1
|
Ohishi H, Shimada S, Uchino S, Li J, Sato Y, Shintani M, Owada H, Ohkawa Y, Pertsinidis A, Yamamoto T, Kimura H, Ochiai H. STREAMING-tag system reveals spatiotemporal relationships between transcriptional regulatory factors and transcriptional activity. Nat Commun 2022; 13:7672. [PMID: 36539402 PMCID: PMC9768169 DOI: 10.1038/s41467-022-35286-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 11/25/2022] [Indexed: 12/24/2022] Open
Abstract
Transcription is a dynamic process. To detect the dynamic relationship among protein clusters of RNA polymerase II and coactivators, gene loci, and transcriptional activity, we insert an MS2 repeat, a TetO repeat, and inteins with a selection marker just downstream of the transcription start site. By optimizing the individual elements, we develop the Spliced TetO REpeAt, MS2 repeat, and INtein sandwiched reporter Gene tag (STREAMING-tag) system. Clusters of RNA polymerase II and BRD4 are observed proximal to the transcription start site of Nanog when the gene is transcribed in mouse embryonic stem cells. In contrast, clusters of MED19 and MED22 tend to be located near the transcription start site, even without transcription activity. Thus, the STREAMING-tag system reveals the spatiotemporal relationships between transcriptional activity and protein clusters near the gene. This powerful tool is useful for quantitatively understanding transcriptional regulation in living cells.
Collapse
Affiliation(s)
- Hiroaki Ohishi
- grid.257022.00000 0000 8711 3200Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046 Japan
| | - Seiru Shimada
- grid.257022.00000 0000 8711 3200Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046 Japan
| | - Satoshi Uchino
- grid.32197.3e0000 0001 2179 2105School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Jieru Li
- grid.51462.340000 0001 2171 9952Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065 USA
| | - Yuko Sato
- grid.32197.3e0000 0001 2179 2105School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan ,grid.32197.3e0000 0001 2179 2105Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503 Japan
| | - Manabu Shintani
- grid.257022.00000 0000 8711 3200Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046 Japan
| | - Hitoshi Owada
- grid.257022.00000 0000 8711 3200Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046 Japan
| | - Yasuyuki Ohkawa
- grid.177174.30000 0001 2242 4849Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, 812-8582 Japan
| | - Alexandros Pertsinidis
- grid.51462.340000 0001 2171 9952Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065 USA
| | - Takashi Yamamoto
- grid.257022.00000 0000 8711 3200Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046 Japan
| | - Hiroshi Kimura
- grid.32197.3e0000 0001 2179 2105School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan ,grid.32197.3e0000 0001 2179 2105Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503 Japan
| | - Hiroshi Ochiai
- grid.257022.00000 0000 8711 3200Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046 Japan
| |
Collapse
|
2
|
Ma L, Ouyang H, Su A, Zhang Y, Pang D, Zhang T, Sun R, Wang W, Xie Z, Lv D. AbSE Workflow: Rapid Identification of the Coding Sequence and Linear Epitope of the Monoclonal Antibody at the Single-cell Level. ACS Synth Biol 2022; 11:1856-1864. [PMID: 35503752 DOI: 10.1021/acssynbio.2c00018] [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
Monoclonal antibody (mAb) has been widely used in immunity research and disease diagnosis and therapy. Antibody sequence and epitope are the prerequisites and basis of mAb applications, which determine the properties of antibodies and make the preparation of antibody-based molecules controllable and reliable. Here, we present the antibody sequence and epitope identification (AbSE) workflow, a time-saving and cost-effective route for rapid determination of antibody sequence and linear epitope of mAb even at the single-cell level. The feasibility and accuracy of the AbSE workflow were demonstrated through the identification and validation of the coding sequence and epitope of antihuman serum albumin (antiHSA) mAb. It can be inferred that the AbSE workflow is a powerful and universal approach for paired antibody-epitope sequence identification. It may characterize antibodies not only on a single hybridoma cell but also on any other antibody-secreting cells.
Collapse
Affiliation(s)
- Lerong Ma
- Key Lab for Zoonoses Research, Ministry of Education, Animal Genome Editing Technology Innovation Center, Jilin Province, College of Animal Sciences, Jilin University, Changchun 130062, China
| | - HongSheng Ouyang
- Key Lab for Zoonoses Research, Ministry of Education, Animal Genome Editing Technology Innovation Center, Jilin Province, College of Animal Sciences, Jilin University, Changchun 130062, China
- Chongqing Research Institute, Jilin University, Chongqing 401123, China
- Chongqing Jitang Biotechnology Research Institute Co., Ltd., Chongqing 401123, China
- Shenzhen Kingsino Technology Co., Ltd., Shenzhen 518100, China
| | - Ang Su
- Key Lab for Zoonoses Research, Ministry of Education, Animal Genome Editing Technology Innovation Center, Jilin Province, College of Animal Sciences, Jilin University, Changchun 130062, China
| | - Yuanzhu Zhang
- Key Lab for Zoonoses Research, Ministry of Education, Animal Genome Editing Technology Innovation Center, Jilin Province, College of Animal Sciences, Jilin University, Changchun 130062, China
| | - Daxin Pang
- Key Lab for Zoonoses Research, Ministry of Education, Animal Genome Editing Technology Innovation Center, Jilin Province, College of Animal Sciences, Jilin University, Changchun 130062, China
- Chongqing Research Institute, Jilin University, Chongqing 401123, China
- Chongqing Jitang Biotechnology Research Institute Co., Ltd., Chongqing 401123, China
| | - Tao Zhang
- Key Lab for Zoonoses Research, Ministry of Education, Animal Genome Editing Technology Innovation Center, Jilin Province, College of Animal Sciences, Jilin University, Changchun 130062, China
| | - Ruize Sun
- Key Lab for Zoonoses Research, Ministry of Education, Animal Genome Editing Technology Innovation Center, Jilin Province, College of Animal Sciences, Jilin University, Changchun 130062, China
| | - Wentao Wang
- Key Lab for Zoonoses Research, Ministry of Education, Animal Genome Editing Technology Innovation Center, Jilin Province, College of Animal Sciences, Jilin University, Changchun 130062, China
| | - Zicong Xie
- Key Lab for Zoonoses Research, Ministry of Education, Animal Genome Editing Technology Innovation Center, Jilin Province, College of Animal Sciences, Jilin University, Changchun 130062, China
| | - Dongmei Lv
- Key Lab for Zoonoses Research, Ministry of Education, Animal Genome Editing Technology Innovation Center, Jilin Province, College of Animal Sciences, Jilin University, Changchun 130062, China
| |
Collapse
|
3
|
Uchino S, Ito Y, Sato Y, Handa T, Ohkawa Y, Tokunaga M, Kimura H. Live imaging of transcription sites using an elongating RNA polymerase II-specific probe. J Cell Biol 2022; 221:212888. [PMID: 34854870 PMCID: PMC8647360 DOI: 10.1083/jcb.202104134] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 10/12/2021] [Accepted: 11/10/2021] [Indexed: 12/15/2022] Open
Abstract
In eukaryotic nuclei, most genes are transcribed by RNA polymerase II (RNAP2), whose regulation is a key to understanding the genome and cell function. RNAP2 has a long heptapeptide repeat (Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7), and Ser2 is phosphorylated on an elongation form. To detect RNAP2 Ser2 phosphorylation (RNAP2 Ser2ph) in living cells, we developed a genetically encoded modification-specific intracellular antibody (mintbody) probe. The RNAP2 Ser2ph-mintbody exhibited numerous foci, possibly representing transcription “factories,” and foci were diminished during mitosis and in a Ser2 kinase inhibitor. An in vitro binding assay using phosphopeptides confirmed the mintbody’s specificity. RNAP2 Ser2ph-mintbody foci were colocalized with proteins associated with elongating RNAP2 compared with factors involved in the initiation. These results support the view that mintbody localization represents the sites of RNAP2 Ser2ph in living cells. RNAP2 Ser2ph-mintbody foci showed constrained diffusional motion like chromatin, but they were more mobile than DNA replication domains and p300-enriched foci, suggesting that the elongating RNAP2 complexes are separated from more confined chromatin domains.
Collapse
Affiliation(s)
- Satoshi Uchino
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Yuma Ito
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Yuko Sato
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan.,Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Tetsuya Handa
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Yasuyuki Ohkawa
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Makio Tokunaga
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Hiroshi Kimura
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan.,Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| |
Collapse
|
4
|
Moloney NM, Larkin A, Xu L, Fitzpatrick DA, Crean HL, Walshe K, Haas H, Decristoforo C, Doyle S. Generation and characterisation of a semi-synthetic siderophore-immunogen conjugate and a derivative recombinant triacetylfusarinine C-specific monoclonal antibody with fungal diagnostic application. Anal Biochem 2021; 632:114384. [PMID: 34543643 DOI: 10.1016/j.ab.2021.114384] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 08/16/2021] [Accepted: 09/13/2021] [Indexed: 11/24/2022]
Abstract
Invasive pulmonary aspergillosis (IPA) is a severe life-threatening condition. Diagnosis of fungal disease in general, and especially that caused by Aspergillus fumigatus is problematic. A. fumigatus secretes siderophores to acquire iron during infection, which are also essential for virulence. We describe the chemoacetylation of ferrated fusarinine C to diacetylated fusarinine C (DAFC), followed by protein conjugation, which facilitated triacetylfusarinine C (TAFC)-specific monoclonal antibody production with specific recognition of the ferrated form of TAFC. A single monoclonal antibody sequence was ultimately elucidated by a combinatorial strategy involving protein LC-MS/MS, cDNA sequencing and RNAseq. The resultant murine IgG2a monoclonal antibody was secreted in, and purified from, mammalian cell culture (5 mg) and demonstrated to be highly specific for TAFC detection by competitive ELISA (detection limit: 15 nM) and in a lateral flow test system (detection limit: 3 ng), using gold nanoparticle conjugated- DAFC-bovine serum albumin for competition. Overall, this work reveals for the first time a recombinant TAFC-specific monoclonal antibody with diagnostic potential for IPA diagnosis in traditional and emerging patient groups (e.g., COVID-19) and presents a useful strategy for murine Ig sequence determination, and expression in HEK293 cells, to overcome unexpected limitations associated with aberrant or deficient murine monoclonal antibody production.
Collapse
Affiliation(s)
- Nicola M Moloney
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, W23 F2H6, Ireland
| | - Annemarie Larkin
- National Institute for Cellular Biotechnology, Dublin City University, Dublin, Ireland
| | - Linan Xu
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, W23 F2H6, Ireland
| | - David A Fitzpatrick
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, W23 F2H6, Ireland
| | - Holly L Crean
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, W23 F2H6, Ireland
| | - Kieran Walshe
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, W23 F2H6, Ireland
| | - Hubertus Haas
- Institute of Molecular Biology, Medical University Innsbruck, A-6020, Innsbruck, Austria
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstrasse 5, A-6020, Innsbruck, Austria
| | - Sean Doyle
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, W23 F2H6, Ireland.
| |
Collapse
|
5
|
Foreman HCC, Frank A, Stedman TT. Determination of variable region sequences from hybridoma immunoglobulins that target Mycobacterium tuberculosis virulence factors. PLoS One 2021; 16:e0256079. [PMID: 34415957 PMCID: PMC8378720 DOI: 10.1371/journal.pone.0256079] [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: 05/06/2021] [Accepted: 07/29/2021] [Indexed: 11/19/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) infects one-quarter of the world's population. Mtb and HIV coinfections enhance the comorbidity of tuberculosis (TB) and AIDS, accounting for one-third of all AIDS-associated mortalities. Humoral antibody to Mtb correlates with TB susceptibility, and engineering of Mtb antibodies may lead to new diagnostics and therapeutics. The characterization and validation of functional immunoglobulin (Ig) variable chain (IgV) sequences provide a necessary first step towards developing therapeutic antibodies against pathogens. The virulence-associated Mtb antigens SodA (Superoxide Dismutase), KatG (Catalase), PhoS1/PstS1 (regulatory factor), and GroES (heat shock protein) are potential therapeutic targets but lacked IgV sequence characterization. Putative IgV sequences were identified from the mRNA of hybridomas targeting these antigens and isotype-switched into a common immunoglobulin fragment crystallizable region (Fc region) backbone, subclass IgG2aκ. Antibodies were validated by demonstrating recombinant Ig assembly and secretion, followed by the determination of antigen-binding specificity using ELISA and immunoblot assay.
Collapse
Affiliation(s)
- Hui-Chen Chang Foreman
- BEI Resources, ATCC., Manassas, Virginia, United States of America
- * E-mail: (HCCF); (TTS)
| | - Andrew Frank
- BEI Resources, ATCC., Manassas, Virginia, United States of America
| | - Timothy T. Stedman
- BEI Resources, ATCC., Manassas, Virginia, United States of America
- * E-mail: (HCCF); (TTS)
| |
Collapse
|
6
|
Tjalsma SJD, Hori M, Sato Y, Bousard A, Ohi A, Raposo AC, Roensch J, Le Saux A, Nogami J, Maehara K, Kujirai T, Handa T, Bagés‐Arnal S, Ohkawa Y, Kurumizaka H, da Rocha ST, Żylicz JJ, Kimura H, Heard E. H4K20me1 and H3K27me3 are concurrently loaded onto the inactive X chromosome but dispensable for inducing gene silencing. EMBO Rep 2021; 22:e51989. [PMID: 33605056 PMCID: PMC7926250 DOI: 10.15252/embr.202051989] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/22/2020] [Accepted: 01/07/2021] [Indexed: 12/13/2022] Open
Abstract
During X chromosome inactivation (XCI), in female placental mammals, gene silencing is initiated by the Xist long non-coding RNA. Xist accumulation at the X leads to enrichment of specific chromatin marks, including PRC2-dependent H3K27me3 and SETD8-dependent H4K20me1. However, the dynamics of this process in relation to Xist RNA accumulation remains unknown as is the involvement of H4K20me1 in initiating gene silencing. To follow XCI dynamics in living cells, we developed a genetically encoded, H3K27me3-specific intracellular antibody or H3K27me3-mintbody. By combining live-cell imaging of H3K27me3, H4K20me1, the X chromosome and Xist RNA, with ChIP-seq analysis we uncover concurrent accumulation of both marks during XCI, albeit with distinct genomic distributions. Furthermore, using a Xist B and C repeat mutant, which still shows gene silencing on the X but not H3K27me3 deposition, we also find a complete lack of H4K20me1 enrichment. This demonstrates that H4K20me1 is dispensable for the initiation of gene silencing, although it may have a role in the chromatin compaction that characterises facultative heterochromatin.
Collapse
Affiliation(s)
- Sjoerd J D Tjalsma
- Mammalian Developmental Epigenetics GroupInstitut CurieCNRS UMR3215, INSERM U934PSL UniversityParisFrance
| | - Mayako Hori
- Graduate School of Bioscience and BiotechnologyTokyo Institute of TechnologyYokohamaJapan
| | - Yuko Sato
- Graduate School of Bioscience and BiotechnologyTokyo Institute of TechnologyYokohamaJapan
- Cell Biology CenterInstitute of Innovative ResearchTokyo Institute of TechnologyYokohamaJapan
| | - Aurelie Bousard
- Mammalian Developmental Epigenetics GroupInstitut CurieCNRS UMR3215, INSERM U934PSL UniversityParisFrance
| | - Akito Ohi
- Graduate School of Bioscience and BiotechnologyTokyo Institute of TechnologyYokohamaJapan
| | - Ana Cláudia Raposo
- Faculdade de MedicinaInstituto de Medicina MolecularJoão Lobo AntunesUniversidade de LisboaLisboaPortugal
| | - Julia Roensch
- Mammalian Developmental Epigenetics GroupInstitut CurieCNRS UMR3215, INSERM U934PSL UniversityParisFrance
| | - Agnes Le Saux
- Mammalian Developmental Epigenetics GroupInstitut CurieCNRS UMR3215, INSERM U934PSL UniversityParisFrance
| | - Jumpei Nogami
- Division of TranscriptomicsMedical Institute of BioregulationKyushu UniversityFukuokaJapan
| | - Kazumitsu Maehara
- Division of TranscriptomicsMedical Institute of BioregulationKyushu UniversityFukuokaJapan
| | - Tomoya Kujirai
- Institute for Quantitative BiosciencesThe University of TokyoTokyoJapan
| | - Tetsuya Handa
- Cell Biology CenterInstitute of Innovative ResearchTokyo Institute of TechnologyYokohamaJapan
| | - Sandra Bagés‐Arnal
- The Novo Nordisk Foundation Center for Stem Cell BiologyCopenhagenDenmark
| | - Yasuyuki Ohkawa
- Division of TranscriptomicsMedical Institute of BioregulationKyushu UniversityFukuokaJapan
| | | | - Simão Teixeira da Rocha
- Faculdade de MedicinaInstituto de Medicina MolecularJoão Lobo AntunesUniversidade de LisboaLisboaPortugal
| | - Jan J Żylicz
- Mammalian Developmental Epigenetics GroupInstitut CurieCNRS UMR3215, INSERM U934PSL UniversityParisFrance
- The Novo Nordisk Foundation Center for Stem Cell BiologyCopenhagenDenmark
- Department of PhysiologyDevelopment and NeuroscienceUniversity of CambridgeCambridgeUK
| | - Hiroshi Kimura
- Graduate School of Bioscience and BiotechnologyTokyo Institute of TechnologyYokohamaJapan
- Cell Biology CenterInstitute of Innovative ResearchTokyo Institute of TechnologyYokohamaJapan
| | - Edith Heard
- EMBL HeidelbergHeidelbergGermany
- Collège de FranceParisFrance
| |
Collapse
|
7
|
Meyer L, López T, Espinosa R, Arias CF, Vollmers C, DuBois RM. A simplified workflow for monoclonal antibody sequencing. PLoS One 2019; 14:e0218717. [PMID: 31233538 PMCID: PMC6590890 DOI: 10.1371/journal.pone.0218717] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 06/07/2019] [Indexed: 11/19/2022] Open
Abstract
The diversity of antibody variable regions makes cDNA sequencing challenging, and conventional monoclonal antibody cDNA amplification requires the use of degenerate primers. Here, we describe a simplified workflow for amplification of IgG antibody variable regions from hybridoma RNA by a specialized RT-PCR followed by Sanger sequencing. We perform three separate reactions for each hybridoma: one each for kappa, lambda, and heavy chain transcripts. We prime reverse transcription with a primer specific to the respective constant region and use a template-switch oligonucleotide, which creates a custom sequence at the 5’ end of the antibody cDNA. This template-switching circumvents the issue of low sequence homology and the need for degenerate primers. Instead, subsequent PCR amplification of the antibody cDNA molecules requires only two primers: one primer specific for the template-switch oligonucleotide sequence and a nested primer to the respective constant region. We successfully sequenced the variable regions of five mouse monoclonal IgG antibodies using this method, which enabled us to design chimeric mouse/human antibody expression plasmids for recombinant antibody production in mammalian cell culture expression systems. All five recombinant antibodies bind their respective antigens with high affinity, confirming that the amino acid sequences determined by our method are correct and demonstrating the high success rate of our method. Furthermore, we also designed RT-PCR primers and amplified the variable regions from RNA of cells transfected with chimeric mouse/human antibody expression plasmids, showing that our approach is also applicable to IgG antibodies of human origin. Our monoclonal antibody sequencing method is highly accurate, user-friendly, and very cost-effective.
Collapse
Affiliation(s)
- Lena Meyer
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Tomás López
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Rafaela Espinosa
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Carlos F. Arias
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Christopher Vollmers
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
- * E-mail: (RMD); (CV)
| | - Rebecca M. DuBois
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
- * E-mail: (RMD); (CV)
| |
Collapse
|
8
|
Sato Y, Stasevich TJ, Kimura H. Visualizing the Dynamics of Inactive X Chromosomes in Living Cells Using Antibody-Based Fluorescent Probes. Methods Mol Biol 2018; 1861:91-102. [PMID: 30218362 DOI: 10.1007/978-1-4939-8766-5_8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The inactive X chromosome (Xi) harbors characteristic epigenetic features, including the enrichment of histone H3 lysine 27 trimethylation (H3K27me3) and H4 lysine 20 monomethylation (H4K20me1) as well as a lack of histone acetylation. Recently, these modifications have been visualized not only in fixed specimen, but also in living cells via probes derived from modification-specific antibodies. The probes include fluorescently labeled antigen binding fragments (Fabs), which can be loaded into cells, as well as genetically encoded single-chain variable fragments tagged with the green fluorescent protein. We refer to the latter as modification specific intracellular antibodies, or "mintbodies" for short. By using Fabs or mintbodies to target Xi-specific modifications, the dynamics of Xi in living cells can be visualized.
Collapse
Affiliation(s)
- Yuko Sato
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Timothy J Stasevich
- World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan.,Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Hiroshi Kimura
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan. .,World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan.
| |
Collapse
|
9
|
Identification and verification of hybridoma-derived monoclonal antibody variable region sequences using recombinant DNA technology and mass spectrometry. Mol Immunol 2017; 90:287-294. [PMID: 28865256 DOI: 10.1016/j.molimm.2017.08.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/10/2017] [Accepted: 08/16/2017] [Indexed: 11/24/2022]
Abstract
Antibody engineering requires the identification of antigen binding domains or variable regions (VR) unique to each antibody. It is the VR that define the unique antigen binding properties and proper sequence identification is essential for functional evaluation and performance of recombinant antibodies (rAb). This determination can be achieved by sequence analysis of immunoglobulin (Ig) transcripts obtained from a monoclonal antibody (MAb) producing hybridoma and subsequent expression of a rAb. However the polyploidy nature of a hybridoma cell often results in the added expression of aberrant immunoglobulin-like transcripts or even production of anomalous antibodies which can confound production of rAb. An incorrect VR sequence will result in a non-functional rAb and de novo assembly of Ig primary structure without a sequence map is challenging. To address these problems, we have developed a methodology which combines: 1) selective PCR amplification of VR from both the heavy and light chain IgG from hybridoma, 2) molecular cloning and DNA sequence analysis and 3) tandem mass spectrometry (MS/MS) on enzyme digests obtained from the purified IgG. Peptide analysis proceeds by evaluating coverage of the predicted primary protein sequence provided by the initial DNA maps for the VR. This methodology serves to both identify and verify the primary structure of the MAb VR for production as rAb.
Collapse
|