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Lin BC, Higgins NR, Phung TH, Monteiro MJ. UBQLN proteins in health and disease with a focus on UBQLN2 in ALS/FTD. FEBS J 2022; 289:6132-6153. [PMID: 34273246 PMCID: PMC8761781 DOI: 10.1111/febs.16129] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/08/2021] [Accepted: 07/16/2021] [Indexed: 01/12/2023]
Abstract
Ubiquilin (UBQLN) proteins are a dynamic and versatile family of proteins found in all eukaryotes that function in the regulation of proteostasis. Besides their canonical function as shuttle factors in delivering misfolded proteins to the proteasome and autophagy systems for degradation, there is emerging evidence that UBQLN proteins play broader roles in proteostasis. New information suggests the proteins function as chaperones in protein folding, protecting proteins prior to membrane insertion, and as guardians for mitochondrial protein import. In this review, we describe the evidence for these different roles, highlighting how different domains of the proteins impart these functions. We also describe how changes in the structure and phase separation properties of UBQLNs may regulate their activity and function. Finally, we discuss the pathogenic mechanisms by which mutations in UBQLN2 cause amyotrophic lateral sclerosis and frontotemporal dementia. We describe the animal model systems made for different UBQLN2 mutations and how lessons learnt from these systems provide fundamental insight into the molecular mechanisms by which UBQLN2 mutations drive disease pathogenesis through disturbances in proteostasis.
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Affiliation(s)
- Brian C. Lin
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, USA,Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Nicole R. Higgins
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA,Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Trong H. Phung
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mervyn J. Monteiro
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, USA,Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA,Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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Cashen BA, Naufer M, Morse M, Jones CE, Williams M, Furano A. The L1-ORF1p coiled coil enables formation of a tightly compacted nucleic acid-bound complex that is associated with retrotransposition. Nucleic Acids Res 2022; 50:8690-8699. [PMID: 35871298 PMCID: PMC9410894 DOI: 10.1093/nar/gkac628] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/30/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
Long interspersed nuclear element 1 (L1) parasitized most vertebrates and constitutes ∼20% of the human genome. It encodes ORF1p and ORF2p which form an L1-ribonucleoprotein (RNP) with their encoding transcript that is copied into genomic DNA (retrotransposition). ORF1p binds single-stranded nucleic acid (ssNA) and exhibits NA chaperone activity. All vertebrate ORF1ps contain a coiled coil (CC) domain and we previously showed that a CC-retrotransposition null mutant prevented formation of stably bound ORF1p complexes on ssNA. Here, we compared CC variants using our recently improved method that measures ORF1p binding to ssDNA at different forces. Bound proteins decrease ssDNA contour length and at low force, retrotransposition-competent ORF1ps (111p and m14p) exhibit two shortening phases: the first is rapid, coincident with ORF1p binding; the second is slower, consistent with formation of tightly compacted complexes by NA-bound ORF1p. In contrast, two retrotransposition-null CC variants (151p and m15p) did not attain the second tightly compacted state. The C-terminal half of the ORF1p trimer (not the CC) contains the residues that mediate NA-binding. Our demonstrating that the CC governs the ability of NA-bound retrotransposition-competent trimers to form tightly compacted complexes reveals the biochemical phenotype of these coiled coil mutants.
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Affiliation(s)
- Ben A Cashen
- Northeastern University, Department of Physics, Boston, MA02115, USA
| | - M Nabuan Naufer
- Northeastern University, Department of Physics, Boston, MA02115, USA
| | - Michael Morse
- Northeastern University, Department of Physics, Boston, MA02115, USA
| | - Charles E Jones
- The Laboratory of Molecular and Cellular Biology, NIDDK, NIH, Bethesda, MD 20892, USA
| | - Mark C Williams
- Northeastern University, Department of Physics, Boston, MA02115, USA
| | - Anthony V Furano
- The Laboratory of Molecular and Cellular Biology, NIDDK, NIH, Bethesda, MD 20892, USA
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53
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Morales-Polanco F, Lee JH, Barbosa NM, Frydman J. Cotranslational Mechanisms of Protein Biogenesis and Complex Assembly in Eukaryotes. Annu Rev Biomed Data Sci 2022; 5:67-94. [PMID: 35472290 PMCID: PMC11040709 DOI: 10.1146/annurev-biodatasci-121721-095858] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The formation of protein complexes is crucial to most biological functions. The cellular mechanisms governing protein complex biogenesis are not yet well understood, but some principles of cotranslational and posttranslational assembly are beginning to emerge. In bacteria, this process is favored by operons encoding subunits of protein complexes. Eukaryotic cells do not have polycistronic mRNAs, raising the question of how they orchestrate the encounter of unassembled subunits. Here we review the constraints and mechanisms governing eukaryotic co- and posttranslational protein folding and assembly, including the influence of elongation rate on nascent chain targeting, folding, and chaperone interactions. Recent evidence shows that mRNAs encoding subunits of oligomeric assemblies can undergo localized translation and form cytoplasmic condensates that might facilitate the assembly of protein complexes. Understanding the interplay between localized mRNA translation and cotranslational proteostasis will be critical to defining protein complex assembly in vivo.
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Affiliation(s)
| | - Jae Ho Lee
- Department of Biology, Stanford University, Stanford, California, USA;
| | - Natália M Barbosa
- Department of Biology, Stanford University, Stanford, California, USA;
| | - Judith Frydman
- Department of Biology, Stanford University, Stanford, California, USA;
- Department of Genetics, Stanford University, Stanford, California, USA
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54
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The ribosome stabilizes partially folded intermediates of a nascent multi-domain protein. Nat Chem 2022; 14:1165-1173. [PMID: 35927328 PMCID: PMC7613651 DOI: 10.1038/s41557-022-01004-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 06/20/2022] [Indexed: 12/13/2022]
Abstract
Co-translational folding is crucial to ensure the production of biologically active proteins. The ribosome can alter the folding pathways of nascent polypeptide chains, yet a structural understanding remains largely inaccessible experimentally. We have developed site-specific labelling of nascent chains to detect and measure, using 19F nuclear magnetic resonance (NMR) spectroscopy, multiple states accessed by an immunoglobulin-like domain within a tandem repeat protein during biosynthesis. By examining ribosomes arrested at different stages during translation of this common structural motif, we observe highly broadened NMR resonances attributable to two previously unidentified intermediates, which are stably populated across a wide folding transition. Using molecular dynamics simulations and corroborated by cryo-electron microscopy, we obtain models of these partially folded states, enabling experimental verification of a ribosome-binding site that contributes to their high stabilities. We thus demonstrate a mechanism by which the ribosome could thermodynamically regulate folding and other co-translational processes. ![]()
Most proteins must fold co-translationally on the ribosome to adopt biologically active conformations, yet structural, mechanistic descriptions are lacking. Using 19F NMR spectroscopy to study a nascent multi-domain protein has now enabled the identification of two co-translational folding intermediates that are significantly more stable than intermediates formed off the ribosome, suggesting that the ribosome may thermodynamically regulate folding.
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55
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Esposito E, Weidemann DE, Rogers JM, Morton CM, Baybay EK, Chen J, Hauf S. Mitotic checkpoint gene expression is tuned by codon usage bias. EMBO J 2022; 41:e107896. [PMID: 35811551 PMCID: PMC9340482 DOI: 10.15252/embj.2021107896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/30/2022] [Accepted: 06/06/2022] [Indexed: 11/09/2022] Open
Abstract
The mitotic checkpoint (also called spindle assembly checkpoint, SAC) is a signaling pathway that safeguards proper chromosome segregation. Correct functioning of the SAC depends on adequate protein concentrations and appropriate stoichiometries between SAC proteins. Yet very little is known about the regulation of SAC gene expression. Here, we show in the fission yeast Schizosaccharomyces pombe that a combination of short mRNA half-lives and long protein half-lives supports stable SAC protein levels. For the SAC genes mad2+ and mad3+ , their short mRNA half-lives are caused, in part, by a high frequency of nonoptimal codons. In contrast, mad1+ mRNA has a short half-life despite a higher frequency of optimal codons, and despite the lack of known RNA-destabilizing motifs. Hence, different SAC genes employ different strategies of expression. We further show that Mad1 homodimers form co-translationally, which may necessitate a certain codon usage pattern. Taken together, we propose that the codon usage of SAC genes is fine-tuned to ensure proper SAC function. Our work shines light on gene expression features that promote spindle assembly checkpoint function and suggests that synonymous mutations may weaken the checkpoint.
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Affiliation(s)
- Eric Esposito
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
| | - Douglas E Weidemann
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
| | - Jessie M Rogers
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
| | - Claire M Morton
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
| | - Erod Keaton Baybay
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
| | - Jing Chen
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
| | - Silke Hauf
- Department of Biological SciencesVirginia TechBlacksburgVAUSA
- Fralin Life Sciences InstituteVirginia TechBlacksburgVAUSA
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56
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Badonyi M, Marsh JA. Large protein complex interfaces have evolved to promote cotranslational assembly. eLife 2022; 11:79602. [PMID: 35899946 PMCID: PMC9365393 DOI: 10.7554/elife.79602] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Assembly pathways of protein complexes should be precise and efficient to minimise misfolding and unwanted interactions with other proteins in the cell. One way to achieve this efficiency is by seeding assembly pathways during translation via the cotranslational assembly of subunits. While recent evidence suggests that such cotranslational assembly is widespread, little is known about the properties of protein complexes associated with the phenomenon. Here, using a combination of proteome-specific protein complex structures and publicly available ribosome profiling data, we show that cotranslational assembly is particularly common between subunits that form large intermolecular interfaces. To test whether large interfaces have evolved to promote cotranslational assembly, as opposed to cotranslational assembly being a non-adaptive consequence of large interfaces, we compared the sizes of first and last translated interfaces of heteromeric subunits in bacterial, yeast, and human complexes. When considering all together, we observe the N-terminal interface to be larger than the C-terminal interface 54% of the time, increasing to 64% when we exclude subunits with only small interfaces, which are unlikely to cotranslationally assemble. This strongly suggests that large interfaces have evolved as a means to maximise the chance of successful cotranslational subunit binding.
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Affiliation(s)
- Mihaly Badonyi
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Joseph A Marsh
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
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57
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pSNAP: Proteome-wide analysis of elongating nascent polypeptide chains. iScience 2022; 25:104516. [PMID: 35754732 PMCID: PMC9218386 DOI: 10.1016/j.isci.2022.104516] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 02/10/2022] [Accepted: 05/31/2022] [Indexed: 12/27/2022] Open
Abstract
Cellular global translation is often measured using ribosome profiling or quantitative mass spectrometry, but these methods do not provide direct information at the level of elongating nascent polypeptide chains (NPCs) and associated co-translational events. Here, we describe pSNAP, a method for proteome-wide profiling of NPCs by affinity enrichment of puromycin- and stable isotope-labeled polypeptides. pSNAP does not require ribosome purification and/or chemical labeling, and captures bona fide NPCs that characteristically exhibit protein N-terminus-biased positions. We applied pSNAP to evaluate the effect of silmitasertib, a potential molecular therapy for cancer, and revealed acute translational repression through casein kinase II and mTOR pathways. We also characterized modifications on NPCs and demonstrated that the combination of different types of modifications, such as acetylation and phosphorylation in the N-terminal region of histone H1.5, can modulate interactions with ribosome-associated factors. Thus, pSNAP provides a framework for dissecting co-translational regulations on a proteome-wide scale. Nascent polypeptidome analysis with a simplified protocol Quantification of acute changes in nascent polypeptides induced by external stimuli Profiling and characterization of chemical modifications on nascent polypeptides
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58
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Maki Y, Kawata K, Liu Y, Goo KY, Okamoto R, Kajihara Y, Satoh A. Design and Synthesis of Glycosylated Cholera Toxin B Subunit as a Tracer of Glycoprotein Trafficking in Organelles of Living Cells. Chemistry 2022; 28:e202201253. [PMID: 35604098 DOI: 10.1002/chem.202201253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Indexed: 12/15/2022]
Abstract
Glycosylation of proteins is known to be essential for changing biological activity and stability of glycoproteins on the cell surfaces and in body fluids. Delivering of homogeneous glycoproteins into the endoplasmic reticulum (ER) and the Golgi apparatus would enable us to investigate the function of asparagine-linked (N-) glycans in the organelles. In this work, we designed and synthesized an intentionally glycosylated cholera toxin B-subunit (CTB) to be transported to the organelles of mammalian cells. The heptasaccharide, the intermediate structure of various complex-type N-glycans, was introduced to the CTB. The synthesized monomeric glycosyl-CTB successfully entered mammalian cells and was transported to the Golgi and the ER, suggesting the potential use of synthetic CTB to deliver and investigate the functions of homogeneous N-glycans in specific organelles of living cells.
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Affiliation(s)
- Yuta Maki
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
- Project Research Center for Fundamental Sciences, Graduate Scholl of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Kazuki Kawata
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Yanbo Liu
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Kang-Ying Goo
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Ryo Okamoto
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
- Project Research Center for Fundamental Sciences, Graduate Scholl of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Yasuhiro Kajihara
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
- Project Research Center for Fundamental Sciences, Graduate Scholl of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Ayano Satoh
- Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, 3-1-1 Tsushimanaka, Okayama, 700-8530, Japan
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59
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Yang X, Da Q, Qian P, Veeravalli B, Leong TW, Dai L, Nordlund P, Prabhu N, Zhao Z, Zeng Z. CETSA Feature Based Clustering for Protein Outlier Discovery by Protein-to-Protein Interaction Prediction. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2022; 2022:1659-1662. [PMID: 36085889 DOI: 10.1109/embc48229.2022.9871558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The Cellular Thermal Shift Assay (CETSA) is a biophysical assay based on the principle of ligand-induced thermal stabilization of target proteins. This technology has revolutionized cell-based target engagement studies and has been used as guidance for drug design. Although many ap-plications of CETSA data have been explored, the correlations between CETSA data and protein-protein interactions (PPI) have barely been touched. In this study, we conduct the first exploration study applying CETSA data for PPI prediction. We use a machine learning method, Decision Tree, to predict PPI scores using proteins' CETSA features. It shows promising results that the predicted PPI scores closely match the ground-truth PPI scores. Furthermore, for a small number of protein pairs, whose PPI score predictions mismatch the ground truth, we use iterative clustering strategy to gradually reduce the number of these pairs. At the end of iterative clustering, the remaining protein pairs may have some unusual properties and are of scientific value for further biological investigation. Our study has demonstrated that PPI is a brand-new application of CETSA data. At the same time, it also manifests that CETSA data can be used as a new data source for PPI exploration study.
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60
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Zhu H, Chen Z, Chen Y, Zhu JJ. Affinities and Kinetics Detection of Protein-Small Molecule Interactions with a Monolayer MoS 2 -Based Optical Imaging Platform. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2202622. [PMID: 35726050 DOI: 10.1002/smll.202202622] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/01/2022] [Indexed: 06/15/2023]
Abstract
Quantifying the binding kinetics and affinities of protein-small molecule interactions is critical for biomarker validation, drug discovery, and deep understanding of various biological processes at the molecular-scale. Novel approaches are demanded as most common label-free techniques are mass-sensitive, which are not suitable for the detection of small molecule interactions. Here, an optical imaging platform is developed to measure the binding kinetics of both protein-small molecules and protein-ions based on monolayer MoS2 , an ultra-thin 2D material whose optical absorption is extremely sensitive to charge. A model is established to calibrate the optical response due to the charged analyte binding and it is applied to quantify the interactions between abl1 kinase and different small-molecule inhibitors. Such a presented method is capable of distinguishing different inhibitors binding to a wild or mutated kinase, which provides guidance for drug evaluation and drug mechanism exploration. The binding kinetics of calcium ions to calmodulin is also measured, further broadening the application field of the method. In addition, the imaging capability allows mapping the local binding kinetics of the molecular interactions with a high resolution, which reveals visible spatial variability and offers a promising tool for studying heterogeneous local interfacial interactions.
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Affiliation(s)
- Hao Zhu
- School of Pharmacy, Nanjing Medical University, Nanjing, 211166, P. R. China
| | - Zixuan Chen
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Yun Chen
- School of Pharmacy, Nanjing Medical University, Nanjing, 211166, P. R. China
| | - Jun-Jie Zhu
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China
- Shenzhen Research Institute of Nanjing University, Shenzhen, 518000, P. R. China
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61
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Hsu KL, Yen HCS, Yeang CH. Cooperative stability renders protein complex formation more robust and controllable. Sci Rep 2022; 12:10490. [PMID: 35729235 PMCID: PMC9213465 DOI: 10.1038/s41598-022-14362-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/06/2022] [Indexed: 11/19/2022] Open
Abstract
Protein complexes are the fundamental units of many biological functions. Despite their many advantages, one major adverse impact of protein complexes is accumulations of unassembled subunits that may disrupt other processes or exert cytotoxic effects. Synthesis of excess subunits can be inhibited via negative feedback control or they can be degraded more efficiently than assembled subunits, with this latter being termed cooperative stability. Whereas controlled synthesis of complex subunits has been investigated extensively, how cooperative stability acts in complex formation remains largely unexplored. To fill this knowledge gap, we have built quantitative models of heteromeric complexes with or without cooperative stability and compared their behaviours in the presence of synthesis rate variations. A system displaying cooperative stability is robust against synthesis rate variations as it retains high dimer/monomer ratios across a broad range of parameter configurations. Moreover, cooperative stability can alleviate the constraint of limited supply of a given subunit and makes complex abundance more responsive to unilateral upregulation of another subunit. We also conducted an in silico experiment to comprehensively characterize and compare four types of circuits that incorporate combinations of negative feedback control and cooperative stability in terms of eight systems characteristics pertaining to optimality, robustness and controllability. Intriguingly, though individual circuits prevailed for distinct characteristics, the system with cooperative stability alone achieved the most balanced performance across all characteristics. Our study provides theoretical justification for the contribution of cooperative stability to natural biological systems and represents a guideline for designing synthetic complex formation systems with desirable characteristics.
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Affiliation(s)
- Kuan-Lun Hsu
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Taipei, Taiwan
| | - Hsueh-Chi S Yen
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Taipei, Taiwan
| | - Chen-Hsiang Yeang
- Institute of Statistical Science, Academia Sinica, 128 Academia Road, Section 2, Taipei, Taiwan.
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62
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Thermodynamics of co-translational folding and ribosome-nascent chain interactions. Curr Opin Struct Biol 2022; 74:102357. [PMID: 35390638 DOI: 10.1016/j.sbi.2022.102357] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/22/2022] [Accepted: 02/22/2022] [Indexed: 11/03/2022]
Abstract
Proteins can begin the conformational search for their native structure in parallel with biosynthesis on the ribosome, in a process termed co-translational folding. In contrast to the reversible folding of isolated domains, as a nascent chain emerges from the ribosome exit tunnel during translation the free energy landscape it explores also evolves as a function of chain length. While this presents a substantially more complex measurement problem, this review will outline the progress that has been made recently in understanding, quantitatively, the process by which a nascent chain attains its full native stability, as well as the mechanisms through which interactions with the nearby ribosome surface can perturb or modulate this process.
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63
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Pla-Prats C, Thomä NH. Quality control of protein complex assembly by the ubiquitin-proteasome system. Trends Cell Biol 2022; 32:696-706. [PMID: 35300891 DOI: 10.1016/j.tcb.2022.02.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/17/2022] [Accepted: 02/21/2022] [Indexed: 12/12/2022]
Abstract
The majority of human proteins operate as multimeric complexes with defined compositions and distinct architectures. How the assembly of these complexes is surveyed and how defective complexes are recognized is just beginning to emerge. In eukaryotes, over 600 E3 ubiquitin ligases form part of the ubiquitin-proteasome system (UPS) which detects structural characteristics in its target proteins and selectively induces their degradation. The UPS has recently been shown to oversee key quality control steps during the assembly of protein complexes. We review recent findings on how E3 ubiquitin ligases regulate protein complex assembly and highlight unanswered questions relating to their mechanism of action.
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Affiliation(s)
- Carlos Pla-Prats
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; Faculty of Science, University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Nicolas H Thomä
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
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64
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Padovani C, Jevtić P, Rapé M. Quality control of protein complex composition. Mol Cell 2022; 82:1439-1450. [PMID: 35316660 DOI: 10.1016/j.molcel.2022.02.029] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/26/2022] [Accepted: 02/21/2022] [Indexed: 12/13/2022]
Abstract
Eukaryotic cells possess hundreds of protein complexes that contain multiple subunits and must be formed at the correct time and place during development. Despite specific assembly pathways, cells frequently encounter complexes with missing or aberrant subunits that can disrupt important signaling events. Cells, therefore, employ several ubiquitin-dependent quality control pathways that can prevent, correct, or degrade flawed complexes. In this review, we will discuss our emerging understanding of such quality control of protein complex composition.
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Affiliation(s)
- Chris Padovani
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Predrag Jevtić
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Michael Rapé
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA 94720, USA; California Institute for Quantitative Biosciences (QB3), University of California at Berkeley, Berkeley, CA 94720, USA.
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65
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Seidel M, Becker A, Pereira F, Landry JJM, de Azevedo NTD, Fusco CM, Kaindl E, Romanov N, Baumbach J, Langer JD, Schuman EM, Patil KR, Hummer G, Benes V, Beck M. Co-translational assembly orchestrates competing biogenesis pathways. Nat Commun 2022; 13:1224. [PMID: 35264577 PMCID: PMC8907234 DOI: 10.1038/s41467-022-28878-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 02/11/2022] [Indexed: 12/27/2022] Open
Abstract
During the co-translational assembly of protein complexes, a fully synthesized subunit engages with the nascent chain of a newly synthesized interaction partner. Such events are thought to contribute to productive assembly, but their exact physiological relevance remains underexplored. Here, we examine structural motifs contained in nucleoporins for their potential to facilitate co-translational assembly. We experimentally test candidate structural motifs and identify several previously unknown co-translational interactions. We demonstrate by selective ribosome profiling that domain invasion motifs of beta-propellers, coiled-coils, and short linear motifs may act as co-translational assembly domains. Such motifs are often contained in proteins that are members of multiple complexes (moonlighters) and engage with closely related paralogs. Surprisingly, moonlighters and paralogs assemble co-translationally in only some but not all of the relevant biogenesis pathways. Our results highlight the regulatory complexity of assembly pathways.
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Affiliation(s)
- Maximilian Seidel
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany
- Faculty of Bioscience, Heidelberg University, Heidelberg, Germany
| | - Anja Becker
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Filipa Pereira
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Jonathan J M Landry
- Genomics Core Facility, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | | | - Claudia M Fusco
- Department of Synaptic Plasticity, Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Eva Kaindl
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Natalie Romanov
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Janina Baumbach
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Julian D Langer
- Department of Synaptic Plasticity, Max Planck Institute for Brain Research, Frankfurt, Germany
- Membrane Proteomics and Mass Spectrometry, Max Planck Institute of Biophysics, Frankfurt, Germany
- Mass Spectrometry, Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Erin M Schuman
- Department of Synaptic Plasticity, Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Kiran Raosaheb Patil
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Medical Research Council Toxicology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt, Germany
- Institute of Biophysics, Goethe University Frankfurt, Frankfurt, Germany
| | - Vladimir Benes
- Genomics Core Facility, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Martin Beck
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany.
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
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66
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Fujita T, Yokoyama T, Shirouzu M, Taguchi H, Ito T, Iwasaki S. The landscape of translational stall sites in bacteria revealed by monosome and disome profiling. RNA (NEW YORK, N.Y.) 2022; 28:290-302. [PMID: 34906996 PMCID: PMC8848927 DOI: 10.1261/rna.078188.120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 11/24/2021] [Indexed: 05/29/2023]
Abstract
Ribosome pauses are associated with various cotranslational events and determine the fate of mRNAs and proteins. Thus, the identification of precise pause sites across the transcriptome is desirable; however, the landscape of ribosome pauses in bacteria remains ambiguous. Here, we harness monosome and disome (or collided ribosome) profiling strategies to survey ribosome pause sites in Escherichia coli Compared to eukaryotes, ribosome collisions in bacteria showed remarkable differences: a low frequency of disomes at stop codons, collisions occurring immediately after 70S assembly on start codons, and shorter queues of ribosomes trailing upstream. The pause sites corresponded with the biochemical validation by integrated nascent chain profiling (iNP) to detect polypeptidyl-tRNA, an elongation intermediate. Moreover, the subset of those sites showed puromycin resistance, presenting slow peptidyl transfer. Among the identified sites, the ribosome pause at Asn586 of ycbZ was validated by biochemical reporter assay, tRNA sequencing (tRNA-seq), and cryo-electron microscopy (cryo-EM) experiments. Our results provide a useful resource for ribosome stalling sites in bacteria.
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Affiliation(s)
- Tomoya Fujita
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198 Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
| | - Takeshi Yokoyama
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan
- Graduate School of Life Sciences, Tohoku University, Aoba-ku, Sendai 980-8577, Japan
| | - Mikako Shirouzu
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Hideki Taguchi
- School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Midori-ku, Yokohama 226-8503, Japan
| | - Takuhiro Ito
- Laboratory for Translation Structural Biology, RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Shintaro Iwasaki
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198 Japan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan
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67
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Younus I, Kochkina S, Choi CC, Sun W, Ford RC. ATP-Binding Cassette Transporters: Snap-on Complexes? Subcell Biochem 2022; 99:35-82. [PMID: 36151373 DOI: 10.1007/978-3-031-00793-4_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
ATP-binding cassette (ABC) transporters are one of the largest families of membrane proteins in prokaryotic organisms. Much is now understood about the structure of these transporters and many reviews have been written on that subject. In contrast, less has been written on the assembly of ABC transporter complexes and this will be a major focus of this book chapter. The complexes are formed from two cytoplasmic subunits that are highly conserved (in terms of their primary and three-dimensional structures) across the whole family. These ATP-binding subunits give rise to the name of the family. They must assemble with two transmembrane subunits that will typically form the permease component of the transporter. The transmembrane subunits have been found to be surprisingly diverse in structure when the whole family is examined, with seven distinct folds identified so far. Hence nucleotide-binding subunits appear to have been bolted on to a variety of transmembrane platforms during evolution, leading to a greater variety in function. Furthermore, many importers within the family utilise a further external substrate-binding component to trap scarce substrates and deliver them to the correct permease components. In this chapter, we will discuss whether assembly of the various ABC transporter subunits occurs with high fidelity within the crowded cellular environment and whether promiscuity in assembly of transmembrane and cytoplasmic components can occur. We also discuss the new AlphaFold protein structure prediction tool which predicts a new type of transmembrane domain fold within the ABC transporters that is associated with cation exporters of bacteria and plants.
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Affiliation(s)
- Iqra Younus
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Sofia Kochkina
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Cheri C Choi
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Wenjuan Sun
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Robert C Ford
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK.
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68
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Houben B, Rousseau F, Schymkowitz J. Protein structure and aggregation: a marriage of necessity ruled by aggregation gatekeepers. Trends Biochem Sci 2021; 47:194-205. [PMID: 34561149 DOI: 10.1016/j.tibs.2021.08.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/25/2021] [Accepted: 08/31/2021] [Indexed: 12/27/2022]
Abstract
Protein aggregation propensity is a pervasive and seemingly inescapable property of proteomes. Strikingly, a significant fraction of the proteome is supersaturated, meaning that, for these proteins, their native conformation is less stable than the aggregated state. Maintaining the integrity of a proteome under such conditions is precarious and requires energy-consuming proteostatic regulation. Why then is aggregation propensity maintained at such high levels over long evolutionary timescales? Here, we argue that the conformational stability of the native and aggregated states are correlated thermodynamically and that codon usage strengthens this correlation. As a result, the folding of stable proteins requires kinetic control to avoid aggregation, provided by aggregation gatekeepers. These unique residues are evolutionarily selected to kinetically favor native folding, either on their own or by coopting chaperones.
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Affiliation(s)
- Bert Houben
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium; Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Frederic Rousseau
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium; Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.
| | - Joost Schymkowitz
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium; Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.
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69
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Pomplun S, Jbara M, Schissel CK, Wilson Hawken S, Boija A, Li C, Klein I, Pentelute BL. Parallel Automated Flow Synthesis of Covalent Protein Complexes That Can Inhibit MYC-Driven Transcription. ACS CENTRAL SCIENCE 2021; 7:1408-1418. [PMID: 34471684 PMCID: PMC8393199 DOI: 10.1021/acscentsci.1c00663] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Indexed: 06/11/2023]
Abstract
Dysregulation of the transcription factor MYC is involved in many human cancers. The dimeric transcription factor complexes of MYC/MAX and MAX/MAX activate or inhibit, respectively, gene transcription upon binding to the same enhancer box DNA. Targeting these complexes in cancer is a long-standing challenge. Inspired by the inhibitory activity of the MAX/MAX dimer, we engineered covalently linked, synthetic homo- and heterodimeric protein complexes to attenuate oncogenic MYC-driven transcription. We prepared the covalent protein complexes (∼20 kDa, 167-231 residues) in a single shot via parallel automated flow synthesis in hours. The stabilized covalent dimers display DNA binding activity, are intrinsically cell-penetrant, and inhibit cancer cell proliferation in different cell lines. RNA sequencing and gene set enrichment analysis in A549 cancer cells confirmed that the synthetic dimers interfere with MYC-driven transcription. Our results demonstrate the potential of automated flow technology to rapidly deliver engineered synthetic protein complex mimetics that can serve as a starting point in developing inhibitors of MYC-driven cancer cell growth.
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Affiliation(s)
- Sebastian Pomplun
- Department
of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Muhammad Jbara
- Department
of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Carly K. Schissel
- Department
of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Susana Wilson Hawken
- Whitehead
Institute for Biomedical Research, Cambridge, Massachusetts 02142, United States
- Department
of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Ann Boija
- Whitehead
Institute for Biomedical Research, Cambridge, Massachusetts 02142, United States
- Department
of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Charles Li
- Whitehead
Institute for Biomedical Research, Cambridge, Massachusetts 02142, United States
- Department
of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Isaac Klein
- Whitehead
Institute for Biomedical Research, Cambridge, Massachusetts 02142, United States
- Department
of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Bradley L. Pentelute
- Department
of Chemistry, Massachusetts Institute of
Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- The
Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, Massachusetts 02142, United States
- Center
for Environmental Health Sciences, Massachusetts
Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Broad Institute
of MIT and Harvard, 415
Main Street, Cambridge, Massachusetts 02142, United States
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70
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Dong H, Li H, Xue Y, Su S, Li S, Shan X, Liu H, Jiang N, Wu X, Zhang Z, Yuan Y. E183K Mutation in Chalcone Synthase C2 Causes Protein Aggregation and Maize Colorless. FRONTIERS IN PLANT SCIENCE 2021; 12:679654. [PMID: 34249050 PMCID: PMC8261305 DOI: 10.3389/fpls.2021.679654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 05/12/2021] [Indexed: 06/13/2023]
Abstract
Flavonoids give plants their rich colors and play roles in a number of physiological processes. In this study, we identified a novel colorless maize mutant showing reduced pigmentation throughout the whole life cycle by EMS mutagenesis. E183K mutation in maize chalcone synthase C2 (ZmC2) was mapped using MutMap strategy as the causal for colorless, which was further validated by transformation in Arabidopsis. We evaluated transcriptomic and metabolic changes in maize first sheaths caused by the mutation. The downstream biosynthesis was blocked while very few genes changed their expression pattern. ZmC2-E183 site is highly conserved in chalcone synthase among Plantae kingdom and within species' different varieties. Through prokaryotic expression, transient expression in maize leaf protoplasts and stable expression in Arabidopsis, we observed that E183K and other mutations on E183 could cause almost complete protein aggregation of chalcone synthase. Our findings will benefit the characterization of flavonoid biosynthesis and contribute to the body of knowledge on protein aggregation in plants.
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Affiliation(s)
- Haixiao Dong
- College of Plant Science, Jilin University, Changchun, China
| | - He Li
- College of Plant Science, Jilin University, Changchun, China
| | - Yingjie Xue
- College of Plant Science, Jilin University, Changchun, China
| | - Shengzhong Su
- College of Plant Science, Jilin University, Changchun, China
| | - Shipeng Li
- College of Plant Science, Jilin University, Changchun, China
| | - Xiaohui Shan
- College of Plant Science, Jilin University, Changchun, China
| | - Hongkui Liu
- College of Plant Science, Jilin University, Changchun, China
| | - Nan Jiang
- College of Plant Science, Jilin University, Changchun, China
| | - Xuyang Wu
- College of Plant Science, Jilin University, Changchun, China
| | - Zhiwu Zhang
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, United States
| | - Yaping Yuan
- College of Plant Science, Jilin University, Changchun, China
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71
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Lashkevich KA, Dmitriev SE. mRNA Targeting, Transport and Local Translation in Eukaryotic Cells: From the Classical View to a Diversity of New Concepts. Mol Biol 2021; 55:507-537. [PMID: 34092811 PMCID: PMC8164833 DOI: 10.1134/s0026893321030080] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 02/26/2021] [Accepted: 03/12/2021] [Indexed: 12/28/2022]
Abstract
Spatial organization of protein biosynthesis in the eukaryotic cell has been studied for more than fifty years, thus many facts have already been included in textbooks. According to the classical view, mRNA transcripts encoding secreted and transmembrane proteins are translated by ribosomes associated with endoplasmic reticulum membranes, while soluble cytoplasmic proteins are synthesized on free polysomes. However, in the last few years, new data has emerged, revealing selective translation of mRNA on mitochondria and plastids, in proximity to peroxisomes and endosomes, in various granules and at the cytoskeleton (actin network, vimentin intermediate filaments, microtubules and centrosomes). There are also long-standing debates about the possibility of protein synthesis in the nucleus. Localized translation can be determined by targeting signals in the synthesized protein, nucleotide sequences in the mRNA itself, or both. With RNA-binding proteins, many transcripts can be assembled into specific RNA condensates and form RNP particles, which may be transported by molecular motors to the sites of active translation, form granules and provoke liquid-liquid phase separation in the cytoplasm, both under normal conditions and during cell stress. The translation of some mRNAs occurs in specialized "translation factories," assemblysomes, transperons and other structures necessary for the correct folding of proteins, interaction with functional partners and formation of oligomeric complexes. Intracellular localization of mRNA has a significant impact on the efficiency of its translation and presumably determines its response to cellular stress. Compartmentalization of mRNAs and the translation machinery also plays an important role in viral infections. Many viruses provoke the formation of specific intracellular structures, virus factories, for the production of their proteins. Here we review the current concepts of the molecular mechanisms of transport, selective localization and local translation of cellular and viral mRNAs, their effects on protein targeting and topogenesis, and on the regulation of protein biosynthesis in different compartments of the eukaryotic cell. Special attention is paid to new systems biology approaches, providing new cues to the study of localized translation.
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Affiliation(s)
- Kseniya A Lashkevich
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119234 Moscow, Russia.,Faculty of Bioengineering and Bioinformatics, Moscow State University, 119234 Moscow, Russia
| | - Sergey E Dmitriev
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119234 Moscow, Russia.,Faculty of Bioengineering and Bioinformatics, Moscow State University, 119234 Moscow, Russia.,Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
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72
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Koubek J, Schmitt J, Galmozzi CV, Kramer G. Mechanisms of Cotranslational Protein Maturation in Bacteria. Front Mol Biosci 2021; 8:689755. [PMID: 34113653 PMCID: PMC8185961 DOI: 10.3389/fmolb.2021.689755] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/10/2021] [Indexed: 01/05/2023] Open
Abstract
Growing cells invest a significant part of their biosynthetic capacity into the production of proteins. To become functional, newly-synthesized proteins must be N-terminally processed, folded and often translocated to other cellular compartments. A general strategy is to integrate these protein maturation processes with translation, by cotranslationally engaging processing enzymes, chaperones and targeting factors with the nascent polypeptide. Precise coordination of all factors involved is critical for the efficiency and accuracy of protein synthesis and cellular homeostasis. This review provides an overview of the current knowledge on cotranslational protein maturation, with a focus on the production of cytosolic proteins in bacteria. We describe the role of the ribosome and the chaperone network in protein folding and how the dynamic interplay of all cotranslationally acting factors guides the sequence of cotranslational events. Finally, we discuss recent data demonstrating the coupling of protein synthesis with the assembly of protein complexes and end with a brief discussion of outstanding questions and emerging concepts in the field of cotranslational protein maturation.
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Affiliation(s)
- Jiří Koubek
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Jaro Schmitt
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Carla Veronica Galmozzi
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Günter Kramer
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
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73
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Pleiner T, Hazu M, Tomaleri GP, Januszyk K, Oania RS, Sweredoski MJ, Moradian A, Guna A, Voorhees RM. WNK1 is an assembly factor for the human ER membrane protein complex. Mol Cell 2021; 81:2693-2704.e12. [PMID: 33964204 DOI: 10.1016/j.molcel.2021.04.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 03/02/2021] [Accepted: 04/14/2021] [Indexed: 12/13/2022]
Abstract
The assembly of nascent proteins into multi-subunit complexes is a tightly regulated process that must occur at high fidelity to maintain cellular homeostasis. The ER membrane protein complex (EMC) is an essential insertase that requires seven membrane-spanning and two soluble cytosolic subunits to function. Here, we show that the kinase with no lysine 1 (WNK1), known for its role in hypertension and neuropathy, functions as an assembly factor for the human EMC. WNK1 uses a conserved amphipathic helix to stabilize the soluble subunit, EMC2, by binding to the EMC2-8 interface. Shielding this hydrophobic surface prevents promiscuous interactions of unassembled EMC2 and directly competes for binding of E3 ubiquitin ligases, permitting assembly. Depletion of WNK1 thus destabilizes both the EMC and its membrane protein clients. This work describes an unexpected role for WNK1 in protein biogenesis and defines the general requirements of an assembly factor that will apply across the proteome.
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Affiliation(s)
- Tino Pleiner
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
| | - Masami Hazu
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
| | - Giovani Pinton Tomaleri
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
| | - Kurt Januszyk
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
| | - Robert S Oania
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
| | - Michael J Sweredoski
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
| | - Annie Moradian
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
| | - Alina Guna
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
| | - Rebecca M Voorhees
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA.
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74
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Cassaignau AME, Włodarski T, Chan SHS, Woodburn LF, Bukvin IV, Streit JO, Cabrita LD, Waudby CA, Christodoulou J. Interactions between nascent proteins and the ribosome surface inhibit co-translational folding. Nat Chem 2021; 13:1214-1220. [PMID: 34650236 PMCID: PMC8627912 DOI: 10.1038/s41557-021-00796-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 08/24/2021] [Indexed: 11/19/2022]
Abstract
Most proteins begin to fold during biosynthesis on the ribosome. It has been suggested that interactions between the emerging polypeptide and the ribosome surface might allow the ribosome itself to modulate co-translational folding. Here we combine protein engineering and NMR spectroscopy to characterize a series of interactions between the ribosome surface and unfolded nascent chains of the immunoglobulin-like FLN5 filamin domain. The strongest interactions are found for a C-terminal segment that is essential for folding, and we demonstrate quantitative agreement between the strength of this interaction and the energetics of the co-translational folding process itself. Mutations in this region that reduce the extent of binding result in a shift in the co-translational folding equilibrium towards the native state. Our results therefore demonstrate that a competition between folding and binding provides a simple, dynamic mechanism for the modulation of co-translational folding by the ribosome.
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Affiliation(s)
- Anaïs M. E. Cassaignau
- grid.83440.3b0000000121901201Institute of Structural and Molecular Biology, University College London, London, UK
| | - Tomasz Włodarski
- grid.83440.3b0000000121901201Institute of Structural and Molecular Biology, University College London, London, UK
| | - Sammy H. S. Chan
- grid.83440.3b0000000121901201Institute of Structural and Molecular Biology, University College London, London, UK
| | - Lauren F. Woodburn
- grid.83440.3b0000000121901201Institute of Structural and Molecular Biology, University College London, London, UK
| | - Ivana V. Bukvin
- grid.83440.3b0000000121901201Institute of Structural and Molecular Biology, University College London, London, UK
| | - Julian O. Streit
- grid.83440.3b0000000121901201Institute of Structural and Molecular Biology, University College London, London, UK
| | - Lisa D. Cabrita
- grid.83440.3b0000000121901201Institute of Structural and Molecular Biology, University College London, London, UK
| | - Christopher A. Waudby
- grid.83440.3b0000000121901201Institute of Structural and Molecular Biology, University College London, London, UK
| | - John Christodoulou
- grid.83440.3b0000000121901201Institute of Structural and Molecular Biology, University College London, London, UK ,grid.4464.20000 0001 2161 2573Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, UK
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