1
|
Kroeger B, Manning SA, Fonseka Y, Oorschot V, Crawford SA, Ramm G, Harvey KF. Basal spot junctions of Drosophila epithelial tissues respond to morphogenetic forces and regulate Hippo signaling. Dev Cell 2024; 59:262-279.e6. [PMID: 38134928 DOI: 10.1016/j.devcel.2023.11.024] [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: 08/03/2022] [Revised: 09/08/2023] [Accepted: 11/21/2023] [Indexed: 12/24/2023]
Abstract
Organ size is controlled by numerous factors including mechanical forces, which are mediated in part by the Hippo pathway. In growing Drosophila epithelial tissues, cytoskeletal tension influences Hippo signaling by modulating the localization of key pathway proteins to different apical domains. Here, we discovered a Hippo signaling hub at basal spot junctions, which form at the basal-most point of the lateral membranes and resemble adherens junctions in protein composition. Basal spot junctions recruit the central kinase Warts via Ajuba and E-cadherin, which prevent Warts activation by segregating it from upstream Hippo pathway proteins. Basal spot junctions are prominent when tissues undergo morphogenesis and are highly sensitive to fluctuations in cytoskeletal tension. They are distinct from focal adhesions, but the latter profoundly influences basal spot junction abundance by modulating the basal-medial actomyosin network and tension experienced by spot junctions. Thus, basal spot junctions couple morphogenetic forces to Hippo pathway activity and organ growth.
Collapse
Affiliation(s)
- Benjamin Kroeger
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Melbourne, VIC 3800, Australia; Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
| | - Samuel A Manning
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Melbourne, VIC 3800, Australia; Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
| | - Yoshana Fonseka
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Melbourne, VIC 3800, Australia
| | - Viola Oorschot
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Clayton, Melbourne, VIC 3168, Australia
| | - Simon A Crawford
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Clayton, Melbourne, VIC 3168, Australia
| | - Georg Ramm
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Clayton, Melbourne, VIC 3168, Australia
| | - Kieran F Harvey
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Melbourne, VIC 3800, Australia; Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Melbourne, VIC 3010, Australia.
| |
Collapse
|
2
|
Ogawa Y, Ueda TP, Obara K, Nishimura K, Kamura T. Targeted Protein Degradation Systems: Controlling Protein Stability Using E3 Ubiquitin Ligases in Eukaryotic Species. Cells 2024; 13:175. [PMID: 38247866 PMCID: PMC10814424 DOI: 10.3390/cells13020175] [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: 12/12/2023] [Revised: 01/12/2024] [Accepted: 01/12/2024] [Indexed: 01/23/2024] Open
Abstract
This review explores various methods for modulating protein stability to achieve target protein degradation, which is a crucial aspect in the study of biological processes and drug design. Thirty years have passed since the introduction of heat-inducible degron cells utilizing the N-end rule, and methods for controlling protein stability using the ubiquitin-proteasome system have moved from academia to industry. This review covers protein stability control methods, from the early days to recent advancements, and discusses the evolution of techniques in this field. This review also addresses the challenges and future directions of protein stability control techniques by tracing their development from the inception of protein stability control methods to the present day.
Collapse
Affiliation(s)
| | | | | | - Kohei Nishimura
- Department of Biological Science, Division of Natural Science, Graduate School of Science, Nagoya University, Nagoya 464-8601, Japan; (Y.O.); (T.P.U.); (K.O.)
| | - Takumi Kamura
- Department of Biological Science, Division of Natural Science, Graduate School of Science, Nagoya University, Nagoya 464-8601, Japan; (Y.O.); (T.P.U.); (K.O.)
| |
Collapse
|
3
|
Sun X, Yu B, Zhang R, Wei J, Pan G, Li C, Zhou Z. Generation of Resistance to Nosema bombycis (Dissociodihaplophasida: Nosematidae) by Degrading NbSWP12 Using the Ubiquitin-Proteasome Pathway in Sf9-III Cells. JOURNAL OF ECONOMIC ENTOMOLOGY 2022; 115:2068-2074. [PMID: 36226858 DOI: 10.1093/jee/toac145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Indexed: 06/16/2023]
Abstract
Nosema bombycis Naegeli (Dissociodihaplophasida: Nosematidae), an obligate intracellular parasite of the silkworm Bombyx mori, causes a devastating disease called pébrine. Every year pébrine will cause huge losses to the sericulture industry worldwide. Until now, there are no effective methods to inhibit the N. bombycis infection in silkworms. In this study, we first applied both the novel protein degradation Trim-Away technology and NSlmb (F-box domain-containing in the N-terminal part of supernumerary limbs from Drosophila melanogaster) to lepidopteran Sf9-III cells to check for specific degradation of a target protein in combination with a single-chain Fv fragment (scFv). Our results showed that the Trim-Away and NSlmb systems are both amenable to Sf9-III cells. We then created transgenic cell lines that overexpressed the protein degradation system and N. bombycis chimeric scFv targeting spore wall protein NbSWP12 and evaluated the effects of the insect transgenic cell lines on the proliferation of N. bombycis. Both methods could be applied to cell lines and both Trim-Away and NSlmb ubiquitin degradation systems effectively inhibited the proliferation of N. bombycis. Further, either of these degradation systems could be applied to individual silkworms through a transgenic platform, which would yield individual silkworms with high resistance to N. bombycis, thus greatly speeding up the process of acquiring resistant strains.
Collapse
Affiliation(s)
- Xi Sun
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Bin Yu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Renze Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Junhong Wei
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Guoqing Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Chunfeng Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Zeyang Zhou
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
- College of Life Sciences, Chongqing Normal University, Chongqing 401331, China
| |
Collapse
|
4
|
Lepeta K, Roubinet C, Bauer M, Vigano MA, Aguilar G, Kanca O, Ochoa-Espinosa A, Bieli D, Cabernard C, Caussinus E, Affolter M. Engineered kinases as a tool for phosphorylation of selected targets in vivo. J Cell Biol 2022; 221:213463. [PMID: 36102907 PMCID: PMC9477969 DOI: 10.1083/jcb.202106179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 05/19/2022] [Accepted: 07/27/2022] [Indexed: 11/22/2022] Open
Abstract
Reversible protein phosphorylation by kinases controls a plethora of processes essential for the proper development and homeostasis of multicellular organisms. One main obstacle in studying the role of a defined kinase–substrate interaction is that kinases form complex signaling networks and most often phosphorylate multiple substrates involved in various cellular processes. In recent years, several new approaches have been developed to control the activity of a given kinase. However, most of them fail to regulate a single protein target, likely hiding the effect of a unique kinase–substrate interaction by pleiotropic effects. To overcome this limitation, we have created protein binder-based engineered kinases that permit a direct, robust, and tissue-specific phosphorylation of fluorescent fusion proteins in vivo. We show the detailed characterization of two engineered kinases based on Rho-associated protein kinase (ROCK) and Src. Expression of synthetic kinases in the developing fly embryo resulted in phosphorylation of their respective GFP-fusion targets, providing for the first time a means to direct the phosphorylation to a chosen and tagged target in vivo. We presume that after careful optimization, the novel approach we describe here can be adapted to other kinases and targets in various eukaryotic genetic systems to regulate specific downstream effectors.
Collapse
Affiliation(s)
| | - Chantal Roubinet
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK 2
| | - Milena Bauer
- Biozentrum, University of Basel, Basel, Switzerland 1
| | | | | | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 3
| | | | | | | | | | | |
Collapse
|
5
|
Lepeta K, Bauer M, Aguilar G, Vigano MA, Matsuda S, Affolter M. Studying Protein Function Using Nanobodies and Other Protein Binders in Drosophila. Methods Mol Biol 2022; 2540:219-237. [PMID: 35980580 DOI: 10.1007/978-1-0716-2541-5_10] [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: 06/15/2023]
Abstract
The direct manipulation of proteins by nanobodies and other protein binders has become an additional and valuable approach to investigate development and homeostasis in Drosophila. In contrast to other techniques, that indirectly interfere with proteins via their nucleic acids (CRISPR, RNAi, etc.), protein binders permit direct and acute protein manipulation. Since the first use of a nanobody in Drosophila a decade ago, many different applications exploiting protein binders have been introduced. Most of these applications use nanobodies against GFP to regulate GFP fusion proteins. In order to exert specific protein manipulations, protein binders are linked to domains that confer them precise biochemical functions. Here, we reflect on the use of tools based on protein binders in Drosophila. We describe their key features and provide an overview of the available reagents. Finally, we briefly explore the future avenues that protein binders might open up and thus further contribute to better understand development and homeostasis of multicellular organisms.
Collapse
Affiliation(s)
| | - Milena Bauer
- Biozentrum der Universität Basel, Basel, Switzerland
| | | | | | | | | |
Collapse
|
6
|
McNutt PM, Vazquez-Cintron EJ, Tenezaca L, Ondeck CA, Kelly KE, Mangkhalakhili M, Machamer JB, Angeles CA, Glotfelty EJ, Cika J, Benjumea CH, Whitfield JT, Band PA, Shoemaker CB, Ichtchenko K. Neuronal delivery of antibodies has therapeutic effects in animal models of botulism. Sci Transl Med 2021; 13:eabd7789. [PMID: 33408188 PMCID: PMC8176400 DOI: 10.1126/scitranslmed.abd7789] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/20/2020] [Indexed: 11/02/2022]
Abstract
Botulism is caused by a potent neurotoxin that blocks neuromuscular transmission, resulting in death by asphyxiation. Currently, the therapeutic options are limited and there is no antidote. Here, we harness the structural and trafficking properties of an atoxic derivative of botulinum neurotoxin (BoNT) to transport a function-blocking single-domain antibody into the neuronal cytosol where it can inhibit BoNT serotype A (BoNT/A1) molecular toxicity. Post-symptomatic treatment relieved toxic signs of botulism and rescued mice, guinea pigs, and nonhuman primates after lethal BoNT/A1 challenge. These data demonstrate that atoxic BoNT derivatives can be harnessed to deliver therapeutic protein moieties to the neuronal cytoplasm where they bind and neutralize intracellular targets in experimental models. The generalizability of this platform might enable delivery of antibodies and other protein-based therapeutics to previously inaccessible intraneuronal targets.
Collapse
Affiliation(s)
- Patrick M McNutt
- Wake Forest School of Medicine, Wake Forest Institute for Regenerative Medicine, Winston-Salem, NC 27101, USA
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Edwin J Vazquez-Cintron
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
- CytoDel Inc., New York, NY 10016, USA
- City College of City University of New York, NY 10031, USA
| | - Luis Tenezaca
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
- CytoDel Inc., New York, NY 10016, USA
| | - Celinia A Ondeck
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Kyle E Kelly
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Mark Mangkhalakhili
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - James B Machamer
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Christopher A Angeles
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Elliot J Glotfelty
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Jaclyn Cika
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Cesar H Benjumea
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | | | - Philip A Band
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
- CytoDel Inc., New York, NY 10016, USA
- Department of Orthopaedic Surgery, New York University Langone Orthopedic Hospital, New York, NY 10016, USA
| | - Charles B Shoemaker
- Department of Infectious Diseases and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA 01536, USA
| | - Konstantin Ichtchenko
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA.
| |
Collapse
|
7
|
Prozzillo Y, Fattorini G, Santopietro MV, Suglia L, Ruggiero A, Ferreri D, Messina G. Targeted Protein Degradation Tools: Overview and Future Perspectives. BIOLOGY 2020; 9:biology9120421. [PMID: 33256092 PMCID: PMC7761331 DOI: 10.3390/biology9120421] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/23/2020] [Accepted: 11/25/2020] [Indexed: 12/28/2022]
Abstract
Simple Summary Gene inactivation is a powerful strategy to study the function of specific proteins in the context of cellular physiology that can be applied for only non-essential genes since their DNA sequence is destroyed. On the other hand, perturbing the amount of the transcript can lead to incomplete protein depletion and generate potential off-target effects. Instead, targeting at the protein level is desirable to overcome these limitations. In the last decade, several approaches have been developed and wisely improved, including compartment delocalization tools and protein degradation systems. This review highlights the most recent advances in targeted protein inactivation (TPI) and focuses on a putative novel tool to specifically degrade endogenous genetically unmodified target protein. Abstract Targeted protein inactivation (TPI) is an elegant approach to investigate protein function and its role in the cellular landscape, overcoming limitations of genetic perturbation strategies. These systems act in a reversible manner and reduce off-target effects exceeding the limitations of CRISPR/Cas9 and RNA interference, respectively. Several TPI have been developed and wisely improved, including compartment delocalization tools and protein degradation systems. However, unlike chemical tools such as PROTACs (PROteolysis TArgeting Chimeras), which work in a wild-type genomic background, TPI technologies require adding an aminoacidic signal sequence (tag) to the protein of interest (POI). On the other hand, the design and optimization of PROTACs are very laborious and time-consuming. In this review, we focus on anchor-away, deGradFP, auxin-inducible degron (AID) and dTAG technologies and discuss their recent applications and advances. Finally, we propose nano-grad, a novel nanobody-based protein degradation tool, which specifically proteolyzes endogenous tag-free target protein.
Collapse
Affiliation(s)
- Yuri Prozzillo
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy; (G.F.); (M.V.S.); (L.S.); (D.F.)
- Correspondence: (Y.P.); (G.M.)
| | - Gaia Fattorini
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy; (G.F.); (M.V.S.); (L.S.); (D.F.)
| | - Maria Virginia Santopietro
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy; (G.F.); (M.V.S.); (L.S.); (D.F.)
| | - Luigi Suglia
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy; (G.F.); (M.V.S.); (L.S.); (D.F.)
| | - Alessandra Ruggiero
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool L69 3BX, UK;
- Immune and Infectious Disease Division, Academic Department of Pediatrics (DPUO), Bambino Gesù Children’s Hospital, 00165 Rome, Italy
| | - Diego Ferreri
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy; (G.F.); (M.V.S.); (L.S.); (D.F.)
| | - Giovanni Messina
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy; (G.F.); (M.V.S.); (L.S.); (D.F.)
- Pasteur Institute of Italy, Fondazione Cenci-Bolognetti, 00161 Rome, Italy
- Correspondence: (Y.P.); (G.M.)
| |
Collapse
|
8
|
Zhang C, Ötjengerdes RM, Roewe J, Mejias R, Marschall ALJ. Applying Antibodies Inside Cells: Principles and Recent Advances in Neurobiology, Virology and Oncology. BioDrugs 2020; 34:435-462. [PMID: 32301049 PMCID: PMC7391400 DOI: 10.1007/s40259-020-00419-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
To interfere with cell function, many scientists rely on methods that target DNA or RNA due to the ease with which they can be applied. Proteins are usually the final executors of function but are targeted only indirectly by these methods. Recent advances in targeted degradation of proteins based on proteolysis-targeting chimaeras (PROTACs), ubiquibodies, deGradFP (degrade Green Fluorescent Protein) and other approaches have demonstrated the potential of interfering directly at the protein level for research and therapy. Proteins can be targeted directly and very specifically by antibodies, but using antibodies inside cells has so far been considered to be challenging. However, it is possible to deliver antibodies or other proteins into the cytosol using standard laboratory equipment. Physical methods such as electroporation have been demonstrated to be efficient and validated thoroughly over time. The expression of intracellular antibodies (intrabodies) inside cells is another way to interfere with intracellular targets at the protein level. Methodological strategies to target the inside of cells with antibodies, including delivered antibodies and expressed antibodies, as well as applications in the research areas of neurobiology, viral infections and oncology, are reviewed here. Antibodies have already been used to interfere with a wide range of intracellular targets. Disease-related targets included proteins associated with neurodegenerative diseases such as Parkinson's disease (α-synuclein), Alzheimer's disease (amyloid-β) or Huntington's disease (mutant huntingtin [mHtt]). The applications of intrabodies in the context of viral infections include targeting proteins associated with HIV (e.g. HIV1-TAT, Rev, Vif, gp41, gp120, gp160) and different oncoviruses such as human papillomavirus (HPV), hepatitis B virus (HBV), hepatitis C virus (HCV) and Epstein-Barr virus, and they have been used to interfere with various targets related to different processes in cancer, including oncogenic pathways, proliferation, cell cycle, apoptosis, metastasis, angiogenesis or neo-antigens (e.g. p53, human epidermal growth factor receptor-2 [HER2], signal transducer and activator of transcription 3 [STAT3], RAS-related RHO-GTPase B (RHOB), cortactin, vascular endothelial growth factor receptor 2 [VEGFR2], Ras, Bcr-Abl). Interfering at the protein level allows questions to be addressed that may remain unanswered using alternative methods. This review addresses why direct targeting of proteins allows unique insights, what is currently feasible in vitro, and how this relates to potential therapeutic applications.
Collapse
Affiliation(s)
- Congcong Zhang
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt am Main, Germany
- German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, Frankfurt am Main, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Rina M Ötjengerdes
- Hannover Medical School (MHH), Carl-Neuberg-Straße 1, 30625, Hannover, Germany
| | - Julian Roewe
- German Cancer Consortium (DKTK) Clinical Cooperation Unit (CCU) Neuroimmunology and Brain TumorImmunology (D170), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Rebeca Mejias
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Andrea L J Marschall
- Technische Universität Braunschweig, Institute of Biochemistry, Biotechnology and Bioinformatics, Brunswick, Germany.
| |
Collapse
|
9
|
Bobkov GOM, Huang A, van den Berg SJW, Mitra S, Anselm E, Lazou V, Schunter S, Feederle R, Imhof A, Lusser A, Jansen LET, Heun P. Spt6 is a maintenance factor for centromeric CENP-A. Nat Commun 2020; 11:2919. [PMID: 32522980 PMCID: PMC7287101 DOI: 10.1038/s41467-020-16695-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 05/19/2020] [Indexed: 12/19/2022] Open
Abstract
Replication and transcription of genomic DNA requires partial disassembly of nucleosomes to allow progression of polymerases. This presents both an opportunity to remodel the underlying chromatin and a danger of losing epigenetic information. Centromeric transcription is required for stable incorporation of the centromere-specific histone dCENP-A in M/G1 phase, which depends on the eviction of previously deposited H3/H3.3-placeholder nucleosomes. Here we demonstrate that the histone chaperone and transcription elongation factor Spt6 spatially and temporarily coincides with centromeric transcription and prevents the loss of old CENP-A nucleosomes in both Drosophila and human cells. Spt6 binds directly to dCENP-A and dCENP-A mutants carrying phosphomimetic residues alleviate this association. Retention of phosphomimetic dCENP-A mutants is reduced relative to wildtype, while non-phosphorylatable dCENP-A retention is increased and accumulates at the centromere. We conclude that Spt6 acts as a conserved CENP-A maintenance factor that ensures long-term stability of epigenetic centromere identity during transcription-mediated chromatin remodeling.
Collapse
Affiliation(s)
- Georg O M Bobkov
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
- Faculty of Biology, Albert-Ludwigs-Universität Freiburg, 79104, Freiburg, Germany
| | - Anming Huang
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innrain 80-82, A-6020, Innsbruck, Austria
| | - Sebastiaan J W van den Berg
- Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Sreyoshi Mitra
- Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Eduard Anselm
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Vasiliki Lazou
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Sarah Schunter
- Molecular Biology Division, Biomedical Center, Faculty of Medicine, LMU, Munich, Germany
| | - Regina Feederle
- Monoclonal Antibody Core Facility, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764, Neuherberg, Germany
| | - Axel Imhof
- BioMedical Center and Center for Integrated Protein Sciences Munich, Ludwig-Maximilians-University of Munich, Großhaderner Straße 9, 82152, Planegg-Martinsried, Germany
| | - Alexandra Lusser
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innrain 80-82, A-6020, Innsbruck, Austria
| | - Lars E T Jansen
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Patrick Heun
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK.
| |
Collapse
|
10
|
Delker RK, Ranade V, Loker R, Voutev R, Mann RS. Low affinity binding sites in an activating CRM mediate negative autoregulation of the Drosophila Hox gene Ultrabithorax. PLoS Genet 2019; 15:e1008444. [PMID: 31589607 PMCID: PMC6797233 DOI: 10.1371/journal.pgen.1008444] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/17/2019] [Accepted: 09/23/2019] [Indexed: 12/11/2022] Open
Abstract
Specification of cell identity and the proper functioning of a mature cell depend on precise regulation of gene expression. Both binary ON/OFF regulation of transcription, as well as more fine-tuned control of transcription levels in the ON state, are required to define cell types. The Drosophila melanogaster Hox gene, Ultrabithorax (Ubx), exhibits both of these modes of control during development. While ON/OFF regulation is needed to specify the fate of the developing wing (Ubx OFF) and haltere (Ubx ON), the levels of Ubx within the haltere differ between compartments along the proximal-distal axis. Here, we identify and molecularly dissect the novel contribution of a previously identified Ubx cis-regulatory module (CRM), anterobithorax (abx), to a negative auto-regulatory loop that decreases Ubx expression in the proximal compartment of the haltere as compared to the distal compartment. We find that Ubx, in complex with the known Hox cofactors, Homothorax (Hth) and Extradenticle (Exd), acts through low-affinity Ubx-Exd binding sites to reduce the levels of Ubx transcription in the proximal compartment. Importantly, we also reveal that Ubx-Exd-binding site mutations sufficient to result in de-repression of abx activity in a transgenic context are not sufficient to de-repress Ubx expression when mutated at the endogenous locus, suggesting the presence of multiple mechanisms through which Ubx-mediated repression occurs. Our results underscore the complementary nature of CRM analysis through transgenic reporter assays and genome modification of the endogenous locus; but, they also highlight the increasing need to understand gene regulation within the native context to capture the potential input of multiple genomic elements on gene control.
Collapse
Affiliation(s)
- Rebecca K. Delker
- Department of Biochemistry and Molecular Biophysics and Systems Biology, Columbia University, New York, NY, United States of America
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States of America
| | - Vikram Ranade
- Department of Genetics, Columbia University, New York, NY, United States of America
| | - Ryan Loker
- Department of Genetics, Columbia University, New York, NY, United States of America
| | - Roumen Voutev
- Department of Biochemistry and Molecular Biophysics and Systems Biology, Columbia University, New York, NY, United States of America
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States of America
| | - Richard S. Mann
- Department of Biochemistry and Molecular Biophysics and Systems Biology, Columbia University, New York, NY, United States of America
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States of America
| |
Collapse
|
11
|
Röth S, Fulcher LJ, Sapkota GP. Advances in targeted degradation of endogenous proteins. Cell Mol Life Sci 2019; 76:2761-2777. [PMID: 31030225 PMCID: PMC6588652 DOI: 10.1007/s00018-019-03112-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/23/2019] [Accepted: 04/16/2019] [Indexed: 01/07/2023]
Abstract
Protein silencing is often employed as a means to aid investigations in protein function and is increasingly desired as a therapeutic approach. Several types of protein silencing methodologies have been developed, including targeting the encoding genes, transcripts, the process of translation or the protein directly. Despite these advances, most silencing systems suffer from limitations. Silencing protein expression through genetic ablation, for example by CRISPR/Cas9 genome editing, is irreversible, time consuming and not always feasible. Similarly, RNA interference approaches warrant prolonged treatments, can lead to incomplete protein depletion and are often associated with off-target effects. Targeted proteolysis has the potential to overcome some of these limitations. The field of targeted proteolysis has witnessed the emergence of many methodologies aimed at targeting specific proteins for degradation in a spatio-temporal manner. In this review, we provide an appraisal of the different targeted proteolytic systems and discuss their applications in understanding protein function, as well as their potential in therapeutics.
Collapse
Affiliation(s)
- Sascha Röth
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Luke J Fulcher
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Gopal P Sapkota
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK.
| |
Collapse
|
12
|
Li T, Bellen HJ, Groves AK. Using Drosophila to study mechanisms of hereditary hearing loss. Dis Model Mech 2018; 11:11/6/dmm031492. [PMID: 29853544 PMCID: PMC6031363 DOI: 10.1242/dmm.031492] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Johnston's organ - the hearing organ of Drosophila - has a very different structure and morphology to that of the hearing organs of vertebrates. Nevertheless, it is becoming clear that vertebrate and invertebrate auditory organs share many physiological, molecular and genetic similarities. Here, we compare the molecular and cellular features of hearing organs in Drosophila with those of vertebrates, and discuss recent evidence concerning the functional conservation of Usher proteins between flies and mammals. Mutations in Usher genes cause Usher syndrome, the leading cause of human deafness and blindness. In Drosophila, some Usher syndrome proteins appear to physically interact in protein complexes that are similar to those described in mammals. This functional conservation highlights a rational role for Drosophila as a model for studying hearing, and for investigating the evolution of auditory organs, with the aim of advancing our understanding of the genes that regulate human hearing and the pathogenic mechanisms that lead to deafness.
Collapse
Affiliation(s)
- Tongchao Li
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hugo J Bellen
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Andrew K Groves
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA .,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| |
Collapse
|
13
|
Barton LJ, LeBlanc MG, Lehmann R. Finding their way: themes in germ cell migration. Curr Opin Cell Biol 2016; 42:128-137. [PMID: 27484857 DOI: 10.1016/j.ceb.2016.07.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 06/15/2016] [Accepted: 07/08/2016] [Indexed: 11/26/2022]
Abstract
Embryonic germ cell migration is a vital component of the germline lifecycle. The translocation of germ cells from the place of origin to the developing somatic gonad involves several processes including passive movements with underlying tissues, transepithelial migration, cell adhesion dynamics, the establishment of environmental guidance cues and the ability to sustain directed migration. How germ cells accomplish these feats in established model organisms will be discussed in this review, with a focus on recent discoveries and themes conserved across species.
Collapse
Affiliation(s)
- Lacy J Barton
- HHMI and Skirball Institute at NYU School of Medicine, 540 First Avenue, New York, NY 10016, United States
| | - Michelle G LeBlanc
- HHMI and Skirball Institute at NYU School of Medicine, 540 First Avenue, New York, NY 10016, United States
| | - Ruth Lehmann
- HHMI and Skirball Institute at NYU School of Medicine, 540 First Avenue, New York, NY 10016, United States.
| |
Collapse
|
14
|
Wang Y, Fan Z, Shao L, Kong X, Hou X, Tian D, Sun Y, Xiao Y, Yu L. Nanobody-derived nanobiotechnology tool kits for diverse biomedical and biotechnology applications. Int J Nanomedicine 2016; 11:3287-303. [PMID: 27499623 PMCID: PMC4959585 DOI: 10.2147/ijn.s107194] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Owing to peculiar properties of nanobody, including nanoscale size, robust structure, stable and soluble behaviors in aqueous solution, reversible refolding, high affinity and specificity for only one cognate target, superior cryptic cleft accessibility, and deep tissue penetration, as well as a sustainable source, it has been an ideal research tool for the development of sophisticated nanobiotechnologies. Currently, the nanobody has been evolved into versatile research and application tool kits for diverse biomedical and biotechnology applications. Various nanobody-derived formats, including the nanobody itself, the radionuclide or fluorescent-labeled nanobodies, nanobody homo- or heteromultimers, nanobody-coated nanoparticles, and nanobody-displayed bacteriophages, have been successfully demonstrated as powerful nanobiotechnological tool kits for basic biomedical research, targeting drug delivery and therapy, disease diagnosis, bioimaging, and agricultural and plant protection. These applications indicate a special advantage of these nanobody-derived technologies, already surpassing the “me-too” products of other equivalent binders, such as the full-length antibodies, single-chain variable fragments, antigen-binding fragments, targeting peptides, and DNA-based aptamers. In this review, we summarize the current state of the art in nanobody research, focusing on the nanobody structural features, nanobody production approach, nanobody-derived nanobiotechnology tool kits, and the potentially diverse applications in biomedicine and biotechnology. The future trends, challenges, and limitations of the nanobody-derived nanobiotechnology tool kits are also discussed.
Collapse
Affiliation(s)
- Yongzhong Wang
- School of Life Sciences, Collaborative Innovation Center of Modern Bio-manufacture, Anhui University, Hefei, People's Republic of China
| | - Zhen Fan
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - Lei Shao
- State Key Laboratory of New Drugs and Pharmaceutical Process, Shanghai Institute of Pharmaceutical Industry, Shanghai
| | - Xiaowei Kong
- School of Life Sciences, Collaborative Innovation Center of Modern Bio-manufacture, Anhui University, Hefei, People's Republic of China
| | - Xianjuan Hou
- School of Life Sciences, Collaborative Innovation Center of Modern Bio-manufacture, Anhui University, Hefei, People's Republic of China
| | - Dongrui Tian
- School of Life Sciences, Collaborative Innovation Center of Modern Bio-manufacture, Anhui University, Hefei, People's Republic of China
| | - Ying Sun
- School of Life Sciences, Collaborative Innovation Center of Modern Bio-manufacture, Anhui University, Hefei, People's Republic of China
| | - Yazhong Xiao
- School of Life Sciences, Collaborative Innovation Center of Modern Bio-manufacture, Anhui University, Hefei, People's Republic of China
| | - Li Yu
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology, Anhui Key Laboratory of Zoonoses, Anhui Medical University, Hefei, People's Republic of China
| |
Collapse
|
15
|
Abstract
Protein depletion by genetic means, in a very general sense including the use of RNA interference [1, 2] or CRISPR/Cas9-based methods, represents a central paradigm of modern biology to study protein functions in vivo. However, acting upstream the proteic level is a limiting factor if the turnover of the target protein is slow or the existing pool of the target protein is important (for instance, in insect embryos, as a consequence of a strong maternal contribution). In order to circumvent these problems, we developed deGradFP [3, 4]. deGradFP harnesses the ubiquitin-proteasome pathway to achieve direct depletion of GFP-tagged proteins. deGradFP is in essence a universal method because it relies on an evolutionarily conserved machinery for protein catabolism in eukaryotic cells; see refs. 5, 6 for review. deGradFP is particularly convenient in Drosophila melanogaster where it is implemented by a genetically encoded effector expressed under the control of the Gal4 system. deGradFP is a ready-to-use solution to perform knockdowns at the protein level if a fly line carrying a functional GFP-tagged version of the gene of interest is available. Many such lines have already been generated by the Drosophila community through different technologies allowing to make genomic rescue constructs or direct GFP knockins: protein-trap stock collections [7, 8] ( http://cooley.medicine.yale.edu/flytrap/ , http://www.flyprot.org/ ), P[acman] system [9], MiMIC lines [10, 11], and CRISPR/Cas9-driven homologous recombination.Two essential controls of a protein knockdown experiment are easily achieved using deGradFP. First, the removal of the target protein can be assessed by monitoring the disappearance of the GFP tag by fluorescence microscopy in parallel to the documentation of the phenotype of the protein knockdown (see Note 1 ). Second, the potential nonspecific effects of deGradFP can be assessed in control fly lacking a GFP-tagged target protein. So far, no nonspecific effects of the deGradFP effector have been reported [3].
Collapse
Affiliation(s)
- Emmanuel Caussinus
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Markus Affolter
- Growth & Development, Biozentrum, University of Basel, Room 200B, Klingelbergstrasse 50/70, 4056, Basel, Switzerland.
| |
Collapse
|
16
|
Brauchle M, Hansen S, Caussinus E, Lenard A, Ochoa-Espinosa A, Scholz O, Sprecher SG, Plückthun A, Affolter M. Protein interference applications in cellular and developmental biology using DARPins that recognize GFP and mCherry. Biol Open 2014; 3:1252-61. [PMID: 25416061 PMCID: PMC4265764 DOI: 10.1242/bio.201410041] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Protein–protein interactions are crucial for cellular homeostasis and play important roles in the dynamic execution of biological processes. While antibodies represent a well-established tool to study protein interactions of extracellular domains and secreted proteins, as well as in fixed and permeabilized cells, they usually cannot be functionally expressed in the cytoplasm of living cells. Non-immunoglobulin protein-binding scaffolds have been identified that also function intracellularly and are now being engineered for synthetic biology applications. Here we used the Designed Ankyrin Repeat Protein (DARPin) scaffold to generate binders to fluorescent proteins and used them to modify biological systems directly at the protein level. DARPins binding to GFP or mCherry were selected by ribosome display. For GFP, binders with KD as low as 160 pM were obtained, while for mCherry the best affinity was 6 nM. We then verified in cell culture their specific binding in a complex cellular environment and found an affinity cut-off in the mid-nanomolar region, above which binding is no longer detectable in the cell. Next, their binding properties were employed to change the localization of the respective fluorescent proteins within cells. Finally, we performed experiments in Drosophila melanogaster and Danio rerio and utilized these DARPins to either degrade or delocalize fluorescently tagged fusion proteins in developing organisms, and to phenocopy loss-of-function mutations. Specific protein binders can thus be selected in vitro and used to reprogram developmental systems in vivo directly at the protein level, thereby bypassing some limitations of approaches that function at the DNA or the RNA level.
Collapse
Affiliation(s)
- Michael Brauchle
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland Department of Zoology, University of Fribourg, Chemi du Musée 10, 1700 Fribourg, Switzerland
| | - Simon Hansen
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Emmanuel Caussinus
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Anna Lenard
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | | | - Oliver Scholz
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Simon G Sprecher
- Department of Zoology, University of Fribourg, Chemi du Musée 10, 1700 Fribourg, Switzerland
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Markus Affolter
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| |
Collapse
|
17
|
Kanca O, Ochoa-Espinosa A, Affolter M. IV. Tools and methods for studying cell migration and cell rearrangement in tissue and organ development. Methods 2014; 68:228-32. [PMID: 24631575 DOI: 10.1016/j.ymeth.2014.03.004] [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: 02/15/2014] [Accepted: 03/03/2014] [Indexed: 10/25/2022] Open
Abstract
A vast diversity of biological systems, ranging from prokaryotes to multicellular organisms, show cell migration behavior. Many of the basic cellular and molecular concepts in cell migration apply to diverse model organisms. Drosophila, with its vast repertoire of tools for imaging and for manipulation, is one of the favorite organisms to study cell migration. Moreover, distinct Drosophila tissues and organs offer diverse cell migration models that are amenable to live imaging and genetic manipulations. In this review, we will provide an overview of the fruit fly toolbox that is of particular interest for the analysis of cell migration. We provide examples to highlight how those tools were used in diverse migration systems, with an emphasis on tracheal morphogenesis, a process that combines morphogenesis with cell migration.
Collapse
Affiliation(s)
- Oguz Kanca
- Biozentrum der Universität Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | | | - Markus Affolter
- Biozentrum der Universität Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
| |
Collapse
|
18
|
De Meyer T, Muyldermans S, Depicker A. Nanobody-based products as research and diagnostic tools. Trends Biotechnol 2014; 32:263-70. [PMID: 24698358 DOI: 10.1016/j.tibtech.2014.03.001] [Citation(s) in RCA: 299] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 02/17/2014] [Accepted: 03/05/2014] [Indexed: 01/25/2023]
Abstract
Since the serendipitous discovery 20 years ago of bona fide camelid heavy-chain antibodies, their single-domain antigen-binding fragments, known as VHHs or nanobodies, have received a progressively growing interest. As a result of the beneficial properties of these stable recombinant entities, they are currently highly valued proteins for multiple applications, including fundamental research, diagnostics, and therapeutics. Today, with the original patents expiring, even more academic and industrial groups are expected to explore innovative VHH applications. Here, we provide a thorough overview of novel implementations of VHHs as research and diagnostic tools, and of the recently evaluated production platforms for several VHHs and VHH-derived antibody formats.
Collapse
Affiliation(s)
- Thomas De Meyer
- Department of Plant Systems Biology, VIB, 9052 Gent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Serge Muyldermans
- Structural Biology Research Center, VIB, 1050 Brussel, Belgium; Research Unit of Cellular and Molecular Immunology, Vrije Universiteit Brussel, 1050 Brussel, Belgium
| | - Ann Depicker
- Department of Plant Systems Biology, VIB, 9052 Gent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium.
| |
Collapse
|