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Pinello JF, Loidl J, Seltzer ES, Cassidy-Hanley D, Kolbin D, Abdelatif A, Rey FA, An R, Newberger NJ, Bisharyan Y, Papoyan H, Byun H, Aguilar HC, Lai AL, Freed JH, Maugel T, Cole ES, Clark TG. Novel requirements for HAP2/GCS1-mediated gamete fusion in Tetrahymena. iScience 2024; 27:110146. [PMID: 38904066 PMCID: PMC11187246 DOI: 10.1016/j.isci.2024.110146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 04/29/2024] [Accepted: 05/27/2024] [Indexed: 06/22/2024] Open
Abstract
The ancestral gamete fusion protein, HAP2/GCS1, plays an essential role in fertilization in a broad range of taxa. To identify factors that may regulate HAP2/GCS1 activity, we screened mutants of the ciliate Tetrahymena thermophila for behaviors that mimic Δhap2/gcs1 knockout phenotypes in this species. Using this approach, we identified two new genes, GFU1 and GFU2, whose products are necessary for membrane pore formation following mating type recognition and adherence. GFU2 is predicted to be a single-pass transmembrane protein, while GFU1, though lacking obvious transmembrane domains, has the potential to interact directly with membrane phospholipids in the cytoplasm. Like Tetrahymena HAP2/GCS1, expression of GFU1 is required in both cells of a mating pair for efficient fusion to occur. To explain these bilateral requirements, we propose a model that invokes cooperativity between the fusion machinery on apposed membranes of mating cells and accounts for successful fertilization in Tetrahymena's multiple mating type system.
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Affiliation(s)
- Jennifer F. Pinello
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Josef Loidl
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna, Austria
| | - Ethan S. Seltzer
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Donna Cassidy-Hanley
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Daniel Kolbin
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Anhar Abdelatif
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Félix A. Rey
- Unité de Virologie Structurale, Institut Pasteur, 75724 Paris, France
- CNRS UMR 3569, 75724 Paris, France
| | - Rocky An
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Nicole J. Newberger
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Yelena Bisharyan
- Office of Technology Development, Harvard University, Cambridge, MA 02138, USA
| | - Hayk Papoyan
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Haewon Byun
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Hector C. Aguilar
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Alex L. Lai
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14850, USA
| | - Jack H. Freed
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14850, USA
| | - Timothy Maugel
- Department of Biology, Laboratory for Biological Ultrastructure, University of Maryland, College Park, MD 20742, USA
| | - Eric S. Cole
- Biology Department, St. Olaf College, Northfield, MN 55057, USA
| | - Theodore G. Clark
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
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Fukuda Y, Akematsu T, Bando H, Kato K. Snf2 Proteins Are Required to Generate Gamete Pronuclei in Tetrahymena thermophila. Microorganisms 2022; 10:microorganisms10122426. [PMID: 36557679 PMCID: PMC9786623 DOI: 10.3390/microorganisms10122426] [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: 11/03/2022] [Revised: 12/03/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022] Open
Abstract
During sexual reproduction/conjugation of the ciliate Tetrahymena thermophila, the germinal micronucleus undergoes meiosis resulting in four haploid micronuclei (hMICs). All hMICs undergo post-meiotic DNA double-strand break (PM-DSB) formation, cleaving their genome. DNA lesions are subsequently repaired in only one ‘selected’ hMIC, which eventually produces gametic pronuclei. DNA repair in the selected hMIC involves chromatin remodeling by switching from the heterochromatic to the euchromatic state of its genome. Here, we demonstrate that, among the 15 Tetrahymena Snf2 family proteins, a core of the ATP-dependent chromatin remodeling complex in Tetrahymena, the germline nucleus specific Iswi in Tetrahymena IswiGTt and Rad5Tt is crucial for the generation of gametic pronuclei. In either gene knockout, the selected hMIC which shows euchromatin markers such as lysine-acetylated histone H3 does not appear, but all hMICs in which markers for DNA lesions persist are degraded, indicating that both IswiGTt and Rad5Tt have important roles in repairing PM-DSB DNA lesions and remodeling chromatin for the euchromatic state in the selected hMIC.
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Affiliation(s)
- Yasuhiro Fukuda
- Graduate School of Agricultural Science, Tohoku University, Osaki 989-6711, Miyagi, Japan
- Correspondence: ; Tel.: +81-229-84-7387
| | - Takahiko Akematsu
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo 156-8550, Japan
| | - Hironori Bando
- Graduate School of Agricultural Science, Tohoku University, Osaki 989-6711, Miyagi, Japan
| | - Kentaro Kato
- Graduate School of Agricultural Science, Tohoku University, Osaki 989-6711, Miyagi, Japan
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3
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Tian M, Cai X, Liu Y, Liucong M, Howard-Till R. A practical reference for studying meiosis in the model ciliate Tetrahymena thermophila. MARINE LIFE SCIENCE & TECHNOLOGY 2022; 4:595-608. [PMID: 37078080 PMCID: PMC10077211 DOI: 10.1007/s42995-022-00149-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 09/28/2022] [Indexed: 05/03/2023]
Abstract
Meiosis is a critical cell division program that produces haploid gametes for sexual reproduction. Abnormalities in meiosis are often causes of infertility and birth defects (e.g., Down syndrome). Most organisms use a highly specialized zipper-like protein complex, the synaptonemal complex (SC), to guide and stabilize pairing of homologous chromosomes in meiosis. Although the SC is critical for meiosis in many eukaryotes, there are organisms that perform meiosis without a functional SC. However, such SC-less meiosis is poorly characterized. To understand the features of SC-less meiosis and its adaptive significance, the ciliated protozoan Tetrahymena was selected as a model. Meiosis research in Tetrahymena has revealed intriguing aspects of the regulatory programs utilized in its SC-less meiosis, yet additional efforts are needed for obtaining an in-depth comprehension of mechanisms that are associated with the absence of SC. Here, aiming at promoting a wider application of Tetrahymena for meiosis research, we introduce basic concepts and core techniques for studying meiosis in Tetrahymena and then suggest future directions for expanding the current Tetrahymena meiosis research toolbox. These methodologies could be adopted for dissecting meiosis in poorly characterized ciliates that might reveal novel features. Such data will hopefully provide insights into the function of the SC and the evolution of meiosis from a unique perspective. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-022-00149-8.
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Affiliation(s)
- Miao Tian
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
- Institute of Human Genetics, CNRS, University of Montpellier, 34090 Montpellier, France
| | - Xia Cai
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Yujie Liu
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Mingmei Liucong
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Rachel Howard-Till
- Department of Molecular and Cellular Biology, University of California Davis, Davis, CA USA
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4
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Nabeel-Shah S, Garg J, Saettone A, Ashraf K, Lee H, Wahab S, Ahmed N, Fine J, Derynck J, Pu S, Ponce M, Marcon E, Zhang Z, Greenblatt JF, Pearlman RE, Lambert JP, Fillingham J. Functional characterization of RebL1 highlights the evolutionary conservation of oncogenic activities of the RBBP4/7 orthologue in Tetrahymena thermophila. Nucleic Acids Res 2021; 49:6196-6212. [PMID: 34086947 PMCID: PMC8216455 DOI: 10.1093/nar/gkab413] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/22/2021] [Accepted: 05/04/2021] [Indexed: 12/18/2022] Open
Abstract
Retinoblastoma-binding proteins 4 and 7 (RBBP4 and RBBP7) are two highly homologous human histone chaperones. They function in epigenetic regulation as subunits of multiple chromatin-related complexes and have been implicated in numerous cancers. Due to their overlapping functions, our understanding of RBBP4 and 7, particularly outside of Opisthokonts, has remained limited. Here, we report that in the ciliate protozoan Tetrahymena thermophila a single orthologue of human RBBP4 and 7 proteins, RebL1, physically interacts with histone H4 and functions in multiple epigenetic regulatory pathways. Functional proteomics identified conserved functional links for Tetrahymena RebL1 protein as well as human RBBP4 and 7. We found that putative subunits of multiple chromatin-related complexes including CAF1, Hat1, Rpd3, and MuvB, co-purified with RebL1 during Tetrahymena growth and conjugation. Iterative proteomics analyses revealed that the cell cycle regulatory MuvB-complex in Tetrahymena is composed of at least five subunits including evolutionarily conserved Lin54, Lin9 and RebL1 proteins. Genome-wide analyses indicated that RebL1 and Lin54 (Anqa1) bind within genic and intergenic regions. Moreover, Anqa1 targets primarily promoter regions suggesting a role for Tetrahymena MuvB in transcription regulation. RebL1 depletion inhibited cellular growth and reduced the expression levels of Anqa1 and Lin9. Consistent with observations in glioblastoma tumors, RebL1 depletion suppressed DNA repair protein Rad51 in Tetrahymena, thus underscoring the evolutionarily conserved functions of RBBP4/7 proteins. Our results suggest the essentiality of RebL1 functions in multiple epigenetic regulatory complexes in which it impacts transcription regulation and cellular viability.
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Affiliation(s)
- Syed Nabeel-Shah
- Department of Chemistry and Biology, Ryerson University, 350 Victoria St., Toronto M5B 2K3, Canada
| | - Jyoti Garg
- Department of Chemistry and Biology, Ryerson University, 350 Victoria St., Toronto M5B 2K3, Canada.,Department of Biology, York University, 4700 Keele St., Toronto M3J 1P3, Canada
| | - Alejandro Saettone
- Department of Chemistry and Biology, Ryerson University, 350 Victoria St., Toronto M5B 2K3, Canada
| | - Kanwal Ashraf
- Department of Biology, York University, 4700 Keele St., Toronto M3J 1P3, Canada
| | - Hyunmin Lee
- Department of Computer Science, University of Toronto, Toronto M5S 1A8, Canada.,Donnelly Centre, University of Toronto, Toronto M5S 3E1, Canada
| | - Suzanne Wahab
- Department of Chemistry and Biology, Ryerson University, 350 Victoria St., Toronto M5B 2K3, Canada
| | - Nujhat Ahmed
- Donnelly Centre, University of Toronto, Toronto M5S 3E1, Canada.,Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
| | - Jacob Fine
- Department of Biology, York University, 4700 Keele St., Toronto M3J 1P3, Canada
| | - Joanna Derynck
- Department of Chemistry and Biology, Ryerson University, 350 Victoria St., Toronto M5B 2K3, Canada
| | - Shuye Pu
- Donnelly Centre, University of Toronto, Toronto M5S 3E1, Canada
| | - Marcelo Ponce
- SciNet HPC Consortium, University of Toronto, 661 University Avenue, Suite 1140, Toronto M5G 1M1, Canada
| | - Edyta Marcon
- Donnelly Centre, University of Toronto, Toronto M5S 3E1, Canada
| | - Zhaolei Zhang
- Department of Computer Science, University of Toronto, Toronto M5S 1A8, Canada.,Donnelly Centre, University of Toronto, Toronto M5S 3E1, Canada.,Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
| | - Jack F Greenblatt
- Donnelly Centre, University of Toronto, Toronto M5S 3E1, Canada.,Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
| | - Ronald E Pearlman
- Department of Biology, York University, 4700 Keele St., Toronto M3J 1P3, Canada
| | - Jean-Philippe Lambert
- Department of Molecular Medicine, Cancer Research Center, Big Data Research Center, Université Laval, Quebec City, Canada; CHU de Québec Research Center, CHUL, 2705 Laurier Boulevard, Quebec City G1V 4G2, Canada
| | - Jeffrey Fillingham
- Department of Chemistry and Biology, Ryerson University, 350 Victoria St., Toronto M5B 2K3, Canada
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