1
|
Sehrawat U. Exploiting Translation Machinery for Cancer Therapy: Translation Factors as Promising Targets. Int J Mol Sci 2024; 25:10835. [PMID: 39409166 PMCID: PMC11477148 DOI: 10.3390/ijms251910835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2024] [Revised: 09/26/2024] [Accepted: 10/02/2024] [Indexed: 10/20/2024] Open
Abstract
Eukaryotic protein translation has slowly gained the scientific community's attention for its advanced and powerful therapeutic potential. However, recent technical developments in studying ribosomes and global translation have revolutionized our understanding of this complex multistep process. These developments have improved and deepened the current knowledge of mRNA translation, sparking excitement and new possibilities in this field. Translation factors are crucial for maintaining protein synthesis homeostasis. Since actively proliferating cancer cells depend on protein synthesis, dysregulated protein translation is central to tumorigenesis. Translation factors and their abnormal expressions directly affect multiple oncogenes and tumor suppressors. Recently, small molecules have been used to target translation factors, resulting in translation inhibition in a gene-specific manner, opening the door for developing translation inhibitors that can lead to novel chemotherapeutic drugs for treating multiple cancer types caused by dysregulated translation machinery. This review comprehensively summarizes the involvement of translation factors in tumor progression and oncogenesis. Also, it sheds light on the evolution of translation factors as novel drug targets for developing future therapeutic drugs for treating cancer.
Collapse
Affiliation(s)
- Urmila Sehrawat
- Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| |
Collapse
|
2
|
Marshall GF, Fasol M, Davies FCJ, Le Seelleur M, Fernandez Alvarez A, Bennett-Ness C, Gonzalez-Sulser A, Abbott CM. Face-valid phenotypes in a mouse model of the most common mutation in EEF1A2-related neurodevelopmental disorder. Dis Model Mech 2024; 17:dmm050501. [PMID: 38179821 PMCID: PMC10855229 DOI: 10.1242/dmm.050501] [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: 09/07/2023] [Accepted: 12/21/2023] [Indexed: 01/06/2024] Open
Abstract
De novo heterozygous missense mutations in EEF1A2, encoding neuromuscular translation-elongation factor eEF1A2, are associated with developmental and epileptic encephalopathies. We used CRISPR/Cas9 to recapitulate the most common mutation, E122K, in mice. Although E122K heterozygotes were not observed to have convulsive seizures, they exhibited frequent electrographic seizures and EEG abnormalities, transient early motor deficits and growth defects. Both E122K homozygotes and Eef1a2-null mice developed progressive motor abnormalities, with E122K homozygotes reaching humane endpoints by P31. The null phenotype is driven by progressive spinal neurodegeneration; however, no signs of neurodegeneration were observed in E122K homozygotes. The E122K protein was relatively stable in neurons yet highly unstable in skeletal myocytes, suggesting that the E122K/E122K phenotype is instead driven by loss of function in muscle. Nevertheless, motor abnormalities emerged far earlier in E122K homozygotes than in nulls, suggesting a toxic gain of function and/or a possible dominant-negative effect. This mouse model represents the first animal model of an EEF1A2 missense mutation with face-valid phenotypes and has provided mechanistic insights needed to inform rational treatment design.
Collapse
Affiliation(s)
- Grant F. Marshall
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Melissa Fasol
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Faith C. J. Davies
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Matthew Le Seelleur
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | - Alejandra Fernandez Alvarez
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | - Cavan Bennett-Ness
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | - Alfredo Gonzalez-Sulser
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Catherine M. Abbott
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
| |
Collapse
|
3
|
Zhang W, Wang J, Shan C. The eEF1A protein in cancer: Clinical significance, oncogenic mechanisms, and targeted therapeutic strategies. Pharmacol Res 2024; 204:107195. [PMID: 38677532 DOI: 10.1016/j.phrs.2024.107195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/09/2024] [Accepted: 04/22/2024] [Indexed: 04/29/2024]
Abstract
Eukaryotic elongation factor 1A (eEF1A) is among the most abundant proteins in eukaryotic cells. Evolutionarily conserved across species, eEF1A is in charge of translation elongation for protein biosynthesis as well as a plethora of non-translational moonlighting functions for cellular homeostasis. In malignant cells, however, eEF1A becomes a pleiotropic driver of cancer progression via a broad diversity of pathways, which are not limited to hyperactive translational output. In the past decades, mounting studies have demonstrated the causal link between eEF1A and carcinogenesis, gaining deeper insights into its multifaceted mechanisms and corroborating its value as a prognostic marker in various cancers. On the other hand, an increasing number of natural and synthetic compounds were discovered as anticancer eEF1A-targeting inhibitors. Among them, plitidepsin was approved for the treatment of multiple myeloma whereas metarrestin was currently under clinical development. Despite significant achievements in these two interrelated fields, hitherto there lacks a systematic examination of the eEF1A protein in the context of cancer research. Therefore, the present work aims to delineate its clinical implications, molecular oncogenic mechanisms, and targeted therapeutic strategies as reflected in the ever expanding body of literature, so as to deepen mechanistic understanding of eEF1A-involved tumorigenesis and inspire the development of eEF1A-targeted chemotherapeutics and biologics.
Collapse
Affiliation(s)
- Weicheng Zhang
- The State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, People's Republic of China.
| | - Jiyan Wang
- The State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, People's Republic of China
| | - Changliang Shan
- The State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, People's Republic of China.
| |
Collapse
|
4
|
Treekitkarnmongkol W, Solis LM, Sankaran D, Gagea M, Singh PK, Mistry R, Nguyen T, Kai K, Liu J, Sasai K, Jitsumori Y, Liu J, Nagao N, Stossi F, Mancini MA, Wistuba II, Thompson AM, Lee JM, Cadiñanos J, Wong KK, Abbott CM, Sahin AA, Liu S, Katayama H, Sen S. eEF1A2 promotes PTEN-GSK3β-SCF complex-dependent degradation of Aurora kinase A and is inactivated in breast cancer. Sci Signal 2024; 17:eadh4475. [PMID: 38442201 DOI: 10.1126/scisignal.adh4475] [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] [Received: 03/03/2023] [Accepted: 02/15/2024] [Indexed: 03/07/2024]
Abstract
The translation elongation factor eEF1A promotes protein synthesis. Its methylation by METTL13 increases its activity, supporting tumor growth. However, in some cancers, a high abundance of eEF1A isoforms is associated with a good prognosis. Here, we found that eEF1A2 exhibited oncogenic or tumor-suppressor functions depending on its interaction with METTL13 or the phosphatase PTEN, respectively. METTL13 and PTEN competed for interaction with eEF1A2 in the same structural domain. PTEN-bound eEF1A2 promoted the ubiquitination and degradation of the mitosis-promoting Aurora kinase A in the S and G2 phases of the cell cycle. eEF1A2 bridged the interactions between the SKP1-CUL1-FBXW7 (SCF) ubiquitin ligase complex, the kinase GSK3β, and Aurora-A, thereby facilitating the phosphorylation of Aurora-A in a degron site that was recognized by FBXW7. Genetic ablation of Eef1a2 or Pten in mice resulted in a greater abundance of Aurora-A and increased cell cycling in mammary tumors, which was corroborated in breast cancer tissues from patients. Reactivating this pathway using fimepinostat, which relieves inhibitory signaling directed at PTEN and increases FBXW7 expression, combined with inhibiting Aurora-A with alisertib, suppressed breast cancer cell proliferation in culture and tumor growth in vivo. The findings demonstrate a therapeutically exploitable, tumor-suppressive role for eEF1A2 in breast cancer.
Collapse
Affiliation(s)
- Warapen Treekitkarnmongkol
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Luisa M Solis
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Deivendran Sankaran
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Mihai Gagea
- Department of Veterinary Medicine and Surgery, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Pankaj K Singh
- Center for Translational Cancer Research, Texas A&M Health Science Center, Institute of Biosciences and Technology, Houston, TX 77030, USA
| | - Ragini Mistry
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Tristian Nguyen
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Kazuharu Kai
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jiajun Liu
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, PR China
| | - Kaori Sasai
- Department of Molecular Oncology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Yoshimi Jitsumori
- Department of Molecular Oncology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Jianwen Liu
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, PR China
| | - Norio Nagao
- Department of Life and Environmental Sciences, Prefectural University of Hiroshima, Shobara, 727-0023, Japan
| | - Fabio Stossi
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Michael A Mancini
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ignacio I Wistuba
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | | | - Jonathan M Lee
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Juan Cadiñanos
- Fundación Centro Médico de Asturias, 33193 Oviedo, Spain
- Instituto de Medicina Oncológica y Molecular de Asturias (IMOMA), 33193 Oviedo, Spain
| | - Kwong-Kwok Wong
- Department of Gynecologic Oncology and Reproductive Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Catherine M Abbott
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Aysegul A Sahin
- Department of Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Suyu Liu
- Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Hiroshi Katayama
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Molecular Oncology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Subrata Sen
- Department of Translational Molecular Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| |
Collapse
|
5
|
Davies FCJ, Marshall GF, Pegram E, Gadd D, Abbott CM. Endogenous epitope tagging of eEF1A2 in mice reveals early embryonic expression of eEF1A2 and subcellular compartmentalisation of neuronal eEF1A1 and eEF1A2. Mol Cell Neurosci 2023; 126:103879. [PMID: 37429391 DOI: 10.1016/j.mcn.2023.103879] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/29/2023] [Accepted: 07/06/2023] [Indexed: 07/12/2023] Open
Abstract
All vertebrate species express two independently-encoded forms of translation elongation factor eEF1A. In humans and mice eEF1A1 and eEF1A2 are 92 % identical at the amino acid level, but the well conserved developmental switch between the two variants in specific tissues suggests the existence of important functional differences. Heterozygous mutations in eEF1A2 result in neurodevelopmental disorders in humans; the mechanism of pathogenicity is unclear, but one hypothesis is that there is a dominant negative effect on eEF1A1 during development. The high degree of similarity between the eEF1A proteins has complicated expression analysis in the past; here we describe a gene edited mouse line in which we have introduced a V5 tag in the gene encoding eEF1A2. Expression analysis using anti-V5 and anti-eEF1A1 antibodies demonstrates that, in contrast to the prevailing view that eEF1A2 is only expressed postnatally, it is expressed from as early as E11.5 in the developing neural tube. Two colour immunofluorescence also reveals coordinated switching between eEF1A1 and eEF1A2 in different regions of postnatal brain. Completely reciprocal expression of the two variants is seen in post-weaning mouse brain with eEF1A1 expressed in oligodendrocytes and astrocytes and eEF1A2 in neuronal soma. Although eEF1A1 is absent from neuronal cell bodies after development, it is widely expressed in axons. This expression does not appear to coincide with myelin sheaths originating from oligodendrocytes but rather results from localised translation within the axon, suggesting that both variants are transcribed in neurons but show completely distinct subcellular localisation at the protein level. These findings will form an underlying framework for understanding how missense mutations in eEF1A2 result in neurodevelopmental disorders.
Collapse
Affiliation(s)
- Faith C J Davies
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Grant F Marshall
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Eleanor Pegram
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom
| | - Danni Gadd
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom
| | - Catherine M Abbott
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom.
| |
Collapse
|
6
|
Khwanraj K, Prommahom A, Dharmasaroja P. eEF1A2 siRNA Suppresses MPP+-Induced Activation of Akt and mTOR and Potentiates Caspase-3 Activation in a Parkinson’s Disease Model. ScientificWorldJournal 2023; 2023:1335201. [PMID: 37051183 PMCID: PMC10085650 DOI: 10.1155/2023/1335201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/19/2023] [Accepted: 03/21/2023] [Indexed: 04/05/2023] Open
Abstract
The tissue-specific protein eEF1A2 has been linked to the development of neurological disorders. The role of eEF1A2 in the pathogenesis of Parkinson’s disease (PD) has yet to be investigated. The aim of this study was to determine the potential neuroprotective effects of eEF1A2 in an MPP+ model of PD. Differentiated SH-SY5Y cells were transfected with eEF1A2 siRNA, followed by MPP+ exposure. The expression of p-Akt1 and p-mTORC1 was determined using Western blotting. The expression of p53, Bax, Bcl-2, and caspase-3 was evaluated using qRT-PCR. Cleaved caspase-3 levels and Annexin V/propidium iodide flow cytometry were used to determine apoptosis. The effects of PI3K inhibition were examined. The results showed that eEF1A2 siRNA significantly reduced the eEF1A2 expression induced by MPP+. MPP+ treatment activated Akt1 and mTORC1; however, eEF1A2 knockdown suppressed this activation. In eEF1A2-knockdown cells, MPP+ treatment increased the expression of p53 and caspase-3 mRNA levels as well as increased apoptotic cell death when compared to MPP+ treatment alone. In cells exposed to MPP+, upstream inhibition of the Akt/mTOR pathway, by either LY294002 or wortmannin, inhibited the phosphorylation of Akt1 and mTORC1. Both PI3K inhibitors increased eEF1A2 expression in cells, whether or not they were also treated with MPP+. In conclusion, eEF1A2 may function as a neuroprotective factor against MPP+, in part by regulating the Akt/mTOR pathway upstream.
Collapse
Affiliation(s)
- Kawinthra Khwanraj
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Athinan Prommahom
- Chakri Naruebodindra Medical Institute, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Samut Prakan, Thailand
| | | |
Collapse
|
7
|
RACK1 Regulates Poxvirus Protein Synthesis Independently of Its Role in Ribosome-Based Stress Signaling. J Virol 2022; 96:e0109322. [PMID: 36098514 PMCID: PMC9517738 DOI: 10.1128/jvi.01093-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Receptor for activated C kinase 1 (RACK1) is a small ribosomal subunit protein that is phosphorylated by vaccinia virus (VacV) to maximize translation of postreplicative (PR) mRNAs that harbor 5' polyA leaders. However, RACK1 is a multifunctional protein that both controls translation directly and acts as a scaffold for signaling to and from the ribosome. This includes stress signaling that is activated by ribosome-associated quality control (RQC) and ribotoxic stress response (RSR) pathways. As VacV infection activates RQC and stress signaling, whether RACK1 influences viral protein synthesis through its effects on translation, signaling, or both remains unclear. Examining the effects of genetic knockout of RACK1 on the phosphorylation of key mitogenic and stress-related kinases, we reveal that loss of RACK1 specifically blunts the activation of c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) at late stages of infection. However, RACK1 was not required for JNK recruitment to ribosomes, and unlike RACK1 knockout, JNK inhibitors had no effect on viral protein synthesis. Moreover, reduced JNK activity during infection in RACK1 knockout cells contrasted with the absolute requirement for RACK1 in RSR-induced JNK phosphorylation. Comparing the effects of RACK1 knockout alongside inhibitors of late stage replication, our data suggest that JNK activation is only indirectly affected by the absence of RACK1 due to reduced viral protein accumulation. Cumulatively, our findings in the context of infection add further support for a model whereby RACK1 plays a specific and direct role in controlling translation of PR viral mRNAs that is independent of its role in ribosome-based stress signaling. IMPORTANCE Receptor for activated C kinase 1 (RACK1) is a multifunctional ribosomal protein that regulates translation directly and mediates signaling to and from the ribosome. While recent work has shown that RACK1 is phosphorylated by vaccinia virus (VacV) to stimulate translation of postreplicative viral mRNAs, whether RACK1 also contributes to VacV replication through its roles in ribosome-based stress signaling remains unclear. Here, we characterize the role of RACK1 in infected cells. In doing so, we find that RACK1 is essential for stress signal activation by ribotoxic stress responses but not by VacV infection. Moreover, although the loss of RACK1 reduces the level of stress-associated JNK activation in infected cells, this is an indirect consequence of RACK1's specific requirement for the synthesis of postreplicative viral proteins, the accumulation of which determines the level of cellular stress. Our findings reveal both the specific role of RACK1 and the complex downstream effects of its control of viral protein synthesis in the context of infection.
Collapse
|
8
|
Analysis of the Expression and Subcellular Distribution of eEF1A1 and eEF1A2 mRNAs during Neurodevelopment. Cells 2022; 11:cells11121877. [PMID: 35741005 PMCID: PMC9220863 DOI: 10.3390/cells11121877] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 12/04/2022] Open
Abstract
Neurodevelopment is accompanied by a precise change in the expression of the translation elongation factor 1A variants from eEF1A1 to eEF1A2. These are paralogue genes that encode 92% identical proteins in mammals. The switch in the expression of eEF1A variants has been well studied in mouse motor neurons, which solely express eEF1A2 by four weeks of postnatal development. However, changes in the subcellular localization of eEF1A variants during neurodevelopment have not been studied in detail in other neuronal types because antibodies lack perfect specificity, and immunofluorescence has a low sensitivity. In hippocampal neurons, eEF1A is related to synaptic plasticity and memory consolidation, and decreased eEF1A expression is observed in the hippocampus of Alzheimer's patients. However, the specific variant involved in these functions is unknown. To distinguish eEF1A1 from eEF1A2 expression, we have designed single-molecule fluorescence in-situ hybridization probes to detect either eEF1A1 or eEF1A2 mRNAs in cultured primary hippocampal neurons and brain tissues. We have developed a computational framework, ARLIN (analysis of RNA localization in neurons), to analyze and compare the subcellular distribution of eEF1A1 and eEF1A2 mRNAs at specific developmental stages and in mature neurons. We found that eEF1A1 and eEF1A2 mRNAs differ in expression and subcellular localization over neurodevelopment, and eEF1A1 mRNAs localize in dendrites and synapses during dendritogenesis and synaptogenesis. Interestingly, mature hippocampal neurons coexpress both variant mRNAs, and eEF1A1 remains the predominant variant in dendrites.
Collapse
|
9
|
Moustafa-Kamal M, Kucharski TJ, El-Assaad W, Abbas YM, Gandin V, Nagar B, Pelletier J, Topisirovic I, Teodoro JG. The mTORC1/S6K/PDCD4/eIF4A Axis Determines Outcome of Mitotic Arrest. Cell Rep 2021; 33:108230. [PMID: 33027666 DOI: 10.1016/j.celrep.2020.108230] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/29/2020] [Accepted: 09/14/2020] [Indexed: 12/26/2022] Open
Abstract
mTOR is a serine/threonine kinase and a master regulator of cell growth and proliferation. Raptor, a scaffolding protein that recruits substrates to mTOR complex 1 (mTORC1), is known to be phosphorylated during mitosis, but the significance of this phosphorylation remains largely unknown. Here we show that raptor expression and mTORC1 activity are dramatically reduced in cells arrested in mitosis. Expression of a non-phosphorylatable raptor mutant reactivates mTORC1 and significantly reduces cytotoxicity of the mitotic poison Taxol. This effect is mediated via degradation of PDCD4, a tumor suppressor protein that inhibits eIF4A activity and is negatively regulated by the mTORC1/S6K pathway. Moreover, pharmacological inhibition of eIF4A is able to enhance the effects of Taxol and restore sensitivity in Taxol-resistant cancer cells. These findings indicate that the mTORC1/S6K/PDCD4/eIF4A axis has a pivotal role in the death versus slippage decision during mitotic arrest and may be exploited clinically to treat tumors resistant to anti-mitotic agents.
Collapse
Affiliation(s)
- Mohamed Moustafa-Kamal
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Thomas J Kucharski
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Wissal El-Assaad
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada
| | - Yazan M Abbas
- Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Valentina Gandin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Bhushan Nagar
- Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Jerry Pelletier
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Ivan Topisirovic
- Department of Biochemistry, McGill University, Montréal, QC, Canada; Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, and Department of Oncology, McGill University, Montréal, QC, Canada.
| | - Jose G Teodoro
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada.
| |
Collapse
|
10
|
Mendoza MB, Gutierrez S, Ortiz R, Moreno DF, Dermit M, Dodel M, Rebollo E, Bosch M, Mardakheh FK, Gallego C. The elongation factor eEF1A2 controls translation and actin dynamics in dendritic spines. Sci Signal 2021; 14:14/691/eabf5594. [PMID: 34257105 DOI: 10.1126/scisignal.abf5594] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Synaptic plasticity involves structural modifications in dendritic spines that are modulated by local protein synthesis and actin remodeling. Here, we investigated the molecular mechanisms that connect synaptic stimulation to these processes. We found that the phosphorylation of isoform-specific sites in eEF1A2-an essential translation elongation factor in neurons-is a key modulator of structural plasticity in dendritic spines. Expression of a nonphosphorylatable eEF1A2 mutant stimulated mRNA translation but reduced actin dynamics and spine density. By contrast, a phosphomimetic eEF1A2 mutant exhibited decreased association with F-actin and was inactive as a translation elongation factor. Activation of metabotropic glutamate receptor signaling triggered transient dissociation of eEF1A2 from its regulatory guanine exchange factor (GEF) protein in dendritic spines in a phosphorylation-dependent manner. We propose that eEF1A2 establishes a cross-talk mechanism that coordinates translation and actin dynamics during spine remodeling.
Collapse
Affiliation(s)
- Mònica B Mendoza
- Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain
| | - Sara Gutierrez
- Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain
| | - Raúl Ortiz
- Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain
| | - David F Moreno
- Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain
| | - Maria Dermit
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse square, London EC1M 6BQ, UK
| | - Martin Dodel
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse square, London EC1M 6BQ, UK
| | - Elena Rebollo
- Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain
| | - Miquel Bosch
- Department of Basic Sciences, Universitat Internacional de Catalunya (UIC-Barcelona), Sant Cugat del Vallès 08195, Spain.,Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona 08028, Spain
| | - Faraz K Mardakheh
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse square, London EC1M 6BQ, UK
| | - Carme Gallego
- Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain.
| |
Collapse
|
11
|
Mills A, Gago F. On the Need to Tell Apart Fraternal Twins eEF1A1 and eEF1A2, and Their Respective Outfits. Int J Mol Sci 2021; 22:6973. [PMID: 34203525 PMCID: PMC8268798 DOI: 10.3390/ijms22136973] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/25/2021] [Accepted: 06/25/2021] [Indexed: 01/03/2023] Open
Abstract
eEF1A1 and eEF1A2 are paralogous proteins whose presence in most normal eukaryotic cells is mutually exclusive and developmentally regulated. Often described in the scientific literature under the collective name eEF1A, which stands for eukaryotic elongation factor 1A, their best known activity (in a monomeric, GTP-bound conformation) is to bind aminoacyl-tRNAs and deliver them to the A-site of the 80S ribosome. However, both eEF1A1 and eEF1A2 are endowed with multitasking abilities (sometimes performed by homo- and heterodimers) and can be located in different subcellular compartments, from the plasma membrane to the nucleus. Given the high sequence identity of these two sister proteins and the large number of post-translational modifications they can undergo, we are often confronted with the dilemma of discerning which is the particular proteoform that is actually responsible for the ascribed biochemical or cellular effects. We argue in this review that acquiring this knowledge is essential to help clarify, in molecular and structural terms, the mechanistic involvement of these two ancestral and abundant G proteins in a variety of fundamental cellular processes other than translation elongation. Of particular importance for this special issue is the fact that several de novo heterozygous missense mutations in the human EEF1A2 gene are associated with a subset of rare but severe neurological syndromes and cardiomyopathies.
Collapse
Affiliation(s)
| | - Federico Gago
- Department of Biomedical Sciences & “Unidad Asociada IQM-CSIC”, School of Medicine and Health Sciences, University of Alcalá, E-28805 Alcalá de Henares, Spain;
| |
Collapse
|
12
|
Niu X, Nong S, Gong J, Zhang X, Tang H, Zhou T, Li W. Hepatitis B Virus DNA Polymerase Displays an Anti-Apoptotic Effect by Interacting with Elongation Factor-1 Alpha-2 in Hepatoma Cells. J Microbiol Biotechnol 2021; 31:16-24. [PMID: 33144545 PMCID: PMC9705884 DOI: 10.4014/jmb.2002.02039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 09/07/2020] [Accepted: 10/21/2020] [Indexed: 12/15/2022]
Abstract
Hepatitis B virus (HBV) genome P-encoded protein HBV DNA polymerase (Pol) has long been known as a reverse transcriptase during HBV replication. In this study, we investigated the impact of HBV Pol on host cellular processes, mainly apoptosis, and the underlying mechanisms. We showed a marked reduction in apoptotic rates in the HBV Pol-expressed HepG2 cells compared to controls. Moreover, a series of assays, i.e., yeast two-hybrid, GST pull-down, co-immunoprecipitation, and confocal laser scanning microscopy, identified the host factor eEF1A2 to be associated with HBV Pol. Furthermore, knockdown of eEF1A2 gene by siRNA abrogated the HBV Pol-mediated anti-apoptotic effect with apoptosis induced by endoplasmatic reticulum (ER) stress-inducer thapsigargin (TG), thus suggesting that the host factor eEF1A2 is essential for HBV Pol's anti-apoptosis properties. Our findings have revealed a novel role for HBV Pol in its modulation of apoptosis through integrating with eEF1A2.
Collapse
Affiliation(s)
- Xianli Niu
- Department of Biochemistry and Molecular Biology, Zunyi Medical University, Zhuhai, Guangdong 5904, P.R. China,Key Laboratory of Genetic Engineering and Medicine, Key Laboratory of Viral Biology, Jinan University, Guangzhou, Guangdong 51063, P.R. China
| | - Shirong Nong
- Key Laboratory of Genetic Engineering and Medicine, Key Laboratory of Viral Biology, Jinan University, Guangzhou, Guangdong 51063, P.R. China
| | - Junyuan Gong
- Key Laboratory of Genetic Engineering and Medicine, Key Laboratory of Viral Biology, Jinan University, Guangzhou, Guangdong 51063, P.R. China
| | - Xin Zhang
- Key Laboratory of Genetic Engineering and Medicine, Key Laboratory of Viral Biology, Jinan University, Guangzhou, Guangdong 51063, P.R. China
| | - Hui Tang
- Key Laboratory of Genetic Engineering and Medicine, Key Laboratory of Viral Biology, Jinan University, Guangzhou, Guangdong 51063, P.R. China
| | - Tianhong Zhou
- Key Laboratory of Genetic Engineering and Medicine, Key Laboratory of Viral Biology, Jinan University, Guangzhou, Guangdong 51063, P.R. China,T.H. Zhou E-mail:
| | - Wei Li
- Key Laboratory of Genetic Engineering and Medicine, Key Laboratory of Viral Biology, Jinan University, Guangzhou, Guangdong 51063, P.R. China,Corresponding authors W. Li Phone: +19945656624 Fax +0208895322 E-mail:
| |
Collapse
|
13
|
Dersh D, Phelan JD, Gumina ME, Wang B, Arbuckle JH, Holly J, Kishton RJ, Markowitz TE, Seedhom MO, Fridlyand N, Wright GW, Huang DW, Ceribelli M, Thomas CJ, Lack JB, Restifo NP, Kristie TM, Staudt LM, Yewdell JW. Genome-wide Screens Identify Lineage- and Tumor-Specific Genes Modulating MHC-I- and MHC-II-Restricted Immunosurveillance of Human Lymphomas. Immunity 2021; 54:116-131.e10. [PMID: 33271120 PMCID: PMC7874576 DOI: 10.1016/j.immuni.2020.11.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 09/25/2020] [Accepted: 11/06/2020] [Indexed: 12/23/2022]
Abstract
Tumors frequently subvert major histocompatibility complex class I (MHC-I) peptide presentation to evade CD8+ T cell immunosurveillance, though how this is accomplished is not always well defined. To identify the global regulatory networks controlling antigen presentation, we employed genome-wide screening in human diffuse large B cell lymphomas (DLBCLs). This approach revealed dozens of genes that positively and negatively modulate MHC-I cell surface expression. Validated genes clustered in multiple pathways including cytokine signaling, mRNA processing, endosomal trafficking, and protein metabolism. Genes can exhibit lymphoma subtype- or tumor-specific MHC-I regulation, and a majority of primary DLBCL tumors displayed genetic alterations in multiple regulators. We established SUGT1 as a major positive regulator of both MHC-I and MHC-II cell surface expression. Further, pharmacological inhibition of two negative regulators of antigen presentation, EZH2 and thymidylate synthase, enhanced DLBCL MHC-I presentation. These and other genes represent potential targets for manipulating MHC-I immunosurveillance in cancers, infectious diseases, and autoimmunity.
Collapse
Affiliation(s)
- Devin Dersh
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - James D Phelan
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Megan E Gumina
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Boya Wang
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jesse H Arbuckle
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jaroslav Holly
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rigel J Kishton
- Surgery Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 USA
| | - Tovah E Markowitz
- NIAID Collaborative Bioinformatics Resource, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Mina O Seedhom
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nathan Fridlyand
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - George W Wright
- Biometric Research Branch, Division of Cancer Diagnosis and Treatment, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Da Wei Huang
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michele Ceribelli
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Craig J Thomas
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Justin B Lack
- NIAID Collaborative Bioinformatics Resource, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Nicholas P Restifo
- Surgery Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 USA
| | - Thomas M Kristie
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Louis M Staudt
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jonathan W Yewdell
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|
14
|
Zhang S, Chen Y, Wang Y, Zhang P, Chen G, Zhou Y. Insights Into Translatomics in the Nervous System. Front Genet 2021; 11:599548. [PMID: 33408739 PMCID: PMC7779767 DOI: 10.3389/fgene.2020.599548] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 11/30/2020] [Indexed: 12/11/2022] Open
Abstract
Most neurological disorders are caused by abnormal gene translation. Generally, dysregulation of elements involved in the translational process disrupts homeostasis in neurons and neuroglia. Better understanding of how the gene translation process occurs requires detailed analysis of transcriptomic and proteomic profile data. However, a lack of strictly direct correlations between mRNA and protein levels limits translational investigation by combining transcriptomic and proteomic profiling. The much better correlation between proteins and translated mRNAs than total mRNAs in abundance and insufficiently sensitive proteomics approach promote the requirement of advances in translatomics technology. Translatomics which capture and sequence the mRNAs associated with ribosomes has been effective in identifying translational changes by genetics or projections, ribosome stalling, local translation, and transcript isoforms in the nervous system. Here, we place emphasis on the main three translatomics methods currently used to profile mRNAs attached to ribosome-nascent chain complex (RNC-mRNA). Their prominent applications in neurological diseases including glioma, neuropathic pain, depression, fragile X syndrome (FXS), neurodegenerative disorders are outlined. The content reviewed here expands our understanding on the contributions of aberrant translation to neurological disease development.
Collapse
Affiliation(s)
- Shuxia Zhang
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yeru Chen
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yongjie Wang
- Key Laboratory of Elemene Anti-Cancer Medicine of Zhejiang Province and Holistic Integrative Pharmacy Institutes, Hangzhou Normal University, Hangzhou, China.,Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province, Holistic Integrative Pharmacy Institutes, Hangzhou Normal University, Hangzhou, China
| | - Piao Zhang
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Gang Chen
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Youfa Zhou
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| |
Collapse
|
15
|
Wirakiat W, Prommahom A, Dharmasaroja P. Inhibition of the antioxidant enzyme PRDX1 activity promotes MPP +-induced death in differentiated SH-SY5Y cells and may impair its colocalization with eEF1A2. Life Sci 2020; 258:118227. [PMID: 32781074 DOI: 10.1016/j.lfs.2020.118227] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/29/2020] [Accepted: 08/04/2020] [Indexed: 12/31/2022]
Abstract
AIM eEF1A2 is highly expressed in postmitotic cells and has been reported to interact with the antioxidant enzyme peroxiredoxin 1 (PRDX1). PRDX1 is involved in motor neuron differentiation. Here, we studied the relationship between eEF1A2 and PRDX1 during dopaminergic neuron differentiation, and examined their possible association in an oxidative stress model of Parkinson's disease (PD). MAIN METHODS Expression of eEF1A2 and PRDX1 in SH-SY5Y cells at various durations of retinoic acid (RA) induction was detected using qRT-PCR, Western blotting and immunofluorescence. Neurons of 10-day differentiation were treated with the PRDX1 inhibitor H7, MPP+ and H7 plus MPP+. The cell viability, the amounts of apoptotic nuclei, DHE signals, and the expression of p53, p-Akt and p-mTOR were determined. The colocalization of eEF1A2 and PRDX1 was visualized using confocal microscopy. KEY FINDINGS eEF1A2 gradually increased after RA-induced differentiation of SH-SY5Y cells, while PRDX1 protein gradually decreased. MPP+ treatment increased eEF1A2 in both undifferentiated and differentiated neurons; however, PRDX1 appeared to elevate only in mature neurons. The inhibition of the PRDX1 activity with H7 promoted MPP+-induced cell death, as evidenced by decreased cell viability, increased apoptotic nuclei, increased the DHE signal, and increased p53. However, H7 induced the activation of the prosurvival Akt and mTOR in MPP+-treated cells. Besides, a colocalization of eEF1A2 and PRDX1 was evidenced in MPP+-treated neurons. This colocalization was possibly prevented by inhibiting the PRDX1 activity, resulting in aggravated neuronal death. SIGNIFICANCE Our results suggest that the possible association between eEF1A2 and PRDX1 may be a promising target for modifying neuronal death in PD.
Collapse
Affiliation(s)
- Wimon Wirakiat
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Athinan Prommahom
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Permphan Dharmasaroja
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
| |
Collapse
|
16
|
Ormsby AR, Cox D, Daly J, Priest D, Hinde E, Hatters DM. Nascent mutant Huntingtin exon 1 chains do not stall on ribosomes during translation but aggregates do recruit machinery involved in ribosome quality control and RNA. PLoS One 2020; 15:e0233583. [PMID: 32735619 PMCID: PMC7394408 DOI: 10.1371/journal.pone.0233583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 07/13/2020] [Indexed: 11/18/2022] Open
Abstract
Mutations that cause Huntington’s Disease involve a polyglutamine (polyQ) sequence expansion beyond 35 repeats in exon 1 of Huntingtin. Intracellular inclusion bodies of mutant Huntingtin protein are a key feature of Huntington’s disease brain pathology. We previously showed that in cell culture the formation of inclusions involved the assembly of disordered structures of mHtt exon 1 fragments (Httex1) and they were enriched with translational machinery when first formed. We hypothesized that nascent mutant Httex1 chains co-aggregate during translation by phase separation into liquid-like disordered aggregates and then convert to more rigid, amyloid structures. Here we further examined the mechanisms of inclusion assembly in a human epithelial kidney (AD293) cell culture model. We found mHttex1 did not appear to stall translation of its own nascent chain, or at best was marginal. We also found the inclusions appeared to recruit low levels of RNA but there was no difference in enrichment between early formed and mature inclusions. Proteins involved in translation or ribosome quality control were co-recruited to the inclusions (Ltn1 Rack1) compared to a protein not anticipated to be involved (NACAD), but there was no major specificity of enrichment in the early formed inclusions compared to mature inclusions. Furthermore, we observed co-aggregation with other proteins previously identified in inclusions, including Upf1 and chaperone-like proteins Sgta and Hspb1, which also suppressed aggregation at high co-expression levels. The newly formed inclusions also contained immobile mHttex1 molecules which points to the disordered aggregates being mechanically rigid prior to amyloid formation. Collectively our findings show little evidence that inclusion assembly arises by a discrete clustering of stalled nascent chains and associated quality control machinery. Instead, the machinery appear to be recruited continuously, or secondarily, to the nucleation of inclusion formation.
Collapse
Affiliation(s)
- Angelique R. Ormsby
- Department of Biochemistry and Molecular Biology; and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC, Australia
| | - Dezerae Cox
- Department of Biochemistry and Molecular Biology; and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC, Australia
| | - James Daly
- Department of Biochemistry and Molecular Biology; and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC, Australia
| | - David Priest
- Department of Biochemistry and Molecular Biology; and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC, Australia
| | - Elizabeth Hinde
- Department of Biochemistry and Molecular Biology; and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC, Australia
| | - Danny M. Hatters
- Department of Biochemistry and Molecular Biology; and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC, Australia
- * E-mail:
| |
Collapse
|
17
|
Prommahom A, Dharmasaroja P. Effects of eEF1A2 knockdown on autophagy in an MPP +-induced cellular model of Parkinson's disease. Neurosci Res 2020; 164:55-69. [PMID: 32275913 DOI: 10.1016/j.neures.2020.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/16/2020] [Accepted: 03/30/2020] [Indexed: 11/17/2022]
Abstract
1-Methyl-4-phenylpyridinium ion (MPP+) is widely used to induce a cellular model of Parkinson's disease (PD) in dopaminergic cell lines. Downregulation of the protein translation elongation factor 1 alpha (eEF1A) has been reported in the brain tissue of PD patients. eEF1A2, an isoform of eEF1A, is associated with lysosome biogenesis that involves the autophagy process. However, the role of eEF1A2 on autophagic activity in PD has not been elucidated. In this work, we investigated the role of eEF1A2 on autophagy using eEF1A2 siRNA knockdown in differentiated SH-SY5Y neuronal cells treated with MPP+. We found that eEF1A2 was upregulated in differentiated cells, which could be silenced by eEF1A2 siRNA. Significantly, cells treated with MPP+ after eEF1A2 knockdown showed a decreased number of LC3 puncta, decreased LC3-II/LC3-I ratio, and decreased phospho-Beclin-1, compared to the MPP+ alone group. These cells showed extensive areas of mitochondria damage, with a reduction of mitochondrial membrane potential, but reduced mitophagy as indicated by the reduced colocalization of LC3 puncta with damaged mitochondria. Cells with eEF1A2 siRNA plus MPP+ treatment aggravated α-synuclein accumulation but reduced colocalization with LC3. As a result, eEF1A2 knockdown decreased viability, increased apoptotic nuclei, increased caspase-3/7 activation and increased cleaved caspase-3 when cells were treated with MPP+. These results suggest that eEF1A2 is essential for dopaminergic neuron survival against MPP+, in part through autophagy regulation.
Collapse
Affiliation(s)
- Athinan Prommahom
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Permphan Dharmasaroja
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand.
| |
Collapse
|
18
|
Pu Y, Liu YQ, Zhou Y, Qi YF, Liao SP, Miao SK, Zhou LM, Wan LH. Dual role of RACK1 in airway epithelial mesenchymal transition and apoptosis. J Cell Mol Med 2020; 24:3656-3668. [PMID: 32064783 PMCID: PMC7131927 DOI: 10.1111/jcmm.15061] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/04/2020] [Accepted: 01/21/2020] [Indexed: 02/05/2023] Open
Abstract
Airway epithelial apoptosis and epithelial mesenchymal transition (EMT) are two crucial components of asthma pathogenesis, concomitantly mediated by TGF‐β1. RACK1 is the downstream target gene of TGF‐β1 shown to enhancement in asthma mice in our previous study. Balb/c mice were sensitized twice and challenged with OVA every day for 7 days. Transformed human bronchial epithelial cells, BEAS‐2B cells were cultured and exposed to recombinant soluble human TGF‐β1 to induced apoptosis (30 ng/mL, 72 hours) and EMT (10 ng/mL, 48 hours) in vitro, respectively. siRNA and pharmacological inhibitors were used to evaluate the regulation of RACK1 protein in apoptosis and EMT. Western blotting analysis and immunostaining were used to detect the protein expressions in vivo and in vitro. Our data showed that RACK1 protein levels were significantly increased in OVA‐challenged mice, as well as TGF‐β1‐induced apoptosis and EMT of BEAS‐2B cells. Knockdown of RACK1 (siRACK1) significantly inhibited apoptosis and decreased TGF‐β1 up‐regulated EMT related protein levels (N‐cadherin and Snail) in vitro via suppression of JNK and Smad3 activation. Moreover, siSmad3 or siJNK impaired TGF‐β1‐induced N‐cadherin and Snail up‐regulation in vitro. Importantly, JNK gene silencing (siERK) also impaired the regulatory effect of TGF‐β1 on Smad3 activation. Our present data demonstrate that RACK1 is a concomitant regulator of TGF‐β1 induces airway apoptosis and EMT via JNK/Smad/Snail signalling axis. Our findings may provide a new insight into understanding the regulation mechanism of RACK1 in asthma pathogenesis.
Collapse
Affiliation(s)
- Yue Pu
- Department of Pharmacology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, PR China
| | - Yuan-Qi Liu
- Department of Pharmacology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, PR China
| | - Yan Zhou
- Department of Intensive Care Unit, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China
| | - Yi-Fan Qi
- Grade 2015, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, PR China
| | - Shi-Ping Liao
- Functional Laboratory, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, PR China
| | - Shi-Kun Miao
- Department of Pharmacology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, PR China
| | - Li-Ming Zhou
- Department of Pharmacology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, PR China
| | - Li-Hong Wan
- Department of Pharmacology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, PR China
| |
Collapse
|
19
|
Generation of endoplasmic reticulum stress and inhibition of autophagy by plitidepsin induces proteotoxic apoptosis in cancer cells. Biochem Pharmacol 2020; 172:113744. [DOI: 10.1016/j.bcp.2019.113744] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 12/02/2019] [Indexed: 12/21/2022]
|
20
|
Yewdell JW, Dersh D, Fåhraeus R. Peptide Channeling: The Key to MHC Class I Immunosurveillance? Trends Cell Biol 2019; 29:929-939. [PMID: 31662235 DOI: 10.1016/j.tcb.2019.09.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 09/24/2019] [Accepted: 09/25/2019] [Indexed: 12/11/2022]
Abstract
MHC class I presentation of short peptides enables CD8+ T cell (TCD8+) immunosurveillance of tumors and intracellular pathogens. A key feature of the class I pathway is that the immunopeptidome is highly skewed from the cellular degradome, indicating high selectivity of the access of protease-generated peptides to class I molecules. Similarly, in professional antigen-presenting cells, peptides from minute amounts of proteins introduced into the cytosol outcompete an overwhelming supply of constitutively generated peptides. Here, we propose that antigen processing is based on substrate channeling and review recent studies from the antigen processing and cell biology fields that provide a starting point for testing this hypothesis.
Collapse
Affiliation(s)
- Jonathan W Yewdell
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, MD 20892, USA.
| | - Devin Dersh
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, MD 20892, USA
| | - Robin Fåhraeus
- Inserm, 27 rue Juliette Dodu, 750 10 Paris, France; International Centre for Cancer Vaccine Science (ICCVS), University of Gdańsk, Science, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland; Department of Medical Biosciences, Umeå University, 90187 Umeå, Sweden; RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, 65653 Brno, Czech Republic
| |
Collapse
|
21
|
DiGiuseppe S, Rollins MG, Bartom ET, Walsh D. ZNF598 Plays Distinct Roles in Interferon-Stimulated Gene Expression and Poxvirus Protein Synthesis. Cell Rep 2019; 23:1249-1258. [PMID: 29719242 PMCID: PMC5951170 DOI: 10.1016/j.celrep.2018.03.132] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 02/20/2018] [Accepted: 03/29/2018] [Indexed: 10/25/2022] Open
Abstract
Post-translational modification of ribosomal subunit proteins (RPs) is emerging as an important means of regulating gene expression. Recently, regulatory ubiquitination of small RPs RPS10 and RPS20 by the ubiquitin ligase ZNF598 was found to function in ribosome sensing and stalling on internally polyadenylated mRNAs during ribosome quality control (RQC). Here, we reveal that ZNF598 and RPS10 negatively regulate interferon-stimulated gene (ISG) expression in primary cells, depletion of which induced ISG expression and a broad antiviral state. However, cell lines lacking interferon responses revealed that ZNF598 E3 ligase activity and ubiquitination of RPS20, but not RPS10, were specifically required for poxvirus replication and synthesis of poxvirus proteins whose encoding mRNAs contain unusual 5' poly(A) leaders. Our findings reveal distinct functions for ZNF598 and its downstream RPS targets, one that negatively regulates ISG expression and infection by a range of viruses while the other is positively exploited by poxviruses.
Collapse
Affiliation(s)
- Stephen DiGiuseppe
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Madeline G Rollins
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Elizabeth T Bartom
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Derek Walsh
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
| |
Collapse
|
22
|
Liu S, Hausmann S, Carlson SM, Fuentes ME, Francis JW, Pillai R, Lofgren SM, Hulea L, Tandoc K, Lu J, Li A, Nguyen ND, Caporicci M, Kim MP, Maitra A, Wang H, Wistuba II, Porco JA, Bassik MC, Elias JE, Song J, Topisirovic I, Van Rechem C, Mazur PK, Gozani O. METTL13 Methylation of eEF1A Increases Translational Output to Promote Tumorigenesis. Cell 2019; 176:491-504.e21. [PMID: 30612740 PMCID: PMC6499081 DOI: 10.1016/j.cell.2018.11.038] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/18/2018] [Accepted: 11/21/2018] [Indexed: 12/25/2022]
Abstract
Increased protein synthesis plays an etiologic role in diverse cancers. Here, we demonstrate that METTL13 (methyltransferase-like 13) dimethylation of eEF1A (eukaryotic elongation factor 1A) lysine 55 (eEF1AK55me2) is utilized by Ras-driven cancers to increase translational output and promote tumorigenesis in vivo. METTL13-catalyzed eEF1A methylation increases eEF1A's intrinsic GTPase activity in vitro and protein production in cells. METTL13 and eEF1AK55me2 levels are upregulated in cancer and negatively correlate with pancreatic and lung cancer patient survival. METTL13 deletion and eEF1AK55me2 loss dramatically reduce Ras-driven neoplastic growth in mouse models and in patient-derived xenografts (PDXs) from primary pancreatic and lung tumors. Finally, METTL13 depletion renders PDX tumors hypersensitive to drugs that target growth-signaling pathways. Together, our work uncovers a mechanism by which lethal cancers become dependent on the METTL13-eEF1AK55me2 axis to meet their elevated protein synthesis requirement and suggests that METTL13 inhibition may constitute a targetable vulnerability of tumors driven by aberrant Ras signaling.
Collapse
Affiliation(s)
- Shuo Liu
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Simone Hausmann
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | | | - Mary Esmeralda Fuentes
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | | | - Renjitha Pillai
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Shane Michael Lofgren
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Laura Hulea
- Lady Davis Institute and Gerald Bronfman Department of Oncology, McGill University, Montreal, QC H3T 1E2, Canada
| | - Kristofferson Tandoc
- Lady Davis Institute and Gerald Bronfman Department of Oncology, McGill University, Montreal, QC H3T 1E2, Canada
| | - Jiuwei Lu
- Department of Biochemistry, University of California, Riverside, Riverside, CA 92521, USA
| | - Ami Li
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nicholas Dang Nguyen
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Marcello Caporicci
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Michael Paul Kim
- Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Anirban Maitra
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Huamin Wang
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Ignacio Ivan Wistuba
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | | | - Michael Cory Bassik
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Joshua Eric Elias
- Deparment of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jikui Song
- Department of Biochemistry, University of California, Riverside, Riverside, CA 92521, USA
| | - Ivan Topisirovic
- Lady Davis Institute and Gerald Bronfman Department of Oncology, McGill University, Montreal, QC H3T 1E2, Canada
| | - Capucine Van Rechem
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Pawel Karol Mazur
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
| | - Or Gozani
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
| |
Collapse
|
23
|
Romano N, Veronese M, Manfrini N, Zolla L, Ceci M. Ribosomal RACK1 promotes proliferation of neuroblastoma cells independently of global translation upregulation. Cell Signal 2019; 53:102-110. [DOI: 10.1016/j.cellsig.2018.09.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 09/26/2018] [Accepted: 09/26/2018] [Indexed: 02/04/2023]
|
24
|
RACK1 Specifically Regulates Translation through Its Binding to Ribosomes. Mol Cell Biol 2018; 38:MCB.00230-18. [PMID: 30201806 PMCID: PMC6234289 DOI: 10.1128/mcb.00230-18] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 08/26/2018] [Indexed: 12/22/2022] Open
Abstract
The translational capability of ribosomes deprived of specific nonfundamental ribosomal proteins may be altered. Physiological mechanisms are scanty, and it is unclear whether free ribosomal proteins can cross talk with the signaling machinery. The translational capability of ribosomes deprived of specific nonfundamental ribosomal proteins may be altered. Physiological mechanisms are scanty, and it is unclear whether free ribosomal proteins can cross talk with the signaling machinery. RACK1 (receptor for activated C kinase 1) is a highly conserved scaffold protein, located on the 40S subunit near the mRNA exit channel. RACK1 is involved in a variety of intracellular contexts, both on and off the ribosomes, acting as a receptor for proteins in signaling, such as the protein kinase C (PKC) family. Here we show that the binding of RACK1 to ribosomes is essential for full translation of capped mRNAs and efficient recruitment of eukaryotic initiation factor 4E (eIF4E). In vitro, when RACK1 is partially depleted, supplementing the ribosome machinery with wild-type RACK1 restores the translational capability, whereas the addition of a RACK1 mutant that is unable to bind ribosomes does not. Outside the ribosome, RACK1 has a reduced half-life. By accumulating in living cells, free RACK1 exerts an inhibitory phenotype, impairing cell cycle progression and repressing global translation. Here we present RACK1 binding to ribosomes as a crucial way to regulate translation, possibly through interaction with known partners on or off the ribosome that are involved in signaling.
Collapse
|
25
|
Cesaratto F, Sasset L, Myers MP, Re A, Petris G, Burrone OR. BiP/GRP78 Mediates ERAD Targeting of Proteins Produced by Membrane-Bound Ribosomes Stalled at the STOP-Codon. J Mol Biol 2018; 431:123-141. [PMID: 30367842 PMCID: PMC7094721 DOI: 10.1016/j.jmb.2018.10.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 11/29/2022]
Abstract
Translational stalling of ribosome bound to endoplasmic reticulum (ER) membrane requires an accurate clearance of the associated polypeptides, which is not completely understood in mammals. We characterized in mammalian cells the model of ribosomal stalling at the STOP-codon based on proteins tagged at the C-terminus with the picornavirus 2A peptide followed by a termination codon instead of the Proline (2A*). We exploited the 2A* stalling model to characterize the pathway of degradation of ER-targeted polypeptides. We report that the ER chaperone BiP/GRP78 is a new main factor involved. Moreover, degradation of the ER-stalled polypeptides required the activities of the AAA-ATPase VCP/p97, its associated deubiquitinylase YOD1, the ribosome-associated ubiquitin ligase Listerin and the proteasome. In human proteome, we found two human C-terminal amino acid sequences that cause similar stalling at the STOP-codon. Our data suggest that translational stalling at the ER membrane activates protein degradation at the interface of ribosomal- and ER-associated quality control systems. Ribosomal stalling at the STOP-codon causes degradation of the translated protein. Picornavirus 2A peptide and related sequences cause ribosome stalling at STOP-codon. BiP/GRP78 recognizes polypeptides produced by membrane-bound stalled ribosomes. ER-stalled polypeptides are disposed of through the ERAD pathway. BIP/GRP78 is a novel key player for ERAD targeting of stalled ribosomal peptides.
Collapse
Affiliation(s)
- Francesca Cesaratto
- Laboratory of Molecular Immunology, International Centre for Genetic Engineering and Biotechnology, ICGEB, Padriciano 99, 34149 Trieste, Italy
| | - Linda Sasset
- Laboratory of Molecular Immunology, International Centre for Genetic Engineering and Biotechnology, ICGEB, Padriciano 99, 34149 Trieste, Italy
| | - Michael P Myers
- Laboratory of Protein Networks, International Centre for Genetic Engineering and Biotechnology, ICGEB, Padriciano 99, 34149 Trieste, Italy
| | - Angela Re
- Centre for Integrative Biology (CIBIO), University of Trento, Via Sommarive 9, 38123 Trento, Italy; Center for Sustainable Future Technologies, Fondazione Istituto Italiano di Tecnologia, C.so Trento 21, 10129 Torino, Italy; Center for Sustainable Future Technologies, Fondazione Istituto Italiano di Tecnologia, C.so Trento 21, 10129 Torino, Italy
| | - Gianluca Petris
- Centre for Integrative Biology (CIBIO), University of Trento, Via Sommarive 9, 38123 Trento, Italy.
| | - Oscar R Burrone
- Laboratory of Molecular Immunology, International Centre for Genetic Engineering and Biotechnology, ICGEB, Padriciano 99, 34149 Trieste, Italy.
| |
Collapse
|
26
|
Karamyshev AL, Karamysheva ZN. Lost in Translation: Ribosome-Associated mRNA and Protein Quality Controls. Front Genet 2018; 9:431. [PMID: 30337940 PMCID: PMC6180196 DOI: 10.3389/fgene.2018.00431] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 09/11/2018] [Indexed: 12/15/2022] Open
Abstract
Aberrant, misfolded, and mislocalized proteins are often toxic to cells and result in many human diseases. All proteins and their mRNA templates are subject to quality control. There are several distinct mechanisms that control the quality of mRNAs and proteins during translation at the ribosome. mRNA quality control systems, nonsense-mediated decay, non-stop decay, and no-go decay detect premature stop codons, the absence of a natural stop codon, and stalled ribosomes in translation, respectively, and degrade their mRNAs. Defective truncated polypeptide nascent chains generated from faulty mRNAs are degraded by ribosome-associated protein quality control pathways. Regulation of aberrant protein production, a novel pathway, senses aberrant proteins by monitoring the status of nascent chain interactions during translation and triggers degradation of their mRNA. Here, we review the current progress in understanding of the molecular mechanisms of mRNA and protein quality controls at the ribosome during translation.
Collapse
Affiliation(s)
- Andrey L Karamyshev
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - Zemfira N Karamysheva
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, United States
| |
Collapse
|
27
|
Abstract
Translation is a key step in the regulation of gene expression and one of the most energy-consuming processes in the cell. In response to various stimuli, multiple signaling pathways converge on the translational machinery to regulate its function. To date, the roles of phosphoinositide 3-kinase (PI3K)/AKT and the mitogen-activated protein kinase (MAPK) pathways in the regulation of translation are among the best understood. Both pathways engage the mechanistic target of rapamycin (mTOR) to regulate a variety of components of the translational machinery. While these pathways regulate protein synthesis in homeostasis, their dysregulation results in aberrant translation leading to human diseases, including diabetes, neurological disorders, and cancer. Here we review the roles of the PI3K/AKT and MAPK pathways in the regulation of mRNA translation. We also highlight additional signaling mechanisms that have recently emerged as regulators of the translational apparatus.
Collapse
|
28
|
Ribosome-dependent conformational flexibility changes and RNA dynamics of IRES domains revealed by differential SHAPE. Sci Rep 2018; 8:5545. [PMID: 29615727 PMCID: PMC5882922 DOI: 10.1038/s41598-018-23845-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 03/21/2018] [Indexed: 12/11/2022] Open
Abstract
Internal ribosome entry site (IRES) elements are RNA regions that recruit the translation machinery internally. Here we investigated the conformational changes and RNA dynamics of a picornavirus IRES upon incubation with distinct ribosomal fractions. Differential SHAPE analysis of the free RNA showed that nucleotides reaching the final conformation on long timescales were placed at domains 4 and 5, while candidates for long-range interactions were located in domain 3. Salt-washed ribosomes induced a fast RNA local flexibility modification of domains 2 and 3, while ribosome-associated factors changed domains 4 and 5. Consistent with this, modeling of the three-dimensional RNA structure indicated that incubation of the IRES with native ribosomes induced a local rearrangement of the apical region of domain 3, and a reorientation of domains 4 and 5. Furthermore, specific motifs within domains 2 and 3 showed a decreased flexibility upon incubation with ribosomal subunits in vitro, and presence of the IRES enhanced mRNA association to the ribosomal subunits in whole cell lysates. The finding that RNA modules can provide direct IRES-ribosome interaction suggests that linking these motifs to additional sequences able to recruit trans-acting factors could be useful to design synthetic IRESs with novel activities.
Collapse
|
29
|
Opitz N, Schmitt K, Hofer-Pretz V, Neumann B, Krebber H, Braus GH, Valerius O. Capturing the Asc1p/ Receptor for Activated C Kinase 1 (RACK1) Microenvironment at the Head Region of the 40S Ribosome with Quantitative BioID in Yeast. Mol Cell Proteomics 2017; 16:2199-2218. [PMID: 28982715 DOI: 10.1074/mcp.m116.066654] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 09/29/2017] [Indexed: 12/13/2022] Open
Abstract
The Asc1 protein of Saccharomyces cerevisiae is a scaffold protein at the head region of ribosomal 40S that links mRNA translation to cellular signaling. In this study, proteins that colocalize with Asc1p were identified with proximity-dependent Biotin IDentification (BioID), an in vivo labeling technique described here for the first time for yeast. Biotinylated Asc1p-birA*-proximal proteins were identified and quantitatively verified against controls applying SILAC and mass spectrometry. The mRNA-binding proteins Sro9p and Gis2p appeared together with Scp160p, each providing ribosomes with nuclear transcripts. The cap-binding protein eIF4E (Cdc33p) and the eIF3/a-subunit (Rpg1p) were identified reflecting the encounter of proteins involved in the initiation of mRNA translation at the head region of ribosomal 40S. Unexpectedly, a protein involved in ribosome preservation (the clamping factor Stm1p), the deubiquitylation complex Ubp3p-Bre5p, the RNA polymerase II degradation factor 1 (Def1p), and transcription factors (Spt5p, Mbf1p) colocalize with Asc1p in exponentially growing cells. For Asc1R38D, K40Ep, a variant considered to be deficient in binding to ribosomes, BioID revealed its predominant ribosome localization. Glucose depletion replaced most of the Asc1p colocalizing proteins for additional ribosomal proteins, suggesting a ribosome aggregation process during early nutrient limitation, possibly concomitant with ribosomal subunit clamping. Overall, the characterization of the Asc1p microenvironment with BioID confirmed and substantiated our recent findings that the β-propeller broadly contributes to signal transduction influencing phosphorylation of colocalizing proteins (e.g. of Bre5p), and by that might affect nuclear gene transcription and the fate of ribosomes.
Collapse
Affiliation(s)
- Nadine Opitz
- From the ‡Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Kerstin Schmitt
- From the ‡Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Verena Hofer-Pretz
- From the ‡Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Bettina Neumann
- §Department of Molecular Genetics, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Heike Krebber
- §Department of Molecular Genetics, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Gerhard H Braus
- From the ‡Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Oliver Valerius
- From the ‡Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany;
| |
Collapse
|
30
|
The role of prostate tumor overexpressed 1 in cancer progression. Oncotarget 2017; 8:12451-12471. [PMID: 28029646 PMCID: PMC5355357 DOI: 10.18632/oncotarget.14104] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/14/2016] [Indexed: 12/15/2022] Open
|
31
|
Russo A, Scardigli R, La Regina F, Murray ME, Romano N, Dickson DW, Wolozin B, Cattaneo A, Ceci M. Increased cytoplasmic TDP-43 reduces global protein synthesis by interacting with RACK1 on polyribosomes. Hum Mol Genet 2017; 26:1407-1418. [PMID: 28158562 DOI: 10.1093/hmg/ddx035] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/20/2017] [Indexed: 12/13/2022] Open
Abstract
TDP-43 is a well known RNA binding protein involved in the pathogenesis of Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Lobar Dementia (FTLD). In physiological conditions, TDP-43 mainly localizes in the nucleus and shuttles, at least in neurons, to the cytoplasm to form TDP-43 RNA granules. In the nucleus, TDP-43 participates to the expression and splicing of RNAs, while in the cytoplasm its functions range from transport to translation of specific mRNAs. However, if loss or gain of these TDP-43 functions are affected in ALS/FTLD pathogenesis is not clear. Here, we report that TDP-43 localizes on ribosomes not only in primary neurons but also in SH-SY5Y human neuroblastoma cells. We find that binding of TDP-43 to the translational machinery is mediated by an interaction with a specific ribosomal protein, RACK1, and that an increase in cytoplasmic TDP-43 represses global protein synthesis, an effect which is rescued by overexpression of RACK1. Ribosomal loss of RACK1, which excludes TDP-43 from the translational machinery, remarkably reduces formation of TDP-43 cytoplasmic inclusions in neuroblastoma cells. Finally, we corroborate the interaction between TDP-43 and RACK1 on polyribosomes of neuroblastoma cells with mis-localization of RACK1 on TDP-43 positive cytoplasmic inclusions in motor neurons of ALS patients. In conclusions, results from this study suggest that TDP-43 represents a translational repressor not only for specific mRNAs but for overall translation and that its binding to polyribosomes through RACK1 may promote, under conditions inducing ALS pathogenesis, the formation of cytoplasmic inclusions.
Collapse
Affiliation(s)
- Arianna Russo
- Department of Ecology and Biology, Tuscia University, Viterbo 01100, Italy
| | - Raffaella Scardigli
- Institute of Translational Pharmacology, National Council of Research, Rome 00133, Italy.,European Brain Research Institute, Rita Levi-Montalcini Foundation, Rome 00133, Italy
| | - Federico La Regina
- European Brain Research Institute, Rita Levi-Montalcini Foundation, Rome 00133, Italy
| | - Melissa E Murray
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Nicla Romano
- Department of Ecology and Biology, Tuscia University, Viterbo 01100, Italy
| | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Benjamin Wolozin
- Department of Pharmacology and Experimental Therapeutics.,Department of Neurology, University School of Medicine, Boston, MA 02118, USA
| | | | - Marcello Ceci
- Department of Ecology and Biology, Tuscia University, Viterbo 01100, Italy
| |
Collapse
|
32
|
Bolger GB. The RNA-binding protein SERBP1 interacts selectively with the signaling protein RACK1. Cell Signal 2017; 35:256-263. [PMID: 28267599 DOI: 10.1016/j.cellsig.2017.03.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 02/23/2017] [Accepted: 03/02/2017] [Indexed: 12/19/2022]
Abstract
The RACK1 protein interacts with numerous proteins involved in signal transduction, the cytoskeleton, and mRNA splicing and translation. We used the 2-hybrid system to identify additional proteins interacting with RACK1 and isolated the RNA-binding protein SERBP1. SERPB1 shares amino acid sequence homology with HABP4 (also known as Ki-1/57), a component of the RNA spicing machinery that has been shown previously to interact with RACK1. Several different isoforms of SERBP1, generated by alternative mRNA splicing, interacted with RACK1 with indistinguishable interaction strength, as determined by a 2-hybrid beta-galactosidase assay. Analysis of deletion constructs of SERBP1 showed that the C-terminal third of the SERBP1 protein, which contains one of its two substrate sites for protein arginine N-methyltransferase 1 (PRMT1), is necessary and sufficient for it to interact with RACK1. Analysis of single amino acid substitutions in RACK1, identified in a reverse 2-hybrid screen, showed very substantial overlap with those implicated in the interaction of RACK1 with the cAMP-selective phosphodiesterase PDE4D5. These data are consistent with SERBP1 interacting selectively with RACK1, mediated by an extensive interaction surface on both proteins.
Collapse
Affiliation(s)
- Graeme B Bolger
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294-3300, USA; Department of Pharmacology, University of Alabama at Birmingham, Birmingham, AL 35294-3300, USA.
| |
Collapse
|
33
|
Nielsen MH, Flygaard RK, Jenner LB. Structural analysis of ribosomal RACK1 and its role in translational control. Cell Signal 2017; 35:272-281. [PMID: 28161490 DOI: 10.1016/j.cellsig.2017.01.026] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 01/31/2017] [Indexed: 12/28/2022]
Abstract
Receptor for Activated C-Kinase 1 (RACK1) belongs to the WD40 family of proteins, known to act as scaffolding proteins in interaction networks. Accordingly, RACK1 is found to have numerous interacting partners ranging from kinases and signaling proteins to membrane bound receptors and ion channels. Interestingly, RACK1 has also been identified as a ribosomal protein present in all eukaryotic ribosomes. Structures of eukaryotic ribosomes have shown RACK1 to be located at the back of the head of the small ribosomal subunit. This suggests that RACK1 could act as a ribosomal scaffolding protein recruiting regulators of translation to the ribosome, and several studies have in fact found RACK1 to play a role in regulation of translation. To fully understand the role of RACK1 we need to understand whether the many reported interaction partners of RACK1 bind to free or ribosomal RACK1. In this review we provide a structural analysis of ribosome-bound RACK1 to provide a basis for answering this fundamental question. Our analysis shows that RACK1 is tightly bound to the ribosome through highly conserved and specific interactions confirming RACK1 as an integral ribosomal protein. Furthermore, we have analyzed whether reported binding sites for RACK1 interacting partners with a proposed role in translational control are accessible on ribosomal RACK1. Our analysis shows that most of the interaction partners with putative regulatory functions have binding sites that are available on ribosomal RACK1, supporting the role of RACK1 as a ribosomal signaling hub. We also discuss the possible role for RACK1 in recruitment of ribosomes to focal adhesion sites and regulation of local translation during cell spreading and migration.
Collapse
Affiliation(s)
- Maja Holch Nielsen
- Department of Molecular Biology and Genetics, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Aarhus University, Denmark
| | - Rasmus Kock Flygaard
- Department of Molecular Biology and Genetics, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Aarhus University, Denmark
| | - Lasse Bohl Jenner
- Department of Molecular Biology and Genetics, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Aarhus University, Denmark
| |
Collapse
|
34
|
Asc1p/RACK1 Connects Ribosomes to Eukaryotic Phosphosignaling. Mol Cell Biol 2017; 37:MCB.00279-16. [PMID: 27821475 DOI: 10.1128/mcb.00279-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 10/24/2016] [Indexed: 02/07/2023] Open
Abstract
WD40 repeat proteins fold into characteristic β-propeller structures and control signaling circuits during cellular adaptation processes within eukaryotes. The RACK1 protein of Saccharomyces cerevisiae, Asc1p, consists exclusively of a single seven-bladed β-propeller that operates from the ribosomal base at the head region of the 40S subunit. Here we show that the R38D K40E ribosomal binding-compromised variant (Asc1DEp) is severely destabilized through mutation of phosphosite T143 to a dephosphorylation-mimicking alanine, probably through proteasomal degradation, leading to asc1- phenotypes. Phosphosite Y250 contributes to resistance to translational inhibitors but does not influence Asc1DEp stability. Beyond its own phosphorylation at T143, Y250, and other sites, Asc1p heavily influences the phosphorylation of as many as 90 proteins at 120 sites. Many of these proteins are regulators of fundamental processes ranging from mRNA translation to protein transport and turnover, cytoskeleton organization, and cellular signaling. Our data expose Asc1p/RACK1 as a key factor in phosphosignaling and manifest it as a control point at the head of the ribosomal 40S subunit itself regulated through posttranslational modification.
Collapse
|
35
|
Yin X, Komatsu S. Plant nuclear proteomics for unraveling physiological function. N Biotechnol 2016; 33:644-654. [PMID: 27004615 DOI: 10.1016/j.nbt.2016.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 03/09/2016] [Accepted: 03/10/2016] [Indexed: 10/22/2022]
Abstract
The nucleus is the subcellular organelle that functions as the regulatory hub of the cell and is responsible for regulating several critical cellular functions, including cell proliferation, gene expression, and cell survival. Nuclear proteomics is a useful approach for investigating the mechanisms underlying plant responses to abiotic stresses, including protein-protein interactions, enzyme activities, and post-translational modifications. Among abiotic stresses, flooding is a major limiting factor for plant growth and yields, particularly for soybean. In this review, plant nuclei purification methods, modifications of plant nuclear proteins, and recent contributions to the field of plant nuclear proteomics are summarized. In addition, to reveal the upstream regulating mechanisms controlling soybean responses to flooding stress, the functions of flooding-responsive nuclear proteins are reviewed based on the results of nuclear proteomic analysis of soybean in the early stages of flooding stress.
Collapse
Affiliation(s)
- Xiaojian Yin
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan; National Institute of Crop Science, National Agriculture and Food Research Organization, Tsukuba 305-8518, Japan
| | - Setsuko Komatsu
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan; National Institute of Crop Science, National Agriculture and Food Research Organization, Tsukuba 305-8518, Japan.
| |
Collapse
|
36
|
Singec I, Crain AM, Hou J, Tobe BTD, Talantova M, Winquist AA, Doctor KS, Choy J, Huang X, La Monaca E, Horn DM, Wolf DA, Lipton SA, Gutierrez GJ, Brill LM, Snyder EY. Quantitative Analysis of Human Pluripotency and Neural Specification by In-Depth (Phospho)Proteomic Profiling. Stem Cell Reports 2016; 7:527-542. [PMID: 27569059 PMCID: PMC5032292 DOI: 10.1016/j.stemcr.2016.07.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 07/25/2016] [Accepted: 07/26/2016] [Indexed: 10/27/2022] Open
Abstract
Controlled differentiation of human embryonic stem cells (hESCs) can be utilized for precise analysis of cell type identities during early development. We established a highly efficient neural induction strategy and an improved analytical platform, and determined proteomic and phosphoproteomic profiles of hESCs and their specified multipotent neural stem cell derivatives (hNSCs). This quantitative dataset (nearly 13,000 proteins and 60,000 phosphorylation sites) provides unique molecular insights into pluripotency and neural lineage entry. Systems-level comparative analysis of proteins (e.g., transcription factors, epigenetic regulators, kinase families), phosphorylation sites, and numerous biological pathways allowed the identification of distinct signatures in pluripotent and multipotent cells. Furthermore, as predicted by the dataset, we functionally validated an autocrine/paracrine mechanism by demonstrating that the secreted protein midkine is a regulator of neural specification. This resource is freely available to the scientific community, including a searchable website, PluriProt.
Collapse
Affiliation(s)
- Ilyas Singec
- Center for Stem Cells and Regenerative Medicine, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA.
| | - Andrew M Crain
- Center for Stem Cells and Regenerative Medicine, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Junjie Hou
- Proteomics Facility, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Brian T D Tobe
- Center for Stem Cells and Regenerative Medicine, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Maria Talantova
- Center for Stem Cells and Regenerative Medicine, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Alicia A Winquist
- Center for Stem Cells and Regenerative Medicine, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Kutbuddin S Doctor
- Informatics and Data Management, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Jennifer Choy
- Center for Stem Cells and Regenerative Medicine, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Xiayu Huang
- Informatics and Data Management, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Esther La Monaca
- Department of Biology, Vrije Universiteit Brussel, 1050 Brussels, Belgium
| | - David M Horn
- Thermo Fisher Scientific Inc., San Jose, CA 95134, USA
| | - Dieter A Wolf
- Proteomics Facility, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Stuart A Lipton
- Center for Stem Cells and Regenerative Medicine, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Gustavo J Gutierrez
- Center for Stem Cells and Regenerative Medicine, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA; Department of Biology, Vrije Universiteit Brussel, 1050 Brussels, Belgium
| | - Laurence M Brill
- Proteomics Facility, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA.
| | - Evan Y Snyder
- Center for Stem Cells and Regenerative Medicine, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA.
| |
Collapse
|
37
|
JNK Signaling: Regulation and Functions Based on Complex Protein-Protein Partnerships. Microbiol Mol Biol Rev 2016; 80:793-835. [PMID: 27466283 DOI: 10.1128/mmbr.00043-14] [Citation(s) in RCA: 321] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The c-Jun N-terminal kinases (JNKs), as members of the mitogen-activated protein kinase (MAPK) family, mediate eukaryotic cell responses to a wide range of abiotic and biotic stress insults. JNKs also regulate important physiological processes, including neuronal functions, immunological actions, and embryonic development, via their impact on gene expression, cytoskeletal protein dynamics, and cell death/survival pathways. Although the JNK pathway has been under study for >20 years, its complexity is still perplexing, with multiple protein partners of JNKs underlying the diversity of actions. Here we review the current knowledge of JNK structure and isoforms as well as the partnerships of JNKs with a range of intracellular proteins. Many of these proteins are direct substrates of the JNKs. We analyzed almost 100 of these target proteins in detail within a framework of their classification based on their regulation by JNKs. Examples of these JNK substrates include a diverse assortment of nuclear transcription factors (Jun, ATF2, Myc, Elk1), cytoplasmic proteins involved in cytoskeleton regulation (DCX, Tau, WDR62) or vesicular transport (JIP1, JIP3), cell membrane receptors (BMPR2), and mitochondrial proteins (Mcl1, Bim). In addition, because upstream signaling components impact JNK activity, we critically assessed the involvement of signaling scaffolds and the roles of feedback mechanisms in the JNK pathway. Despite a clarification of many regulatory events in JNK-dependent signaling during the past decade, many other structural and mechanistic insights are just beginning to be revealed. These advances open new opportunities to understand the role of JNK signaling in diverse physiological and pathophysiological states.
Collapse
|
38
|
Zhu Q, Zhang Y, Liu Y, Cheng H, Wang J, Zhang Y, Rui Y, Li T. MLIF Alleviates SH-SY5Y Neuroblastoma Injury Induced by Oxygen-Glucose Deprivation by Targeting Eukaryotic Translation Elongation Factor 1A2. PLoS One 2016; 11:e0149965. [PMID: 26918757 PMCID: PMC4769291 DOI: 10.1371/journal.pone.0149965] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 02/08/2016] [Indexed: 01/16/2023] Open
Abstract
Monocyte locomotion inhibitory factor (MLIF), a heat-stable pentapeptide, has been shown to exert potent anti-inflammatory effects in ischemic brain injury. In this study, we investigated the neuroprotective action of MLIF against oxygen-glucose deprivation (OGD)-induced injury in human neuroblastoma SH-SY5Y cells. MTT assay was used to assess cell viability, and flow cytometry assay and Hoechst staining were used to evaluate apoptosis. LDH assay was used to exam necrosis. The release of inflammatory cytokines was detected by ELISA. Levels of the apoptosis associated proteins were measured by western blot analysis. To identify the protein target of MLIF, pull-down assay and mass spectrometry were performed. We observed that MLIF enhanced cell survival and inhibited apoptosis and necrosis by inhibiting p-JNK, p53, c-caspase9 and c-caspase3 expression. In the microglia, OGD-induced secretion of inflammatory cytokines was markedly reduced in the presence of MLIF. Furthermore, we found that eukaryotic translation elongation factor 1A2 (eEF1A2) is a downstream target of MLIF. Knockdown eEF1A2 using short interfering RNA (siRNA) almost completely abrogated the anti-apoptotic effect of MLIF in SH-SY5Y cells subjected to OGD, with an associated decrease in cell survival and an increase in expression of p-JNK and p53. These results indicate that MLIF ameliorates OGD-induced SH-SY5Y neuroblastoma injury by inhibiting the p-JNK/p53 apoptotic signaling pathway via eEF1A2. Our findings suggest that eEF1A2 may be a new therapeutic target for ischemic brain injury.
Collapse
Affiliation(s)
- Qiuzhen Zhu
- Department of Pharmacology, College of Pharmacy, Second Military Medical University, Shanghai, China
| | - Yuefan Zhang
- Department of Pharmacology, College of Pharmacy, Second Military Medical University, Shanghai, China
| | - Yulan Liu
- Department of Pharmacology, College of Pharmacy, Second Military Medical University, Shanghai, China
| | - Hao Cheng
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei, Anhui, China
| | - Jing Wang
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei, Anhui, China
| | - Yue Zhang
- College of Pharmacy, Anhui University of Chinese Medicine, Hefei, Anhui, China
| | - Yaocheng Rui
- Department of Pharmacology, College of Pharmacy, Second Military Medical University, Shanghai, China
- * E-mail: (TL); (YR)
| | - Tiejun Li
- Department of Pharmacology, College of Pharmacy, Second Military Medical University, Shanghai, China
- * E-mail: (TL); (YR)
| |
Collapse
|
39
|
Gallo S, Manfrini N. Working hard at the nexus between cell signaling and the ribosomal machinery: An insight into the roles of RACK1 in translational regulation. ACTA ACUST UNITED AC 2015; 3:e1120382. [PMID: 26824030 DOI: 10.1080/21690731.2015.1120382] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 10/19/2015] [Accepted: 11/09/2015] [Indexed: 02/08/2023]
Abstract
RACK1 is a ribosome-associated protein which functions as a receptor for activated PKCs. It also acts as a scaffold for many other proteins involved in diverse signaling pathways, e.g. Src, JNK, PDE4D and FAK signaling. With such a broad interactome, RACK1 has been suggested to function as a linker between cell signaling and the translation machinery. Accordingly, RACK1 modulates translation at different levels in several model organisms. For instance, it regulates ribosome stalling and mRNA quality control in yeasts and promotes translation efficiency downstream of specific cellular stimuli in mammals. However, the molecular mechanism by which RACK1 exerts these roles is widely uncharacterized. Moreover, the full list of ribosome-recruited RACK1 interactors still needs characterization. Here we discuss in vivo and in vitro findings to better delineate the roles of RACK1 in regulating ribosome function and translation.
Collapse
Affiliation(s)
- Simone Gallo
- Molecular Histology and Cell Growth Unit; National Institute of Molecular Genetics - INGM "Romeo and Enrica Invernizzi" ; Milan, Italy
| | - Nicola Manfrini
- Molecular Histology and Cell Growth Unit; National Institute of Molecular Genetics - INGM "Romeo and Enrica Invernizzi" ; Milan, Italy
| |
Collapse
|
40
|
Thandapani P, Song J, Gandin V, Cai Y, Rouleau SG, Garant JM, Boisvert FM, Yu Z, Perreault JP, Topisirovic I, Richard S. Aven recognition of RNA G-quadruplexes regulates translation of the mixed lineage leukemia protooncogenes. eLife 2015; 4. [PMID: 26267306 PMCID: PMC4561382 DOI: 10.7554/elife.06234] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 08/11/2015] [Indexed: 12/17/2022] Open
Abstract
G-quadruplexes (G4) are extremely stable secondary structures forming stacks of guanine tetrads. DNA G4 structures have been extensively studied, however, less is known about G4 motifs in mRNAs, especially in their coding sequences. Herein, we show that Aven stimulates the mRNA translation of the mixed lineage leukemia (MLL) proto-oncogene in an arginine methylation-dependent manner. The Aven RGG/RG motif bound G4 structures within the coding regions of the MLL1 and MLL4 mRNAs increasing their polysomal association and translation, resulting in the induction of transcription of leukemic genes. The DHX36 RNA helicase associated with the Aven complex and was required for optimal translation of G4 mRNAs. Depletion of Aven led to a decrease in synthesis of MLL1 and MLL4 proteins resulting in reduced proliferation of leukemic cells. These findings identify an Aven-centered complex that stimulates the translation of G4 harboring mRNAs, thereby promoting survival of leukemic cells. DOI:http://dx.doi.org/10.7554/eLife.06234.001 To make a protein, the DNA sequence that encodes it is first copied to make a molecule of messenger RNA (or mRNA for short). The mRNA is then used as a set of instructions to assemble a protein in a process called translation. Both DNA and RNA molecules can fold into particular shapes. One such structure is known as a G-quartet and involves the DNA or RNA folding back on itself to form a highly stable planar structure. Stacks of G-quartets can form structures known as G-quadruplexes, but little is known about the G-quadruplexes that form in mRNA molecules. Leukemia affects cells in the bone marrow and causes blood cells to develop abnormally. A protein called Aven is often found in increased amounts in certain types of leukemic cells, but it was not clear how Aven affects how leukemia develops. Thandapani, Song et al. have now found that in leukemic cells, Aven binds to G-quadruplexes found in two mRNA molecules that encode proteins that are linked to leukemia. This binding increases the translation of these mRNAs, with translation occurring most efficiently when a particular enzyme called a helicase—which remodels RNA—also bound to Aven. Reducing the amount of Aven in cells caused fewer of the leukemic proteins to be produced, which also reduced the growth and multiplcation of leukemic cells. These findings raise the possibility that drugs that disrupt how Aven works could form part of treatments for leukemia. The next challenge will be to identify the signaling pathways that communicate with Aven and to define all the G-quadruplex mRNAs that are regulated by Aven. DOI:http://dx.doi.org/10.7554/eLife.06234.002
Collapse
Affiliation(s)
- Palaniraja Thandapani
- Terry Fox Molecular Oncology Group, Segal Cancer Center, Jewish General Hospital, Montréal, Canada
| | - Jingwen Song
- Terry Fox Molecular Oncology Group, Segal Cancer Center, Jewish General Hospital, Montréal, Canada
| | - Valentina Gandin
- Terry Fox Molecular Oncology Group, Segal Cancer Center, Jewish General Hospital, Montréal, Canada
| | - Yutian Cai
- Terry Fox Molecular Oncology Group, Segal Cancer Center, Jewish General Hospital, Montréal, Canada
| | - Samuel G Rouleau
- Département de Biochimie, Université de Sherbrooke, Sherbrooke, Canada
| | | | - Francois-Michel Boisvert
- Département d'Anatomie et de Biologie Cellulaire, Faculté de Médecine et des Sciences de la Santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, Sherbrooke, Canada
| | - Zhenbao Yu
- Terry Fox Molecular Oncology Group, Segal Cancer Center, Jewish General Hospital, Montréal, Canada
| | | | - Ivan Topisirovic
- Terry Fox Molecular Oncology Group, Segal Cancer Center, Jewish General Hospital, Montréal, Canada
| | - Stéphane Richard
- Terry Fox Molecular Oncology Group, Segal Cancer Center, Jewish General Hospital, Montréal, Canada
| |
Collapse
|
41
|
Browning KS, Bailey-Serres J. Mechanism of cytoplasmic mRNA translation. THE ARABIDOPSIS BOOK 2015; 13:e0176. [PMID: 26019692 PMCID: PMC4441251 DOI: 10.1199/tab.0176] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Protein synthesis is a fundamental process in gene expression that depends upon the abundance and accessibility of the mRNA transcript as well as the activity of many protein and RNA-protein complexes. Here we focus on the intricate mechanics of mRNA translation in the cytoplasm of higher plants. This chapter includes an inventory of the plant translational apparatus and a detailed review of the translational processes of initiation, elongation, and termination. The majority of mechanistic studies of cytoplasmic translation have been carried out in yeast and mammalian systems. The factors and mechanisms of translation are for the most part conserved across eukaryotes; however, some distinctions are known to exist in plants. A comprehensive understanding of the complex translational apparatus and its regulation in plants is warranted, as the modulation of protein production is critical to development, environmental plasticity and biomass yield in diverse ecosystems and agricultural settings.
Collapse
Affiliation(s)
- Karen S. Browning
- Department of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas at Austin, Austin TX 78712-0165
- Both authors contributed equally to this work
| | - Julia Bailey-Serres
- Department of Botany and Plant Sciences and Center for Plant Cell Biology, University of California, Riverside, CA, 92521 USA
- Both authors contributed equally to this work
| |
Collapse
|
42
|
Abbas W, Kumar A, Herbein G. The eEF1A Proteins: At the Crossroads of Oncogenesis, Apoptosis, and Viral Infections. Front Oncol 2015; 5:75. [PMID: 25905039 PMCID: PMC4387925 DOI: 10.3389/fonc.2015.00075] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/12/2015] [Indexed: 12/12/2022] Open
Abstract
Eukaryotic translation elongation factors 1 alpha, eEF1A1 and eEF1A2, are not only translation factors but also pleiotropic proteins that are highly expressed in human tumors, including breast cancer, ovarian cancer, and lung cancer. eEF1A1 modulates cytoskeleton, exhibits chaperone-like activity and also controls cell proliferation and cell death. In contrast, eEF1A2 protein favors oncogenesis as shown by the fact that overexpression of eEF1A2 leads to cellular transformation and gives rise to tumors in nude mice. The eEF1A2 protein stimulates the phospholipid signaling and activates the Akt-dependent cell migration and actin remodeling that ultimately favors tumorigenesis. In contrast, inactivation of eEF1A proteins leads to immunodeficiency, neural and muscular defects, and favors apoptosis. Finally, eEF1A proteins interact with several viral proteins resulting in enhanced viral replication, decreased apoptosis, and increased cellular transformation. This review summarizes the recent findings on eEF1A proteins indicating that eEF1A proteins play a critical role in numerous human diseases through enhancement of oncogenesis, blockade of apoptosis, and increased viral pathogenesis.
Collapse
Affiliation(s)
- Wasim Abbas
- Department of Biology, SBA School of Science and Engineering, Lahore University of Management Sciences , Lahore , Pakistan
| | - Amit Kumar
- UPRES EA 4266, Laboratory of Pathogens and Inflammation, Department of Virology, CHRU Besançon, Université de Franche-Comté , Besançon , France
| | - Georges Herbein
- UPRES EA 4266, Laboratory of Pathogens and Inflammation, Department of Virology, CHRU Besançon, Université de Franche-Comté , Besançon , France
| |
Collapse
|
43
|
Crystal structure of Gib2, a signal-transducing protein scaffold associated with ribosomes in Cryptococcus neoformans. Sci Rep 2015; 5:8688. [PMID: 25732347 PMCID: PMC4894404 DOI: 10.1038/srep08688] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 01/27/2015] [Indexed: 11/16/2022] Open
Abstract
The atypical Gβ-like/RACK1 Gib2 protein promotes cAMP signalling that plays a central role in regulating the virulence of Cryptococcus neoformans. Gib2 contains a seven-bladed β transducin structure and is emerging as a scaffold protein interconnecting signalling pathways through interactions with various protein partners. Here, we present the crystal structure of Gib2 at a 2.2-Å resolution. The structure allows us to analyse the association between Gib2 and the ribosome, as well as to identify the Gib2 amino acid residues involved in ribosome binding. Our studies not only suggest that Gib2 has a role in protein translation but also present Gib2 as a physical link at the crossroads of various regulatory pathways important for the growth and virulence of C. neoformans.
Collapse
|
44
|
Rosenberg T, Gal-Ben-Ari S, Dieterich DC, Kreutz MR, Ziv NE, Gundelfinger ED, Rosenblum K. The roles of protein expression in synaptic plasticity and memory consolidation. Front Mol Neurosci 2014; 7:86. [PMID: 25429258 PMCID: PMC4228929 DOI: 10.3389/fnmol.2014.00086] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 10/24/2014] [Indexed: 01/07/2023] Open
Abstract
The amount and availability of proteins are regulated by their synthesis, degradation, and transport. These processes can specifically, locally, and temporally regulate a protein or a population of proteins, thus affecting numerous biological processes in health and disease states. Accordingly, malfunction in the processes of protein turnover and localization underlies different neuronal diseases. However, as early as a century ago, it was recognized that there is a specific need for normal macromolecular synthesis in a specific fragment of the learning process, memory consolidation, which takes place minutes to hours following acquisition. Memory consolidation is the process by which fragile short-term memory is converted into stable long-term memory. It is accepted today that synaptic plasticity is a cellular mechanism of learning and memory processes. Interestingly, similar molecular mechanisms subserve both memory and synaptic plasticity consolidation. In this review, we survey the current view on the connection between memory consolidation processes and proteostasis, i.e., maintaining the protein contents at the neuron and the synapse. In addition, we describe the technical obstacles and possible new methods to determine neuronal proteostasis of synaptic function and better explain the process of memory and synaptic plasticity consolidation.
Collapse
Affiliation(s)
- Tali Rosenberg
- Sagol Department of Neurobiology, University of Haifa Haifa, Israel
| | | | - Daniela C Dieterich
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University Magdeburg, Germany ; Research Group Neuralomics, Leibniz Institute for Neurobiology Magdeburg, Germany ; Center for Behavioral Brain Sciences Magdeburg, Germany
| | - Michael R Kreutz
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology Magdeburg, Germany
| | - Noam E Ziv
- Network Biology Research Laboratories and Faculty of Medicine, Technion - Israel Institute of Technology Haifa, Israel
| | - Eckart D Gundelfinger
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology Magdeburg, Germany ; Center for Behavioral Brain Sciences Magdeburg, Germany ; Medical School, Otto von Guericke University Magdeburg, Germany
| | - Kobi Rosenblum
- Sagol Department of Neurobiology, University of Haifa Haifa, Israel ; Center for Gene Manipulation in the Brain, University of Haifa Haifa, Israel
| |
Collapse
|
45
|
Gandin V, Senft D, Topisirovic I, Ronai ZA. RACK1 Function in Cell Motility and Protein Synthesis. Genes Cancer 2014; 4:369-77. [PMID: 24349634 DOI: 10.1177/1947601913486348] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The receptor for activated C kinase 1 (RACK1) serves as an adaptor for a number of proteins along the MAPK, protein kinase C, and Src signaling pathways. The abundance and near ubiquitous expression of RACK1 reflect its role in coordinating signaling molecules for many critical biological processes, from mRNA translation to cell motility to cell survival and death. Complete deficiency of Rack1 is embryonic lethal, but the recent development of genetic Rack1 hypomorphic mice has highlighted the central role that RACK1 plays in cell movement and protein synthesis. This review focuses on the importance of RACK1 in these processes and places the recent work in the larger context of understanding RACK1 function.
Collapse
Affiliation(s)
- Valentina Gandin
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, QC, Canada ; Department of Oncology, McGill University, Montréal, QC, Canada
| | - Daniela Senft
- Signal Transduction Program, Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - Ivan Topisirovic
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, QC, Canada ; Department of Oncology, McGill University, Montréal, QC, Canada
| | - Ze'ev A Ronai
- Signal Transduction Program, Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| |
Collapse
|
46
|
Gandin V, Sikström K, Alain T, Morita M, McLaughlan S, Larsson O, Topisirovic I. Polysome fractionation and analysis of mammalian translatomes on a genome-wide scale. J Vis Exp 2014. [PMID: 24893926 PMCID: PMC4189431 DOI: 10.3791/51455] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
mRNA translation plays a central role in the regulation of gene expression and represents the most energy consuming process in mammalian cells. Accordingly, dysregulation of mRNA translation is considered to play a major role in a variety of pathological states including cancer. Ribosomes also host chaperones, which facilitate folding of nascent polypeptides, thereby modulating function and stability of newly synthesized polypeptides. In addition, emerging data indicate that ribosomes serve as a platform for a repertoire of signaling molecules, which are implicated in a variety of post-translational modifications of newly synthesized polypeptides as they emerge from the ribosome, and/or components of translational machinery. Herein, a well-established method of ribosome fractionation using sucrose density gradient centrifugation is described. In conjunction with the in-house developed “anota” algorithm this method allows direct determination of differential translation of individual mRNAs on a genome-wide scale. Moreover, this versatile protocol can be used for a variety of biochemical studies aiming to dissect the function of ribosome-associated protein complexes, including those that play a central role in folding and degradation of newly synthesized polypeptides.
Collapse
Affiliation(s)
- Valentina Gandin
- Lady Davis Institute and Department of Oncology, McGill University
| | | | - Tommy Alain
- Goodman Cancer Centre and Department of Biochemistry, McGill University
| | - Masahiro Morita
- Goodman Cancer Centre and Department of Biochemistry, McGill University
| | | | - Ola Larsson
- Department of Oncology-Pathology, Karolinska Institutet;
| | - Ivan Topisirovic
- Lady Davis Institute and Department of Oncology, McGill University;
| |
Collapse
|
47
|
Antón LC, Yewdell JW. Translating DRiPs: MHC class I immunosurveillance of pathogens and tumors. J Leukoc Biol 2014; 95:551-62. [PMID: 24532645 PMCID: PMC3958739 DOI: 10.1189/jlb.1113599] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/15/2014] [Accepted: 01/19/2014] [Indexed: 11/24/2022] Open
Abstract
MHC class I molecules display oligopeptides on the cell surface to enable T cell immunosurveillance of intracellular pathogens and tumors. Speed is of the essence in detecting viruses, which can complete a full replication cycle in just hours, whereas tumor detection is typically a finding-the-needle-in-the-haystack exercise. We review current evidence supporting a nonrandom, compartmentalized selection of peptidogenic substrates that focuses on rapidly degraded translation products as a main source of peptide precursors to optimize immunosurveillance of pathogens and tumors.
Collapse
Affiliation(s)
- Luis C Antón
- 1.NIAID, NIH, Bldg. 33, Bethesda, MD 20892, USA.
| | | |
Collapse
|
48
|
Gandin V, Topisirovic I. Co-translational mechanisms of quality control of newly synthesized polypeptides. ACTA ACUST UNITED AC 2014; 2:e28109. [PMID: 26779401 PMCID: PMC4705825 DOI: 10.4161/trla.28109] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 12/30/2013] [Accepted: 02/04/2014] [Indexed: 01/23/2023]
Abstract
During protein synthesis, nascent polypeptides emerge from ribosomes to fold into functional proteins. Misfolding of newly synthesized polypeptides (NSPs) at this stage leads to their aggregation. These misfolded NSPs must be expediently cleared to circumvent the deleterious effects of protein aggregation on cell physiology. To this end, a sizable portion of NSPs are ubiquitinated and rapidly degraded by the proteasome. This suggests the existence of co-translational mechanisms that play a pivotal role in the quality control of NSPs. It is generally thought that ribosomes play a central role in this process. During mRNA translation, ribosomes sense errors that lead to the accumulation of aberrant polypeptides, and serve as a hub for protein complexes that are required for optimal folding and/or proteasome-dependent degradation of misfolded polypeptides. In this review, we discuss recent findings that shed light on the molecular underpinnings of the co-translational quality control of NSPs.
Collapse
Affiliation(s)
- Valentina Gandin
- Lady Davis Institute for Medical Research; Sir Mortimer B. Davis-Jewish General Hospital; Montréal, QC Canada; Department of Oncology; McGill University; Montréal, QC Canada
| | - Ivan Topisirovic
- Lady Davis Institute for Medical Research; Sir Mortimer B. Davis-Jewish General Hospital; Montréal, QC Canada; Department of Oncology; McGill University; Montréal, QC Canada
| |
Collapse
|
49
|
Intracellular mobility and nuclear trafficking of the stress-activated kinase JNK1 are impeded by hyperosmotic stress. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:253-64. [DOI: 10.1016/j.bbamcr.2013.10.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 10/15/2013] [Accepted: 10/21/2013] [Indexed: 12/22/2022]
|
50
|
Soares DC, Abbott CM. Highly homologous eEF1A1 and eEF1A2 exhibit differential post-translational modification with significant enrichment around localised sites of sequence variation. Biol Direct 2013; 8:29. [PMID: 24220286 PMCID: PMC3868327 DOI: 10.1186/1745-6150-8-29] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 11/11/2013] [Indexed: 12/21/2022] Open
Abstract
REVIEWERS This article was reviewed by Frank Eisenhaber and Ramanathan Sowdhamini.Translation elongation factors eEF1A1 and eEF1A2 are 92% identical but exhibit non-overlapping expression patterns. While the two proteins are predicted to have similar tertiary structures, it is notable that the minor variations between their sequences are highly localised within their modelled structures. We used recently available high-throughput "omics" data to assess the spatial location of post-translational modifications and discovered that they are highly enriched on those surface regions of the protein that correspond to the clusters of sequence variation. This observation suggests how these two isoforms could be differentially regulated allowing them to perform distinct functions.
Collapse
|