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Osterli E, Ellenbecker M, Wang X, Terzo M, Jacobson K, Cuello D, Voronina E. COP9 signalosome component CSN-5 stabilizes PUF proteins FBF-1 and FBF-2 in Caenorhabditis elegans germline stem and progenitor cells. Genetics 2024; 227:iyae033. [PMID: 38427913 PMCID: PMC11075551 DOI: 10.1093/genetics/iyae033] [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: 01/02/2024] [Revised: 02/16/2024] [Accepted: 02/17/2024] [Indexed: 03/03/2024] Open
Abstract
RNA-binding proteins FBF-1 and FBF-2 (FBFs) are required for germline stem cell maintenance and the sperm/oocyte switch in Caenorhabditis elegans, although the mechanisms controlling FBF protein levels remain unknown. We identified an interaction between both FBFs and CSN-5), a component of the constitutive photomorphogenesis 9 (COP9) signalosome best known for its role in regulating protein degradation. Here, we find that the Mpr1/Pad1 N-terminal metalloprotease domain of CSN-5 interacts with the Pumilio and FBF RNA-binding domain of FBFs and the interaction is conserved for human homologs CSN5 and PUM1. The interaction between FBF-2 and CSN-5 can be detected in vivo by proximity ligation. csn-5 mutation results in the destabilization of FBF proteins, which may explain previously observed decrease in the numbers of germline stem and progenitor cells, and disruption of oogenesis. The loss of csn-5 does not decrease the levels of a related PUF protein PUF-3, and csn-5(lf) phenotype is not enhanced by fbf-1/2 knockdown, suggesting that the effect is specific to FBFs. The effect of csn-5 on oogenesis is largely independent of the COP9 signalosome and is cell autonomous. Surprisingly, the regulation of FBF protein levels involves a combination of COP9-dependent and COP9-independent mechanisms differentially affecting FBF-1 and FBF-2. This work supports a previously unappreciated role for CSN-5 in the stabilization of germline stem cell regulatory proteins FBF-1 and FBF-2.
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Affiliation(s)
- Emily Osterli
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
| | - Mary Ellenbecker
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
| | - Xiaobo Wang
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
| | - Mikaya Terzo
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
| | - Ketch Jacobson
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
| | - DeAnna Cuello
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
| | - Ekaterina Voronina
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
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Crittenden SL, Seidel HS, Kimble J. Analysis of the C. elegans Germline Stem Cell Pool. Methods Mol Biol 2023; 2677:1-36. [PMID: 37464233 DOI: 10.1007/978-1-0716-3259-8_1] [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: 07/20/2023]
Abstract
The Caenorhabditis elegans germline is an excellent model for studying the genetic and molecular regulation of stem cell self-renewal and progression of cells from a stem cell state to a differentiated state. The germline tissue is organized in an assembly line with the germline stem cell (GSC) pool at one end and differentiated gametes at the other. A simple mesenchymal niche caps the GSC pool and maintains GSCs in an undifferentiated state by signaling through the conserved Notch pathway. Notch signaling activates transcription of the key GSC regulators lst-1 and sygl-1 proteins in a gradient through the GSC pool. LST-1 and SYGL-1 proteins work with PUF RNA regulators in a self-renewal hub to maintain the GSC pool. In this chapter, we present methods for characterizing the C. elegans GSC pool and early stages of germ cell differentiation. The methods include examination of germlines in living and fixed worms, cell cycle analysis, and analysis of markers. We also discuss assays to separate mutant phenotypes that affect the stem cell vs. differentiation decision from those that affect germ cell processes more generally.
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Affiliation(s)
- Sarah L Crittenden
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
| | - Hannah S Seidel
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
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Hertz HL, Price IF, Tang W. Visualization and Purification of Caenorhabditis elegans Germ Granule Proteins Using Proximity Labeling. Bio Protoc 2022; 12:e4386. [PMID: 35800092 PMCID: PMC9081476 DOI: 10.21769/bioprotoc.4386] [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: 03/04/2022] [Revised: 01/07/2022] [Accepted: 03/07/2022] [Indexed: 12/29/2022] Open
Abstract
Membraneless organelles, such as germ granules and stress granules, are liquid-like condensates formed by phase transition. Recently, we and others have adopted proximity-based labeling methods to determine the composition of these membraneless compartments. Here, we describe the use of TurboID-an engineered promiscuous biotin ligase-to label and purify proteins localizing to Caenorhabditis elegans germ granules, known as P granules. We provide a detailed protocol for visualization of the subcellular localization of biotinylated proteins from dissected gonads, assessment of TurboID enrichment using streptavidin blots, and enrichment of biotinylated proteins under stringent conditions. Altogether, this protocol provides a workflow to unravel the proteome of C. elegans germ granules. Importantly, the assays described here can be applied to interrogate many membraneless organelles, in a diversity of living multicellular organisms. Graphical abstract.
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Affiliation(s)
- Hannah L. Hertz
- Department of Biological Chemistry and Pharmacology, Ohio State University, Columbus, OH 43210, USA
,Center for RNA Biology, Ohio State University, Columbus, OH 43210, USA
| | - Ian F. Price
- Department of Biological Chemistry and Pharmacology, Ohio State University, Columbus, OH 43210, USA
,Center for RNA Biology, Ohio State University, Columbus, OH 43210, USA
,Ohio State Biochemistry Program; Ohio State University, Columbus, OH 43210, USA
| | - Wen Tang
- Department of Biological Chemistry and Pharmacology, Ohio State University, Columbus, OH 43210, USA
,Center for RNA Biology, Ohio State University, Columbus, OH 43210, USA
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*For correspondence:
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Day NJ, Ellenbecker M, Wang X, Voronina E. DLC-1 facilitates germ granule assembly in C. elegans embryo. Mol Biol Cell 2022; 33:ar41. [PMID: 35274966 PMCID: PMC9282019 DOI: 10.1091/mbc.e21-05-0275] [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] [Indexed: 11/11/2022] Open
Abstract
Germ granules are cytoplasmic assemblies of RNA-binding proteins (RBPs) required for germ cell development and fertility. During the first four cell divisions of the Caenorhabditis elegans zygote, regulated assembly of germ (P) granules leads to their selective segregation to the future germ cell. Here we investigate the role of DLC-1, a hub protein implicated in stabilization and function of diverse protein complexes, in maintaining P granule integrity. We find that DLC-1 directly interacts with several core P granule proteins, predominantly during embryogenesis. The loss of dlc-1 disrupts assembly of P granule components into phase-separated organelles in the embryos, regardless of whether or not DLC-1 directly interacts with these proteins. Finally, we infer that P granule dispersal in the absence of dlc-1 is likely independent of DLC-1’s function as a subunit of the dynein motor and does not result from a loss of cell polarity.
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Affiliation(s)
- Nicholas J Day
- Division of Biological Sciences, University of Montana, Missoula, MT 59812
| | - Mary Ellenbecker
- Division of Biological Sciences, University of Montana, Missoula, MT 59812
| | - Xiaobo Wang
- Division of Biological Sciences, University of Montana, Missoula, MT 59812
| | - Ekaterina Voronina
- Division of Biological Sciences, University of Montana, Missoula, MT 59812
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Puri D, Ponniah K, Biswas K, Basu A, Dey S, Lundquist EA, Ghosh-Roy A. Wnt signaling establishes the microtubule polarity in neurons through regulation of Kinesin-13. J Cell Biol 2021; 220:212396. [PMID: 34137792 DOI: 10.1083/jcb.202005080] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Neuronal polarization is facilitated by the formation of axons with parallel arrays of plus-end-out and dendrites with the nonuniform orientation of microtubules. In C. elegans, the posterior lateral microtubule (PLM) neuron is bipolar with its two processes growing along the anterior-posterior axis under the guidance of Wnt signaling. Here we found that loss of the Kinesin-13 family microtubule-depolymerizing enzyme KLP-7 led to the ectopic extension of axon-like processes from the PLM cell body. Live imaging of the microtubules and axonal transport revealed mixed polarity of the microtubules in the short posterior process, which is dependent on both KLP-7 and the minus-end binding protein PTRN-1. KLP-7 is positively regulated in the posterior process by planar cell polarity components of Wnt involving rho-1/rock to induce mixed polarity of microtubules, whereas it is negatively regulated in the anterior process by the unc-73/ced-10 cascade to establish a uniform microtubule polarity. Our work elucidates how evolutionarily conserved Wnt signaling establishes the microtubule polarity in neurons through Kinesin-13.
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Affiliation(s)
- Dharmendra Puri
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Keerthana Ponniah
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Kasturi Biswas
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Atrayee Basu
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Swagata Dey
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Erik A Lundquist
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS
| | - Anindya Ghosh-Roy
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
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Wang X, Ellenbecker M, Hickey B, Day NJ, Osterli E, Terzo M, Voronina E. Antagonistic control of Caenorhabditis elegans germline stem cell proliferation and differentiation by PUF proteins FBF-1 and FBF-2. eLife 2020; 9:52788. [PMID: 32804074 PMCID: PMC7467723 DOI: 10.7554/elife.52788] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 08/14/2020] [Indexed: 02/07/2023] Open
Abstract
Stem cells support tissue maintenance, but the mechanisms that coordinate the rate of stem cell self-renewal with differentiation at a population level remain uncharacterized. We find that two PUF family RNA-binding proteins FBF-1 and FBF-2 have opposite effects on Caenorhabditis elegans germline stem cell dynamics: FBF-1 restricts the rate of meiotic entry, while FBF-2 promotes both cell division and meiotic entry rates. Antagonistic effects of FBFs are mediated by their distinct activities toward the shared set of target mRNAs, where FBF-1-mediated post-transcriptional control requires the activity of CCR4-NOT deadenylase, while FBF-2 is deadenylase-independent and might protect the targets from deadenylation. These regulatory differences depend on protein sequences outside of the conserved PUF family RNA-binding domain. We propose that the opposing FBF-1 and FBF-2 activities serve to modulate stem cell division rate simultaneously with the rate of meiotic entry.
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Affiliation(s)
- Xiaobo Wang
- Division of Biological Sciences, University of Montana, Missoula, United States
| | - Mary Ellenbecker
- Division of Biological Sciences, University of Montana, Missoula, United States
| | - Benjamin Hickey
- Division of Biological Sciences, University of Montana, Missoula, United States
| | - Nicholas J Day
- Division of Biological Sciences, University of Montana, Missoula, United States
| | - Emily Osterli
- Division of Biological Sciences, University of Montana, Missoula, United States
| | - Mikaya Terzo
- Division of Biological Sciences, University of Montana, Missoula, United States
| | - Ekaterina Voronina
- Division of Biological Sciences, University of Montana, Missoula, United States
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