chromatin domain formed by the transcriptionally inactive sex chromosomes. Moreover, many other, but not all, translation-related proteins are also localized in the XY body. These unanticipated observations implicate roles for the XY body in controlling mRNA metabolism and/or "poising" protein translation complexes before the meiotic division phase in spermatocytes.
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Affiliation(s)
| | - Fengyun Sun
- The Jackson Laboratory, Bar Harbor, Maine, USA
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Coutinho de Oliveira L, Volpon L, Osborne MJ, Borden KLB. Chemical shift assignment of the viral protein genome-linked (VPg) from potato virus Y. BIOMOLECULAR NMR ASSIGNMENTS 2019; 13:9-13. [PMID: 30242622 PMCID: PMC6428624 DOI: 10.1007/s12104-018-9842-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 09/14/2018] [Indexed: 06/08/2023]
Abstract
The dysregulation of translation contributes to many pathogenic conditions in humans. Discovering new translational mechanisms is important to understanding the diversity of this process and its potential mechanisms. Such mechanisms can be initially observed in viruses. With this in mind, we studied the viral protein genome-linked VPg factor from the largest genus of plant viruses. Studies in plants show that VPg binds to the eukaryotic translation initiation factor eIF4E for translation of viral RNAs. VPg contains no known eIF4E binding motifs and no sequence homology to any known proteins. Thus, as a first step in understanding the structural basis of this interaction, we carried out NMR assignments of the VPg from the potato virus Y potyvirus protein.
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Affiliation(s)
- Luciana Coutinho de Oliveira
- Department of Pathology and Cell Biology, Institute of Research in Immunology and Cancer (IRIC), Université de Montréal, Pavilion Marcelle-Coutu, Chemin Polytechnique, Montreal, QC, Canada
| | - Laurent Volpon
- Department of Pathology and Cell Biology, Institute of Research in Immunology and Cancer (IRIC), Université de Montréal, Pavilion Marcelle-Coutu, Chemin Polytechnique, Montreal, QC, Canada
| | - Michael J Osborne
- Department of Pathology and Cell Biology, Institute of Research in Immunology and Cancer (IRIC), Université de Montréal, Pavilion Marcelle-Coutu, Chemin Polytechnique, Montreal, QC, Canada
| | - Katherine L B Borden
- Department of Pathology and Cell Biology, Institute of Research in Immunology and Cancer (IRIC), Université de Montréal, Pavilion Marcelle-Coutu, Chemin Polytechnique, Montreal, QC, Canada.
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Choi SH, Martinez TF, Kim S, Donaldson C, Shokhirev MN, Saghatelian A, Jones KA. CDK12 phosphorylates 4E-BP1 to enable mTORC1-dependent translation and mitotic genome stability. Genes Dev 2019; 33:418-435. [PMID: 30819820 PMCID: PMC6446539 DOI: 10.1101/gad.322339.118] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/22/2019] [Indexed: 01/23/2023]
Abstract
Here, Choi et al. show that CDK12, the RNA polymerase II C-terminal domain kinase, which regulates genome stability, expression of DNA repair genes, and cancer cell drug resistance, also phosphorylates the mRNA 5′ cap-binding repressor 4E-BP1 to promote translation of mTORC1-dependent mRNAs. Using RIP-seq and Ribo-seq, the authors found that CDK12 regulates binding of eIF4G to many mTORC1 target mRNAs, and identified specific CDK12 “translation-only” target mRNAs. The RNA polymerase II (RNAPII) C-terminal domain kinase, CDK12, regulates genome stability, expression of DNA repair genes, and cancer cell resistance to chemotherapy and immunotherapy. In addition to its role in mRNA biosynthesis of DNA repair genes, we show here that CDK12 phosphorylates the mRNA 5′ cap-binding repressor, 4E-BP1, to promote translation of mTORC1-dependent mRNAs. In particular, we found that phosphorylation of 4E-BP1 by mTORC1 (T37 and T46) facilitates subsequent CDK12 phosphorylation at two Ser–Pro sites (S65 and T70) that control the exchange of 4E-BP1 with eIF4G at the 5′ cap of CHK1 and other target mRNAs. RNA immunoprecipitation coupled with deep sequencing (RIP-seq) revealed that CDK12 regulates release of 4E-BP1, and binding of eIF4G, to many mTORC1 target mRNAs, including those needed for MYC transformation. Genome-wide ribosome profiling (Ribo-seq) further identified specific CDK12 “translation-only” target mRNAs, including many mTORC1 target mRNAs as well as many subunits of mitotic and centromere/centrosome complexes. Accordingly, confocal imaging analyses revealed severe chromosome misalignment, bridging, and segregation defects in cells deprived of CDK12 or CCNK. We conclude that the nuclear RNAPII-CTD kinase CDK12 cooperates with mTORC1, and controls a specialized translation network that is essential for mitotic chromosome stability.
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Affiliation(s)
- Seung H Choi
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Thomas F Martinez
- Clayton Foundation Laboratory for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Seongjae Kim
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Cynthia Donaldson
- Clayton Foundation Laboratory for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Maxim N Shokhirev
- Razavi Newman Integrative Genomics and Bioinformatics Core, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Alan Saghatelian
- Clayton Foundation Laboratory for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Katherine A Jones
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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Selinexor plus low-dose bortezomib and dexamethasone for patients with relapsed or refractory multiple myeloma. Blood 2018; 132:2546-2554. [PMID: 30352784 DOI: 10.1182/blood-2018-06-858852] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/17/2018] [Indexed: 12/21/2022] Open
Abstract
Selinexor is an oral inhibitor of the nuclear export protein exportin 1. Preclinical studies demonstrated synergistic antimyeloma activity between selinexor and proteasome inhibitors (PI) through suppression of NF-κB signaling and nuclear retention of tumor suppressor proteins. We tested selinexor in combination with low-dose bortezomib and dexamethasone (SVd) for the treatment of relapsed or refractory multiple myeloma (MM). The primary objectives of this study were to determine the safety profile, overall response rate (ORR), and a recommended phase 2 dose (RP2D) of SVd. We enrolled 42 patients to receive selinexor (60, 80, or 100 mg orally) plus bortezomib (1.3 mg/m2 subcutaneously) and dexamethasone (20 mg orally) once or twice weekly in 21- or 35-day cycles. Patients had a median of 3 (range 1-11) prior lines of therapy, and 50% were refractory to a PI. Treatment-related grade 3 or 4 adverse events reported in ≥10% of patients were thrombocytopenia (45%), neutropenia (24%), fatigue (14%), and anemia (12%). Incidence (4 patients, 10%) and grade (≤2) of peripheral neuropathy were low. The ORR for the entire population was 63%: 84% ORR for PI nonrefractory and 43% for PI-refractory patients. The median progression-free survival for all patients was 9.0 months; 17.8 months for PI nonrefractory, and 6.1 months for PI refractory. SVd treatment produced high response rates in patients with relapsed or refractory MM, including borezomib-refractory MM, with no unexpected side effects. The RP2D is selinexor (100 mg once weekly), bortezomib (1.3 mg/m2 once weekly for 4 weeks), and dexamethasone (40 mg once weekly) per 35-day cycle. This trial was registered at www.clinicaltrials.gov as #NCT02343042.
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Piserà A, Campo A, Campo S. Structure and functions of the translation initiation factor eIF4E and its role in cancer development and treatment. J Genet Genomics 2018; 45:13-24. [DOI: 10.1016/j.jgg.2018.01.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 01/12/2018] [Accepted: 01/15/2018] [Indexed: 12/22/2022]
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Zahreddine HA, Culjkovic-Kraljacic B, Emond A, Pettersson F, Midura R, Lauer M, Del Rincon S, Cali V, Assouline S, Miller WH, Hascall V, Borden KL. The eukaryotic translation initiation factor eIF4E harnesses hyaluronan production to drive its malignant activity. eLife 2017; 6:29830. [PMID: 29111978 PMCID: PMC5705209 DOI: 10.7554/elife.29830] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 11/03/2017] [Indexed: 01/03/2023] Open
Abstract
The microenvironment provides a functional substratum supporting tumour growth. Hyaluronan (HA) is a major component of this structure. While the role of HA in malignancy is well-defined, the mechanisms driving its biosynthesis in cancer are poorly understood. We show that the eukaryotic translation initiation factor eIF4E, an oncoprotein, drives HA biosynthesis. eIF4E stimulates production of enzymes that synthesize the building blocks of HA, UDP-Glucuronic acid and UDP-N-Acetyl-Glucosamine, as well as hyaluronic acid synthase which forms the disaccharide chain. Strikingly, eIF4E inhibition alone repressed HA levels as effectively as directly targeting HA with hyaluronidase. Unusually, HA was retained on the surface of high-eIF4E cells, rather than being extruded into the extracellular space. Surface-associated HA was required for eIF4E’s oncogenic activities suggesting that eIF4E potentiates an oncogenic HA program. These studies provide unique insights into the mechanisms driving HA production and demonstrate that an oncoprotein can co-opt HA biosynthesis to drive malignancy.
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Affiliation(s)
- Hiba Ahmad Zahreddine
- Department of Pathology and Cell Biology, Institute for Research in Immunology and Cancer, Université de Montréal, Québec, Canada
| | - Biljana Culjkovic-Kraljacic
- Department of Pathology and Cell Biology, Institute for Research in Immunology and Cancer, Université de Montréal, Québec, Canada
| | - Audrey Emond
- Segal Cancer Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Québec, Canada
| | - Filippa Pettersson
- Segal Cancer Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Québec, Canada
| | - Ronald Midura
- Orthopaedic Research Center, The Cleveland Clinic Foundation, Cleveland, United States.,Department of Biomedical Engineering, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, United States
| | - Mark Lauer
- Orthopaedic Research Center, The Cleveland Clinic Foundation, Cleveland, United States.,Department of Biomedical Engineering, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, United States
| | - Sonia Del Rincon
- Segal Cancer Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Québec, Canada
| | - Valbona Cali
- Orthopaedic Research Center, The Cleveland Clinic Foundation, Cleveland, United States.,Department of Biomedical Engineering, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, United States
| | - Sarit Assouline
- Segal Cancer Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Québec, Canada
| | - Wilson H Miller
- Segal Cancer Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Québec, Canada
| | - Vincent Hascall
- Orthopaedic Research Center, The Cleveland Clinic Foundation, Cleveland, United States.,Department of Biomedical Engineering, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, United States
| | - Katherine Lb Borden
- Department of Pathology and Cell Biology, Institute for Research in Immunology and Cancer, Université de Montréal, Québec, Canada
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The Role of Cytoplasmic mRNA Cap-Binding Protein Complexes in Trypanosoma brucei and Other Trypanosomatids. Pathogens 2017; 6:pathogens6040055. [PMID: 29077018 PMCID: PMC5750579 DOI: 10.3390/pathogens6040055] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 10/21/2017] [Accepted: 10/22/2017] [Indexed: 11/16/2022] Open
Abstract
Trypanosomatid protozoa are unusual eukaryotes that are well known for having unusual ways of controlling their gene expression. The lack of a refined mode of transcriptional control in these organisms is compensated by several post-transcriptional control mechanisms, such as control of mRNA turnover and selection of mRNA for translation, that may modulate protein synthesis in response to several environmental conditions found in different hosts. In other eukaryotes, selection of mRNA for translation is mediated by the complex eIF4F, a heterotrimeric protein complex composed by the subunits eIF4E, eIF4G, and eIF4A, where the eIF4E binds to the 5'-cap structure of mature mRNAs. In this review, we present and discuss the characteristics of six trypanosomatid eIF4E homologs and their associated proteins that form multiple eIF4F complexes. The existence of multiple eIF4F complexes in trypanosomatids evokes exquisite mechanisms for differential mRNA recognition for translation.
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Sesma A, Castresana C, Castellano MM. Regulation of Translation by TOR, eIF4E and eIF2α in Plants: Current Knowledge, Challenges and Future Perspectives. FRONTIERS IN PLANT SCIENCE 2017; 8:644. [PMID: 28491073 PMCID: PMC5405063 DOI: 10.3389/fpls.2017.00644] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/10/2017] [Indexed: 05/06/2023]
Abstract
An important step in eukaryotic gene expression is the synthesis of proteins from mRNA, a process classically divided into three stages, initiation, elongation, and termination. Translation is a precisely regulated and conserved process in eukaryotes. The presence of plant-specific translation initiation factors and the lack of well-known translational regulatory pathways in this kingdom nonetheless indicate how a globally conserved process can diversify among organisms. The control of protein translation is a central aspect of plant development and adaptation to environmental stress, but the mechanisms are still poorly understood. Here we discuss current knowledge of the principal mechanisms that regulate translation initiation in plants, with special attention to the singularities of this eukaryotic kingdom. In addition, we highlight the major recent breakthroughs in the field and the main challenges to address in the coming years.
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Affiliation(s)
- Ane Sesma
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid – Instituto Nacional de Investigación y Tecnología Agraria y AlimentariaMadrid, Spain
- Departamento Biotecnología y Biología Vegetal, Universidad Politécnica de MadridMadrid, Spain
| | - Carmen Castresana
- Centro Nacional de Biotecnología – Consejo Superior de Investigaciones Científicas (CSIC)Madrid, Spain
| | - M. Mar Castellano
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid – Instituto Nacional de Investigación y Tecnología Agraria y AlimentariaMadrid, Spain
- *Correspondence: M. Mar Castellano,
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Frydryskova K, Masek T, Borcin K, Mrvova S, Venturi V, Pospisek M. Distinct recruitment of human eIF4E isoforms to processing bodies and stress granules. BMC Mol Biol 2016; 17:21. [PMID: 27578149 PMCID: PMC5006505 DOI: 10.1186/s12867-016-0072-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 08/16/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Eukaryotic translation initiation factor 4E (eIF4E) plays a pivotal role in the control of cap-dependent translation initiation, modulates the fate of specific mRNAs, occurs in processing bodies (PBs) and is required for formation of stress granules (SGs). In this study, we focused on the subcellular localization of a representative compendium of eIF4E protein isoforms, particularly on the less studied members of the human eIF4E protein family, eIF4E2 and eIF4E3. RESULTS We showed that unlike eIF4E1, its less studied isoform eIF4E3_A, encoded by human chromosome 3, localized to stress granules but not PBs upon both heat shock and arsenite stress. Furthermore, we found that eIF4E3_A interacts with human translation initiation factors eIF4G1, eIF4G3 and PABP1 in vivo and sediments into the same fractions as canonical eIF4E1 during polysome analysis in sucrose gradients. Contrary to this finding, the truncated human eIF4E3 isoform, eIF4E3_B, showed no localization to SGs and no binding to eIF4G. We also highlighted that eIF4E2 may exhibit distinct functions under different stresses as it readily localizes to P-bodies during arsenite and heat stresses, whereas it is redirected to stress granules only upon heat shock. We extended our study to a number of protein variants, arising from alternative mRNA splicing, of each of the three eIF4E isoforms. Our results surprisingly uncovered differences in the ability of eIF4E1_1 and eIF4E1_3 to form stress granules in response to cellular stresses. CONCLUSION Our comparison of all three human eIF4E isoforms and their protein variants enriches the intriguing spectrum of roles attributed to the eukaryotic initiation translation factors of the 4E family, which exhibit a distinctive localization within different RNA granules under different stresses. The localization of eIF4E3_A to stress granules, but not to processing bodies, along with its binding to eIF4G and PABP1 suggests a role of human eIF4E3_A in translation initiation rather than its involvement in a translational repression and mRNA decay and turnover. The localization of eIF4E2 to stress granules under heat shock but not arsenite stress indicates its distinct function in cellular response to these stresses and points to the variable protein content of SGs as a consequence of different stress insults.
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Affiliation(s)
- Klara Frydryskova
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 00, Prague 2, Czech Republic
| | - Tomas Masek
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 00, Prague 2, Czech Republic.
| | - Katerina Borcin
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 00, Prague 2, Czech Republic
| | - Silvia Mrvova
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 00, Prague 2, Czech Republic
| | - Veronica Venturi
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 00, Prague 2, Czech Republic.,Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003, Barcelona, Spain
| | - Martin Pospisek
- Laboratory of RNA Biochemistry, Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 00, Prague 2, Czech Republic.
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Yang R, Zeng Y, Xu H, Chen Z, Xiang M, Fu Y, Yin Y, Zhong J, Zeng M, Wang P, You Q, Zeng X. Heterogeneous nuclear ribonucleoprotein K is overexpressed and associated with poor prognosis in gastric cancer. Oncol Rep 2016; 36:929-35. [DOI: 10.3892/or.2016.4845] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Accepted: 02/24/2016] [Indexed: 11/06/2022] Open
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Cekan P, Hasegawa K, Pan Y, Tubman E, Odde D, Chen JQ, Herrmann MA, Kumar S, Kalab P. RCC1-dependent activation of Ran accelerates cell cycle and DNA repair, inhibiting DNA damage-induced cell senescence. Mol Biol Cell 2016; 27:1346-57. [PMID: 26864624 PMCID: PMC4831887 DOI: 10.1091/mbc.e16-01-0025] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 02/05/2016] [Indexed: 11/11/2022] Open
Abstract
The coordination of cell cycle progression with the repair of DNA damage supports the genomic integrity of dividing cells. The function of many factors involved in DNA damage response (DDR) and the cell cycle depends on their Ran GTPase-regulated nuclear-cytoplasmic transport (NCT). The loading of Ran with GTP, which is mediated by RCC1, the guanine nucleotide exchange factor for Ran, is critical for NCT activity. However, the role of RCC1 or Ran⋅GTP in promoting cell proliferation or DDR is not clear. We show that RCC1 overexpression in normal cells increased cellular Ran⋅GTP levels and accelerated the cell cycle and DNA damage repair. As a result, normal cells overexpressing RCC1 evaded DNA damage-induced cell cycle arrest and senescence, mimicking colorectal carcinoma cells with high endogenous RCC1 levels. The RCC1-induced inhibition of senescence required Ran and exportin 1 and involved the activation of importin β-dependent nuclear import of 53BP1, a large NCT cargo. Our results indicate that changes in the activity of the Ran⋅GTP-regulated NCT modulate the rate of the cell cycle and the efficiency of DNA repair. Through the essential role of RCC1 in regulation of cellular Ran⋅GTP levels and NCT, RCC1 expression enables the proliferation of cells that sustain DNA damage.
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Affiliation(s)
- Pavol Cekan
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Keisuke Hasegawa
- Department of Physics, Grinnell College, Grinnell, IA 50112 Physiology Course, Marine Biological Laboratory, Woods Hole, MA 02543
| | - Yu Pan
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Emily Tubman
- Physiology Course, Marine Biological Laboratory, Woods Hole, MA 02543 Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455
| | - David Odde
- Physiology Course, Marine Biological Laboratory, Woods Hole, MA 02543 Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455
| | - Jin-Qiu Chen
- Collaborative Protein Technology Resource, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Michelle A Herrmann
- Collaborative Protein Technology Resource, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Sheetal Kumar
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Petr Kalab
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
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Combinatorial targeting of nuclear export and translation of RNA inhibits aggressive B-cell lymphomas. Blood 2015; 127:858-68. [PMID: 26603836 DOI: 10.1182/blood-2015-05-645069] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 11/20/2015] [Indexed: 11/20/2022] Open
Abstract
Aggressive double- and triple-hit (DH/TH) diffuse large B-cell lymphomas (DLBCLs) feature activation of Hsp90 stress pathways. Herein, we show that Hsp90 controls posttranscriptional dynamics of key messenger RNA (mRNA) species including those encoding BCL6, MYC, and BCL2. Using a proteomics approach, we found that Hsp90 binds to and maintains activity of eIF4E. eIF4E drives nuclear export and translation of BCL6, MYC, and BCL2 mRNA. eIF4E RNA-immunoprecipitation sequencing in DLBCL suggests that nuclear eIF4E controls an extended program that includes B-cell receptor signaling, cellular metabolism, and epigenetic regulation. Accordingly, eIF4E was required for survival of DLBCL including the most aggressive subtypes, DH/TH lymphomas. Indeed, eIF4E inhibition induces tumor regression in cell line and patient-derived tumorgrafts of TH-DLBCL, even in the presence of elevated Hsp90 activity. Targeting Hsp90 is typically limited by counterregulatory elevation of Hsp70B, which induces resistance to Hsp90 inhibitors. Surprisingly, we identify Hsp70 mRNA as an eIF4E target. In this way, eIF4E inhibition can overcome drug resistance to Hsp90 inhibitors. Accordingly, rational combinatorial inhibition of eIF4E and Hsp90 inhibitors resulted in cooperative antilymphoma activity in DH/TH DLBCL in vitro and in vivo.
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Pankiewicz KW, Felczak K. From ribavirin to NAD analogues and back to ribavirin in search for anticancer agents. HETEROCYCL COMMUN 2015. [DOI: 10.1515/hc-2015-0133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
AbstractRibavirin, a broad-spectrum antiviral agent is used in the clinic alone or in combination with other antivirals and/or interferons. Numerous structural analogues of ribavirin have been developed, among them tiazofurin, which is inactive against viruses but is a potent anticancer drug. Tiazofurin was found to inhibit nicotinamide adenine dinucleotide (NAD)-dependent inosine monophosphate dehydrogenase (IMPDH) after metabolic conversion into tiazofurin adenine dinucleotide (TAD), which binds well but could not serve as IMPDH cofactor. TAD showed high selectivity against human IMPDH vs. other cellular dehydrogenases. Mycophenolic acid (MPA) was even more specific, binding at the cofactor-binding domain of IMPDH. Ribavirin adenine dinucleotide, however, did not show any significant inhibition at the enzymatic level. We synthesized numerous NAD analogues in which natural nicotinamide riboside was replaced by tiazofurin, MPA moiety, or benzamide riboside, and the adenosine moiety as well as the pyrophosphate linker were broadly modified. Some of these compounds were found to be low nanomolar inhibitors of the enzyme and sub-micromolar inhibitors of cancer cell line proliferation. The best were as potent as tyrosine kinase inhibitor gleevec heralded as a ‘magic bullet’ against chronic myelogenous leukemia. In recent years, ribavirin was rediscovered as a potential anticancer agent against number of tumors including leukemia. It was clearly established that its antitumor activity is related to the inhibition of an oncogene, the eukaryotic translation initiation factor (eIF4E).
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Affiliation(s)
- Krzysztof W. Pankiewicz
- 1University of Minnesota Center for Drug Design, MMC 204, 516 Delaware Street NE, Minneapolis, MN 55455, USA
| | - Krzysztof Felczak
- 1University of Minnesota Center for Drug Design, MMC 204, 516 Delaware Street NE, Minneapolis, MN 55455, USA
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50
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Carroll M. When cancer and immunology meet. Immunol Rev 2014; 263:2-5. [PMID: 25510267 DOI: 10.1111/imr.12250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Martin Carroll
- Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
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