1
|
Musiol E, Fromme T, Hau J, Di Pizio A, Klingenspor M. Comparative functional analysis reveals differential nucleotide sensitivity between human and mouse UCP1. Acta Physiol (Oxf) 2024:e14209. [PMID: 39072954 DOI: 10.1111/apha.14209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 07/15/2024] [Accepted: 07/16/2024] [Indexed: 07/30/2024]
Abstract
AIM Mitochondrial uncoupling protein 1 (UCP1) is a unique protein of brown adipose tissue. Upon activation by free fatty acids, UCP1 facilitates a thermogenic net proton flux across the mitochondrial inner membrane. Non-complexed purine nucleotides inhibit this fatty acid-induced activity of UCP1. The most available data have been generated from rodent model systems. In light of its role as a putative pharmacological target for treating metabolic disease, in-depth analyses of human UCP1 activity, regulation, and structural features are essential. METHODS In the present study, we established a doxycycline-regulated cell model with inducible human or murine UCP1 expression and conducted functional studies using respirometry comparing wild-type and mutant variants of human UCP1. RESULTS We demonstrate that human and mouse UCP1 exhibit similar specific fatty acid-induced activity but a different inhibitory potential of purine nucleotides. Mutagenesis of non-conserved residues in human UCP1 revealed structural components in α-helix 56 and α-helix 6 crucial for uncoupling function. CONCLUSION Comparative studies of human UCP1 with other orthologs can provide new insights into the structure-function relationship for this mitochondrial carrier and will be instrumental in searching for new activators.
Collapse
Affiliation(s)
- Eva Musiol
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences, Research Department of Molecular Life Sciences, Technical University of Munich, Freising, Germany
| | - Tobias Fromme
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences, Research Department of Molecular Life Sciences, Technical University of Munich, Freising, Germany
- EKFZ-Else Kröner Fresenius Center for Nutritional Medicine, Technical University of Munich, Munich, Germany
| | - Julia Hau
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences, Research Department of Molecular Life Sciences, Technical University of Munich, Freising, Germany
| | - Antonella Di Pizio
- Molecular Modeling Group, Leibniz Institute for Food Systems Biology at the Technical University of Munich, Freising, Germany
- Professorship of Chemoinformatics and Protein Modelling, TUM School of Life Sciences, Research Department of Molecular Life Sciences, Technical University of Munich, Freising, Germany
| | - Martin Klingenspor
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences, Research Department of Molecular Life Sciences, Technical University of Munich, Freising, Germany
- EKFZ-Else Kröner Fresenius Center for Nutritional Medicine, Technical University of Munich, Munich, Germany
| |
Collapse
|
2
|
Jones RM, Ruiz JH, Scaramuzza S, Nath S, Liu C, Henklewska M, Natsume T, Bristow RG, Romero F, Kanemaki MT, Gambus A. Characterizing replisome disassembly in human cells. iScience 2024; 27:110260. [PMID: 39055910 PMCID: PMC11269944 DOI: 10.1016/j.isci.2024.110260] [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: 08/09/2023] [Revised: 03/22/2024] [Accepted: 06/10/2024] [Indexed: 07/28/2024] Open
Abstract
To ensure timely duplication of the entire eukaryotic genome, thousands of replication machineries (replisomes) act on genomic DNA at any time during S phase. In the final stages of this process, replisomes are unloaded from chromatin. Unloading is driven by polyubiquitylation of MCM7, a subunit of the terminated replicative helicase, and processed by p97/VCP segregase. Most of our knowledge of replication termination comes from model organisms, and little is known about how this process is executed and regulated in human somatic cells. Here we show that replisome disassembly in this system requires CUL2LRR1-driven MCM7 ubiquitylation, p97, and UBXN7 for unloading and provide evidence for "backup" mitotic replisome disassembly, demonstrating conservation of such mechanisms. Finally, we find that small-molecule inhibitors against Cullin ubiquitin ligases (CULi) and p97 (p97i) affect replisome unloading but also lead to induction of replication stress in cells, which limits their usefulness to specifically target replisome disassembly processes.
Collapse
Affiliation(s)
- Rebecca M. Jones
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
| | - Joaquin Herrero Ruiz
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka, Japan
| | - Shaun Scaramuzza
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
| | - Sarmi Nath
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
| | - Chaoyu Liu
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
| | - Marta Henklewska
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
| | - Toyoaki Natsume
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems, Mishima, Shizuoka, Japan
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka, Japan
| | - Robert G. Bristow
- Cancer Research UK – Manchester Institute, Manchester Cancer Research Center, Manchester, UK
| | - Francisco Romero
- Department of Microbiology, University of Seville, Seville, Spain
| | - Masato T. Kanemaki
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems, Mishima, Shizuoka, Japan
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka, Japan
- Department of Biological Science, The University of Tokyo, Tokyo, Japan
| | - Agnieszka Gambus
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
| |
Collapse
|
3
|
Liu Y, Theil S, Ibach M, Walter J. DAP12 interacts with RER1 and is retained in the secretory pathway before assembly with TREM2. Cell Mol Life Sci 2024; 81:302. [PMID: 39008111 DOI: 10.1007/s00018-024-05298-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 07/16/2024]
Abstract
DNAX-activating protein of 12 kDa (DAP12) is a transmembrane adapter protein expressed in lymphoid and myeloid lineage cells. It interacts with several immunoreceptors forming functional complexes that trigger intracellular signaling pathways. One of the DAP12 associated receptors is the triggering receptor expressed on myeloid cells 2 (TREM2). Mutations in both DAP12 and TREM2 have been linked to neurodegenerative diseases. However, mechanisms involved in the regulation of subcellular trafficking and turnover of these proteins are not well understood. Here, we demonstrate that proteasomal degradation of DAP12 is increased in the absence of TREM2. Interestingly, unassembled DAP12 is also retained in early secretory compartments, including the endoplasmic reticulum (ER) and the ER-Golgi intermediate compartment (ERGIC), thereby preventing its transport to the plasma membrane. We also show that unassembled DAP12 interacts with the retention in ER sorting receptor 1 (RER1). The deletion of endogenous RER1 decreases expression of functional TREM2-DAP12 complexes and membrane proximal signaling, and resulted in almost complete inhibition of phagocytic activity in THP-1 differentiated macrophage-like cells. These results indicate that RER1 acts as an important regulator of DAP12 containing immunoreceptor complexes and immune cell function.
Collapse
Affiliation(s)
- Yanxia Liu
- Department of Neurology, University of Bonn, Bonn, 53127, Germany
| | - Sandra Theil
- Department of Neurology, University of Bonn, Bonn, 53127, Germany
| | - Melanie Ibach
- Department of Neurology, University of Bonn, Bonn, 53127, Germany
| | - Jochen Walter
- Department of Neurology, University of Bonn, Bonn, 53127, Germany.
| |
Collapse
|
4
|
Hu CW, Wang A, Fan D, Worth M, Chen Z, Huang J, Xie J, Macdonald J, Li L, Jiang J. OGA mutant aberrantly hydrolyzes O-GlcNAc modification from PDLIM7 to modulate p53 and cytoskeleton in promoting cancer cell malignancy. Proc Natl Acad Sci U S A 2024; 121:e2320867121. [PMID: 38838015 PMCID: PMC11181094 DOI: 10.1073/pnas.2320867121] [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: 11/27/2023] [Accepted: 05/10/2024] [Indexed: 06/07/2024] Open
Abstract
O-GlcNAcase (OGA) is the only human enzyme that catalyzes the hydrolysis (deglycosylation) of O-linked beta-N-acetylglucosaminylation (O-GlcNAcylation) from numerous protein substrates. OGA has broad implications in many challenging diseases including cancer. However, its role in cell malignancy remains mostly unclear. Here, we report that a cancer-derived point mutation on the OGA's noncatalytic stalk domain aberrantly modulates OGA interactome and substrate deglycosylation toward a specific set of proteins. Interestingly, our quantitative proteomic studies uncovered that the OGA stalk domain mutant preferentially deglycosylated protein substrates with +2 proline in the sequence relative to the O-GlcNAcylation site. One of the most dysregulated substrates is PDZ and LIM domain protein 7 (PDLIM7), which is associated with the tumor suppressor p53. We found that the aberrantly deglycosylated PDLIM7 suppressed p53 gene expression and accelerated p53 protein degradation by promoting the complex formation with E3 ubiquitin ligase MDM2. Moreover, deglycosylated PDLIM7 significantly up-regulated the actin-rich membrane protrusions on the cell surface, augmenting the cancer cell motility and aggressiveness. These findings revealed an important but previously unappreciated role of OGA's stalk domain in protein substrate recognition and functional modulation during malignant cell progression.
Collapse
Affiliation(s)
- Chia-Wei Hu
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI53705
| | - Ao Wang
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI53705
| | - Dacheng Fan
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI53705
| | - Matthew Worth
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI53705
| | - Zhengwei Chen
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Junfeng Huang
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI53705
| | - Jinshan Xie
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI53705
| | - John Macdonald
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI53705
| | - Lingjun Li
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI53705
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Jiaoyang Jiang
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI53705
| |
Collapse
|
5
|
Marinov GK, Ramalingam V, Greenleaf WJ, Kundaje A. An updated compendium and reevaluation of the evidence for nuclear transcription factor occupancy over the mitochondrial genome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.04.597442. [PMID: 38895386 PMCID: PMC11185660 DOI: 10.1101/2024.06.04.597442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
In most eukaryotes, mitochondrial organelles contain their own genome, usually circular, which is the remnant of the genome of the ancestral bacterial endosymbiont that gave rise to modern mitochondria. Mitochondrial genomes are dramatically reduced in their gene content due to the process of endosymbiotic gene transfer to the nucleus; as a result most mitochondrial proteins are encoded in the nucleus and imported into mitochondria. This includes the components of the dedicated mitochondrial transcription and replication systems and regulatory factors, which are entirely distinct from the information processing systems in the nucleus. However, since the 1990s several nuclear transcription factors have been reported to act in mitochondria, and previously we identified 8 human and 3 mouse transcription factors (TFs) with strong localized enrichment over the mitochondrial genome using ChIP-seq (Chromatin Immunoprecipitation) datasets from the second phase of the ENCODE (Encyclopedia of DNA Elements) Project Consortium. Here, we analyze the greatly expanded in the intervening decade ENCODE compendium of TF ChIP-seq datasets (a total of 6,153 ChIP experiments for 942 proteins, of which 763 are sequence-specific TFs) combined with interpretative deep learning models of TF occupancy to create a comprehensive compendium of nuclear TFs that show evidence of association with the mitochondrial genome. We find some evidence for chrM occupancy for 50 nuclear TFs and two other proteins, with bZIP TFs emerging as most likely to be playing a role in mitochondria. However, we also observe that in cases where the same TF has been assayed with multiple antibodies and ChIP protocols, evidence for its chrM occupancy is not always reproducible. In the light of these findings, we discuss the evidential criteria for establishing chrM occupancy and reevaluate the overall compendium of putative mitochondrial-acting nuclear TFs.
Collapse
Affiliation(s)
- Georgi K Marinov
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | | | - William J Greenleaf
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, California 94305, USA
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
| | - Anshul Kundaje
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
- Department of Computer Science, Stanford University, Stanford, CA 94305, USA
| |
Collapse
|
6
|
Didiasova M, Cesaro S, Feldhoff S, Bettin I, Tiegel N, Füssgen V, Bertoldi M, Tikkanen R. Functional Characterization of a Spectrum of Genetic Variants in a Family with Succinic Semialdehyde Dehydrogenase Deficiency. Int J Mol Sci 2024; 25:5237. [PMID: 38791277 PMCID: PMC11121183 DOI: 10.3390/ijms25105237] [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: 04/04/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
Succinic semialdehyde dehydrogenase (SSADH) is a mitochondrial enzyme involved in the catabolism of the neurotransmitter γ-amino butyric acid. Pathogenic variants in the gene encoding this enzyme cause SSADH deficiency, a developmental disease that manifests as hypotonia, autism, and epilepsy. SSADH deficiency patients usually have family-specific gene variants. Here, we describe a family exhibiting four different SSADH variants: Val90Ala, Cys93Phe, and His180Tyr/Asn255Asp (a double variant). We provide a structural and functional characterization of these variants and show that Cys93Phe and Asn255Asp are pathogenic variants that affect the stability of the SSADH protein. Due to the impairment of the cofactor NAD+ binding, these variants show a highly reduced enzyme activity. However, Val90Ala and His180Tyr exhibit normal activity and expression. The His180Tyr/Asn255Asp variant exhibits a highly reduced activity as a recombinant species, is inactive, and shows a very low expression in eukaryotic cells. A treatment with substances that support protein folding by either increasing chaperone protein expression or by chemical means did not increase the expression of the pathogenic variants of the SSADH deficiency patient. However, stabilization of the folding of pathogenic SSADH variants by other substances may provide a treatment option for this disease.
Collapse
Affiliation(s)
- Miroslava Didiasova
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, DE-35390 Giessen, Germany; (M.D.); (S.F.)
| | - Samuele Cesaro
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie, 8, 37134 Verona, Italy; (S.C.); (I.B.); (M.B.)
| | - Simon Feldhoff
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, DE-35390 Giessen, Germany; (M.D.); (S.F.)
| | - Ilaria Bettin
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie, 8, 37134 Verona, Italy; (S.C.); (I.B.); (M.B.)
| | - Nana Tiegel
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, DE-35390 Giessen, Germany; (M.D.); (S.F.)
| | - Vera Füssgen
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, DE-35390 Giessen, Germany; (M.D.); (S.F.)
| | - Mariarita Bertoldi
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie, 8, 37134 Verona, Italy; (S.C.); (I.B.); (M.B.)
| | - Ritva Tikkanen
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, DE-35390 Giessen, Germany; (M.D.); (S.F.)
| |
Collapse
|
7
|
Ni Z, Ahmed N, Nabeel-Shah S, Guo X, Pu S, Song J, Marcon E, Burke G, Tong AH, Chan K, Ha KH, Blencowe B, Moffat J, Greenblatt J. Identifying human pre-mRNA cleavage and polyadenylation factors by genome-wide CRISPR screens using a dual fluorescence readthrough reporter. Nucleic Acids Res 2024; 52:4483-4501. [PMID: 38587191 PMCID: PMC11077057 DOI: 10.1093/nar/gkae240] [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: 09/23/2023] [Revised: 01/29/2024] [Accepted: 04/02/2024] [Indexed: 04/09/2024] Open
Abstract
Messenger RNA precursors (pre-mRNA) generally undergo 3' end processing by cleavage and polyadenylation (CPA), which is specified by a polyadenylation site (PAS) and adjacent RNA sequences and regulated by a large variety of core and auxiliary CPA factors. To date, most of the human CPA factors have been discovered through biochemical and proteomic studies. However, genetic identification of the human CPA factors has been hampered by the lack of a reliable genome-wide screening method. We describe here a dual fluorescence readthrough reporter system with a PAS inserted between two fluorescent reporters. This system enables measurement of the efficiency of 3' end processing in living cells. Using this system in combination with a human genome-wide CRISPR/Cas9 library, we conducted a screen for CPA factors. The screens identified most components of the known core CPA complexes and other known CPA factors. The screens also identified CCNK/CDK12 as a potential core CPA factor, and RPRD1B as a CPA factor that binds RNA and regulates the release of RNA polymerase II at the 3' ends of genes. Thus, this dual fluorescence reporter coupled with CRISPR/Cas9 screens reliably identifies bona fide CPA factors and provides a platform for investigating the requirements for CPA in various contexts.
Collapse
Affiliation(s)
- Zuyao Ni
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Nujhat Ahmed
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5A 1A8, Canada
| | - Syed Nabeel-Shah
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5A 1A8, Canada
| | - Xinghua Guo
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Shuye Pu
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Jingwen Song
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Edyta Marcon
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Giovanni L Burke
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5A 1A8, Canada
| | - Amy Hin Yan Tong
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5A 1A8, Canada
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON Canada
| | - Katherine Chan
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5A 1A8, Canada
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON Canada
| | - Kevin C H Ha
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5A 1A8, Canada
| | - Benjamin J Blencowe
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5A 1A8, Canada
| | - Jason Moffat
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5A 1A8, Canada
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON Canada
- Institute for Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON Canada
| | - Jack F Greenblatt
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5A 1A8, Canada
| |
Collapse
|
8
|
Wang Z, Chen C, Ge X. Large T antigen mediated target gene replication improves site-specific recombination efficiency. Front Bioeng Biotechnol 2024; 12:1377167. [PMID: 38737535 PMCID: PMC11082406 DOI: 10.3389/fbioe.2024.1377167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 04/11/2024] [Indexed: 05/14/2024] Open
Abstract
With advantages of high-fidelity, monoclonality and large cargo capacity, site-specific recombination (SSR) holds great promises for precise genomic modifications. However, broad applications of SSR have been hurdled by low integration efficiency, and the amount of donor DNA available in nucleus for SSR presents as a limiting factor. Inspired by the DNA replication mechanisms observed in double-stranded DNA virus SV40, we hypothesized that expression of SV40 large T antigen (TAg) can increase the copy number of the donor plasmid bearing an SV40 origin, and in consequence promote recombination events. This hypothesis was tested with dual recombinase-mediated cassette exchange (RMCE) in suspension 293F cells. Results showed that TAg co-transfection significantly enhanced SSR in polyclonal cells. In the monoclonal cell line carrying a single landing pad at an identified genomic locus, 12% RMCE efficiency was achieved, and such improvement was indeed correlated with donor plasmid amplification. The developed TAg facilitated RMCE (T-RMCE) was exploited for the construction of large libraries of >107 diversity, from which GFP variants with enhanced fluorescence were isolated. We expect the underlying principle of target gene amplification can be applicable to other SSR processes and gene editing approaches in general for directed evolution and large-scale genomic screening in mammalian cells.
Collapse
Affiliation(s)
- Zening Wang
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, United States
- Department of Chemical and Environmental Engineering, University of California Riverside, Riverside, CA, United States
| | - Chuan Chen
- Department of Chemical and Environmental Engineering, University of California Riverside, Riverside, CA, United States
| | - Xin Ge
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, United States
- Department of Chemical and Environmental Engineering, University of California Riverside, Riverside, CA, United States
| |
Collapse
|
9
|
Yang Q, Wang J, Chen Z. Conditional splicing system for tight control of viral overlapping genes. J Virol 2024; 98:e0024224. [PMID: 38446633 PMCID: PMC11019872 DOI: 10.1128/jvi.00242-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 02/11/2024] [Indexed: 03/08/2024] Open
Abstract
Viral genomes frequently harbor overlapping genes, complicating the development of virus-vectored vaccines and gene therapies. This study introduces a novel conditional splicing system to precisely control the expression of such overlapping genes through recombinase-mediated conditional splicing. We refined site-specific recombinase (SSR) conditional splicing systems and explored their mechanisms. The systems demonstrated exceptional inducibility (116,700-fold increase) with negligible background expression, facilitating the conditional expression of overlapping genes in adenovirus-associated virus (AAV) and human immunodeficiency virus type 1. Notably, this approach enabled the establishment of stable AAV producer cell lines, encapsulating all necessary packaging genes. Our findings underscore the potential of the SSR-conditional splicing system to significantly advance vector engineering, enhancing the efficacy and scalability of viral-vector-based therapies and vaccines. IMPORTANCE Regulating overlapping genes is vital for gene therapy and vaccine development using viral vectors. The regulation of overlapping genes presents challenges, including cytotoxicity and impacts on vector capacity and genome stability, which restrict stable packaging cell line development and broad application. To address these challenges, we present a "loxp-splice-loxp"-based conditional splicing system, offering a novel solution for conditional expression of overlapping genes and stable cell line establishment. This system may also regulate other cytotoxic genes, representing a significant advancement in cell engineering and gene therapy as well as biomass production.
Collapse
Affiliation(s)
- Qing Yang
- AIDS Institute and Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Jinlin Wang
- AIDS Institute and Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Zhiwei Chen
- AIDS Institute and Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
- State Key Laboratory of Emerging Infectious Diseases, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| |
Collapse
|
10
|
Misra J, Carlson KR, Spandau DF, Wek RC. Multiple mechanisms activate GCN2 eIF2 kinase in response to diverse stress conditions. Nucleic Acids Res 2024; 52:1830-1846. [PMID: 38281137 PMCID: PMC10899773 DOI: 10.1093/nar/gkae006] [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: 08/04/2023] [Revised: 12/22/2023] [Accepted: 01/02/2024] [Indexed: 01/30/2024] Open
Abstract
Diverse environmental insults induce the integrated stress response (ISR), which features eIF2 phosphorylation and translational control that serves to restore protein homeostasis. The eIF2 kinase GCN2 is a first responder in the ISR that is activated by amino acid depletion and other stresses not directly related to nutrients. Two mechanisms are suggested to trigger an ordered process of GCN2 activation during stress: GCN2 monitoring stress via accumulating uncharged tRNAs or by stalled and colliding ribosomes. Our results suggest that while ribosomal collisions are indeed essential for GCN2 activation in response to translational elongation inhibitors, conditions that trigger deacylation of tRNAs activate GCN2 via its direct association with affected tRNAs. Both mechanisms require the GCN2 regulatory domain related to histidyl tRNA synthetases. GCN2 activation by UV irradiation features lowered amino acids and increased uncharged tRNAs and UV-induced ribosome collisions are suggested to be dispensable. We conclude that there are multiple mechanisms that activate GCN2 during diverse stresses.
Collapse
Affiliation(s)
- Jagannath Misra
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS4067 Indianapolis, Indiana 46202, USA
| | - Kenneth R Carlson
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS4067 Indianapolis, Indiana 46202, USA
| | - Dan F Spandau
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS4067 Indianapolis, Indiana 46202, USA
- Department of Dermatology, Indiana University School of Medicine, 635 Barnhill Drive, MS4067 Indianapolis, Indiana 46202, USA
- Richard L. Roudebush Veterans Administration Medical Center, Indiana University School of Medicine, 635 Barnhill Drive, MS4067 Indianapolis, Indiana 46202, USA
| | - Ronald C Wek
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS4067 Indianapolis, Indiana 46202, USA
| |
Collapse
|
11
|
Stevens TA, Tomaleri GP, Hazu M, Wei S, Nguyen VN, DeKalb C, Voorhees RM, Pleiner T. A nanobody-based strategy for rapid and scalable purification of human protein complexes. Nat Protoc 2024; 19:127-158. [PMID: 37974029 DOI: 10.1038/s41596-023-00904-w] [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: 08/18/2023] [Indexed: 11/19/2023]
Abstract
The isolation of proteins in high yield and purity is a major bottleneck for the analysis of their three-dimensional structure, function and interactome. Here, we present a streamlined workflow for the rapid production of proteins or protein complexes using lentiviral transduction of human suspension cells, combined with highly specific nanobody-mediated purification and proteolytic elution. Application of the method requires prior generation of a plasmid coding for a protein of interest (POI) fused to an N- or C-terminal GFP or ALFA peptide tag using a lentiviral plasmid toolkit we have designed. The plasmid is then used to generate human suspension cell lines stably expressing the tagged fusion protein by lentiviral transduction. By leveraging the picomolar affinity of the GFP and ALFA nanobodies for their respective tags, the POI can be specifically captured from the resulting cell lysate even when expressed at low levels and under a variety of conditions, including detergents and mild denaturants. Finally, rapid and specific elution of the POI (in its tagged or untagged form) under native conditions is achieved within minutes at 4 °C, using the engineered SUMO protease SENPEuB. We demonstrate the wide applicability of the method by purifying multiple challenging soluble and membrane protein complexes to high purity from human cells. Our strategy is also directly compatible with many widely used GFP-expression plasmids, cell lines and transgenic model organisms. Finally, our method is faster than alternative approaches, requiring only 8 d from plasmid to purified protein, and results in substantially improved yields and purity.
Collapse
Affiliation(s)
- Taylor Anthony Stevens
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Giovani Pinton Tomaleri
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Masami Hazu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Sophia Wei
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Vy N Nguyen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Charlene DeKalb
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Rebecca M Voorhees
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
| | - Tino Pleiner
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.
| |
Collapse
|
12
|
Logette E, Ranjan R. Ready-to-Record Cells for Kinetic Screening of VGICs. Methods Mol Biol 2024; 2796:87-95. [PMID: 38856896 DOI: 10.1007/978-1-0716-3818-7_5] [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: 06/11/2024]
Abstract
Voltage-gated ion channels (VGICs) are integral membrane proteins crucial for transmitting electrical signals in excitable cells. Understanding the kinetics of these ion channels requires conducting patch-clamp experiments using genetically modified cell lines that express a single type of ion channel gene. However, this process relies on the continuous maintenance of cell lines to ensure an adequate supply of sample cells for patch-clamp experiments. Advancements in automated patch-clamp methods have enabled researchers to significantly increase the number of patch-clamped cells per experiment, from just a few cells to as many as 384 cells. Despite this progress, the manual task of preparing the cell samples remains a significant bottleneck in the kinetic screening of VGICs. Here we describe a method to address this challenge by generating ready-to-record (RTR) VGIC-expressing cells that can be frozen and stored separately from patch-clamp experiments. This decoupling of the cell sample preparation process from the patch-clamp experiments offers a streamlined approach to studying VGICs on manual or an automated patch-clamp system.
Collapse
Affiliation(s)
- Emmanuelle Logette
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Rajnish Ranjan
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland.
| |
Collapse
|
13
|
Lee SW, Frankston CM, Kim J. Epigenome editing in cancer: Advances and challenges for potential therapeutic options. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2023; 383:191-230. [PMID: 38359969 DOI: 10.1016/bs.ircmb.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Cancers are diseases caused by genetic and non-genetic environmental factors. Epigenetic alterations, some attributed to non-genetic factors, can lead to cancer development. Epigenetic changes can occur in tumor suppressors or oncogenes, or they may contribute to global cell state changes, making cells abnormal. Recent advances in gene editing technology show potential for cancer treatment. Herein, we will discuss our current knowledge of epigenetic alterations occurring in cancer and epigenetic editing technologies that can be applied to developing therapeutic options.
Collapse
Affiliation(s)
- Seung-Won Lee
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, Portland, OR, United States; Department of Molecular and Medical Genetics, School of Medicine, Oregon Health & Science University, Portland, OR, United States
| | - Connor Mitchell Frankston
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, Portland, OR, United States; Biomedical Engineering Graduate Program, Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, OR, United States
| | - Jungsun Kim
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, Portland, OR, United States; Department of Molecular and Medical Genetics, School of Medicine, Oregon Health & Science University, Portland, OR, United States; Cancer Biology Research Program, Knight Cancer Institute, Oregon Health & Science University, Portland, OR, United States.
| |
Collapse
|
14
|
Farberov L, Weissglas-Volkov D, Shapira G, Zoabi Y, Schiff C, Kloeckener-Gruissem B, Neidhardt J, Shomron N. mRNA splicing is modulated by intronic microRNAs. iScience 2023; 26:107723. [PMID: 37692287 PMCID: PMC10492213 DOI: 10.1016/j.isci.2023.107723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 08/06/2023] [Accepted: 08/22/2023] [Indexed: 09/12/2023] Open
Abstract
Splicing of transcripts is catalyzed by the spliceosome, a mega-complex consisting of hundreds of proteins and five snRNAs, which employs direct interactions. When U1 snRNA forms high-affinity binding, namely more than eight base pairs, with the 5'SS, the result is usually a suppressing effect on the splicing activity. This likely occurs due to the inefficient unwinding of U1/5'SS base-pairing or other regulatory obstructions. Here, we show in vitro and in patient-derived cell lines that pre-microRNAs can modulate the splicing reaction by interacting with U1 snRNA. This leads to reduced binding affinity to the 5'SS, and hence promotes the inclusion of exons containing 5'SS, despite sequence-based high affinity to U1. Application of the mechanism resulted in correction of the splicing defect in the disease-causing VCAN gene from an individual with Wagner syndrome. This pre-miRNA/U1 interaction can regulate the expression of alternatively spliced exons, thus extending the scope of mechanisms regulating splicing.
Collapse
Affiliation(s)
- Luba Farberov
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Daphna Weissglas-Volkov
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Edmond J. Safra Center for Bioinformatics, Tel Aviv University, Tel Aviv, Israel
| | - Guy Shapira
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Edmond J. Safra Center for Bioinformatics, Tel Aviv University, Tel Aviv, Israel
| | - Yazeed Zoabi
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Edmond J. Safra Center for Bioinformatics, Tel Aviv University, Tel Aviv, Israel
| | - Chen Schiff
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Barbara Kloeckener-Gruissem
- Institute of Medical Molecular Genetics, University of Zurich, Zurich, Switzerland
- Department of Biology, ETHZ, Zurich, Switzerland
| | - John Neidhardt
- Human Genetics, Faculty of Medicine and Health Sciences, University of Oldenburg, Germany
- Research Center Neurosensory Science, University Oldenburg, Germany
| | - Noam Shomron
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Edmond J. Safra Center for Bioinformatics, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
15
|
Diabate M, Islam MM, Nagy G, Banerjee T, Dhar S, Smith N, Adamovich AI, Starita LM, Parvin JD. DNA repair function scores for 2172 variants in the BRCA1 amino-terminus. PLoS Genet 2023; 19:e1010739. [PMID: 37578980 PMCID: PMC10449183 DOI: 10.1371/journal.pgen.1010739] [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: 04/06/2023] [Revised: 08/24/2023] [Accepted: 07/16/2023] [Indexed: 08/16/2023] Open
Abstract
Single nucleotide variants are the most frequent type of sequence changes detected in the genome and these are frequently variants of uncertain significance (VUS). VUS are changes in DNA for which disease risk association is unknown. Thus, methods that classify the functional impact of a VUS can be used as evidence for variant interpretation. In the case of the breast and ovarian cancer specific tumor suppressor protein, BRCA1, pathogenic missense variants frequently score as loss of function in an assay for homology-directed repair (HDR) of DNA double-strand breaks. We previously published functional results using a multiplexed assay for 1056 amino acid substitutions residues 2-192 in the amino terminus of BRCA1. In this study, we have re-assessed the data from this multiplexed assay using an improved analysis pipeline. These new analysis methods yield functional scores for more variants in the first 192 amino acids of BRCA1, plus we report new results for BRCA1 amino acid residues 193-302. We now present the functional classification of 2172 BRCA1 variants in BRCA1 residues 2-302 using the multiplexed HDR assay. Comparison of the functional determinations of the missense variants with clinically known benign or pathogenic variants indicated 93% sensitivity and 100% specificity for this assay. The results from BRCA1 variants tested in this assay are a resource for clinical geneticists for evidence to evaluate VUS in BRCA1.
Collapse
Affiliation(s)
- Mariame Diabate
- The Ohio State University, Department of Biomedical Informatics, Columbus, Ohio, United States of America
- The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| | - Muhtadi M. Islam
- The Ohio State University, Department of Biomedical Informatics, Columbus, Ohio, United States of America
- The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| | - Gregory Nagy
- The Ohio State University, Department of Biomedical Informatics, Columbus, Ohio, United States of America
- The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| | - Tapahsama Banerjee
- The Ohio State University, Department of Biomedical Informatics, Columbus, Ohio, United States of America
- The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| | - Shruti Dhar
- The Ohio State University, Department of Biomedical Informatics, Columbus, Ohio, United States of America
- The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| | - Nahum Smith
- The University of Washington, Department of Genome Sciences, Seattle, Washington, United States of America
- Brotman Baty Institute for Precision Medicine, Seattle, Washington, United States of America
| | - Aleksandra I. Adamovich
- The Ohio State University, Department of Biomedical Informatics, Columbus, Ohio, United States of America
- The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| | - Lea M. Starita
- The University of Washington, Department of Genome Sciences, Seattle, Washington, United States of America
- Brotman Baty Institute for Precision Medicine, Seattle, Washington, United States of America
| | - Jeffrey D. Parvin
- The Ohio State University, Department of Biomedical Informatics, Columbus, Ohio, United States of America
- The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America
| |
Collapse
|
16
|
Wang Y, Zhang K, Zhao Y, Li Y, Su W, Li S. Construction and Applications of Mammalian Cell-Based DNA-Encoded Peptide/Protein Libraries. ACS Synth Biol 2023; 12:1874-1888. [PMID: 37315219 DOI: 10.1021/acssynbio.3c00043] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
DNA-encoded peptide/protein libraries are the starting point for protein evolutionary modification and functional peptide/antibody selection. Different display technologies, protein directed evolution, and deep mutational scanning (DMS) experiments employ DNA-encoded libraries to provide sequence variations for downstream affinity- or function-based selections. Mammalian cells promise the inherent post-translational modification and near-to-natural conformation of exogenously expressed mammalian proteins and thus are the best platform for studying transmembrane proteins or human disease-related proteins. However, due to the current technical bottlenecks of constructing mammalian cell-based large size DNA-encoded libraries, the advantages of mammalian cells as screening platforms have not been fully exploited. In this review, we summarize the current efforts in constructing DNA-encoded libraries in mammalian cells and the existing applications of these libraries in different fields.
Collapse
Affiliation(s)
- Yi Wang
- Department of Breast Cancer Pathology and Research Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Kaili Zhang
- Department of Breast Cancer Pathology and Research Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Yanjie Zhao
- Department of Breast Cancer Pathology and Research Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Yifan Li
- Department of Breast Cancer Pathology and Research Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Weijun Su
- School of Medicine, Nankai University, Tianjin 300071, China
| | - Shuai Li
- Department of Breast Cancer Pathology and Research Laboratory, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| |
Collapse
|
17
|
Huhtinen O, Salbo R, Lamminmäki U, Prince S. Selection of biophysically favorable antibody variants using a modified Flp-In CHO mammalian display platform. Front Bioeng Biotechnol 2023; 11:1170081. [PMID: 37229492 PMCID: PMC10203562 DOI: 10.3389/fbioe.2023.1170081] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 04/17/2023] [Indexed: 05/27/2023] Open
Abstract
Mammalian display enables the selection of biophysically favorable antibodies from a large IgG antibody library displayed on the plasma membrane of mammalian cells. We constructed and validated a novel mammalian display platform utilizing the commercially available Flp-In CHO cell line as a starting point. We introduced a single copy of a landing pad for Bxb1 integrase-driven recombinase-mediated cassette exchange into the FRT site of the Flp-In CHO line to facilitate the efficient single-copy integration of an antibody display cassette into the genome of the cell line. We then proceeded to demonstrate the ability of our platform to select biophysically favorable antibodies from a library of 1 × 106 displayed antibodies designed to improve the biophysical properties of bococizumab via randomization of problematic hydrophobic surface residues of the antibody. Enrichment of bococizumab variants via fluorescence-activated cell sorting selections was followed by next generation sequencing and thorough characterization of biophysical properties of 10 bococizumab variants that subsequently allowed attribution of the mutations to the biophysical properties of the antibody variants. The mammalian displayed variants exhibited reduced aggregation propensity and polyreactivity, while critically retaining its target binding thereby demonstrating the utility of this valuable tool.
Collapse
Affiliation(s)
- Olli Huhtinen
- Protein and Antibody Engineering, Orion Corporation, Turku, Finland
- Department of Life Technologies, University of Turku, Turku, Finland
| | - Rune Salbo
- Protein and Antibody Engineering, Orion Corporation, Turku, Finland
| | - Urpo Lamminmäki
- Department of Life Technologies, University of Turku, Turku, Finland
| | - Stuart Prince
- MediCity Research Laboratory, University of Turku, Turku, Finland
- Institute of Biomedicine, University of Turku, Turku, Finland
| |
Collapse
|
18
|
Diabate M, Islam MM, Nagy G, Banerjee T, Dhar S, Smith N, Adamovich AI, Starita LM, Parvin JD. DNA Repair Function Scores for 2172 Variants in the BRCA1 Amino-Terminus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.10.536331. [PMID: 37090572 PMCID: PMC10120616 DOI: 10.1101/2023.04.10.536331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Single nucleotide variants are the most frequent type of sequence changes detected in the genome and these are frequently variants of uncertain significance (VUS). VUS are changes in DNA for which disease risk association is unknown. Thus, methods that classify the functional impact of a VUS can be used as evidence for variant interpretation. In the case of the breast and ovarian cancer specific tumor suppressor protein, BRCA1, pathogenic missense variants frequently score as loss of function in an assay for homology-directed repair (HDR) of DNA double-strand breaks. We previously published functional results using a multiplexed assay for 1056 amino acid substitutions residues 2-192 in the amino terminus of BRCA1. In this study, we have re-assessed the data from this multiplexed assay using an improved analysis pipeline. These new analysis methods yield functional scores for more variants in the first 192 amino acids of BRCA1, plus we report new results for BRCA1 amino acid residues 193-302. We now present the functional classification of 2172 BRCA1 variants in BRCA1 residues 2-302 using the multiplexed HDR assay. Comparison of the functional determinations of the missense variants with clinically known benign or pathogenic variants indicated 93% sensitivity and 100% specificity for this assay. The results from BRCA1 variants tested in this assay are a resource for clinical geneticists for evidence to evaluate VUS in BRCA1 . AUTHOR SUMMARY Most missense substitutions in BRCA1 are variants of unknown significance (VUS), and individuals with a VUS in BRCA1 cannot know from genetic information alone whether this variant predisposes to breast or ovarian cancer. We apply a multiplexed functional assay for homology directed repair of DNA double strand breaks to assess variant impact on this important BRCA1 protein function. We analyzed 2172 variants in the amino-terminus of BRCA1 and demonstrate that variants that are known as pathogenic have a loss of function in the DNA repair assay. Conversely, variants that are known to be benign are functionally normal in the multiplexed assay. We suggest that these functional determinations of BRCA1 variants can be used to augment the information that clinical cancer geneticists provide to patients who have a VUS in BRCA1 .
Collapse
Affiliation(s)
- Mariame Diabate
- The Ohio State University, Department of Biomedical Informatics, and The Ohio State University Comprehensive Center, Columbus, OH 43210
| | - Muhtadi M Islam
- The Ohio State University, Department of Biomedical Informatics, and The Ohio State University Comprehensive Center, Columbus, OH 43210
| | - Gregory Nagy
- The Ohio State University, Department of Biomedical Informatics, and The Ohio State University Comprehensive Center, Columbus, OH 43210
| | - Tapahsama Banerjee
- The Ohio State University, Department of Biomedical Informatics, and The Ohio State University Comprehensive Center, Columbus, OH 43210
| | - Shruti Dhar
- The Ohio State University, Department of Biomedical Informatics, and The Ohio State University Comprehensive Center, Columbus, OH 43210
| | - Nahum Smith
- The University of Washington, Department of Genome Sciences, Seattle, WA 98195
- Brotman Baty Institute for Precision Medicine, Seattle WA, 98195
| | - Aleksandra I Adamovich
- The Ohio State University, Department of Biomedical Informatics, and The Ohio State University Comprehensive Center, Columbus, OH 43210
| | - Lea M Starita
- The University of Washington, Department of Genome Sciences, Seattle, WA 98195
- Brotman Baty Institute for Precision Medicine, Seattle WA, 98195
| | - Jeffrey D Parvin
- The Ohio State University, Department of Biomedical Informatics, and The Ohio State University Comprehensive Center, Columbus, OH 43210
| |
Collapse
|
19
|
Hu CW, Wang A, Fan D, Worth M, Chen Z, Huang J, Xie J, Macdonald J, Li L, Jiang J. Cancer-derived mutation in the OGA stalk domain promotes cell malignancy through dysregulating PDLIM7 and p53. RESEARCH SQUARE 2023:rs.3.rs-2709128. [PMID: 36993758 PMCID: PMC10055641 DOI: 10.21203/rs.3.rs-2709128/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
O-GlcNAcase (OGA) is the sole enzyme that hydrolyzes O-GlcNAcylation from thousands of proteins and is dysregulated in many diseases including cancer. However, the substrate recognition and pathogenic mechanisms of OGA remain largely unknown. Here we report the first discovery of a cancer-derived point mutation on the OGA's non-catalytic stalk domain that aberrantly regulated a small set of OGA-protein interactions and O-GlcNAc hydrolysis in critical cellular processes. We uncovered a novel cancer-promoting mechanism in which the OGA mutant preferentially hydrolyzed the O-GlcNAcylation from modified PDLIM7 and promoted cell malignancy by down-regulating p53 tumor suppressor in different types of cells through transcription inhibition and MDM2-mediated ubiquitination. Our study revealed the OGA deglycosylated PDLIM7 as a novel regulator of p53-MDM2 pathway, offered the first set of direct evidence on OGA substrate recognition beyond its catalytic site, and illuminated new directions to interrogate OGA's precise role without perturbing global O-GlcNAc homeostasis for biomedical applications.
Collapse
Affiliation(s)
| | - Ao Wang
- University of Wisconsin-Madison
| | | | | | | | | | | | | | | | - Jiaoyang Jiang
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison
| |
Collapse
|
20
|
O'Connell RW, Rai K, Piepergerdes TC, Samra KD, Wilson JA, Lin S, Zhang TH, Ramos EM, Sun A, Kille B, Curry KD, Rocks JW, Treangen TJ, Mehta P, Bashor CJ. Ultra-high throughput mapping of genetic design space. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.16.532704. [PMID: 36993481 PMCID: PMC10055055 DOI: 10.1101/2023.03.16.532704] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Massively parallel genetic screens have been used to map sequence-to-function relationships for a variety of genetic elements. However, because these approaches only interrogate short sequences, it remains challenging to perform high throughput (HT) assays on constructs containing combinations of sequence elements arranged across multi-kb length scales. Overcoming this barrier could accelerate synthetic biology; by screening diverse gene circuit designs, "composition-to-function" mappings could be created that reveal genetic part composability rules and enable rapid identification of behavior-optimized variants. Here, we introduce CLASSIC, a generalizable genetic screening platform that combines long- and short-read next-generation sequencing (NGS) modalities to quantitatively assess pooled libraries of DNA constructs of arbitrary length. We show that CLASSIC can measure expression profiles of >10 5 drug-inducible gene circuit designs (ranging from 6-9 kb) in a single experiment in human cells. Using statistical inference and machine learning (ML) approaches, we demonstrate that data obtained with CLASSIC enables predictive modeling of an entire circuit design landscape, offering critical insight into underlying design principles. Our work shows that by expanding the throughput and understanding gained with each design-build-test-learn (DBTL) cycle, CLASSIC dramatically augments the pace and scale of synthetic biology and establishes an experimental basis for data-driven design of complex genetic systems.
Collapse
|
21
|
Aggarwal N, Kitano S, Puah GRY, Kittelmann S, Hwang IY, Chang MW. Microbiome and Human Health: Current Understanding, Engineering, and Enabling Technologies. Chem Rev 2023; 123:31-72. [PMID: 36317983 PMCID: PMC9837825 DOI: 10.1021/acs.chemrev.2c00431] [Citation(s) in RCA: 54] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Indexed: 01/12/2023]
Abstract
The human microbiome is composed of a collection of dynamic microbial communities that inhabit various anatomical locations in the body. Accordingly, the coevolution of the microbiome with the host has resulted in these communities playing a profound role in promoting human health. Consequently, perturbations in the human microbiome can cause or exacerbate several diseases. In this Review, we present our current understanding of the relationship between human health and disease development, focusing on the microbiomes found across the digestive, respiratory, urinary, and reproductive systems as well as the skin. We further discuss various strategies by which the composition and function of the human microbiome can be modulated to exert a therapeutic effect on the host. Finally, we examine technologies such as multiomics approaches and cellular reprogramming of microbes that can enable significant advancements in microbiome research and engineering.
Collapse
Affiliation(s)
- Nikhil Aggarwal
- NUS
Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore 117456, Singapore
- Synthetic
Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456, Singapore
| | - Shohei Kitano
- NUS
Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore 117456, Singapore
- Synthetic
Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456, Singapore
| | - Ginette Ru Ying Puah
- NUS
Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore 117456, Singapore
- Synthetic
Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456, Singapore
- Wilmar-NUS
(WIL@NUS) Corporate Laboratory, National
University of Singapore, Singapore 117599, Singapore
- Wilmar
International Limited, Singapore 138568, Singapore
| | - Sandra Kittelmann
- Wilmar-NUS
(WIL@NUS) Corporate Laboratory, National
University of Singapore, Singapore 117599, Singapore
- Wilmar
International Limited, Singapore 138568, Singapore
| | - In Young Hwang
- NUS
Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore 117456, Singapore
- Synthetic
Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456, Singapore
- Department
of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
- Singapore
Institute of Technology, Singapore 138683, Singapore
| | - Matthew Wook Chang
- NUS
Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, Singapore 117456, Singapore
- Synthetic
Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456, Singapore
- Wilmar-NUS
(WIL@NUS) Corporate Laboratory, National
University of Singapore, Singapore 117599, Singapore
- Department
of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| |
Collapse
|
22
|
Pszenny V, Tjhin E, Alves‐Ferreira EV, Spada S, Bouamr F, Nair V, Ganesan S, Grigg ME. Using the Sleeping Beauty (SB) Transposon to Generate Stable Cells Producing Enveloped Virus-Like Particles (eVLPs) Pseudotyped with SARS-CoV-2 Proteins for Vaccination. Curr Protoc 2022; 2:e575. [PMID: 36300895 PMCID: PMC9874545 DOI: 10.1002/cpz1.575] [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] [Indexed: 11/06/2022]
Abstract
The Sleeping Beauty (SB) transposon system is an efficient non-viral tool for gene transfer into a variety of cells, including human cells. Through a cut-and-paste mechanism, your favorite gene (YFG) is integrated into AT-rich regions within the genome, providing stable long-term expression of the transfected gene. The SB system is evolving and has become a powerful tool for gene therapy. There are no safety concerns using this system, the handling is easy, and the time required to obtain a stable cell line is significantly reduced compared to other systems currently available. Here, we present a novel application of this system to generate, within 8 days, a stable producer HEK293T cell line capable of constitutively delivering enveloped virus-like particles (eVLPs) for vaccination. We provide step-by-step protocols for generation of the SB transposon constructs, transfection procedures, and validation of the produced eVLPs. We next describe a method to pseudotype the constitutively produced eVLPs using the Spike protein derived from the SARS-CoV-2 virus (by coating the eVLP capsid with the heterologous antigen). We also describe optimization methods to scale up the production of pseudotyped eVLPs in a laboratory setting (from 100 µg to 5 mg). © Published 2022. This article is a U.S. Government work and is in the public domain in the USA. Basic Protocol 1: Generation of the SB plasmids Basic Protocol 2: Generation of a stable HEK293T cell line constitutively secreting MLV-based eVLPs Basic Protocol 3: Evaluation of the SB constructs by immunofluorescence assay Basic Protocol 4: Validation of eVLPs by denaturing PAGE and western blot Alternate Protocol 1: Analysis of SARS-CoV-2 Spike protein oligomerization using blue native gel electrophoresis and western blot Alternate Protocol 2: Evaluation of eVLP quality by electron microscopy (negative staining) Basic Protocol 5: Small-scale production of eVLPs Alternate Protocol 3: Large-scale production of eVLPs (up to about 1 to 3 mg VLPs) Alternate Protocol 4: Large-scale production of eVLPs (up to about 3 to 5 mg VLPs) Support Protocol: Quantification of total protein concentration by Bradford assay.
Collapse
Affiliation(s)
- Viviana Pszenny
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMaryland
| | - Erick Tjhin
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMaryland
| | - Eliza V.C. Alves‐Ferreira
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMaryland
| | - Stephanie Spada
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMaryland
| | - Fadila Bouamr
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMaryland
| | - Vinod Nair
- Microscopy Unit, Rocky Mountain Laboratories, National Institute of Allergy and Infectious DiseasesNational Institutes of HealthHamiltonMontana
| | - Sundar Ganesan
- Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMaryland
| | - Michael E. Grigg
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMaryland
| |
Collapse
|
23
|
Yang W, Zhang J, Xiao Y, Li W, Wang T. Screening Strategies for High-Yield Chinese Hamster Ovary Cell Clones. Front Bioeng Biotechnol 2022; 10:858478. [PMID: 35782513 PMCID: PMC9247297 DOI: 10.3389/fbioe.2022.858478] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 05/23/2022] [Indexed: 12/20/2022] Open
Abstract
Chinese hamster ovary (CHO) cells are by far the most commonly used mammalian expression system for recombinant expression of therapeutic proteins in the pharmaceutical industry. The development of high-yield stable cell lines requires processes of transfection, selection, screening and adaptation, among which the screening process requires tremendous time and determines the level of forming highly productive monoclonal cell lines. Therefore, how to achieve productive cell lines is a major question prior to industrial manufacturing. Cell line development (CLD) is one of the most critical steps in the production of recombinant therapeutic proteins. Generation of high-yield cell clones is mainly based on the time-consuming, laborious process of selection and screening. With the increase in recombinant therapeutic proteins expressed by CHO cells, CLD has become a major bottleneck in obtaining cell lines for manufacturing. The basic principles for CLD include preliminary screening for high-yield cell pool, single-cell isolation and improvement of productivity, clonality and stability. With the development of modern analysis and testing technologies, various screening methods have been used for CLD to enhance the selection efficiency of high-yield clonal cells. This review provides a comprehensive overview on preliminary screening methods for high-yield cell pool based on drug selective pressure. Moreover, we focus on high throughput methods for isolating high-yield cell clones and increasing the productivity and stability, as well as new screening strategies used for the biopharmaceutical industry.
Collapse
Affiliation(s)
- Wenwen Yang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
| | - Junhe Zhang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
- Institutes of Health Central Plains, Xinxiang Medical University, Xinxiang, China
- *Correspondence: Tianyun Wang, ; Junhe Zhang,
| | - Yunxi Xiao
- Institutes of Health Central Plains, Xinxiang Medical University, Xinxiang, China
| | - Wenqing Li
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
| | - Tianyun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
- *Correspondence: Tianyun Wang, ; Junhe Zhang,
| |
Collapse
|
24
|
Multimodal detection of dopamine by sniffer cells expressing genetically encoded fluorescent sensors. Commun Biol 2022; 5:578. [PMID: 35689020 PMCID: PMC9187629 DOI: 10.1038/s42003-022-03488-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 05/13/2022] [Indexed: 12/21/2022] Open
Abstract
Dopamine supports locomotor control and higher brain functions such as motivation and learning. Consistently, dopaminergic dysfunction is involved in a spectrum of neurological and neuropsychiatric diseases. Detailed data on dopamine dynamics is needed to understand how dopamine signals translate into cellular and behavioral responses, and to uncover pathological disturbances in dopamine-related diseases. Genetically encoded fluorescent dopamine sensors have recently enabled unprecedented monitoring of dopamine dynamics in vivo. However, these sensors' utility for in vitro and ex vivo assays remains unexplored. Here, we present a blueprint for making dopamine sniffer cells for multimodal dopamine detection. We generated sniffer cell lines with inducible expression of seven different dopamine sensors and perform a head-to-head comparison of sensor properties to guide users in sensor selection. In proof-of-principle experiments, we apply the sniffer cells to record endogenous dopamine release from cultured neurons and striatal slices, and for determining tissue dopamine content. Furthermore, we use the sniffer cells to measure dopamine uptake and release via the dopamine transporter as a radiotracer free, high-throughput alternative to electrochemical- and radiotracer-based assays. Importantly, the sniffer cell framework can readily be applied to the growing list of genetically encoded fluorescent neurotransmitter sensors.
Collapse
|
25
|
McQuaid ME, Ahmed K, Tran S, Rousseau J, Shaheen R, Kernohan KD, Yuki KE, Grover P, Dreseris ES, Ahmed S, Dupuis L, Stimec J, Shago M, Al-Hassnan ZN, Tremblay R, Maass PG, Wilson MD, Grunebaum E, Boycott KM, Boisvert FM, Maddirevula S, Faqeih EA, Almanjomi F, Khan ZU, Alkuraya FS, Campeau PM, Kannu P, Campos EI, Wurtele H. Hypomorphic GINS3 variants alter DNA replication and cause Meier-Gorlin syndrome. JCI Insight 2022; 7:155648. [PMID: 35603789 PMCID: PMC9215265 DOI: 10.1172/jci.insight.155648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 04/12/2022] [Indexed: 11/17/2022] Open
Abstract
The eukaryotic CDC45/MCM2-7/GINS (CMG) helicase unwinds the DNA double helix during DNA replication. The GINS subcomplex is required for helicase activity and is, therefore, essential for DNA replication and cell viability. Here, we report the identification of 7 individuals from 5 unrelated families presenting with a Meier-Gorlin syndrome–like (MGS-like) phenotype associated with hypomorphic variants of GINS3, a gene not previously associated with this syndrome. We found that MGS-associated GINS3 variants affecting aspartic acid 24 (D24) compromised cell proliferation and caused accumulation of cells in S phase. These variants shortened the protein half-life, altered key protein interactions at the replisome, and negatively influenced DNA replication fork progression. Yeast expressing MGS-associated variants of PSF3 (the yeast GINS3 ortholog) also displayed impaired growth, S phase progression defects, and decreased Psf3 protein stability. We further showed that mouse embryos homozygous for a D24 variant presented intrauterine growth retardation and did not survive to birth, and that fibroblasts derived from these embryos displayed accelerated cellular senescence. Taken together, our findings implicate GINS3 in the pathogenesis of MGS and support the notion that hypomorphic variants identified in this gene impaired cell and organismal growth by compromising DNA replication.
Collapse
Affiliation(s)
- Mary E. McQuaid
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec, Canada
| | - Kashif Ahmed
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stephanie Tran
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | | | - Ranad Shaheen
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Kristin D. Kernohan
- CHEO Research Institute, Ottawa, Ontario, Canada
- Newborn Screening Ontario, CHEO, Ottawa, Ontario, Canada
| | - Kyoko E. Yuki
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Prerna Grover
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ema S. Dreseris
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Sameen Ahmed
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Lucie Dupuis
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jennifer Stimec
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mary Shago
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Zuhair N. Al-Hassnan
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Roch Tremblay
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec, Canada
| | - Philipp G. Maass
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Michael D. Wilson
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Eyal Grunebaum
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | - Sateesh Maddirevula
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Eissa A. Faqeih
- Section of Medical Genetics, Children’s Specialist Hospital, and
| | - Fahad Almanjomi
- Department of Pediatric Hematology and Oncology, Comprehensive Cancer Center, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Zaheer Ullah Khan
- Department of Pediatric Hematology and Oncology, Comprehensive Cancer Center, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Fowzan S. Alkuraya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | | | - Peter Kannu
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
| | - Eric I. Campos
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Hugo Wurtele
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec, Canada
- Department of Medicine, University of Montreal, Montreal, Quebec, Canada
| |
Collapse
|
26
|
Rider SD, Gadgil RY, Hitch DC, Damewood FJ, Zavada N, Shanahan M, Alhawach V, Shrestha R, Shin-Ya K, Leffak M. Stable G-quadruplex DNA structures promote replication-dependent genome instability. J Biol Chem 2022; 298:101947. [PMID: 35447109 PMCID: PMC9142560 DOI: 10.1016/j.jbc.2022.101947] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 04/12/2022] [Accepted: 04/13/2022] [Indexed: 10/27/2022] Open
Abstract
G-quadruplex (G4)-prone structures are abundant in mammalian genomes, where they have been shown to influence DNA replication, transcription, and genome stability. In this article, we constructed cells with a single ectopic homopurine/homopyrimidine repeat tract derived from the polycystic kidney disease type 1 (PKD1) locus, which is capable of forming triplex (H3) and G4 DNA structures. We show that ligand stabilization of these G4 structures results in deletions of the G4 consensus sequence, as well as kilobase deletions spanning the G4 and ectopic sites. Furthermore, we show that DNA double-strand breaks at the ectopic site are dependent on the nuclease Mus81. Hypermutagenesis during sister chromatid repair extends several kilobases from the G4 site and breaks at the G4 site resulting in microhomology-mediated translocations. To determine whether H3 or G4 structures are responsible for homopurine/homopyrimidine tract instability, we derived constructs and cell lines from the PKD1 repeat, which can only form H3 or G4 structures. Under normal growth conditions, we found that G4 cell lines lost the G4 consensus sequence early during clonal outgrowth, whereas H3 cells showed DNA instability early during outgrowth but only lost reporter gene expression after prolonged growth. Thus, both the H3 and G4 non-B conformation DNAs exhibit genomic instability, but they respond differently to endogenous replication stress. Our results show that the outcomes of replication-dependent double-strand breaks at non-B-DNAs model the instability observed in microhomology-mediated break-induced replication (BIR). Marked variability in the frequency of mutagenesis during BIR suggests possible dynamic heterogeneity in the BIR replisome.
Collapse
Affiliation(s)
- S Dean Rider
- Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, USA
| | - Rujuta Yashodhan Gadgil
- Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, USA
| | - David C Hitch
- Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, USA
| | - French J Damewood
- Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, USA
| | - Nathen Zavada
- Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, USA
| | - Matilyn Shanahan
- Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, USA
| | - Venicia Alhawach
- Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, USA
| | - Resha Shrestha
- Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, USA
| | - Kazuo Shin-Ya
- Biomedical Information Research Center, National Institute of Advanced Industrial Science and Technology, Koto-ku, Tokyo, Japan
| | - Michael Leffak
- Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, USA.
| |
Collapse
|
27
|
Herman JA, Arora S, Carter L, Zhu J, Biggins S, Paddison PJ. Functional dissection of human mitotic genes using CRISPR-Cas9 tiling screens. Genes Dev 2022; 36:495-510. [PMID: 35483740 PMCID: PMC9067404 DOI: 10.1101/gad.349319.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 04/12/2022] [Indexed: 12/03/2022]
Abstract
In this Resource/Methodology, Herman et al. developed a method that leverages CRISPR–Cas9-induced mutations across protein-coding genes for the a priori identification of functional regions at the sequence level. As a test case, they applied this method to 48 human mitotic genes, revealing hundreds of regions required for cell proliferation, including domains that were experimentally characterized, ones that were predicted based on homology, and novel ones. The identity of human protein-coding genes is well known, yet our in-depth knowledge of their molecular functions and domain architecture remains limited by shortcomings in homology-based predictions and experimental approaches focused on whole-gene depletion. To bridge this knowledge gap, we developed a method that leverages CRISPR–Cas9-induced mutations across protein-coding genes for the a priori identification of functional regions at the sequence level. As a test case, we applied this method to 48 human mitotic genes, revealing hundreds of regions required for cell proliferation, including domains that were experimentally characterized, ones that were predicted based on homology, and novel ones. We validated screen outcomes for 15 regions, including amino acids 387–402 of Mad1, which were previously uncharacterized but contribute to Mad1 kinetochore localization and chromosome segregation fidelity. Altogether, we demonstrate that CRISPR–Cas9-based tiling mutagenesis identifies key functional domains in protein-coding genes de novo, which elucidates separation of function mutants and allows functional annotation across the human proteome.
Collapse
Affiliation(s)
- Jacob A Herman
- Howard Hughes Medical Institute, Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.,Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Sonali Arora
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Lucas Carter
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Jun Zhu
- Department of Genetics and Genomic Sciences, Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Sue Biggins
- Howard Hughes Medical Institute, Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Patrick J Paddison
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| |
Collapse
|
28
|
Floxed exon (Flexon): A flexibly positioned stop cassette for recombinase-mediated conditional gene expression. Proc Natl Acad Sci U S A 2022; 119:2117451119. [PMID: 35027456 PMCID: PMC8784106 DOI: 10.1073/pnas.2117451119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2021] [Indexed: 12/15/2022] Open
Abstract
Tools that afford spatiotemporal control of gene expression are crucial for studying genes and processes in multicellular organisms. Stop cassettes consist of exogenous sequences that interrupt gene expression and flanking site-specific recombinase sites to allow for tissue-specific excision and restoration of function by expression of the cognate recombinase. We describe a stop cassette called a flexon, composed of an artificial exon flanked by artificial introns that can be flexibly positioned in a gene. We demonstrate its efficacy in Caenorhabditis elegans for lineage-specific control of gene expression and for tissue-specific RNA interference and discuss other potential uses. The Flexon approach should be feasible in any system amenable to site-specific recombination-based methods and applicable to diverse areas including development, neuroscience, and metabolism. Conditional gene expression is a powerful tool for genetic analysis of biological phenomena. In the widely used “lox-stop-lox” approach, insertion of a stop cassette consisting of a series of stop codons and polyadenylation signals flanked by lox sites into the 5′ untranslated region (UTR) of a gene prevents expression until the cassette is excised by tissue-specific expression of Cre recombinase. Although lox-stop-lox and similar approaches using other site-specific recombinases have been successfully used in many experimental systems, this design has certain limitations. Here, we describe the Floxed exon (Flexon) approach, which uses a stop cassette composed of an artificial exon flanked by artificial introns, designed to cause premature termination of translation and nonsense-mediated decay of the mRNA and allowing for flexible placement into a gene. We demonstrate its efficacy in Caenorhabditis elegans by showing that, when promoters that cause weak and/or transient cell-specific expression are used to drive Cre in combination with a gfp(flexon) transgene, strong and sustained expression of green fluorescent protein (GFP) is obtained in specific lineages. We also demonstrate its efficacy in an endogenous gene context: we inserted a flexon into the Argonaute gene rde-1 to abrogate RNA interference (RNAi), and restored RNAi tissue specifically by expression of Cre. Finally, we describe several potential additional applications of the Flexon approach, including more precise control of gene expression using intersectional methods, tissue-specific protein degradation, and generation of genetic mosaics. The Flexon approach should be feasible in any system where a site-specific recombination-based method may be applied.
Collapse
|
29
|
Rupil LL, Del Carmen Serradell M, Luján HD. Production of Oral Vaccines Based on Virus-Like Particles Pseudotyped with Protozoan-Surface Proteins. Methods Mol Biol 2022; 2410:503-537. [PMID: 34914065 DOI: 10.1007/978-1-0716-1884-4_26] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Giardia lamblia is the only known parasite that can inhabit the harsh upper gastrointestinal tract, where most of the digestive proteases are secreted. Intestinal and free-living protozoa express surface proteins containing an extraordinarily high percentage of cysteine. These cysteine-rich variant-specific surface proteins (VSPs) form a dense coat on the entire surface of Giardia trophozoites, that coat protects the parasite inside the host intestine. VSPs not only are resistant to proteolytic digestion, extreme pH and temperatures, but also stimulate host immune responses. These properties can be used to protect as well as to increase the immunogenicity of vaccine antigens for oral administration. The incorporation of VSPs onto virus-like particles bearing viral antigens allows oral administration of these vaccines, protecting the antigens from degradation and generating robust and protective immune responses. In this chapter we describe the development of this versatile vaccine platform for the generation of safe, stable, and efficient oral vaccines, including their production and validation, as well as the characterization of immune response to oral immunization.
Collapse
Affiliation(s)
- Lucía Lara Rupil
- Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas (CIDIE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Universidad Católica de Córdoba (UCC), Córdoba, Argentina
- Facultad de Ciencias de la Salud, Universidad Católica de Córdoba (UCC), Córdoba, Argentina
| | - Marianela Del Carmen Serradell
- Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas (CIDIE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Universidad Católica de Córdoba (UCC), Córdoba, Argentina
- Laboratorio de Parasitología y Micología, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba (UNC). Haya de la Torre y Medina Allende, Ciudad Universitaria, Córdoba, Argentina
| | - Hugo Daniel Luján
- Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas (CIDIE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Universidad Católica de Córdoba (UCC), Córdoba, Argentina.
- Facultad de Ciencias de la Salud, Universidad Católica de Córdoba (UCC), Córdoba, Argentina.
| |
Collapse
|
30
|
Capecchi MR. The origin and evolution of gene targeting. Dev Biol 2021; 481:179-187. [PMID: 34743970 DOI: 10.1016/j.ydbio.2021.10.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 01/07/2023]
Affiliation(s)
- Mario R Capecchi
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA.
| |
Collapse
|
31
|
Barbosa JAF, Sparapani S, Boulais J, Lodge R, Cohen ÉA. Human Immunodeficiency Virus Type 1 Vpr Mediates Degradation of APC1, a Scaffolding Component of the Anaphase-Promoting Complex/Cyclosome. J Virol 2021; 95:e0097120. [PMID: 34011540 PMCID: PMC8274603 DOI: 10.1128/jvi.00971-20] [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: 05/20/2020] [Accepted: 05/05/2021] [Indexed: 11/20/2022] Open
Abstract
HIV-1 encodes several accessory proteins-Nef, Vif, Vpr, and Vpu-whose functions are to modulate the cellular environment to favor immune evasion and viral replication. While Vpr was shown to mediate a G2/M cell cycle arrest and provide a replicative advantage during infection of myeloid cells, the mechanisms underlying these functions remain unclear. In this study, we defined HIV-1 Vpr proximity interaction network using the BioID proximity labeling approach and identified 352 potential Vpr partners/targets, including several complexes, such as the cell cycle-regulatory anaphase-promoting complex/cyclosome (APC/C). Herein, we demonstrate that both the wild type and cell cycle-defective mutants of Vpr induce the degradation of APC1, an essential APC/C scaffolding protein, and show that this activity relies on the recruitment of DCAF1 by Vpr and the presence of a functional proteasome. Vpr forms a complex with APC1, and the APC/C coactivators Cdh1 and Cdc20 are associated with these complexes. Interestingly, we found that Vpr encoded by the prototypic HIV-1 NL4.3 does not interact efficiently with APC1 and is unable to mediate its degradation as a result of a N28S-G41N amino acid substitution. In contrast, we show that APC1 degradation is a conserved feature of several primary Vpr variants from transmitted/founder virus. Functionally, Vpr-mediated APC1 degradation did not impact the ability of the protein to induce a G2 cell cycle arrest during infection of CD4+ T cells or enhance HIV-1 replication in macrophages, suggesting that this conserved activity may be important for other aspects of HIV-1 pathogenesis. IMPORTANCE The function of the Vpr accessory protein during HIV-1 infection remains poorly defined. Several cellular targets of Vpr were previously identified, but their individual degradation does not fully explain the ability of Vpr to impair the cell cycle or promote HIV-1 replication in macrophages. Here, we used the unbiased proximity labeling approach, called BioID, to further define the Vpr proximity interaction network and identified several potentially new Vpr partners/targets. We validated our approach by focusing on a cell cycle master regulator, the APC/C complex, and demonstrated that Vpr mediated the degradation of a critical scaffolding component of APC/C called APC1. Furthermore, we showed that targeting of APC/C by Vpr did not impact the known activity of Vpr. Since degradation of APC1 is a conserved feature of several primary variants of Vpr, it is likely that the interplay between Vpr and APC/C governs other aspects of HIV-1 pathogenesis.
Collapse
Affiliation(s)
| | | | | | - Robert Lodge
- Montreal Clinical Research Institute, Montréal, Québec, Canada
| | - Éric A. Cohen
- Montreal Clinical Research Institute, Montréal, Québec, Canada
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montréal, Québec, Canada
| |
Collapse
|
32
|
Popp AP, Hettich J, Gebhardt J. Altering transcription factor binding reveals comprehensive transcriptional kinetics of a basic gene. Nucleic Acids Res 2021; 49:6249-6266. [PMID: 34060631 PMCID: PMC8216454 DOI: 10.1093/nar/gkab443] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 05/03/2021] [Accepted: 05/06/2021] [Indexed: 12/17/2022] Open
Abstract
Transcription is a vital process activated by transcription factor (TF) binding. The active gene releases a burst of transcripts before turning inactive again. While the basic course of transcription is well understood, it is unclear how binding of a TF affects the frequency, duration and size of a transcriptional burst. We systematically varied the residence time and concentration of a synthetic TF and characterized the transcription of a synthetic reporter gene by combining single molecule imaging, single molecule RNA-FISH, live transcript visualisation and analysis with a novel algorithm, Burst Inference from mRNA Distributions (BIRD). For this well-defined system, we found that TF binding solely affected burst frequency and variations in TF residence time had a stronger influence than variations in concentration. This enabled us to device a model of gene transcription, in which TF binding triggers multiple successive steps before the gene transits to the active state and actual mRNA synthesis is decoupled from TF presence. We quantified all transition times of the TF and the gene, including the TF search time and the delay between TF binding and the onset of transcription. Our quantitative measurements and analysis revealed detailed kinetic insight, which may serve as basis for a bottom-up understanding of gene regulation.
Collapse
Affiliation(s)
- Achim P Popp
- Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Johannes Hettich
- Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - J Christof M Gebhardt
- Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| |
Collapse
|
33
|
Tan ZZ, Li XD, Kong CD, Sha N, Hou YN, Zhao KH. Engineering Bacteria to Monitor the Bleeding of Animals Using Far-Red Fluorescence. ACS Sens 2021; 6:1770-1778. [PMID: 33978416 DOI: 10.1021/acssensors.0c02482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Microorganisms living in animals can function as drug delivery systems or as detectors for some diseases. Here, we developed a biosensor constructed by the deletion of hemF and harboring ho1, chuA, and bdfp1.6 in Escherichia coli. HemF is an enzyme involved in heme synthesis in E. coli. ChuA and HO1 can transfer extracellular heme into cells and generate biliverdin (BV). BDFP1.6 can bind BV autocatalytically, and it emits a far-red fluorescence signal at 667 nm. Therefore, we named this biosensor as the far-red light for bleeding detector (FRLBD). Our results indicated that the FRLBD was highly efficient and specific for detecting heme or blood in vitro. Moreover, the FRLBD could be used to detect bleeding in the zebrafish induced by aspirin, and a convolutional neural network was an appropriate model to identify the fluorescence features in the images.
Collapse
Affiliation(s)
- Zi-Zhu Tan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Xiao-Dan Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Chao-Di Kong
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Na Sha
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Ya-Nan Hou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Kai-Hong Zhao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| |
Collapse
|
34
|
Single-molecule FRET imaging of GPCR dimers in living cells. Nat Methods 2021; 18:397-405. [PMID: 33686301 PMCID: PMC8232828 DOI: 10.1038/s41592-021-01081-y] [Citation(s) in RCA: 101] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 01/29/2021] [Indexed: 12/18/2022]
Abstract
Class C G protein-coupled receptors (GPCRs) are known to form stable homodimers or heterodimers critical for function, but the oligomeric status of class A and B receptors, which constitute >90% of all GPCRs, remains hotly debated. Single-molecule fluorescence resonance energy transfer (smFRET) is a powerful approach with the potential to reveal valuable insights into GPCR organization but has rarely been used in living cells to study protein systems. Here, we report generally applicable methods for using smFRET to detect and track transmembrane proteins diffusing within the plasma membrane of mammalian cells. We leverage this in-cell smFRET approach to show agonist-induced structural dynamics within individual metabotropic glutamate receptor dimers. We apply these methods to representative class A, B and C receptors, finding evidence for receptor monomers, density-dependent dimers and constitutive dimers, respectively.
Collapse
|
35
|
Herman JA, Miller MP, Biggins S. chTOG is a conserved mitotic error correction factor. eLife 2020; 9:e61773. [PMID: 33377866 PMCID: PMC7773332 DOI: 10.7554/elife.61773] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 12/22/2020] [Indexed: 12/28/2022] Open
Abstract
Accurate chromosome segregation requires kinetochores on duplicated chromatids to biorient by attaching to dynamic microtubules from opposite spindle poles, which exerts forces to bring kinetochores under tension. However, kinetochores initially bind to microtubules indiscriminately, resulting in errors that must be corrected. While the Aurora B protein kinase destabilizes low-tension attachments by phosphorylating kinetochores, low-tension attachments are intrinsically less stable than those under higher tension in vitro independent of Aurora activity. Intrinsic tension-sensitive behavior requires the microtubule regulator Stu2 (budding yeast Dis1/XMAP215 ortholog), which we demonstrate here is likely a conserved function for the TOG protein family. The human TOG protein, chTOG, localizes to kinetochores independent of microtubules by interacting with Hec1. We identify a chTOG mutant that regulates microtubule dynamics but accumulates erroneous kinetochore-microtubule attachments that are not destabilized by Aurora B. Thus, TOG proteins confer a unique, intrinsic error correction activity to kinetochores that ensures accurate chromosome segregation.
Collapse
Affiliation(s)
- Jacob A Herman
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research CenterSeattleUnited States
| | - Matthew P Miller
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research CenterSeattleUnited States
| | - Sue Biggins
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research CenterSeattleUnited States
| |
Collapse
|
36
|
Hoser SM, Hoffmann A, Meindl A, Gamper M, Fallmann J, Bernhart SH, Müller L, Ploner M, Misslinger M, Kremser L, Lindner H, Geley S, Schaal H, Stadler PF, Huettenhofer A. Intronic tRNAs of mitochondrial origin regulate constitutive and alternative splicing. Genome Biol 2020; 21:299. [PMID: 33292386 PMCID: PMC7722341 DOI: 10.1186/s13059-020-02199-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 11/09/2020] [Indexed: 02/19/2023] Open
Abstract
BACKGROUND The presence of nuclear mitochondrial DNA (numtDNA) has been reported within several nuclear genomes. Next to mitochondrial protein-coding genes, numtDNA sequences also encode for mitochondrial tRNA genes. However, the biological roles of numtDNA remain elusive. RESULTS Employing in silico analysis, we identify 281 mitochondrial tRNA homologs in the human genome, which we term nimtRNAs (nuclear intronic mitochondrial-derived tRNAs), being contained within introns of 76 nuclear host genes. Despite base changes in nimtRNAs when compared to their mtRNA homologs, a canonical tRNA cloverleaf structure is maintained. To address potential functions of intronic nimtRNAs, we insert them into introns of constitutive and alternative splicing reporters and demonstrate that nimtRNAs promote pre-mRNA splicing, dependent on the number and positioning of nimtRNA genes and splice site recognition efficiency. A mutational analysis reveals that the nimtRNA cloverleaf structure is required for the observed splicing increase. Utilizing a CRISPR/Cas9 approach, we show that a partial deletion of a single endogenous nimtRNALys within intron 28 of the PPFIBP1 gene decreases inclusion of the downstream-located exon 29 of the PPFIBP1 mRNA. By employing a pull-down approach followed by mass spectrometry, a 3'-splice site-associated protein network is identified, including KHDRBS1, which we show directly interacts with nimtRNATyr by an electrophoretic mobility shift assay. CONCLUSIONS We propose that nimtRNAs, along with associated protein factors, can act as a novel class of intronic splicing regulatory elements in the human genome by participating in the regulation of splicing.
Collapse
Affiliation(s)
- Simon M Hoser
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020, Innsbruck, Austria.
| | - Anne Hoffmann
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Philipp-Rosenthal-Str. 27, 04103, Leipzig, Germany
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, 04107, Leipzig, Germany
| | - Andreas Meindl
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020, Innsbruck, Austria
| | - Maximilian Gamper
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020, Innsbruck, Austria
| | - Jörg Fallmann
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, 04107, Leipzig, Germany
| | - Stephan H Bernhart
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, 04107, Leipzig, Germany
| | - Lisa Müller
- Institute for Virology, Medical Faculty Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Melanie Ploner
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020, Innsbruck, Austria
| | - Matthias Misslinger
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Leopold Kremser
- Division of Clinical Biochemistry, Protein Micro-Analysis Facility, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Herbert Lindner
- Division of Clinical Biochemistry, Protein Micro-Analysis Facility, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Stephan Geley
- Institute of Pathophysiology, Biocenter, Medical University of Innsbruck, 6020, Innsbruck, Austria
| | - Heiner Schaal
- Institute for Virology, Medical Faculty Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, 04107, Leipzig, Germany
- Max Planck Institute for Mathematics in the Sciences, Inselstraße 22, 04103, Leipzig, Germany
| | - Alexander Huettenhofer
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020, Innsbruck, Austria.
| |
Collapse
|
37
|
Watts LP, Natsume T, Saito Y, Garzon J, Dong Q, Boteva L, Gilbert N, Kanemaki MT, Hiraga SI, Donaldson AD. The RIF1-long splice variant promotes G1 phase 53BP1 nuclear bodies to protect against replication stress. eLife 2020; 9:e58020. [PMID: 33141022 PMCID: PMC7671687 DOI: 10.7554/elife.58020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 11/02/2020] [Indexed: 12/13/2022] Open
Abstract
Human cells lacking RIF1 are highly sensitive to replication inhibitors, but the reasons for this sensitivity have been enigmatic. Here, we show that RIF1 must be present both during replication stress and in the ensuing recovery period to promote cell survival. Of two isoforms produced by alternative splicing, we find that RIF1-Long alone can protect cells against replication inhibition, but RIF1-Short is incapable of mediating protection. Consistent with this isoform-specific role, RIF1-Long is required to promote the formation of the 53BP1 nuclear bodies that protect unrepaired damage sites in the G1 phase following replication stress. Overall, our observations show that RIF1 is needed at several cell cycle stages after replication insult, with the RIF1-Long isoform playing a specific role during the ensuing G1 phase in damage site protection.
Collapse
Affiliation(s)
- Lotte P Watts
- Institute of Medical Sciences, University of AberdeenAberdeenUnited Kingdom
| | - Toyoaki Natsume
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS)MishimaJapan
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI)MishimaJapan
| | - Yuichiro Saito
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS)MishimaJapan
| | - Javier Garzon
- Institute of Medical Sciences, University of AberdeenAberdeenUnited Kingdom
| | - Qianqian Dong
- Institute of Medical Sciences, University of AberdeenAberdeenUnited Kingdom
| | - Lora Boteva
- MRC Human Genetics Unit, The University of EdinburghEdinburghUnited Kingdom
| | - Nick Gilbert
- MRC Human Genetics Unit, The University of EdinburghEdinburghUnited Kingdom
| | - Masato T Kanemaki
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS)MishimaJapan
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI)MishimaJapan
| | - Shin-ichiro Hiraga
- Institute of Medical Sciences, University of AberdeenAberdeenUnited Kingdom
| | - Anne D Donaldson
- Institute of Medical Sciences, University of AberdeenAberdeenUnited Kingdom
| |
Collapse
|
38
|
Voziyanova E, Li F, Shah R, Voziyanov Y. Genome targeting by hybrid Flp-TAL recombinases. Sci Rep 2020; 10:17479. [PMID: 33060660 PMCID: PMC7562724 DOI: 10.1038/s41598-020-74474-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 09/08/2020] [Indexed: 11/09/2022] Open
Abstract
Genome engineering is a rapidly evolving field that benefits from the availability of different tools that can be used to perform genome manipulation tasks. We describe here the development of the Flp-TAL recombinases that can target genomic FRT-like sequences in their native chromosomal locations. Flp-TAL recombinases are hybrid enzymes that are composed of two functional modules: a variant of site-specific tyrosine recombinase Flp, which can have either narrow or broad target specificity, and the DNA-binding domain of the transcription activator-like effector, TAL. In Flp-TAL, the TAL module is responsible for delivering and stabilizing the Flp module onto the desired genomic FRT-like sequence where the Flp module mediates recombination. We demonstrate the functionality of the Flp-TAL recombinases by performing integration and deletion experiments in human HEK-293 cells. In the integration experiments we targeted a vector to three genomic FRT-like sequences located in the β-globin locus. In the deletion experiments we excised ~ 15 kilobases of DNA that contained a fragment of the integrated vector sequence and the neighboring genome sequence. On average, the efficiency of the integration and deletion reactions was about 0.1% and 20%, respectively.
Collapse
Affiliation(s)
- Eugenia Voziyanova
- School of Biological Sciences, Louisiana Tech University, 1 Adams Blvd., Ruston, LA, 71272, USA
| | - Feng Li
- School of Biological Sciences, Louisiana Tech University, 1 Adams Blvd., Ruston, LA, 71272, USA
| | - Riddhi Shah
- Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Yuri Voziyanov
- School of Biological Sciences, Louisiana Tech University, 1 Adams Blvd., Ruston, LA, 71272, USA.
| |
Collapse
|
39
|
The XPO6 Exportin Mediates Herpes Simplex Virus 1 gM Nuclear Release Late in Infection. J Virol 2020; 94:JVI.00753-20. [PMID: 32817212 DOI: 10.1128/jvi.00753-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 08/07/2020] [Indexed: 12/19/2022] Open
Abstract
The glycoprotein M of herpes simplex virus 1 (HSV-1) is dynamically relocated from nuclear membranes to the trans-Golgi network (TGN) during infection, but molecular partners that promote this relocalization are unknown. Furthermore, while the presence of the virus is essential for this phenomenon, it is not clear if this is facilitated by viral or host proteins. Past attempts to characterize glycoprotein M (gM) interacting partners identified the viral protein gN by coimmunoprecipitation and the host protein E-Syt1 through a proteomics approach. Interestingly, both proteins modulate the activity of gM on the viral fusion machinery. However, neither protein is targeted to the nuclear membrane and consequently unlikely explains the dynamic regulation of gM nuclear localization. We thus reasoned that gM may transiently interact with other molecules. To resolve this issue, we opted for a proximity-dependent biotin identification (BioID) proteomics approach by tagging gM with a BirA* biotinylation enzyme and purifying BirA substrates on a streptavidin column followed by mass spectrometry analysis. The data identified gM and 170 other proteins that specifically and reproducibly were labeled by tagged gM at 4 or 12 h postinfection. Surprisingly, 35% of these cellular proteins are implicated in protein transport. Upon testing select candidate proteins, we discovered that XPO6, an exportin, is required for gM to be released from the nucleus toward the TGN. This is the first indication of a host or viral protein that modulates the presence of HSV-1 gM on nuclear membranes.IMPORTANCE The mechanisms that enable integral proteins to be targeted to the inner nuclear membrane are poorly understood. Herpes simplex virus 1 (HSV-1) glycoprotein M (gM) is an interesting candidate, as it is dynamically relocalized from nuclear envelopes to the trans-Golgi network (TGN) in a virus- and time-dependent fashion. However, it was, until now, unclear how gM was directed to the nucleus or evaded that compartment later on. Through a proteomic study relying on a proximity-ligation assay, we identified several novel gM interacting partners, many of which are involved in vesicular transport. Analysis of select proteins revealed that XPO6 is required for gM to leave the nuclear membranes late in the infection. This was unexpected, as XPO6 is an exportin specifically associated with actin/profilin nuclear export. This raises some very interesting questions about the interaction of HSV-1 with the exportin machinery and the cargo specificity of XPO6.
Collapse
|
40
|
Le HP, Ma X, Vaquero J, Brinkmeyer M, Guo F, Heyer WD, Liu J. DSS1 and ssDNA regulate oligomerization of BRCA2. Nucleic Acids Res 2020; 48:7818-7833. [PMID: 32609828 PMCID: PMC7641332 DOI: 10.1093/nar/gkaa555] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 06/16/2020] [Accepted: 06/19/2020] [Indexed: 01/27/2023] Open
Abstract
The tumor suppressor BRCA2 plays a key role in initiating homologous recombination by facilitating RAD51 filament formation on single-stranded DNA. The small acidic protein DSS1 is a crucial partner to BRCA2 in this process. In vitro and in cells (1,2), BRCA2 associates into oligomeric complexes besides also existing as monomers. A dimeric structure was further characterized by electron microscopic analysis (3), but the functional significance of the different BRCA2 assemblies remains to be determined. Here, we used biochemistry and electron microscopic imaging to demonstrate that the multimerization of BRCA2 is counteracted by DSS1 and ssDNA. When validating the findings, we identified three self-interacting regions and two types of self-association, the N-to-C terminal and the N-to-N terminal interactions. The N-to-C terminal self-interaction of BRCA2 is sensitive to DSS1 and ssDNA. The N-to-N terminal self-interaction is modulated by ssDNA. Our results define a novel role of DSS1 to regulate BRCA2 in an RPA-independent fashion. Since DSS1 is required for BRCA2 function in recombination, we speculate that the monomeric and oligomeric forms of BRCA2 might be active for different cellular events in recombinational DNA repair and replication fork stabilization.
Collapse
Affiliation(s)
- Hang Phuong Le
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616-8665, USA
| | - Xiaoyan Ma
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616-8665, USA
| | - Jorge Vaquero
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616-8665, USA
| | - Megan Brinkmeyer
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616-8665, USA
| | - Fei Guo
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616-8665, USA
| | - Wolf-Dietrich Heyer
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616-8665, USA.,Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616-8665, USA
| | - Jie Liu
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616-8665, USA
| |
Collapse
|
41
|
Sergeeva D, Lee GM, Nielsen LK, Grav LM. Multicopy Targeted Integration for Accelerated Development of High-Producing Chinese Hamster Ovary Cells. ACS Synth Biol 2020; 9:2546-2561. [PMID: 32835482 DOI: 10.1021/acssynbio.0c00322] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The ever-growing biopharmaceutical industry relies on the production of recombinant therapeutic proteins in Chinese hamster ovary (CHO) cells. The traditional timelines of CHO cell line development can be significantly shortened by the use of targeted gene integration (TI). However, broad use of TI has been limited due to the low specific productivity (qP) of TI-generated clones. Here, we show a 10-fold increase in the qP of therapeutic glycoproteins in CHO cells through the development and optimization of a multicopy TI method. We used a recombinase-mediated cassette exchange (RMCE) platform to investigate the effect of gene copy number, 5' and 3' gene regulatory elements, and landing pad features on qP. We evaluated the limitations of multicopy expression from a single genomic site as well as multiple genomic sites and found that a transcriptional bottleneck can appear with an increase in gene dosage. We created a dual-RMCE system for simultaneous multicopy TI in two genomic sites and generated isogenic high-producing clones with qP of 12-14 pg/cell/day and product titer close to 1 g/L in fed-batch. Our study provides an extensive characterization of the multicopy TI method and elucidates the relationship between gene copy number and protein expression in mammalian cells. Moreover, it demonstrates that TI-generated CHO cells are capable of producing therapeutic proteins at levels that can support their industrial manufacture.
Collapse
Affiliation(s)
- Daria Sergeeva
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
| | - Gyun Min Lee
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Lars Keld Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane 4072, Australia
| | - Lise Marie Grav
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
| |
Collapse
|
42
|
Gadgil RY, Romer EJ, Goodman CC, Rider SD, Damewood FJ, Barthelemy JR, Shin-Ya K, Hanenberg H, Leffak M. Replication stress at microsatellites causes DNA double-strand breaks and break-induced replication. J Biol Chem 2020; 295:15378-15397. [PMID: 32873711 DOI: 10.1074/jbc.ra120.013495] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 08/23/2020] [Indexed: 12/12/2022] Open
Abstract
Short tandemly repeated DNA sequences, termed microsatellites, are abundant in the human genome. These microsatellites exhibit length instability and susceptibility to DNA double-strand breaks (DSBs) due to their tendency to form stable non-B DNA structures. Replication-dependent microsatellite DSBs are linked to genome instability signatures in human developmental diseases and cancers. To probe the causes and consequences of microsatellite DSBs, we designed a dual-fluorescence reporter system to detect DSBs at expanded (CTG/CAG) n and polypurine/polypyrimidine (Pu/Py) mirror repeat structures alongside the c-myc replication origin integrated at a single ectopic chromosomal site. Restriction cleavage near the (CTG/CAG)100 microsatellite leads to homology-directed single-strand annealing between flanking AluY elements and reporter gene deletion that can be detected by flow cytometry. However, in the absence of restriction cleavage, endogenous and exogenous replication stressors induce DSBs at the (CTG/CAG)100 and Pu/Py microsatellites. DSBs map to a narrow region at the downstream edge of the (CTG)100 lagging-strand template. (CTG/CAG) n chromosome fragility is repeat length-dependent, whereas instability at the (Pu/Py) microsatellites depends on replication polarity. Strikingly, restriction-generated DSBs and replication-dependent DSBs are not repaired by the same mechanism. Knockdown of DNA damage response proteins increases (Rad18, polymerase (Pol) η, Pol κ) or decreases (Mus81) the sensitivity of the (CTG/CAG)100 microsatellites to replication stress. Replication stress and DSBs at the ectopic (CTG/CAG)100 microsatellite lead to break-induced replication and high-frequency mutagenesis at a flanking thymidine kinase gene. Our results show that non-B structure-prone microsatellites are susceptible to replication-dependent DSBs that cause genome instability.
Collapse
Affiliation(s)
- Rujuta Yashodhan Gadgil
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - Eric J Romer
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - Caitlin C Goodman
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - S Dean Rider
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - French J Damewood
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - Joanna R Barthelemy
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - Kazuo Shin-Ya
- Biomedical Information Research Center, National Institute of Advanced Industrial Science and Technology, Tokyo, Japan
| | - Helmut Hanenberg
- Department of Otorhinolaryngology and Head/Neck Surgery, Heinrich Heine University, Düsseldorf, Germany; Department of Pediatrics III, University Children's Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Michael Leffak
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA.
| |
Collapse
|
43
|
Jensen O, Ansari S, Gebauer L, Müller SF, Lowjaga KAAT, Geyer J, Tzvetkov MV, Brockmöller J. A double-Flp-in method for stable overexpression of two genes. Sci Rep 2020; 10:14018. [PMID: 32820202 PMCID: PMC7441062 DOI: 10.1038/s41598-020-71051-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/30/2020] [Indexed: 12/29/2022] Open
Abstract
Overexpression of single genes in mammalian cells is widely used to investigate protein function in basic and applied biosciences and in drug research. A better understanding of interactions of two proteins is an important next step in the advancement of our understanding of complex biological systems. However, simultaneous and robust overexpression of two or more genes is challenging. The Flp-In system integrates a vector into cell lines at a specific genomic locus, but has not been used for integration of more than one gene. Here we present a modification of the Flp-In system that enables the simultaneous targeted integration of two genes. We describe the modification and generation of the vectors required and give the complete protocol for transfection and validation of correct genomic integration and expression. We also provide results on the stability and reproducibility, and we functionally validated this approach with a pharmacologically relevant combination of a membrane transporter facilitating drug uptake and an enzyme mediating drug metabolism.
Collapse
Affiliation(s)
- Ole Jensen
- Institute of Clinical Pharmacology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany.
| | - Salim Ansari
- Institute of Clinical Pharmacology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Lukas Gebauer
- Institute of Clinical Pharmacology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Simon F Müller
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, 35392, Giessen, Germany
| | - Kira A A T Lowjaga
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, 35392, Giessen, Germany
| | - Joachim Geyer
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, 35392, Giessen, Germany
| | - Mladen V Tzvetkov
- Institute of Clinical Pharmacology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,Institute of Pharmacology, Center of Drug Absorption and Transport (C_DAT), University Medical Center Greifswald, 17489, Greifswald, Germany
| | - Jürgen Brockmöller
- Institute of Clinical Pharmacology, University Medical Center Göttingen, Georg-August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| |
Collapse
|
44
|
Efficient Transgenesis in Caenorhabditis elegans Using Flp Recombinase-Mediated Cassette Exchange. Genetics 2020; 215:903-921. [PMID: 32513816 DOI: 10.1534/genetics.120.303388] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 05/01/2020] [Indexed: 11/18/2022] Open
Abstract
The application of CRISPR technology has greatly facilitated the creation of transgenic Caenorhabditis elegans lines. However, methods to insert multi-kilobase DNA constructs remain laborious even with these advances. Here, I describe a new approach for introducing large DNA constructs into the C. elegans genome at specific sites using a combination of Flp and Cre recombinases. The system utilizes specialized integrated landing sites that express GFP ubiquitously flanked by single loxP, FRT, and FRT3 sites. DNA sequences of interest are inserted into an integration vector that contains a sqt-1 self-excising cassette and FRT and FRT3 sites. Plasmid DNA is injected into the germline of landing site animals. Transgenic animals are identified as Rol progeny, and the sqt-1 marker is subsequently excised with heat shock Cre expression. Integration events were obtained at a rate of approximately one integration per three injected F0 animals-a rate substantially higher than any current approach. To demonstrate the robustness of the approach, I compared the efficiency of the Gal4/UAS, QF (and QF2)/QUAS, tetR(and rtetR)/tetO, and LexA/lexO bipartite expression systems by assessing expression levels in combinations of driver and reporter GFP constructs and a direct promoter GFP fusion each integrated at multiple sites in the genome. My data demonstrate that all four bipartite systems are functional in C. elegans Although the new integration system has several limitations, it greatly reduces the effort required to create single-copy insertions at defined sites in the C. elegans genome.
Collapse
|
45
|
Dobner J, Simons IM, Rufinatscha K, Hänsch S, Schwarten M, Weiergräber OH, Abdollahzadeh I, Gensch T, Bode JG, Hoffmann S, Willbold D. Deficiency of GABARAP but not its Paralogs Causes Enhanced EGF-induced EGFR Degradation. Cells 2020; 9:E1296. [PMID: 32456010 PMCID: PMC7291022 DOI: 10.3390/cells9051296] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 12/20/2022] Open
Abstract
The γ-aminobutyric acid type A receptor-associated protein (GABARAP) and its close paralogs GABARAPL1 and GABARAPL2 constitute a subfamily of the autophagy-related 8 (Atg8) protein family. Being associated with a variety of dynamic membranous structures of autophagic and non-autophagic origin, Atg8 proteins functionalize membranes by either serving as docking sites for other proteins or by acting as membrane tethers or adhesion factors. In this study, we describe that deficiency for GABARAP alone, but not for its close paralogs, is sufficient for accelerated EGF receptor (EGFR) degradation in response to EGF, which is accompanied by the downregulation of EGFR-mediated MAPK signaling, altered target gene expression, EGF uptake, and EGF vesicle composition over time. We further show that GABARAP and EGFR converge in the same distinct compartments at endogenous GABARAP expression levels in response to EGF stimulation. Furthermore, GABARAP associates with EGFR in living cells and binds to synthetic peptides that are derived from the EGFR cytoplasmic tail in vitro. Thus, our data strongly indicate a unique and novel role for GABARAP during EGFR trafficking.
Collapse
Affiliation(s)
- Jochen Dobner
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (J.D.); (I.M.S.)
| | - Indra M. Simons
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (J.D.); (I.M.S.)
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| | - Kerstin Rufinatscha
- Department of Gastroenterology, Hepatology and Infectiology, University Hospital, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (K.R.); (J.G.B.)
| | - Sebastian Hänsch
- Department of Biology, Center for Advanced Imaging (CAi), Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany;
| | - Melanie Schwarten
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| | - Oliver H. Weiergräber
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| | - Iman Abdollahzadeh
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
- Institute of Biological Information Processing: Molecular and Cell Physiology (IBI-1), Forschungszentrum Jülich, 52425 Jülich, Germany;
| | - Thomas Gensch
- Institute of Biological Information Processing: Molecular and Cell Physiology (IBI-1), Forschungszentrum Jülich, 52425 Jülich, Germany;
| | - Johannes G. Bode
- Department of Gastroenterology, Hepatology and Infectiology, University Hospital, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (K.R.); (J.G.B.)
| | - Silke Hoffmann
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| | - Dieter Willbold
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (J.D.); (I.M.S.)
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| |
Collapse
|
46
|
Erdogan M, Fabritius A, Basquin J, Griesbeck O. Targeted In Situ Protein Diversification and Intra-organelle Validation in Mammalian Cells. Cell Chem Biol 2020; 27:610-621.e5. [PMID: 32142629 DOI: 10.1016/j.chembiol.2020.02.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 12/22/2019] [Accepted: 02/14/2020] [Indexed: 02/08/2023]
Abstract
Engineered proteins must be phenotypically selected for function in the appropriate physiological context. Here, we present a versatile approach that allows generating panels of mammalian cells that express diversified heterologous protein libraries in the cytosol or subcellular compartments under stable conditions and in a single-variant-per-cell manner. To this end we adapt CRISPR/Cas9 editing technology to diversify targeted stretches of a protein of interest in situ. We demonstrate the utility of the approach by in situ engineering and intra-lysosome specific selection of an extremely pH-resistant long Stokes shift red fluorescent protein variant. Tailoring properties to specific conditions of cellular sub-compartments or organelles of mammalian cells can be an important asset to optimize various proteins, protein-based tools, and biosensors for distinct functions.
Collapse
Affiliation(s)
- Mutlu Erdogan
- Tools for Bio-Imaging, Max-Planck-Institut für Neurobiologie, Am Klopferspitz 18, Martinsried 82152, Germany
| | - Arne Fabritius
- Tools for Bio-Imaging, Max-Planck-Institut für Neurobiologie, Am Klopferspitz 18, Martinsried 82152, Germany
| | - Jérome Basquin
- Structural Cell Biology, Max-Planck-Institut für Biochemie, Am Klopferspitz 18, Martinsried 82152, Germany
| | - Oliver Griesbeck
- Tools for Bio-Imaging, Max-Planck-Institut für Neurobiologie, Am Klopferspitz 18, Martinsried 82152, Germany.
| |
Collapse
|
47
|
Xu Y, Liu R, Leu NA, Zhang L, Ibragmova I, Schultz DC, Wang PJ. A cell-based high-content screen identifies isocotoin as a small molecule inhibitor of the meiosis-specific MEIOB-SPATA22 complex†. Biol Reprod 2020; 103:333-342. [PMID: 32463099 PMCID: PMC7523692 DOI: 10.1093/biolre/ioaa062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/06/2020] [Accepted: 04/22/2020] [Indexed: 01/17/2023] Open
Abstract
MEIOB and SPATA22 are meiosis-specific proteins, interact with each other, and are essential for meiotic recombination and fertility. Aspartic acid 383 (D383) in MEIOB is critical for its interaction with SPATA22 in biochemical studies. Here we report that genetic studies validate the requirement of D383 for the function of MEIOB in mice. The MeiobD383A/D383A mice display meiotic arrest due to depletion of both MEIOB and SPATA22 proteins in the testes. We developed a cell-based bimolecular fluorescence complementation (BiFC) assay, in which MEIOB and SPATA22 are fused to split YFP moieties and their co-expression in cultured cells leads to the MEIOB–SPATA22 dimerization and reconstitution of the fluorophore. As expected, the interaction-disrupting D383A substitution results in the absence of YFP fluorescence in the BiFC assay. A high-throughput screen of small molecule libraries identified candidate hit compounds at a rate of 0.7%. Isocotoin, a hit compound from the natural product library, inhibits the MEIOB–SPATA22 interaction and promotes their degradation in HEK293 cells in a dose-dependent manner. Therefore, the BiFC assay can be employed to screen for small molecule inhibitors that disrupt protein–protein interactions or promote degradation of meiosis-specific proteins.
Collapse
Affiliation(s)
- Yang Xu
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
| | - Rong Liu
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA.,School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei Province, China
| | - N Adrian Leu
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
| | - Lei Zhang
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
| | - Ilsiya Ibragmova
- High-Throughput Screening Core, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - David C Schultz
- High-Throughput Screening Core, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - P Jeremy Wang
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
| |
Collapse
|
48
|
Huang C, Foster SR, Shah AD, Kleifeld O, Canals M, Schittenhelm RB, Stone MJ. Phosphoproteomic characterization of the signaling network resulting from activation of the chemokine receptor CCR2. J Biol Chem 2020; 295:6518-6531. [PMID: 32241914 DOI: 10.1074/jbc.ra119.012026] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 03/19/2020] [Indexed: 12/13/2022] Open
Abstract
Leukocyte recruitment is a universal feature of tissue inflammation and regulated by the interactions of chemokines with their G protein-coupled receptors. Activation of CC chemokine receptor 2 (CCR2) by its cognate chemokine ligands, including CC chemokine ligand 2 (CCL2), plays a central role in recruitment of monocytes in several inflammatory diseases. In this study, we used phosphoproteomics to conduct an unbiased characterization of the signaling network resulting from CCL2 activation of CCR2. Using data-independent acquisition MS analysis, we quantified both the proteome and phosphoproteome in FlpIn-HEK293T cells stably expressing CCR2 at six time points after activation with CCL2. Differential expression analysis identified 699 significantly regulated phosphorylation sites on 441 proteins. As expected, many of these proteins are known to participate in canonical signal transduction pathways and in the regulation of actin cytoskeleton dynamics, including numerous guanine nucleotide exchange factors and GTPase-activating proteins. Moreover, we identified regulated phosphorylation sites in numerous proteins that function in the nucleus, including several constituents of the nuclear pore complex. The results of this study provide an unprecedented level of detail of CCR2 signaling and identify potential targets for regulation of CCR2 function.
Collapse
Affiliation(s)
- Cheng Huang
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia.,Monash Proteomics and Metabolomics Facility, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
| | - Simon R Foster
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
| | - Anup D Shah
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia.,Monash Proteomics and Metabolomics Facility, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia.,Monash Bioinformatics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
| | - Oded Kleifeld
- Faculty of Biology, Technion-Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Meritxell Canals
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, United Kingdom.,Centre of Membrane Protein and Receptors, Universities of Birmingham and Nottingham, The Midlands NG7 2UH, United Kingdom
| | - Ralf B Schittenhelm
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia .,Monash Proteomics and Metabolomics Facility, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
| | - Martin J Stone
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
| |
Collapse
|
49
|
Lanigan TM, Kopera HC, Saunders TL. Principles of Genetic Engineering. Genes (Basel) 2020; 11:E291. [PMID: 32164255 PMCID: PMC7140808 DOI: 10.3390/genes11030291] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/28/2020] [Accepted: 03/06/2020] [Indexed: 12/12/2022] Open
Abstract
Genetic engineering is the use of molecular biology technology to modify DNA sequence(s) in genomes, using a variety of approaches. For example, homologous recombination can be used to target specific sequences in mouse embryonic stem (ES) cell genomes or other cultured cells, but it is cumbersome, poorly efficient, and relies on drug positive/negative selection in cell culture for success. Other routinely applied methods include random integration of DNA after direct transfection (microinjection), transposon-mediated DNA insertion, or DNA insertion mediated by viral vectors for the production of transgenic mice and rats. Random integration of DNA occurs more frequently than homologous recombination, but has numerous drawbacks, despite its efficiency. The most elegant and effective method is technology based on guided endonucleases, because these can target specific DNA sequences. Since the advent of clustered regularly interspaced short palindromic repeats or CRISPR/Cas9 technology, endonuclease-mediated gene targeting has become the most widely applied method to engineer genomes, supplanting the use of zinc finger nucleases, transcription activator-like effector nucleases, and meganucleases. Future improvements in CRISPR/Cas9 gene editing may be achieved by increasing the efficiency of homology-directed repair. Here, we describe principles of genetic engineering and detail: (1) how common elements of current technologies include the need for a chromosome break to occur, (2) the use of specific and sensitive genotyping assays to detect altered genomes, and (3) delivery modalities that impact characterization of gene modifications. In summary, while some principles of genetic engineering remain steadfast, others change as technologies are ever-evolving and continue to revolutionize research in many fields.
Collapse
Affiliation(s)
- Thomas M. Lanigan
- Biomedical Research Core Facilities, Vector Core, University of Michigan, Ann Arbor, MI 48109, USA; (T.M.L.); (H.C.K.)
- Department of Internal Medicine, Division of Rheumatology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Huira C. Kopera
- Biomedical Research Core Facilities, Vector Core, University of Michigan, Ann Arbor, MI 48109, USA; (T.M.L.); (H.C.K.)
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Thomas L. Saunders
- Biomedical Research Core Facilities, Transgenic Animal Model Core, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Internal Medicine, Division of Genetic Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| |
Collapse
|
50
|
Winczura K, Domanski M, LaCava J. Affinity Proteomic Analysis of the Human Exosome and Its Cofactor Complexes. Methods Mol Biol 2020; 2062:291-325. [PMID: 31768983 DOI: 10.1007/978-1-4939-9822-7_15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In humans, the RNA exosome consists of an enzymatically inactive nine-subunit core, with ribonucleolytic activity contributed by additional components. Several cofactor complexes also interact with the exosome-these enable the recruitment of, and specify the activity upon, diverse substrates. Affinity capture coupled with mass spectrometry has proven to be an effective means to identify the compositions of RNA exosomes and their cofactor complexes: here, we describe a general experimental strategy for proteomic characterization of macromolecular complexes, applied to the exosome and an affiliated adapter protein, ZC3H18.
Collapse
Affiliation(s)
- Kinga Winczura
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Michal Domanski
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - John LaCava
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, NY, USA.
- European Research Institute for the Biology of Ageing, University Medical Center Groningen, Groningen, AV, The Netherlands.
| |
Collapse
|