1
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Martin CG, Bent JS, Hill T, Topalidou I, Singhvi A. Epithelial UNC-23 limits mechanical stress to maintain glia-neuron architecture in C. elegans. Dev Cell 2024; 59:1668-1688.e7. [PMID: 38670103 PMCID: PMC11233253 DOI: 10.1016/j.devcel.2024.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/23/2023] [Accepted: 04/03/2024] [Indexed: 04/28/2024]
Abstract
For an organ to maintain correct architecture and function, its diverse cellular components must coordinate their size and shape. Although cell-intrinsic mechanisms driving homotypic cell-cell coordination are known, it is unclear how cell shape is regulated across heterotypic cells. We find that epithelial cells maintain the shape of neighboring sense-organ glia-neuron units in adult Caenorhabditis elegans (C. elegans). Hsp co-chaperone UNC-23/BAG2 prevents epithelial cell shape from deforming, and its loss causes head epithelia to stretch aberrantly during animal movement. In the sense-organ glia, amphid sheath (AMsh), this causes progressive fibroblast growth factor receptor (FGFR)-dependent disruption of the glial apical cytoskeleton. Resultant glial cell shape alteration causes concomitant shape change in glia-associated neuron endings. Epithelial UNC-23 maintenance of glia-neuron shape is specific both spatially, within a defined anatomical zone, and temporally, in a developmentally critical period. As all molecular components uncovered are broadly conserved across central and peripheral nervous systems, we posit that epithelia may similarly regulate glia-neuron architecture cross-species.
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Affiliation(s)
- Cecilia G Martin
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - James S Bent
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Tyler Hill
- Department of Biology, Brandeis University, Waltham, MA 02454, USA
| | - Irini Topalidou
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98195, USA.
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2
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Hall AE, Klompstra D, Nance J. C. elegans Afadin is required for epidermal morphogenesis and functionally interfaces with the cadherin-catenin complex and RhoGAP PAC-1/ARHGAP21. Dev Biol 2024; 511:12-25. [PMID: 38556137 PMCID: PMC11088504 DOI: 10.1016/j.ydbio.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 03/07/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
During epithelial morphogenesis, the apical junctions connecting cells must remodel as cells change shape and make new connections with their neighbors. In the C. elegans embryo, new apical junctions form when epidermal cells migrate and seal with one another to encase the embryo in skin ('ventral enclosure'), and junctions remodel when epidermal cells change shape to squeeze the embryo into a worm shape ('elongation'). The junctional cadherin-catenin complex (CCC), which links epithelial cells to each other and to cortical actomyosin, is essential for C. elegans epidermal morphogenesis. RNAi genetic enhancement screens have identified several genes encoding proteins that interact with the CCC to promote epidermal morphogenesis, including the scaffolding protein Afadin (AFD-1), whose depletion alone results in only minor morphogenesis defects. Here, by creating a null mutation in afd-1, we show that afd-1 provides a significant contribution to ventral enclosure and elongation on its own. Unexpectedly, we find that afd-1 mutant phenotypes are strongly modified by diet, revealing a previously unappreciated parental nutritional input to morphogenesis. We identify functional interactions between AFD-1 and the CCC by demonstrating that E-cadherin is required for the polarized distribution of AFD-1 to cell contact sites in early embryos. Finally, we show that afd-1 promotes the enrichment of polarity regulator, and CCC-interacting protein, PAC-1/ARHGAP21 to cell contact sites, and we identify genetic interactions suggesting that afd-1 and pac-1 regulate epidermal morphogenesis at least in part through parallel mechanisms. Our findings reveal that C. elegans AFD-1 makes a significant contribution to epidermal morphogenesis and functionally interfaces with core and associated CCC proteins.
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Affiliation(s)
- Allison E Hall
- Department of Cell Biology, NYU School of Medicine, New York, NY, 10016, USA; Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, NY, 10016, USA; Regis University, Biology Department, Denver, CO, 80221, USA.
| | - Diana Klompstra
- Department of Cell Biology, NYU School of Medicine, New York, NY, 10016, USA; Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, NY, 10016, USA
| | - Jeremy Nance
- Department of Cell Biology, NYU School of Medicine, New York, NY, 10016, USA; Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, NY, 10016, USA; University of Wisconsin - Madison, Department of Cell and Regenerative Biology and Center for Quantitative Cell Imaging, Madison, WI, 53706, USA.
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3
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Houston J, Vissotsky C, Deep A, Hakozaki H, Crews E, Oegema K, Corbett KD, Lara-Gonzalez P, Kim T, Desai A. Phospho-KNL-1 recognition by a TPR domain targets the BUB-1-BUB-3 complex to C. elegans kinetochores. J Cell Biol 2024; 223:e202402036. [PMID: 38578284 PMCID: PMC10996584 DOI: 10.1083/jcb.202402036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/21/2024] [Accepted: 03/25/2024] [Indexed: 04/06/2024] Open
Abstract
During mitosis, the Bub1-Bub3 complex concentrates at kinetochores, the microtubule-coupling interfaces on chromosomes, where it contributes to spindle checkpoint activation, kinetochore-spindle microtubule interactions, and protection of centromeric cohesion. Bub1 has a conserved N-terminal tetratricopeptide repeat (TPR) domain followed by a binding motif for its conserved interactor Bub3. The current model for Bub1-Bub3 localization to kinetochores is that Bub3, along with its bound motif from Bub1, recognizes phosphorylated "MELT" motifs in the kinetochore scaffold protein Knl1. Motivated by the greater phenotypic severity of BUB-1 versus BUB-3 loss in C. elegans, we show that the BUB-1 TPR domain directly recognizes a distinct class of phosphorylated motifs in KNL-1 and that this interaction is essential for BUB-1-BUB-3 localization and function. BUB-3 recognition of phospho-MELT motifs additively contributes to drive super-stoichiometric accumulation of BUB-1-BUB-3 on its KNL-1 scaffold during mitotic entry. Bub1's TPR domain interacts with Knl1 in other species, suggesting that collaboration of TPR-dependent and Bub3-dependent interfaces in Bub1-Bub3 localization and functions may be conserved.
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Affiliation(s)
- Jack Houston
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA, USA
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
- Ludwig Institute for Cancer Research, La Jolla, CA, USA
| | | | - Amar Deep
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Hiroyuki Hakozaki
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Enice Crews
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Karen Oegema
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA, USA
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
- Ludwig Institute for Cancer Research, La Jolla, CA, USA
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Kevin D. Corbett
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA, USA
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Pablo Lara-Gonzalez
- Ludwig Institute for Cancer Research, La Jolla, CA, USA
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Taekyung Kim
- Ludwig Institute for Cancer Research, La Jolla, CA, USA
- Department of Biology Education, Pusan National University, Busan, Republic of Korea
| | - Arshad Desai
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA, USA
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
- Ludwig Institute for Cancer Research, La Jolla, CA, USA
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
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4
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Haley JA, Chalasani SH. C. elegans foraging as a model for understanding the neuronal basis of decision-making. Cell Mol Life Sci 2024; 81:252. [PMID: 38849591 DOI: 10.1007/s00018-024-05223-1] [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: 12/14/2023] [Revised: 03/27/2024] [Accepted: 03/30/2024] [Indexed: 06/09/2024]
Abstract
Animals have evolved to seek, select, and exploit food sources in their environment. Collectively termed foraging, these ubiquitous behaviors are necessary for animal survival. As a foundation for understanding foraging, behavioral ecologists established early theoretical and mathematical frameworks which have been subsequently refined and supported by field and laboratory studies of foraging animals. These simple models sought to explain how animals decide which strategies to employ when locating food, what food items to consume, and when to explore the environment for new food sources. These foraging decisions involve integration of prior experience with multimodal sensory information about the animal's current environment and internal state. We suggest that the nematode Caenorhabditis elegans is well-suited for a high-resolution analysis of complex goal-oriented behaviors such as foraging. We focus our discussion on behavioral studies highlighting C. elegans foraging on bacteria and summarize what is known about the underlying neuronal and molecular pathways. Broadly, we suggest that this simple model system can provide a mechanistic understanding of decision-making and present additional avenues for advancing our understanding of complex behavioral processes.
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Affiliation(s)
- Jessica A Haley
- Neurosciences Graduate Program, University of California San Diego, La Jolla, CA, 92093, USA
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Sreekanth H Chalasani
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.
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5
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Chen L, Su P, Wang Y, Liu Y, Chen LM, Gao S. CKR-1 orchestrates two motor states from a single motoneuron in C. elegans. iScience 2024; 27:109390. [PMID: 38510145 PMCID: PMC10952047 DOI: 10.1016/j.isci.2024.109390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/22/2023] [Accepted: 02/28/2024] [Indexed: 03/22/2024] Open
Abstract
Neuromodulation is pivotal in modifying neuronal properties and motor states. CKR-1, a homolog of the cholecystokinin receptor, modulates robust escape steering and undulation body bending in C. elegans. Nevertheless, the mechanisms through which CKR-1 governs these motor states remain elusive. We elucidate the head motoneuron SMD as the orchestrator of both motor states. This regulation involves two neuropeptides: NLP-12 from DVA enhances undulation body curvature, while NLP-18 from ASI amplifies Ω-turn head curvature. Moreover, synthetic NLP-12 and NLP-18 peptides elicit CKR-1-dependent currents in Xenopus oocytes and Ca2+ transients in SMD neurons. Notably, CKR-1 shows higher sensitivity to NLP-18 compared to NLP-12. In situ patch-clamp recordings reveal CKR-1, NLP-12, and NLP-18 are not essential for neurotransmission at C. elegans neuromuscular junction, suggesting that SMD independently regulates head and body bending. Our studies illustrate that a single motoneuron SMD utilizes a cholecystokinin receptor CKR-1 to integrate two motor states.
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Affiliation(s)
- Lili Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Pan Su
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ya Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yuting Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Li-Ming Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
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6
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Meng J, Ahamed T, Yu B, Hung W, EI Mouridi S, Wang Z, Zhang Y, Wen Q, Boulin T, Gao S, Zhen M. A tonically active master neuron modulates mutually exclusive motor states at two timescales. SCIENCE ADVANCES 2024; 10:eadk0002. [PMID: 38598630 PMCID: PMC11006214 DOI: 10.1126/sciadv.adk0002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 03/07/2024] [Indexed: 04/12/2024]
Abstract
Continuity of behaviors requires animals to make smooth transitions between mutually exclusive behavioral states. Neural principles that govern these transitions are not well understood. Caenorhabditis elegans spontaneously switch between two opposite motor states, forward and backward movement, a phenomenon thought to reflect the reciprocal inhibition between interneurons AVB and AVA. Here, we report that spontaneous locomotion and their corresponding motor circuits are not separately controlled. AVA and AVB are neither functionally equivalent nor strictly reciprocally inhibitory. AVA, but not AVB, maintains a depolarized membrane potential. While AVA phasically inhibits the forward promoting interneuron AVB at a fast timescale, it maintains a tonic, extrasynaptic excitation on AVB over the longer timescale. We propose that AVA, with tonic and phasic activity of opposite polarities on different timescales, acts as a master neuron to break the symmetry between the underlying forward and backward motor circuits. This master neuron model offers a parsimonious solution for sustained locomotion consisted of mutually exclusive motor states.
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Affiliation(s)
- Jun Meng
- Department of Physiology, University of Toronto, Toronto, ON, Canada
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Tosif Ahamed
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Bin Yu
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Wesley Hung
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Sonia EI Mouridi
- University Claude Bernard Lyon 1, MeLiS, CNRS UMR 5284, INSERM U1314, 69008 Lyon, France
| | - Zezhen Wang
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Yongning Zhang
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Quan Wen
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Thomas Boulin
- University Claude Bernard Lyon 1, MeLiS, CNRS UMR 5284, INSERM U1314, 69008 Lyon, France
| | - Shangbang Gao
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Mei Zhen
- Department of Physiology, University of Toronto, Toronto, ON, Canada
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
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7
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Lessenger AT, Swaffer MP, Skotheim JM, Feldman JL. Somatic polyploidy supports biosynthesis and tissue function by increasing transcriptional output. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.25.586714. [PMID: 38585999 PMCID: PMC10996643 DOI: 10.1101/2024.03.25.586714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Cell size and biosynthetic capacity generally increase with increased DNA content. Polyploidy has therefore been proposed to be an adaptive strategy to increase cell size in specialized tissues with high biosynthetic demands. However, if and how DNA concentration limits cellular biosynthesis in vivo is not well understood, and the impacts of polyploidy in non-disease states is not well studied. Here, we show that polyploidy in the C. elegans intestine is critical for cell growth and yolk biosynthesis, a central role of this organ. Artificially lowering the DNA/cytoplasm ratio by reducing polyploidization in the intestine gave rise to smaller cells with more dilute mRNA. Highly-expressed transcripts were more sensitive to this mRNA dilution, whereas lowly-expressed genes were partially compensated - in part by loading more RNA Polymerase II on the remaining genomes. DNA-dilute cells had normal total protein concentration, which we propose is achieved by increasing production of translational machinery at the expense of specialized, cell-type specific proteins.
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8
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Ray S, Gurung P, Manning RS, Kravchuk AA, Singhvi A. Neuron cilia restrain glial KCC-3 to a microdomain to regulate multisensory processing. Cell Rep 2024; 43:113844. [PMID: 38421867 PMCID: PMC11296322 DOI: 10.1016/j.celrep.2024.113844] [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: 09/12/2023] [Revised: 12/15/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
Glia interact with multiple neurons, but it is unclear whether their interactions with each neuron are different. Our interrogation at single-cell resolution reveals that a single glial cell exhibits specificity in its interactions with different contacting neurons. Briefly, C. elegans amphid sheath (AMsh) glia apical-like domains contact 12 neuron-endings. At these ad-neuronal membranes, AMsh glia localize the K/Cl transporter KCC-3 to a microdomain exclusively around the thermosensory AFD neuron to regulate its properties. Glial KCC-3 is transported to ad-neuronal regions, where distal cilia of non-AFD glia-associated chemosensory neurons constrain it to a microdomain at AFD-contacting glial membranes. Aberrant KCC-3 localization impacts both thermosensory (AFD) and chemosensory (non-AFD) neuron properties. Thus, neurons can interact non-synaptically through a shared glial cell by regulating microdomain localization of its cues. As AMsh and glia across species compartmentalize multiple cues like KCC-3, we posit that this may be a broadly conserved glial mechanism that modulates information processing across multimodal circuits.
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Affiliation(s)
- Sneha Ray
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Neuroscience Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - Pralaksha Gurung
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Neuroscience Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - R Sean Manning
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Alexandra A Kravchuk
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98195, USA.
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9
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Kenny-Ganzert IW, Sherwood DR. The C. elegans anchor cell: A model to elucidate mechanisms underlying invasion through basement membrane. Semin Cell Dev Biol 2024; 154:23-34. [PMID: 37422376 PMCID: PMC10592375 DOI: 10.1016/j.semcdb.2023.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 06/30/2023] [Accepted: 07/01/2023] [Indexed: 07/10/2023]
Abstract
Cell invasion through basement membrane barriers is crucial during many developmental processes and in immune surveillance. Dysregulation of invasion also drives the pathology of numerous human diseases, such as metastasis and inflammatory disorders. Cell invasion involves dynamic interactions between the invading cell, basement membrane, and neighboring tissues. Owing to this complexity, cell invasion is challenging to study in vivo, which has hampered the understanding of mechanisms controlling invasion. Caenorhabditis elegans anchor cell invasion is a powerful in vivo model where subcellular imaging of cell-basement membrane interactions can be combined with genetic, genomic, and single-cell molecular perturbation studies. In this review, we outline insights gained by studying anchor cell invasion, which span transcriptional networks, translational regulation, secretory apparatus expansion, dynamic and adaptable protrusions that breach and clear basement membrane, and a complex, localized metabolic network that fuels invasion. Together, investigation of anchor cell invasion is building a comprehensive understanding of the mechanisms that underlie invasion, which we expect will ultimately facilitate better therapeutic strategies to control cell invasive activity in human disease.
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Affiliation(s)
| | - David R Sherwood
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA.
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10
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Houston J, Vissotsky C, Deep A, Hakozaki H, Crews E, Oegema K, Corbett KD, Lara-Gonzalez P, Kim T, Desai A. Phospho-KNL-1 recognition by a TPR domain targets the BUB-1-BUB-3 complex to C. elegans kinetochores. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.09.579536. [PMID: 38370671 PMCID: PMC10871365 DOI: 10.1101/2024.02.09.579536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
During mitosis, the Bub1-Bub3 complex concentrates at kinetochores, the microtubule-coupling interfaces on chromosomes, where it contributes to spindle checkpoint activation, kinetochore-spindle microtubule interactions, and protection of centromeric cohesion. Bub1 has a conserved N-terminal tetratricopeptide (TPR) domain followed by a binding motif for its conserved interactor Bub3. The current model for Bub1-Bub3 localization to kinetochores is that Bub3, along with its bound motif from Bub1, recognizes phosphorylated "MELT" motifs in the kinetochore scaffold protein Knl1. Motivated by the greater phenotypic severity of BUB-1 versus BUB-3 loss in C. elegans, we show that the BUB-1 TPR domain directly recognizes a distinct class of phosphorylated motifs in KNL-1 and that this interaction is essential for BUB-1-BUB-3 localization and function. BUB-3 recognition of phospho-MELT motifs additively contributes to drive super-stoichiometric accumulation of BUB-1-BUB-3 on its KNL-1 scaffold during mitotic entry. Bub1's TPR domain interacts with Knl1 in other species, suggesting that collaboration of TPR-dependent and Bub3-dependent interfaces in Bub1-Bub3 localization and functions may be conserved.
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Affiliation(s)
- Jack Houston
- Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California 92093, USA
- Department of Cell & Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, California 92093, USA
- Ludwig Institute for Cancer Research, La Jolla, California 92093, USA
| | | | - Amar Deep
- Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, California 92093, USA
| | - Hiro Hakozaki
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Enice Crews
- Department of Cell & Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, California 92093, USA
| | - Karen Oegema
- Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California 92093, USA
- Department of Cell & Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, California 92093, USA
- Ludwig Institute for Cancer Research, La Jolla, California 92093, USA
- Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, California 92093, USA
| | - Kevin D. Corbett
- Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California 92093, USA
- Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, California 92093, USA
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Pablo Lara-Gonzalez
- Ludwig Institute for Cancer Research, La Jolla, California 92093, USA
- Department of Developmental & Cell Biology, University of California Irvine, Irvine, CA 92697, USA
| | - Taekyung Kim
- Ludwig Institute for Cancer Research, La Jolla, California 92093, USA
- Department of Biology Education, Pusan National University, Busan 46241, Republic of Korea
| | - Arshad Desai
- Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California 92093, USA
- Department of Cell & Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, California 92093, USA
- Ludwig Institute for Cancer Research, La Jolla, California 92093, USA
- Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, California 92093, USA
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11
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Cebul ER, Marivin A, Wexler LR, Perrat PN, Bénard CY, Garcia-Marcos M, Heiman MG. SAX-7/L1CAM acts with the adherens junction proteins MAGI-1, HMR-1/Cadherin, and AFD-1/Afadin to promote glial-mediated dendrite extension. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.11.575259. [PMID: 38260503 PMCID: PMC10802611 DOI: 10.1101/2024.01.11.575259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Adherens junctions (AJs) are a fundamental organizing structure for multicellular life. Although AJs are studied mainly in epithelia, their core function - stabilizing cell contacts by coupling adhesion molecules to the cytoskeleton - is important in diverse tissues. We find that two C. elegans sensory neurons, URX and BAG, require conserved AJ proteins for dendrite morphogenesis. We previously showed that URX and BAG dendrites attach to the embryonic nose via the adhesion molecule SAX-7/L1CAM, acting both in neurons and glia, and then extend by stretch during embryo elongation. Here, we find that a PDZ-binding motif (PB) in the SAX-7 cytoplasmic tail acts with other interaction motifs to promote dendrite extension. Using pull-down assays, we find that the SAX-7 PB binds the multi-PDZ scaffolding protein MAGI-1, which bridges it to the cadherin-catenin complex protein HMP-2/β-catenin. Using cell-specific rescue and depletion, we find that both MAGI-1 and HMR-1/Cadherin act in glia to non-autonomously promote dendrite extension. Double mutant analysis indicates that each protein can act independently of SAX-7, suggesting a multivalent adhesion complex. The SAX-7 PB motif also binds AFD-1/Afadin, loss of which further enhances sax-7 BAG dendrite defects. As MAGI-1, HMR-1, and AFD-1 are all found in epithelial AJs, we propose that an AJ-like complex in glia promotes dendrite extension.
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Affiliation(s)
- Elizabeth R. Cebul
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
- Present address: Section on Sensory Cell Development and Function, National Institute on Deafness and Other Communication Disorders, Bethesda, MD 20892, USA
| | - Arthur Marivin
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA, Boston University School of Medicine, Boston, MA 02118, USA
| | - Leland R. Wexler
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Paola N. Perrat
- Department of Biological Sciences, CERMO-FC Research Center, Universite du Québec à Montréal, Montreál, QC, Canada
| | - Claire Y. Bénard
- Department of Biological Sciences, CERMO-FC Research Center, Universite du Québec à Montréal, Montreál, QC, Canada
| | - Mikel Garcia-Marcos
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA, Boston University School of Medicine, Boston, MA 02118, USA
- Department of Biology, College of Arts & Sciences, Boston University, Boston, MA 02115, USA
| | - Maxwell G. Heiman
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
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12
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Liu J, Murray JI. Mechanisms of lineage specification in Caenorhabditis elegans. Genetics 2023; 225:iyad174. [PMID: 37847877 DOI: 10.1093/genetics/iyad174] [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: 08/26/2023] [Accepted: 09/18/2023] [Indexed: 10/19/2023] Open
Abstract
The studies of cell fate and lineage specification are fundamental to our understanding of the development of multicellular organisms. Caenorhabditis elegans has been one of the premiere systems for studying cell fate specification mechanisms at single cell resolution, due to its transparent nature, the invariant cell lineage, and fixed number of somatic cells. We discuss the general themes and regulatory mechanisms that have emerged from these studies, with a focus on somatic lineages and cell fates. We next review the key factors and pathways that regulate the specification of discrete cells and lineages during embryogenesis and postembryonic development; we focus on transcription factors and include numerous lineage diagrams that depict the expression of key factors that specify embryonic founder cells and postembryonic blast cells, and the diverse somatic cell fates they generate. We end by discussing some future perspectives in cell and lineage specification.
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Affiliation(s)
- Jun Liu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - John Isaac Murray
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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13
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Sherwood DR, Kenny-Ganzert IW, Balachandar Thendral S. Translational regulation of cell invasion through extracellular matrix-an emerging role for ribosomes. F1000Res 2023; 12:1528. [PMID: 38628976 PMCID: PMC11019292 DOI: 10.12688/f1000research.143519.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/22/2023] [Indexed: 04/19/2024] Open
Abstract
Many developmental and physiological processes require cells to invade and migrate through extracellular matrix barriers. This specialized cellular behavior is also misregulated in many diseases, such as immune disorders and cancer. Cell invasive activity is driven by pro-invasive transcriptional networks that activate the expression of genes encoding numerous different proteins that expand and regulate the cytoskeleton, endomembrane system, cell adhesion, signaling pathways, and metabolic networks. While detailed mechanistic studies have uncovered crucial insights into pro-invasive transcriptional networks and the distinct cell biological attributes of invasive cells, less is known about how invasive cells modulate mRNA translation to meet the robust, dynamic, and unique protein production needs of cell invasion. In this review we outline known modes of translation regulation promoting cell invasion and focus on recent studies revealing elegant mechanisms that expand ribosome biogenesis within invasive cells to meet the increased protein production requirements to invade and migrate through extracellular matrix barriers.
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14
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Schwartz AZA, Abdu Y, Nance J. ZIF-1-mediated degradation of zinc finger proteins in the Caenorhabditis elegans germ line. Genetics 2023; 225:iyad160. [PMID: 37647858 PMCID: PMC10627257 DOI: 10.1093/genetics/iyad160] [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: 07/07/2023] [Revised: 08/21/2023] [Accepted: 08/21/2023] [Indexed: 09/01/2023] Open
Abstract
Rapid and conditional protein depletion is the gold standard genetic tool for deciphering the molecular basis of developmental processes. Previously, we showed that by conditionally expressing the E3 ligase substrate adaptor ZIF-1 in Caenorhabditis elegans somatic cells, proteins tagged with the first CCCH Zn finger 1 (ZF1) domain from the germline regulator PIE-1 degrade rapidly, resulting in loss-of-function phenotypes. The described role of ZIF-1 is to clear PIE-1 and several other CCCH Zn finger proteins from early somatic cells, helping to enrich them in germline precursor cells. Here, we show that proteins tagged with the PIE-1 ZF1 domain are subsequently cleared from primordial germ cells (PGCs) in embryos and from undifferentiated germ cells in larvae and adults by ZIF-1. We harness germline ZIF-1 activity to degrade a ZF1-tagged fusion protein from PGCs and show that its depletion produces phenotypes equivalent to those of a null mutation. Our findings reveal that ZIF-1 transitions from degrading CCCH Zn finger proteins in somatic cells to clearing them from undifferentiated germ cells, and that ZIF-1 activity can be harnessed as a new genetic tool to study the early germline.
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Affiliation(s)
- Aaron Z A Schwartz
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY 10016, USA
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Yusuff Abdu
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY 10016, USA
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Jeremy Nance
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY 10016, USA
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, NY 10016, USA
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15
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Heinze SD, Berger S, Engleitner S, Daube M, Hajnal A. Prolonging somatic cell proliferation through constitutive hox gene expression in C. elegans. Nat Commun 2023; 14:6850. [PMID: 37891160 PMCID: PMC10611754 DOI: 10.1038/s41467-023-42644-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
hox genes encode a conserved family of homeodomain transcription factors that are essential to determine the identity of body segments during embryogenesis and maintain adult somatic stem cells competent to regenerate organs. In contrast to higher organisms, somatic cells in C. elegans irreversibly exit the cell cycle after completing their cell lineage and the adult soma cannot regenerate. Here, we show that hox gene expression levels in C. elegans determine the temporal competence of somatic cells to proliferate. Down-regulation of the central hox gene lin-39 in dividing vulval cells results in their premature cell cycle exit, whereas constitutive lin-39 expression causes precocious Pn.p cell and sex myoblast divisions and prolongs the proliferative phase of the vulval cells past their normal point of arrest. Furthermore, ectopic expression of hox genes in the quiescent anchor cell re-activates the cell cycle and induces proliferation until young adulthood. Thus, constitutive expression of a single hox transcription factor is sufficient to prolong somatic cell proliferation beyond the restriction imposed by the cell lineage. The down-regulation of hox gene expression in most somatic cells at the end of larval development may be one cause for the absence of cell proliferation in adult C. elegans.
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Affiliation(s)
- Svenia D Heinze
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
- Molecular Life Science PhD Program, University and ETH Zürich, CH-8057, Zürich, Switzerland
| | - Simon Berger
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
- Institute for Chemical- and Bioengineering, ETH Zürich, Vladimir Prelog Weg 1, 8093, Zürich, Switzerland
| | - Stefanie Engleitner
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
- Molecular Life Science PhD Program, University and ETH Zürich, CH-8057, Zürich, Switzerland
| | - Michael Daube
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Alex Hajnal
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland.
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16
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Stolpner NJ, Manzi NI, Su T, Dickinson DJ. Apical PAR protein caps orient the mitotic spindle in C. elegans early embryos. Curr Biol 2023; 33:4312-4329.e6. [PMID: 37729910 PMCID: PMC10615879 DOI: 10.1016/j.cub.2023.08.069] [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: 03/27/2023] [Revised: 07/24/2023] [Accepted: 08/23/2023] [Indexed: 09/22/2023]
Abstract
During embryonic development, oriented cell divisions are important for patterned tissue growth and cell fate specification. Cell division orientation is controlled in part by asymmetrically localized polarity proteins, which establish functional domains of the cell membrane and interact with microtubule regulators to position the mitotic spindle. For example, in the 8-cell mouse embryo, apical polarity proteins form caps on the outside, contact-free surface of the embryo that position the mitotic spindle to execute asymmetric cell division. A similar radial or "inside-outside" polarity is established at an early stage in many other animal embryos, but in most cases, it remains unclear how inside-outside polarity is established and how it influences downstream cell behaviors. Here, we explore inside-outside polarity in C. elegans somatic blastomeres using spatiotemporally controlled protein degradation and live embryo imaging. We show that PAR polarity proteins, which form apical caps at the center of the contact-free membrane, localize dynamically during the cell cycle and contribute to spindle orientation and proper cell positioning. Surprisingly, isolated single blastomeres lacking cell contacts are able to break symmetry and form PAR-3/atypical protein kinase C (aPKC) caps. Polarity caps form independently of actomyosin flows and microtubules and can regulate spindle orientation in cooperation with the key polarity kinase aPKC. Together, our results reveal a role for apical polarity caps in regulating spindle orientation in symmetrically dividing cells and provide novel insights into how these structures are formed.
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Affiliation(s)
- Naomi J Stolpner
- Department of Molecular Biosciences, The University of Texas at Austin, 2415 Speedway, PAT 206, Austin, TX 78712, USA
| | - Nadia I Manzi
- Department of Molecular Biosciences, The University of Texas at Austin, 2415 Speedway, PAT 206, Austin, TX 78712, USA
| | - Thomas Su
- Department of Molecular Biosciences, The University of Texas at Austin, 2415 Speedway, PAT 206, Austin, TX 78712, USA
| | - Daniel J Dickinson
- Department of Molecular Biosciences, The University of Texas at Austin, 2415 Speedway, PAT 206, Austin, TX 78712, USA.
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17
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Naturale VF, Pickett MA, Feldman JL. Persistent cell contacts enable E-cadherin/HMR-1- and PAR-3-based symmetry breaking within a developing C. elegans epithelium. Dev Cell 2023; 58:1830-1846.e12. [PMID: 37552986 PMCID: PMC10592304 DOI: 10.1016/j.devcel.2023.07.008] [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: 08/12/2022] [Revised: 05/10/2023] [Accepted: 07/17/2023] [Indexed: 08/10/2023]
Abstract
Tissue-wide patterning is essential to multicellular development, requiring cells to individually generate polarity axes and coordinate them in space and time with neighbors. Using the C. elegans intestinal epithelium, we identified a patterning mechanism that is informed by cell contact lifetime asymmetry and executed via the scaffolding protein PAR-3 and the transmembrane protein E-cadherin/HMR-1. Intestinal cells break symmetry as PAR-3 and HMR-1 recruit apical determinants into punctate "local polarity complexes" (LPCs) at homotypic contacts. LPCs undergo an HMR-1-based migration to a common midline, thereby establishing tissue-wide polarity. Thus, symmetry breaking results from PAR-3-dependent intracellular polarization coupled to HMR-1-based tissue-level communication, which occurs through a non-adhesive signaling role for HMR-1. Differential lifetimes between homotypic and heterotypic cell contacts are created by neighbor exchanges and oriented divisions, patterning where LPCs perdure and thereby breaking symmetry. These cues offer a logical and likely conserved framework for how epithelia without obvious molecular asymmetries can polarize.
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Affiliation(s)
| | - Melissa A Pickett
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Jessica L Feldman
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
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18
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Glomb O, Swaim G, Munoz LLancao P, Lovejoy C, Sutradhar S, Park J, Wu Y, Cason SE, Holzbaur ELF, Hammarlund M, Howard J, Ferguson SM, Gramlich MW, Yogev S. A kinesin-1 adaptor complex controls bimodal slow axonal transport of spectrin in Caenorhabditis elegans. Dev Cell 2023; 58:1847-1863.e12. [PMID: 37751746 PMCID: PMC10574138 DOI: 10.1016/j.devcel.2023.08.031] [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: 06/25/2023] [Revised: 08/18/2023] [Accepted: 08/30/2023] [Indexed: 09/28/2023]
Abstract
An actin-spectrin lattice, the membrane periodic skeleton (MPS), protects axons from breakage. MPS integrity relies on spectrin delivery via slow axonal transport, a process that remains poorly understood. We designed a probe to visualize endogenous spectrin dynamics at single-axon resolution in vivo. Surprisingly, spectrin transport is bimodal, comprising fast runs and movements that are 100-fold slower than previously reported. Modeling and genetic analysis suggest that the two rates are independent, yet both require kinesin-1 and the coiled-coil proteins UNC-76/FEZ1 and UNC-69/SCOC, which we identify as spectrin-kinesin adaptors. Knockdown of either protein led to disrupted spectrin motility and reduced distal MPS, and UNC-76 overexpression instructed excessive transport of spectrin. Artificially linking spectrin to kinesin-1 drove robust motility but inefficient MPS assembly, whereas impairing MPS assembly led to excessive spectrin transport, suggesting a balance between transport and assembly. These results provide insight into slow axonal transport and MPS integrity.
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Affiliation(s)
- Oliver Glomb
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA
| | - Grace Swaim
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA; Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Pablo Munoz LLancao
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Christopher Lovejoy
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Sabyasachi Sutradhar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Junhyun Park
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA
| | - Youjun Wu
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | - Sydney E Cason
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marc Hammarlund
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA; Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | - Jonathon Howard
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA; Quantitative Biology Institute, Yale University, New Haven, CT 06510, USA
| | - Shawn M Ferguson
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | | | - Shaul Yogev
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA.
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19
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Land R, Fetter R, Liang X, Tzeng CP, Taylor CA, Shen K. Endoplasmic Reticulum Exit Sites scale with somato-dendritic size in neurons. Mol Biol Cell 2023; 34:ar106. [PMID: 37556208 PMCID: PMC10559313 DOI: 10.1091/mbc.e23-03-0090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 07/10/2023] [Accepted: 08/02/2023] [Indexed: 08/11/2023] Open
Abstract
Nervous systems exhibit dramatic diversity in cell morphology and size. How neurons regulate their biosynthetic and secretory machinery to support such diversity is not well understood. Endoplasmic reticulum exit sites (ERESs) are essential for maintaining secretory flux, and are required for normal dendrite development, but how neurons of different size regulate secretory capacity remains unknown. In Caenorhabditis elegans, we find that the ERES number is strongly correlated with the size of a neuron's dendritic arbor. The elaborately branched sensory neuron, PVD, has especially high ERES numbers. Asymmetric cell division provides PVD with a large initial cell size critical for rapid establishment of PVD's high ERES number before neurite outgrowth, and these ERESs are maintained throughout development. Maintenance of ERES number requires the cell fate transcription factor MEC-3, C. elegans TOR (ceTOR/let-363), and nutrient availability, with mec-3 and ceTOR/let-363 mutant PVDs both displaying reductions in ERES number, soma size, and dendrite size. Notably, mec-3 mutant animals exhibit reduced expression of a ceTOR/let-363 reporter in PVD, and starvation reduces ERES number and somato-dendritic size in a manner genetically redundant with ceTOR/let-363 perturbation. Our data suggest that both asymmetric cell division and nutrient sensing pathways regulate secretory capacities to support elaborate dendritic arbors.
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Affiliation(s)
- Ruben Land
- Department of Biology, Stanford University, Stanford, CA 94305
- Neurosciences IDP, Stanford University, Stanford, CA 94305
| | - Richard Fetter
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305
| | - Xing Liang
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Christopher P. Tzeng
- Department of Biology, Stanford University, Stanford, CA 94305
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305
| | - Caitlin A. Taylor
- Department of Biology, Stanford University, Stanford, CA 94305
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, CA 94305
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305
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20
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Tzeng CP, Shen K. Wnt signaling and contact-mediated repulsion shape sensory dendritic fields. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.14.557812. [PMID: 37781584 PMCID: PMC10540810 DOI: 10.1101/2023.09.14.557812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
The complete and non-redundant coverage of sensory tissues by neighboring neurons enables effective detection of stimuli in the environment. How the neurites of adjacent neurons establish their boundaries to achieve this completeness in coverage remains incompletely understood. Here, we use distinct fluorescent reporters to study two neighboring sensory neurons with complex dendritic arbors, FLP and PVD, in C. elegans . We quantify the sizes of their dendritic fields, and identify CWN-2/Wnt and LIN-17/Frizzled as a ligand and receptor that regulate the relative dendritic field sizes of these two neurons. Loss of either cwn-2 or lin-17 results in complementary changes in the size of the dendritic fields of both neurons; the FLP arbor expands, while that of PVD shrinks. Using an endogenous knock-in mNeonGreen-CWN-2/Wnt, we find that CWN-2/Wnt is localized along the path of growing FLP dendrites. Dynamic imaging shows a significant braking of FLP dendrite growth upon CWN-2/Wnt contact. We find that LIN-17/Frizzled functions cell-autonomously in FLP to limit dendritic field size and propose that PVD fills the space left by FLP through contact-induced retraction. Our results reveal that interactions of dendrites with adjacent dendrites and with environmental cues both shape the boundaries of neighboring dendritic fields. Highlights ▫ Secreted Wnt CWN-2 and cell-autonomous activity of neuronal LIN-17/Frizzled receptors restrict FLP dendritic field sizes▫ Endogenously tagged CWN-2/Wnt is punctate and visible in the same plane of growing FLP dendrites▫ Growth of developing FLP dendrites is inhibited upon contact with extracellular CWN-2/Wnt and with PVD dendrites.
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21
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McIntyre DC, Nance J. Niche cells regulate primordial germ cell quiescence in response to basement membrane signaling. Development 2023; 150:dev201640. [PMID: 37497562 PMCID: PMC10445801 DOI: 10.1242/dev.201640] [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: 01/25/2023] [Accepted: 07/17/2023] [Indexed: 07/28/2023]
Abstract
Stem cell quiescence, proliferation and differentiation are controlled by interactions with niche cells and a specialized extracellular matrix called basement membrane (BM). Direct interactions with adjacent BM are known to regulate stem cell quiescence; however, it is less clear how niche BM relays signals to stem cells that it does not contact. Here, we examine how niche BM regulates Caenorhabditis elegans primordial germ cells (PGCs). BM regulates PGC quiescence even though PGCs are enwrapped by somatic niche cells and do not contact the BM; this can be demonstrated by depleting laminin, which causes normally quiescent embryonic PGCs to proliferate. We show that following laminin depletion, niche cells relay proliferation-inducing signals from the gonadal BM to PGCs via integrin receptors. Disrupting the BM proteoglycan perlecan blocks PGC proliferation when laminin is depleted, indicating that laminin functions to inhibit a proliferation-inducing signal originating from perlecan. Reducing perlecan levels in fed larvae hampers germline growth, suggesting that BM signals regulate germ cell proliferation under physiological conditions. Our results reveal how BM signals can regulate stem cell quiescence indirectly, by activating niche cell integrin receptors.
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Affiliation(s)
- Daniel C. McIntyre
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, NY 10016, USA
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY 10016, USA
- University of Virginia, Department of Biology, 90 Geldard Drive, Physical Life Science Building Room 318, Charlottesville, VA 22904, USA
| | - Jeremy Nance
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, NY 10016, USA
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY 10016, USA
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22
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Hall AE, Klompstra D, Nance J. C. elegans Afadin is required for epidermal morphogenesis and functionally interfaces with the cadherin-catenin complex and RhoGAP PAC-1/ARHGAP21. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.28.551013. [PMID: 37546884 PMCID: PMC10402129 DOI: 10.1101/2023.07.28.551013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
During epithelial morphogenesis, the apical junctions connecting cells must remodel as cells change shape and make new connections with their neighbors. In the C. elegans embryo, new apical junctions form when epidermal cells migrate and seal with one another to encase the embryo in skin ('ventral enclosure'), and junctions remodel when epidermal cells change shape to squeeze the embryo into a worm shape ('elongation'). The junctional cadherin-catenin complex (CCC), which links epithelial cells to each other and to cortical actomyosin, is essential for C. elegans epidermal morphogenesis. RNAi genetic enhancement screens have identified several proteins that interact with the CCC to promote epidermal morphogenesis, including the scaffolding protein Afadin (AFD-1), whose depletion alone results in only minor morphogenesis defects. Here, by creating a null mutation in afd-1 , we show that afd-1 provides a significant contribution to ventral enclosure and elongation on its own. Unexpectedly, we find that afd-1 mutant phenotypes are strongly modified by diet, revealing a previously unappreciated maternal nutritional input to morphogenesis. We identify functional interactions between AFD-1 and the CCC by demonstrating that E-cadherin is required for the polarized distribution of AFD-1 to cell contact sites in early embryos. Finally, we show that afd-1 promotes the enrichment of polarity regulator and CCC-interacting protein PAC-1/ARHGAP21 to cell contact sites, and identify genetic interactions suggesting that afd-1 and pac-1 regulate epidermal morphogenesis at least in part through parallel mechanisms. Our findings reveal that C. elegans AFD-1 makes a significant contribution to epidermal morphogenesis and functionally interfaces with core and associated CCC proteins.
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23
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Schwartz AZ, Abdu Y, Nance J. ZIF-1-mediated degradation of endogenous and heterologous zinc finger proteins in the C. elegans germ line. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.10.548405. [PMID: 37502839 PMCID: PMC10369855 DOI: 10.1101/2023.07.10.548405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Rapid and conditional protein depletion is the gold standard genetic tool for deciphering the molecular basis of developmental processes. Previously, we showed that by conditionally expressing the E3 ligase substrate adaptor ZIF-1 in Caenorhabditis elegans somatic cells, proteins tagged with the first CCCH Zn finger (ZF1) domain from the germline regulator PIE-1 degrade rapidly, resulting in loss-of-function phenotypes. The described role of ZIF-1 is to clear PIE-1 and several other CCCH Zn finger proteins from early somatic cells, helping to enrich them in germline precursor cells. Here, we show that proteins tagged with the PIE-1 ZF1 domain are subsequently cleared from primordial germ cells in embryos and from undifferentiated germ cells in larvae and adults by ZIF-1. We harness germline ZIF-1 activity to degrade a ZF1-tagged heterologous protein from PGCs and show that its depletion produces phenotypes equivalent to those of a null mutation. Our findings reveal that ZIF-1 switches roles from degrading CCCH Zn finger proteins in somatic cells to clearing them from undifferentiated germ cells, and that ZIF-1 activity can be harnessed as a new genetic tool to study the early germ line.
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Affiliation(s)
- Aaron Z.A. Schwartz
- Department of Cell Biology, NYU Grossman School of Medicine, New York NY 10016
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York NY 10016
| | - Yusuff Abdu
- Department of Cell Biology, NYU Grossman School of Medicine, New York NY 10016
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York NY 10016
| | - Jeremy Nance
- Department of Cell Biology, NYU Grossman School of Medicine, New York NY 10016
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York NY 10016
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24
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Hiura T, Yoshida H, Miyata U, Asami T, Suzuki Y. Conferring High IAA Productivity on Low-IAA-Producing Organisms with PonAAS2, an Aromatic Aldehyde Synthase of a Galling Sawfly, and Identification of Its Inhibitor. INSECTS 2023; 14:598. [PMID: 37504604 PMCID: PMC10380194 DOI: 10.3390/insects14070598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/29/2023] [Accepted: 06/29/2023] [Indexed: 07/29/2023]
Abstract
Gall-inducing insects often contain high concentrations of phytohormones, such as auxin and cytokinin, which are suggested to be involved in gall induction, but no conclusive evidence has yet been obtained. There are two possible approaches to investigating the importance of phytohormones in gall induction: demonstrating either that high phytohormone productivity can induce gall-inducing ability in non-gall-inducing insects or that the gall-inducing ability is inhibited when phytohormone productivity in galling insects is suppressed. In this study, we show that the overexpression of PonAAS2, which encodes an aromatic aldehyde synthase (AAS) responsible for the rate-limiting step in indoleacetic acid (IAA) biosynthesis in a galling sawfly (Pontania sp.) that contains high levels of endogenous IAA, conferred high IAA productivity on Caenorhabditis elegans, as the model system. This result strongly suggests that PonAAS2 can also confer high IAA productivity on low-IAA-producing insects. We also successfully identified an inhibitor of PonAAS2 in a chemical library. This highly selective inhibitor showed stronger inhibitory activity against AAS than against aromatic amino acid decarboxylase, which belongs to the same superfamily as AAS. We also confirm that this inhibitor clearly inhibited IAA productivity in the high-IAA-producing C. elegans engineered here.
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Affiliation(s)
- Takeshi Hiura
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-0054, Japan
- Department of Food and Life Sciences, College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami-machi, Inashiki-gun, Ibaraki 300-0393, Japan
| | - Hibiki Yoshida
- Department of Food and Life Sciences, College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami-machi, Inashiki-gun, Ibaraki 300-0393, Japan
| | - Umi Miyata
- Department of Food and Life Sciences, College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami-machi, Inashiki-gun, Ibaraki 300-0393, Japan
| | - Tadao Asami
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yoshihito Suzuki
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-0054, Japan
- Department of Food and Life Sciences, College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami-machi, Inashiki-gun, Ibaraki 300-0393, Japan
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25
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Costa DS, Kenny-Ganzert IW, Chi Q, Park K, Kelley LC, Garde A, Matus DQ, Park J, Yogev S, Goldstein B, Gibney TV, Pani AM, Sherwood DR. The Caenorhabditis elegans anchor cell transcriptome: ribosome biogenesis drives cell invasion through basement membrane. Development 2023; 150:dev201570. [PMID: 37039075 PMCID: PMC10259517 DOI: 10.1242/dev.201570] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/27/2023] [Indexed: 04/12/2023]
Abstract
Cell invasion through basement membrane (BM) barriers is important in development, immune function and cancer progression. As invasion through BM is often stochastic, capturing gene expression profiles of actively invading cells in vivo remains elusive. Using the stereotyped timing of Caenorhabditis elegans anchor cell (AC) invasion, we generated an AC transcriptome during BM breaching. Through a focused RNAi screen of transcriptionally enriched genes, we identified new invasion regulators, including translationally controlled tumor protein (TCTP). We also discovered gene enrichment of ribosomal proteins. AC-specific RNAi, endogenous ribosome labeling and ribosome biogenesis analysis revealed that a burst of ribosome production occurs shortly after AC specification, which drives the translation of proteins mediating BM removal. Ribosomes also enrich near the AC endoplasmic reticulum (ER) Sec61 translocon and the endomembrane system expands before invasion. We show that AC invasion is sensitive to ER stress, indicating a heightened requirement for translation of ER-trafficked proteins. These studies reveal key roles for ribosome biogenesis and endomembrane expansion in cell invasion through BM and establish the AC transcriptome as a resource to identify mechanisms underlying BM transmigration.
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Affiliation(s)
- Daniel S. Costa
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27708, USA
| | | | - Qiuyi Chi
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
| | - Kieop Park
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
| | - Laura C. Kelley
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
| | - Aastha Garde
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
- Howard Hughes Medical Institute, Princeton University, Princeton, NJ 08544, USA
| | - David Q. Matus
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Junhyun Park
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA
| | - Shaul Yogev
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA
| | - Bob Goldstein
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Theresa V. Gibney
- Department of Biology, University of Virginia, Charlottesville, VA 29903, USA
| | - Ariel M. Pani
- Department of Biology, University of Virginia, Charlottesville, VA 29903, USA
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 29904, USA
| | - David R. Sherwood
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
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26
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Xiao Y, Yee C, Zhao CZ, Martinez MAQ, Zhang W, Shen K, Matus DQ, Hammell C. An expandable FLP-ON::TIR1 system for precise spatiotemporal protein degradation in Caenorhabditis elegans. Genetics 2023; 223:iyad013. [PMID: 36722258 PMCID: PMC10319979 DOI: 10.1093/genetics/iyad013] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 01/16/2023] [Indexed: 02/02/2023] Open
Abstract
The auxin-inducible degradation system has been widely adopted in the Caenorhabditis elegans research community for its ability to empirically control the spatiotemporal expression of target proteins. This system can efficiently degrade auxin-inducible degron (AID)-tagged proteins via the expression of a ligand-activatable AtTIR1 protein derived from A. thaliana that adapts target proteins to the endogenous C. elegans proteasome. While broad expression of AtTIR1 using strong, ubiquitous promoters can lead to rapid degradation of AID-tagged proteins, cell type-specific expression of AtTIR1 using spatially restricted promoters often results in less efficient target protein degradation. To circumvent this limitation, we have developed an FLP/FRT3-based system that functions to reanimate a dormant, high-powered promoter that can drive sufficient AtTIR1 expression in a cell type-specific manner. We benchmark the utility of this system by generating a number of tissue-specific FLP-ON::TIR1 drivers to reveal genetically separable cell type-specific phenotypes for several target proteins. We also demonstrate that the FLP-ON::TIR1 system is compatible with enhanced degron epitopes. Finally, we provide an expandable toolkit utilizing the basic FLP-ON::TIR1 system that can be adapted to drive optimized AtTIR1 expression in any tissue or cell type of interest.
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Affiliation(s)
- Yutong Xiao
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Callista Yee
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Chris Z Zhao
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Michael A Q Martinez
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Wan Zhang
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Kang Shen
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - David Q Matus
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
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27
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Stolpner NJ, Manzi NI, Su T, Dickinson DJ. Apical PAR-3 caps orient the mitotic spindle in C. elegans early embryos. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.27.534341. [PMID: 37034756 PMCID: PMC10081169 DOI: 10.1101/2023.03.27.534341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
During embryonic development, oriented cell divisions are important for patterned tissue growth and cell fate specification. Cell division orientation is controlled in part by asymmetrically localized polarity proteins, which establish functional domains of the cell membrane and interact with microtubule regulators to position the mitotic spindle. For example, in the 8-cell mouse embryo, apical polarity proteins form caps on the outside, contact-free surface of the embryo that position the mitotic spindle to execute asymmetric cell division. A similar radial or "inside-outside" polarity is established at an early stage in many other animal embryos, but in most cases it remains unclear how inside-outside polarity is established and how it influences downstream cell behaviors. Here, we explore inside-outside polarity in C. elegans somatic blastomeres using spatiotemporally controlled protein degradation and live embryo imaging. We show that PAR polarity proteins, which form apical caps at the center of the contact free membrane, localize dynamically during the cell cycle and contribute to spindle orientation and proper cell positioning. Surprisingly, apical PAR-3 can form polarity caps independently of actomyosin flows and the small GTPase CDC-42, and can regulate spindle orientation in cooperation with the key polarity kinase aPKC. Together, our results reveal a role for apical polarity caps in regulating spindle orientation in symmetrically dividing cells and provide novel insights into how these structures are formed.
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Affiliation(s)
- Naomi J. Stolpner
- Department of Molecular Biosciences, The University of Texas at Austin, 2415 Speedway, PAT 206, Austin, TX 78712
| | - Nadia I. Manzi
- Department of Molecular Biosciences, The University of Texas at Austin, 2415 Speedway, PAT 206, Austin, TX 78712
| | - Thomas Su
- Department of Molecular Biosciences, The University of Texas at Austin, 2415 Speedway, PAT 206, Austin, TX 78712
| | - Daniel J. Dickinson
- Department of Molecular Biosciences, The University of Texas at Austin, 2415 Speedway, PAT 206, Austin, TX 78712
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28
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Fazeli G, Levin-Konigsberg R, Bassik MC, Stigloher C, Wehman AM. A BORC-dependent molecular pathway for vesiculation of cell corpse phagolysosomes. Curr Biol 2023; 33:607-621.e7. [PMID: 36652947 PMCID: PMC9992095 DOI: 10.1016/j.cub.2022.12.041] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 11/07/2022] [Accepted: 12/15/2022] [Indexed: 01/19/2023]
Abstract
Phagocytic clearance is important to provide cells with metabolites and regulate immune responses, but little is known about how phagolysosomes finally resolve their phagocytic cargo of cell corpses, cell debris, and pathogens. While studying the phagocytic clearance of non-apoptotic polar bodies in C. elegans, we previously discovered that phagolysosomes tubulate into small vesicles to facilitate corpse clearance within 1.5 h. Here, we show that phagolysosome vesiculation depends on amino acid export by the solute transporter SLC-36.1 and the activation of TORC1. We demonstrate that downstream of TORC1, BLOC-1-related complex (BORC) is de-repressed by Ragulator through the BORC subunit BLOS-7. In addition, the BORC subunit SAM-4 is needed continuously to recruit the small GTPase ARL-8 to the phagolysosome for tubulation. We find that disrupting the regulated GTP-GDP cycle of ARL-8 reduces tubulation by kinesin-1, delays corpse clearance, and mislocalizes ARL-8 away from lysosomes. We also demonstrate that mammalian phagocytes use BORC to promote phagolysosomal degradation, confirming the conserved importance of TOR and BORC. Finally, we show that HOPS is required after tubulation for the rapid degradation of cargo in small phagolysosomal vesicles, suggesting that additional rounds of lysosome fusion occur. Thus, by observing single phagolysosomes over time, we identified the molecular pathway regulating phagolysosome vesiculation that promotes efficient resolution of phagocytosed cargos.
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Affiliation(s)
- Gholamreza Fazeli
- Rudolf Virchow Center for Integrative and Translational Bioimaging, University of Würzburg, 97080 Würzburg, Germany; Imaging Core Facility, Biocenter, University of Würzburg, 97074 Würzburg, Germany.
| | - Roni Levin-Konigsberg
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Michael C Bassik
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Christian Stigloher
- Imaging Core Facility, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Ann M Wehman
- Department of Biological Sciences, University of Denver, Denver, CO 80208, USA.
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29
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Mizumoto K, Jin Y, Bessereau JL. Synaptogenesis: unmasking molecular mechanisms using Caenorhabditis elegans. Genetics 2023; 223:iyac176. [PMID: 36630525 PMCID: PMC9910414 DOI: 10.1093/genetics/iyac176] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 10/22/2022] [Indexed: 01/13/2023] Open
Abstract
The nematode Caenorhabditis elegans is a research model organism particularly suited to the mechanistic understanding of synapse genesis in the nervous system. Armed with powerful genetics, knowledge of complete connectomics, and modern genomics, studies using C. elegans have unveiled multiple key regulators in the formation of a functional synapse. Importantly, many signaling networks display remarkable conservation throughout animals, underscoring the contributions of C. elegans research to advance the understanding of our brain. In this chapter, we will review up-to-date information of the contribution of C. elegans to the understanding of chemical synapses, from structure to molecules and to synaptic remodeling.
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Affiliation(s)
- Kota Mizumoto
- Department of Zoology, University of British Columbia, Vancouver V6T 1Z3, Canada
| | - Yishi Jin
- Department of Neurobiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Jean-Louis Bessereau
- Univ Lyon, University Claude Bernard Lyon 1, CNRS UMR 5284, INSERM U 1314, Melis, 69008 Lyon, France
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30
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Naturale VF, Pickett MA, Feldman JL. Context matters: Lessons in epithelial polarity from the Caenorhabditis elegans intestine and other tissues. Curr Top Dev Biol 2023; 154:37-71. [PMID: 37100523 DOI: 10.1016/bs.ctdb.2023.02.007] [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: 04/28/2023]
Abstract
Epithelia are tissues with diverse morphologies and functions across metazoans, ranging from vast cell sheets encasing internal organs to internal tubes facilitating nutrient uptake, all of which require establishment of apical-basolateral polarity axes. While all epithelia tend to polarize the same components, how these components are deployed to drive polarization is largely context-dependent and likely shaped by tissue-specific differences in development and ultimate functions of polarizing primordia. The nematode Caenorhabditis elegans (C. elegans) offers exceptional imaging and genetic tools and possesses unique epithelia with well-described origins and roles, making it an excellent model to investigate polarity mechanisms. In this review, we highlight the interplay between epithelial polarization, development, and function by describing symmetry breaking and polarity establishment in a particularly well-characterized epithelium, the C. elegans intestine. We compare intestinal polarization to polarity programs in two other C. elegans epithelia, the pharynx and epidermis, correlating divergent mechanisms with tissue-specific differences in geometry, embryonic environment, and function. Together, we emphasize the importance of investigating polarization mechanisms against the backdrop of tissue-specific contexts, while also underscoring the benefits of cross-tissue comparisons of polarity.
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Affiliation(s)
- Victor F Naturale
- Department of Biology, Stanford University, Stanford, CA, United States
| | - Melissa A Pickett
- Department of Biology, Stanford University, Stanford, CA, United States; Department of Biological Sciences, San José State University, San José, CA, United States
| | - Jessica L Feldman
- Department of Biology, Stanford University, Stanford, CA, United States.
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31
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Pickett MA, Sallee MD, Cote L, Naturale VF, Akpinaroglu D, Lee J, Shen K, Feldman JL. Separable mechanisms drive local and global polarity establishment in the Caenorhabditiselegans intestinal epithelium. Development 2022; 149:dev200325. [PMID: 36264257 PMCID: PMC9845746 DOI: 10.1242/dev.200325] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 10/06/2022] [Indexed: 11/17/2022]
Abstract
Apico-basolateral polarization is essential for epithelial cells to function as selective barriers and transporters, and to provide mechanical resilience to organs. Epithelial polarity is established locally, within individual cells to establish distinct apical, junctional and basolateral domains, and globally, within a tissue where cells coordinately orient their apico-basolateral axes. Using live imaging of endogenously tagged proteins and tissue-specific protein depletion in the Caenorhabditiselegans embryonic intestine, we found that local and global polarity establishment are temporally and genetically separable. Local polarity is initiated prior to global polarity and is robust to perturbation. PAR-3 is required for global polarization across the intestine but local polarity can arise in its absence, as small groups of cells eventually established polarized domains in PAR-3-depleted intestines in a HMR-1 (E-cadherin)-dependent manner. Despite the role of PAR-3 in localizing PKC-3 to the apical surface, we additionally found that PAR-3 and PKC-3/aPKC have distinct roles in the establishment and maintenance of local and global polarity. Taken together, our results indicate that different mechanisms are required for local and global polarity establishment in vivo.
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Affiliation(s)
- Melissa A. Pickett
- Department of Biology, Stanford University, Stanford, CA 94305, USA
- Department of Biological Sciences, San Jose State University, San Jose, CA 95112, USA
| | - Maria D. Sallee
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Lauren Cote
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | | | | | - Joo Lee
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, CA 94305, USA
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32
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Suzuki N, Zou Y, Sun H, Eichel K, Shao M, Shih M, Shen K, Chang C. Two intrinsic timing mechanisms set start and end times for dendritic arborization of a nociceptive neuron. Proc Natl Acad Sci U S A 2022; 119:e2210053119. [PMID: 36322763 PMCID: PMC9659368 DOI: 10.1073/pnas.2210053119] [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: 06/15/2022] [Accepted: 10/04/2022] [Indexed: 11/05/2022] Open
Abstract
Choreographic dendritic arborization takes place within a defined time frame, but the timing mechanism is currently not known. Here, we report that the precisely timed lin-4-lin-14 regulatory circuit triggers an initial dendritic growth activity, whereas the precisely timed lin-28-let-7-lin-41 regulatory circuit signals a subsequent developmental decline in dendritic growth ability, hence restricting dendritic arborization within a set time frame. Loss-of-function mutations in the lin-4 microRNA gene cause limited dendritic outgrowth, whereas loss-of-function mutations in its direct target, the lin-14 transcription factor gene, cause precocious and excessive outgrowth. In contrast, loss-of-function mutations in the let-7 microRNA gene prevent a developmental decline in dendritic growth ability, whereas loss-of-function mutations in its direct target, the lin-41 tripartite motif protein gene, cause further decline. lin-4 and let-7 regulatory circuits are expressed in the right place at the right time to set start and end times for dendritic arborization. Replacing the lin-4 upstream cis-regulatory sequence at the lin-4 locus with a late-onset let-7 upstream cis-regulatory sequence delays dendrite arborization, whereas replacing the let-7 upstream cis-regulatory sequence at the let-7 locus with an early-onset lin-4 upstream cis-regulatory sequence causes a precocious decline in dendritic growth ability. Our results indicate that the lin-4-lin-14 and the lin-28-let-7-lin-41 regulatory circuits control the timing of dendrite arborization through antagonistic regulation of the DMA-1 receptor level on dendrites. The LIN-14 transcription factor likely directly represses dma-1 gene expression through a transcriptional means, whereas the LIN-41 tripartite motif protein likely indirectly promotes dma-1 gene expression through a posttranscriptional means.
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Affiliation(s)
- Nobuko Suzuki
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607
| | - Yan Zou
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - HaoSheng Sun
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35233
| | - Kelsie Eichel
- HHMI, Stanford University, Stanford, CA 94305
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Meiyu Shao
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Mushaine Shih
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607
| | - Kang Shen
- HHMI, Stanford University, Stanford, CA 94305
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Chieh Chang
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607
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33
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Fragoso-Luna A, Romero-Bueno R, Eibl M, Ayuso C, Muñoz-Jiménez C, Benes V, Cases I, Askjaer P. Expanded FLP toolbox for spatiotemporal protein degradation and transcriptomic profiling in Caenorhabditis elegans. Genetics 2022; 223:6793861. [PMID: 36321973 PMCID: PMC9836023 DOI: 10.1093/genetics/iyac166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 10/24/2022] [Indexed: 11/05/2022] Open
Abstract
Control of gene expression in specific tissues and/or at certain stages of development allows the study and manipulation of gene function with high precision. Site-specific genome recombination by the flippase (FLP) and cyclization recombination (Cre) enzymes has proved particularly relevant. Joint efforts of many research groups have led to the creation of efficient FLP and Cre drivers to regulate gene expression in a variety of tissues in Caenorhabditis elegans. Here, we extend this toolkit by the addition of FLP lines that drive recombination specifically in distal tip cells, the somatic gonad, coelomocytes, and the epithelial P lineage. In some cases, recombination-mediated gene knockouts do not completely deplete protein levels due to persistence of long-lived proteins. To overcome this, we developed a spatiotemporally regulated degradation system for green fluorescent fusion proteins based on FLP-mediated recombination. Using 2 stable nuclear pore proteins, MEL-28/ELYS and NPP-2/NUP85 as examples, we report the benefit of combining tissue-specific gene knockout and protein degradation to achieve complete protein depletion. We also demonstrate that FLP-mediated recombination can be utilized to identify transcriptomes in a C. elegans tissue of interest. We have adapted RNA polymerase DamID for the FLP toolbox and by focusing on a well-characterized tissue, the hypodermis, we show that the vast majority of genes identified by RNA polymerase DamID are known to be expressed in this tissue. These tools allow combining FLP activity for simultaneous gene inactivation and transcriptomic profiling, thus enabling the inquiry of gene function in various complex biological processes.
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Affiliation(s)
| | | | | | - Cristina Ayuso
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
| | - Celia Muñoz-Jiménez
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
| | | | - Ildefonso Cases
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
| | - Peter Askjaer
- Corresponding author: Andalusian Centre for Developmental Biology, Gene Regulation and Morphogenesis, CSIC—Universidad Pablo de Olavide, Carretera de Utrera, km 1, 41013 Seville, Spain.
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34
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Sepers JJ, Verstappen NHM, Vo AA, Ragle JM, Ruijtenberg S, Ward JD, Boxem M. The mIAA7 degron improves auxin-mediated degradation in Caenorhabditiselegans. G3 (BETHESDA, MD.) 2022; 12:jkac222. [PMID: 36029236 PMCID: PMC9526053 DOI: 10.1093/g3journal/jkac222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/15/2022] [Indexed: 04/08/2023]
Abstract
Auxin-inducible degradation is a powerful tool for the targeted degradation of proteins with spatiotemporal control. One limitation of the auxin-inducible degradation system is that not all proteins are degraded efficiently. Here, we demonstrate that an alternative degron sequence, termed mIAA7, improves the efficiency of degradation in Caenorhabditiselegans, as previously reported in human cells. We tested the depletion of a series of proteins with various subcellular localizations in different tissue types and found that the use of the mIAA7 degron resulted in faster depletion kinetics for 5 out of 6 proteins tested. The exception was the nuclear protein HIS-72, which was depleted with similar efficiency as with the conventional AID* degron sequence. The mIAA7 degron also increased the leaky degradation for 2 of the tested proteins. To overcome this problem, we combined the mIAA7 degron with the C. elegans AID2 system, which resulted in complete protein depletion without detectable leaky degradation. Finally, we show that the degradation of ERM-1, a highly stable protein that is challenging to deplete, could be improved further by using multiple mIAA7 degrons. Taken together, the mIAA7 degron further increases the power and applicability of the auxin-inducible degradation system. To facilitate the generation of mIAA7-tagged proteins using CRISPR/Cas9 genome engineering, we generated a toolkit of plasmids for the generation of dsDNA repair templates by PCR.
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Affiliation(s)
- Jorian J Sepers
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Noud H M Verstappen
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - An A Vo
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - James Matthew Ragle
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Suzan Ruijtenberg
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Jordan D Ward
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Mike Boxem
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
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35
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Fergin A, Boesch G, Greter NR, Berger S, Hajnal A. Tissue-specific inhibition of protein sumoylation uncovers diverse SUMO functions during C. elegans vulval development. PLoS Genet 2022; 18:e1009978. [PMID: 35666766 PMCID: PMC9203017 DOI: 10.1371/journal.pgen.1009978] [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: 12/03/2021] [Revised: 06/16/2022] [Accepted: 05/13/2022] [Indexed: 11/18/2022] Open
Abstract
The sumoylation (SUMO) pathway is involved in a variety of processes during C. elegans development, such as gonadal and vulval fate specification, cell cycle progression and maintenance of chromosome structure. The ubiquitous expression and pleiotropic effects have made it difficult to dissect the tissue-specific functions of the SUMO pathway and identify its target proteins. To overcome these challenges, we have established tools to block protein sumoylation and degrade sumoylated target proteins in a tissue-specific and temporally controlled manner. We employed the auxin-inducible protein degradation system (AID) to down-regulate the SUMO E3 ligase GEI-17 or the SUMO ortholog SMO-1, either in the vulval precursor cells (VPCs) or in the gonadal anchor cell (AC). Our results indicate that the SUMO pathway acts in multiple tissues to control different aspects of vulval development, such as AC positioning, basement membrane (BM) breaching, VPC fate specification and morphogenesis. Inhibition of protein sumoylation in the VPCs resulted in abnormal toroid formation and ectopic cell fusions during vulval morphogenesis. In particular, sumoylation of the ETS transcription factor LIN-1 at K169 is necessary for the proper contraction of the ventral vulA toroids. Thus, the SUMO pathway plays several distinct roles throughout vulval development. Many proteins are chemically modified after they have been synthesized. In particular, conjugation with the Small Ubiquitin-like Modifier (SUMO) regulates the functions and activities of a large number of proteins in animal and plant cells. Here, we have used the Nematode Caenorhabditis elegans to study the various effects of SUMO protein modification on organ development. By applying a tissue-specific protein degradation system, we could selectively block the SUMO pathway in different tissues of the animals. We focused on the development of the egg-laying organ as a model, and found that the SUMO pathway acts in multiple tissues to regulate distinct cellular functions. Finally, we show that SUMO modification of one transcription factor, called LIN-1, is necessary for the proper morphogenesis of the organ. Our results indicate that the manifold effects of the SUMO pathway can be attributed to the combined action of a distinct number of SUMO modified proteins acting in different cell types.
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Affiliation(s)
- Aleksandra Fergin
- Department of Molecular Life Sciences, University of Zürich, Zürich, Switzerland
- Molecular Life Science PhD Program, University and ETH Zürich, Zürich, Switzerland
| | - Gabriel Boesch
- Department of Molecular Life Sciences, University of Zürich, Zürich, Switzerland
- Molecular Life Science PhD Program, University and ETH Zürich, Zürich, Switzerland
| | - Nadja R. Greter
- Department of Molecular Life Sciences, University of Zürich, Zürich, Switzerland
- Molecular Life Science PhD Program, University and ETH Zürich, Zürich, Switzerland
| | - Simon Berger
- Department of Molecular Life Sciences, University of Zürich, Zürich, Switzerland
- Molecular Life Science PhD Program, University and ETH Zürich, Zürich, Switzerland
| | - Alex Hajnal
- Department of Molecular Life Sciences, University of Zürich, Zürich, Switzerland
- * E-mail:
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36
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Chen L, Liu Y, Su P, Hung W, Li H, Wang Y, Yue Z, Ge MH, Wu ZX, Zhang Y, Fei P, Chen LM, Tao L, Mao H, Zhen M, Gao S. Escape steering by cholecystokinin peptidergic signaling. Cell Rep 2022; 38:110330. [PMID: 35139370 DOI: 10.1016/j.celrep.2022.110330] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 11/19/2021] [Accepted: 01/11/2022] [Indexed: 11/26/2022] Open
Abstract
Escape is an evolutionarily conserved and essential avoidance response. Considered to be innate, most studies on escape responses focused on hard-wired circuits. We report here that a neuropeptide NLP-18 and its cholecystokinin receptor CKR-1 enable the escape circuit to execute a full omega (Ω) turn. We demonstrate in vivo NLP-18 is mainly secreted by the gustatory sensory neuron (ASI) to activate CKR-1 in the head motor neuron (SMD) and the turn-initiating interneuron (AIB). Removal of NLP-18 or CKR-1 or specific knockdown of CKR-1 in SMD or AIB neurons leads to shallower turns, hence less robust escape steering. Consistently, elevation of head motor neuron (SMD)'s Ca2+ transients during escape steering is attenuated upon the removal of NLP-18 or CKR-1. In vitro, synthetic NLP-18 directly evokes CKR-1-dependent currents in oocytes and CKR-1-dependent Ca2+ transients in SMD. Thus, cholecystokinin peptidergic signaling modulates an escape circuit to generate robust escape steering.
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Affiliation(s)
- Lili Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Yuting Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Pan Su
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Wesley Hung
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Haiwen Li
- Center for Quantitative Biology, Peking University, Beijing 100871, P.R. China; LMAM, School of Mathematical Sciences, Peking University, Beijing 100871, P.R. China
| | - Ya Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Zhongpu Yue
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Ming-Hai Ge
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Zheng-Xing Wu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Yan Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Peng Fei
- School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Li-Ming Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Louis Tao
- Center for Quantitative Biology, Peking University, Beijing 100871, P.R. China
| | - Heng Mao
- LMAM, School of Mathematical Sciences, Peking University, Beijing 100871, P.R. China
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China.
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Floxed exon (Flexon): A flexibly positioned stop cassette for recombinase-mediated conditional gene expression. Proc Natl Acad Sci U S A 2022; 119:2117451119. [PMID: 35027456 PMCID: PMC8784106 DOI: 10.1073/pnas.2117451119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2021] [Indexed: 12/15/2022] Open
Abstract
Tools that afford spatiotemporal control of gene expression are crucial for studying genes and processes in multicellular organisms. Stop cassettes consist of exogenous sequences that interrupt gene expression and flanking site-specific recombinase sites to allow for tissue-specific excision and restoration of function by expression of the cognate recombinase. We describe a stop cassette called a flexon, composed of an artificial exon flanked by artificial introns that can be flexibly positioned in a gene. We demonstrate its efficacy in Caenorhabditis elegans for lineage-specific control of gene expression and for tissue-specific RNA interference and discuss other potential uses. The Flexon approach should be feasible in any system amenable to site-specific recombination-based methods and applicable to diverse areas including development, neuroscience, and metabolism. Conditional gene expression is a powerful tool for genetic analysis of biological phenomena. In the widely used “lox-stop-lox” approach, insertion of a stop cassette consisting of a series of stop codons and polyadenylation signals flanked by lox sites into the 5′ untranslated region (UTR) of a gene prevents expression until the cassette is excised by tissue-specific expression of Cre recombinase. Although lox-stop-lox and similar approaches using other site-specific recombinases have been successfully used in many experimental systems, this design has certain limitations. Here, we describe the Floxed exon (Flexon) approach, which uses a stop cassette composed of an artificial exon flanked by artificial introns, designed to cause premature termination of translation and nonsense-mediated decay of the mRNA and allowing for flexible placement into a gene. We demonstrate its efficacy in Caenorhabditis elegans by showing that, when promoters that cause weak and/or transient cell-specific expression are used to drive Cre in combination with a gfp(flexon) transgene, strong and sustained expression of green fluorescent protein (GFP) is obtained in specific lineages. We also demonstrate its efficacy in an endogenous gene context: we inserted a flexon into the Argonaute gene rde-1 to abrogate RNA interference (RNAi), and restored RNAi tissue specifically by expression of Cre. Finally, we describe several potential additional applications of the Flexon approach, including more precise control of gene expression using intersectional methods, tissue-specific protein degradation, and generation of genetic mosaics. The Flexon approach should be feasible in any system where a site-specific recombination-based method may be applied.
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38
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Hardin J, Serre J, King R, Walck-Shannon E, Reiner D. Imaging Epidermal Cell Rearrangement in the C. elegans Embryo. Methods Mol Biol 2022; 2438:345-376. [PMID: 35147953 PMCID: PMC9528972 DOI: 10.1007/978-1-0716-2035-9_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The Caenorhabditis elegans embryo is well suited for analysis of directed cell rearrangement via modern microscopy, due to its simple organization, short generation time, transparency, invariant lineage, and the ability to generate engineered embryos expressing various fluorescent proteins. This chapter provides an overview of routine microscopy techniques for imaging dorsal intercalation, a convergent extension-like morphogenetic movement in the embryonic epidermis of C. elegans, including making agar mounts, low-cost four-dimensional (4D) Nomarski microscopy, laser microsurgery, and 4D fluorescence microscopy using actin and junctional fusion proteins, as well as tissue-specific promoters useful for studying dorsal intercalation.
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Affiliation(s)
- Jeff Hardin
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA.
| | - Joel Serre
- Program in Genetics, University of Wisconsin-Madison, Madison, WI, USA
| | - Ryan King
- Department of Biology, St. Norbert College, De Pere, WI, USA
| | - Elise Walck-Shannon
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
| | - David Reiner
- Texas A&M Health Science Center, Houston, TX, USA
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39
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Katz M. Genetic Methods for Cellular Manipulation in C. elegans. Methods Mol Biol 2022; 2468:51-72. [PMID: 35320560 DOI: 10.1007/978-1-0716-2181-3_4] [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: 06/14/2023]
Abstract
Neuron manipulation in vivo by ablation, activation or inactivation, and regulation of gene expression is essential for dissecting nervous system function. Here we describe genetic means for neuron manipulation in the nematode C. elegans, and provide protocols for generating transgenic animals containing these genetic tools.
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Affiliation(s)
- Menachem Katz
- Department of Biology, Technion- Israel Institute of Technology, Haifa, Israel.
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40
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Wu Y, Han X, Su Y, Glidewell M, Daniels JS, Liu J, Sengupta T, Rey-Suarez I, Fischer R, Patel A, Combs C, Sun J, Wu X, Christensen R, Smith C, Bao L, Sun Y, Duncan LH, Chen J, Pommier Y, Shi YB, Murphy E, Roy S, Upadhyaya A, Colón-Ramos D, La Riviere P, Shroff H. Multiview confocal super-resolution microscopy. Nature 2021; 600:279-284. [PMID: 34837071 PMCID: PMC8686173 DOI: 10.1038/s41586-021-04110-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 10/07/2021] [Indexed: 12/31/2022]
Abstract
Confocal microscopy1 remains a major workhorse in biomedical optical microscopy owing to its reliability and flexibility in imaging various samples, but suffers from substantial point spread function anisotropy, diffraction-limited resolution, depth-dependent degradation in scattering samples and volumetric bleaching2. Here we address these problems, enhancing confocal microscopy performance from the sub-micrometre to millimetre spatial scale and the millisecond to hour temporal scale, improving both lateral and axial resolution more than twofold while simultaneously reducing phototoxicity. We achieve these gains using an integrated, four-pronged approach: (1) developing compact line scanners that enable sensitive, rapid, diffraction-limited imaging over large areas; (2) combining line-scanning with multiview imaging, developing reconstruction algorithms that improve resolution isotropy and recover signal otherwise lost to scattering; (3) adapting techniques from structured illumination microscopy, achieving super-resolution imaging in densely labelled, thick samples; (4) synergizing deep learning with these advances, further improving imaging speed, resolution and duration. We demonstrate these capabilities on more than 20 distinct fixed and live samples, including protein distributions in single cells; nuclei and developing neurons in Caenorhabditis elegans embryos, larvae and adults; myoblasts in imaginal disks of Drosophila wings; and mouse renal, oesophageal, cardiac and brain tissues.
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Affiliation(s)
- Yicong Wu
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA.
| | - Xiaofei Han
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
- Department of Automation, Tsinghua University, Beijing, China
| | - Yijun Su
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
- Leica Microsystems, Buffalo Grove, IL, USA
- SVision, Bellevue, WA, USA
| | | | | | - Jiamin Liu
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, USA
| | - Titas Sengupta
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Ivan Rey-Suarez
- Institute for Physical Science and Technology, University of Maryland, College Park, MD, USA
| | - Robert Fischer
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Akshay Patel
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Christian Combs
- NHLBI Light Microscopy Facility, National Institutes of Health, Bethesda, MD, USA
| | - Junhui Sun
- Laboratory of Cardiac Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Xufeng Wu
- NHLBI Light Microscopy Facility, National Institutes of Health, Bethesda, MD, USA
| | - Ryan Christensen
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Corey Smith
- Department of Radiology, University of Chicago, Chicago, IL, USA
| | - Lingyu Bao
- Section on Molecular Morphogenesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Yilun Sun
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, National Institutes of Health, Bethesda, MD, USA
| | - Leighton H Duncan
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Jiji Chen
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, USA
| | - Yves Pommier
- Laboratory of Molecular Pharmacology, Developmental Therapeutics Branch, Center for Cancer Research, National Institutes of Health, Bethesda, MD, USA
| | - Yun-Bo Shi
- Section on Molecular Morphogenesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Elizabeth Murphy
- Laboratory of Cardiac Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Sougata Roy
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Arpita Upadhyaya
- Institute for Physical Science and Technology, University of Maryland, College Park, MD, USA
- Department of Physics, University of Maryland, College Park, MD, USA
| | - Daniel Colón-Ramos
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
- Marine Biological Laboratory, Woods Hole, MA, USA
- Instituto de Neurobiología, Recinto de Ciencias Médicas, Universidad de Puerto Rico, San Juan, Puerto Rico
| | - Patrick La Riviere
- Department of Radiology, University of Chicago, Chicago, IL, USA
- Marine Biological Laboratory, Woods Hole, MA, USA
| | - Hari Shroff
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, USA
- Marine Biological Laboratory, Woods Hole, MA, USA
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41
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Sengupta T, Koonce NL, Vázquez-Martínez N, Moyle MW, Duncan LH, Emerson SE, Han X, Shao L, Wu Y, Santella A, Fan L, Bao Z, Mohler W, Shroff H, Colón-Ramos DA. Differential adhesion regulates neurite placement via a retrograde zippering mechanism. eLife 2021; 10:71171. [PMID: 34783657 PMCID: PMC8843091 DOI: 10.7554/elife.71171] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 11/15/2021] [Indexed: 11/13/2022] Open
Abstract
During development, neurites and synapses segregate into specific neighborhoods or layers within nerve bundles. The developmental programs guiding placement of neurites in specific layers, and hence their incorporation into specific circuits, are not well understood. We implement novel imaging methods and quantitative models to document the embryonic development of the C. elegans brain neuropil, and discover that differential adhesion mechanisms control precise placement of single neurites onto specific layers. Differential adhesion is orchestrated via developmentally-regulated expression of the IgCAM SYG-1, and its partner ligand SYG-2. Changes in SYG-1 expression across neuropil layers result in changes in adhesive forces, which sort SYG-2-expressing neurons. Sorting to layers occurs, not via outgrowth from the neurite tip, but via an alternate mechanism of retrograde zippering, involving interactions between neurite shafts. Our study indicates that biophysical principles from differential adhesion govern neurite placement and synaptic specificity in vivo in developing neuropil bundles.
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Affiliation(s)
- Titas Sengupta
- Yale University School of Medicine, New Haven, United States
| | - Noelle L Koonce
- Yale University School of Medicine, New Haven, United States
| | | | - Mark W Moyle
- Yale University School of Medicine, New Haven, United States
| | | | - Sarah E Emerson
- Yale University School of Medicine, New Haven, United States
| | - Xiaofei Han
- National Institutes of Health, Bethesda, United States
| | - Lin Shao
- Yale University School of Medicine, New Haven, United States
| | - Yicong Wu
- National Institutes of Health, Bethesda, United States
| | - Anthony Santella
- Developmental Biology Program, Molecular Cytology Core, Sloan-Kettering Institute, New York, United States
| | - Li Fan
- Helen and Robert Appel Alzheimer's Disease Institute, Weill Cornell Medicine, New York, United States
| | - Zhirong Bao
- Developmental Biology Program, Sloan-Kettering Institute, New York, United States
| | - William Mohler
- Department of Genetics and Developmental Biology, University of Connecticut Health Center, Farmington, United States
| | - Hari Shroff
- National Institutes of Health, Bethesda, United States
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Cohen JD, Cadena del Castillo CE, Serra ND, Kaech A, Spang A, Sundaram MV. The Caenorhabditis elegans Patched domain protein PTR-4 is required for proper organization of the precuticular apical extracellular matrix. Genetics 2021; 219:iyab132. [PMID: 34740248 PMCID: PMC8570789 DOI: 10.1093/genetics/iyab132] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 08/04/2021] [Indexed: 12/30/2022] Open
Abstract
The Patched-related superfamily of transmembrane proteins can transport lipids or other hydrophobic molecules across cell membranes. While the Hedgehog receptor Patched has been intensively studied, much less is known about the biological roles of other Patched-related family members. Caenorhabditis elegans has a large number of Patched-related proteins, despite lacking a canonical Hedgehog pathway. Here, we show that PTR-4 promotes the assembly of the precuticle apical extracellular matrix, a transient and molecularly distinct matrix that precedes and patterns the later collagenous cuticle or exoskeleton. ptr-4 mutants share many phenotypes with precuticle mutants, including defects in eggshell dissolution, tube shaping, alae (cuticle ridge) structure, molting, and cuticle barrier function. PTR-4 localizes to the apical side of a subset of outward-facing epithelia, in a cyclical manner that peaks when precuticle matrix is present. Finally, PTR-4 is required to limit the accumulation of the lipocalin LPR-3 and to properly localize the Zona Pellucida domain protein LET-653 within the precuticle. We propose that PTR-4 transports lipids or other hydrophobic components that help to organize the precuticle and that the cuticle and molting defects seen in ptr-4 mutants result at least in part from earlier disorganization of the precuticle.
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Affiliation(s)
- Jennifer D Cohen
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | | | - Nicholas D Serra
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Andres Kaech
- Center for Microscopy and Image Analysis, University of Zürich, 8006 Zürich, Switzerland
| | - Anne Spang
- Biozentrum, University of Basel, 4001 Basel, Switzerland
| | - Meera V Sundaram
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
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43
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Sanchez AD, Branon TC, Cote LE, Papagiannakis A, Liang X, Pickett MA, Shen K, Jacobs-Wagner C, Ting AY, Feldman JL. Proximity labeling reveals non-centrosomal microtubule-organizing center components required for microtubule growth and localization. Curr Biol 2021; 31:3586-3600.e11. [PMID: 34242576 PMCID: PMC8478408 DOI: 10.1016/j.cub.2021.06.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 04/13/2021] [Accepted: 06/09/2021] [Indexed: 12/24/2022]
Abstract
Microtubules are polarized intracellular polymers that play key roles in the cell, including in transport, polarity, and cell division. Across eukaryotic cell types, microtubules adopt diverse intracellular organization to accommodate these distinct functions coordinated by specific cellular sites called microtubule-organizing centers (MTOCs). Over 50 years of research on MTOC biology has focused mainly on the centrosome; however, most differentiated cells employ non-centrosomal MTOCs (ncMTOCs) to organize their microtubules into diverse arrays, which are critical to cell function. To identify essential ncMTOC components, we developed the biotin ligase-based, proximity-labeling approach TurboID for use in C. elegans. We identified proteins proximal to the microtubule minus end protein PTRN-1/Patronin at the apical ncMTOC of intestinal epithelial cells, focusing on two conserved proteins: spectraplakin protein VAB-10B/MACF1 and WDR-62, a protein we identify as homologous to vertebrate primary microcephaly disease protein WDR62. VAB-10B and WDR-62 do not associate with the centrosome and instead specifically regulate non-centrosomal microtubules and the apical targeting of microtubule minus-end proteins. Depletion of VAB-10B resulted in microtubule mislocalization and delayed localization of a microtubule nucleation complex ɣ-tubulin ring complex (γ-TuRC), while loss of WDR-62 decreased the number of dynamic microtubules and abolished γ-TuRC localization. This regulation occurs downstream of cell polarity and in conjunction with actin. As this is the first report for non-centrosomal roles of WDR62 family proteins, we expand the basic cell biological roles of this important disease protein. Our studies identify essential ncMTOC components and suggest a division of labor where microtubule growth and localization are distinctly regulated.
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Affiliation(s)
- Ariana D Sanchez
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA 94305, USA
| | - Tess C Branon
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA 94305, USA; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA; Departments of Genetics and Chemistry, Stanford University, Stanford, CA, USA
| | - Lauren E Cote
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA 94305, USA
| | | | - Xing Liang
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Melissa A Pickett
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA 94305, USA
| | - Kang Shen
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Christine Jacobs-Wagner
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA; Department of Biology and ChEM-H Institute, Stanford University, Stanford, CA, USA
| | - Alice Y Ting
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA 94305, USA; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA; Departments of Genetics and Chemistry, Stanford University, Stanford, CA, USA; Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Jessica L Feldman
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA 94305, USA.
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44
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Kurashina M, Wang J, Lin J, Lee KK, Johal A, Mizumoto K. Sustained expression of unc-4 homeobox gene and unc-37/Groucho in postmitotic neurons specifies the spatial organization of the cholinergic synapses in C. elegans. eLife 2021; 10:66011. [PMID: 34388088 PMCID: PMC8363302 DOI: 10.7554/elife.66011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 08/07/2021] [Indexed: 11/13/2022] Open
Abstract
Neuronal cell fate determinants establish the identities of neurons by controlling gene expression to regulate neuronal morphology and synaptic connectivity. However, it is not understood if neuronal cell fate determinants have postmitotic functions in synapse pattern formation. Here we identify a novel role for UNC-4 homeobox protein and its corepressor UNC-37/Groucho, in tiled synaptic patterning of the cholinergic motor neurons in Caenorhabditis elegans. We show that unc-4 is not required during neurogenesis but is required in the postmitotic neurons for proper synapse patterning. In contrast, unc-37 is required in both developing and postmitotic neurons. The synaptic tiling defects of unc-4 mutants are suppressed by bar-1/β-catenin mutation, which positively regulates the expression of ceh-12/HB9. Ectopic ceh-12 expression partly underlies the synaptic tiling defects of unc-4 and unc-37 mutants. Our results reveal a novel postmitotic role of neuronal cell fate determinants in synapse pattern formation through inhibiting the canonical Wnt signaling pathway.
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Affiliation(s)
- Mizuki Kurashina
- Department of Zoology, University of British Columbia, Vancouver, Canada.,Graduate Program in Cell and Developmental Biology, University of British Columbia, Vancouver, Canada
| | - Jane Wang
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Jeffrey Lin
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Kathy Kyungeun Lee
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Arpun Johal
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Kota Mizumoto
- Department of Zoology, University of British Columbia, Vancouver, Canada.,Graduate Program in Cell and Developmental Biology, University of British Columbia, Vancouver, Canada.,Life Sciences Institute, University of British Columbia, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
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45
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Lee J, Magescas J, Fetter RD, Feldman JL, Shen K. Inherited apicobasal polarity defines the key features of axon-dendrite polarity in a sensory neuron. Curr Biol 2021; 31:3768-3783.e3. [PMID: 34270949 DOI: 10.1016/j.cub.2021.06.039] [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: 12/01/2020] [Revised: 05/05/2021] [Accepted: 06/14/2021] [Indexed: 11/25/2022]
Abstract
Neurons are highly polarized cells with morphologically and functionally distinct dendritic and axonal processes. The molecular mechanisms that establish axon-dendrite polarity in vivo are poorly understood. Here, we describe the initial polarization of posterior deirid (PDE), a ciliated mechanosensory neuron, during development in vivo through 4D live imaging with endogenously tagged proteins. PDE inherits and maintains apicobasal polarity from its epithelial precursor. Its apical domain is directly transformed into the ciliated dendritic tip through apical constriction, which is followed by axonal outgrowth from the opposite basal side of the cell. The apical Par complex and junctional proteins persistently localize at the developing dendritic domain throughout this transition. Consistent with their instructive role in axon-dendrite polarization, conditional depletion of the Par complex and junctional proteins results in robust defects in dendrite and axon formation. During apical constriction, a microtubule-organizing center (MTOC) containing the microtubule nucleator γ-tubulin ring complex (γ-TuRC) forms along the apical junction between PDE and its sister cell in a manner dependent on the Par complex and junctional proteins. This junctional MTOC patterns neuronal microtubule polarity and facilitate the dynein-dependent recruitment of the basal body for ciliogenesis. When non-ciliated neurons are genetically manipulated to obtain ciliated neuronal fate, inherited apicobasal polarity is required for generating ciliated dendritic tips. We propose that inherited apicobasal polarity, together with apical cell-cell interactions drive the morphological and cytoskeletal polarity in early neuronal differentiation.
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Affiliation(s)
- Joo Lee
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Jérémy Magescas
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Richard D Fetter
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | | | - Kang Shen
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
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46
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Sallee MD, Pickett MA, Feldman JL. Apical PAR complex proteins protect against programmed epithelial assaults to create a continuous and functional intestinal lumen. eLife 2021; 10:64437. [PMID: 34137371 PMCID: PMC8245128 DOI: 10.7554/elife.64437] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 06/16/2021] [Indexed: 12/16/2022] Open
Abstract
Sustained polarity and adhesion of epithelial cells is essential for the protection of our organs and bodies, and this epithelial integrity emerges during organ development amidst numerous programmed morphogenetic assaults. Using the developing Caenorhabditis elegans intestine as an in vivo model, we investigated how epithelia maintain their integrity through cell division and elongation to build a functional tube. Live imaging revealed that apical PAR complex proteins PAR-6/Par6 and PKC-3/aPkc remained apical during mitosis while apical microtubules and microtubule-organizing center (MTOC) proteins were transiently removed. Intestine-specific depletion of PAR-6, PKC-3, and the aPkc regulator CDC-42/Cdc42 caused persistent gaps in the apical MTOC as well as in other apical and junctional proteins after cell division and in non-dividing cells that elongated. Upon hatching, gaps coincided with luminal constrictions that blocked food, and larvae arrested and died. Thus, the apical PAR complex maintains apical and junctional continuity to construct a functional intestinal tube.
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47
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Stevens LM, Kim G, Koromila T, Steele JW, McGehee J, Stathopoulos A, Stein DS. Light-dependent N-end rule-mediated disruption of protein function in Saccharomyces cerevisiae and Drosophila melanogaster. PLoS Genet 2021; 17:e1009544. [PMID: 33999957 PMCID: PMC8158876 DOI: 10.1371/journal.pgen.1009544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 05/27/2021] [Accepted: 04/12/2021] [Indexed: 12/12/2022] Open
Abstract
Here we describe the development and characterization of the photo-N-degron, a peptide tag that can be used in optogenetic studies of protein function in vivo. The photo-N-degron can be expressed as a genetic fusion to the amino termini of other proteins, where it undergoes a blue light-dependent conformational change that exposes a signal for the class of ubiquitin ligases, the N-recognins, which mediate the N-end rule mechanism of proteasomal degradation. We demonstrate that the photo-N-degron can be used to direct light-mediated degradation of proteins in Saccharomyces cerevisiae and Drosophila melanogaster with fine temporal control. In addition, we compare the effectiveness of the photo-N-degron with that of two other light-dependent degrons that have been developed in their abilities to mediate the loss of function of Cactus, a component of the dorsal-ventral patterning system in the Drosophila embryo. We find that like the photo-N-degron, the blue light-inducible degradation (B-LID) domain, a light-activated degron that must be placed at the carboxy terminus of targeted proteins, is also effective in eliciting light-dependent loss of Cactus function, as determined by embryonic dorsal-ventral patterning phenotypes. In contrast, another previously described photosensitive degron (psd), which also must be located at the carboxy terminus of associated proteins, has little effect on Cactus-dependent phenotypes in response to illumination of developing embryos. These and other observations indicate that care must be taken in the selection and application of light-dependent and other inducible degrons for use in studies of protein function in vivo, but importantly demonstrate that N- and C-terminal fusions to the photo-N-degron and the B-LID domain, respectively, support light-dependent degradation in vivo. Much of what we know about biological processes has come from the analysis of mutants whose loss-of-function phenotypes provide insight into their normal functions. However, for genes that are required for viability and which have multiple functions in the life of a cell or organism one can only observe mutant phenotypes produced up to the time of death. Normal functions performed in wild-type individuals later than the time of death of mutants cannot be observed. In one approach to overcoming this limitation, a class of peptide degradation signals (degrons) have been developed, which when fused to proteins-of-interest, can target those proteins for degradation in response to various stimuli (temperature, chemical agents, co-expressed proteins, or light). Here we describe a new inducible degron (the photo-N-degron or PND), which when fused to the N-terminus of a protein, can induce N-end rule-mediated degradation in response to blue-light illumination and have validated its use in both yeast and Drosophila embryos. Moreover, using the Drosophila embryonic patterning protein Cactus, we show that like the PND, the previously-described B-LID domain, but not the previously-described photosensitive degron (psd), can produce detectable light-inducible phenotypes in Drosophila embryos that are consistent with the role of Cactus in dorsal-ventral patterning.
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Affiliation(s)
- Leslie M. Stevens
- Department of Molecular Biosciences and Institute for Molecular and Cellular Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - Goheun Kim
- Department of Molecular Biosciences and Institute for Molecular and Cellular Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - Theodora Koromila
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - John W. Steele
- Department of Molecular Biosciences and Institute for Molecular and Cellular Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - James McGehee
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Angelike Stathopoulos
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, United States of America
- * E-mail: (AS); (DSS)
| | - David S. Stein
- Department of Molecular Biosciences and Institute for Molecular and Cellular Biology, The University of Texas at Austin, Austin, Texas, United States of America
- * E-mail: (AS); (DSS)
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48
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Magescas J, Eskinazi S, Tran MV, Feldman JL. Centriole-less pericentriolar material serves as a microtubule organizing center at the base of C. elegans sensory cilia. Curr Biol 2021; 31:2410-2417.e6. [PMID: 33798428 DOI: 10.1016/j.cub.2021.03.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 01/18/2021] [Accepted: 03/05/2021] [Indexed: 01/20/2023]
Abstract
During mitosis in animal cells, the centrosome acts as a microtubule organizing center (MTOC) to assemble the mitotic spindle. MTOC function at the centrosome is driven by proteins within the pericentriolar material (PCM), however the molecular complexity of the PCM makes it difficult to differentiate the proteins required for MTOC activity from other centrosomal functions. We used the natural spatial separation of PCM proteins during mitotic exit to identify a minimal module of proteins required for centrosomal MTOC function in C. elegans. Using tissue-specific degradation, we show that SPD-5, the functional homolog of CDK5RAP2, is essential for embryonic mitosis, while SPD-2/CEP192 and PCMD-1, which are essential in the one-cell embryo, are dispensable. Surprisingly, although the centriole is known to be degraded in the ciliated sensory neurons in C. elegans,1-3 we find evidence for "centriole-less PCM" at the base of cilia and use this structure as a minimal testbed to dissect centrosomal MTOC function. Super-resolution imaging revealed that this PCM inserts inside the lumen of the ciliary axoneme and directly nucleates the assembly of dendritic microtubules toward the cell body. Tissue-specific degradation in ciliated sensory neurons revealed a role for SPD-5 and the conserved microtubule nucleator γ-TuRC, but not SPD-2 or PCMD-1, in MTOC function at centriole-less PCM. This MTOC function was in the absence of regulation by mitotic kinases, highlighting the intrinsic ability of these proteins to drive microtubule growth and organization and further supporting a model that SPD-5 is the primary driver of MTOC function at the PCM.
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Affiliation(s)
- Jérémy Magescas
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, 94305, CA, USA.
| | - Sani Eskinazi
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, 94305, CA, USA
| | - Michael V Tran
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, 94305, CA, USA
| | - Jessica L Feldman
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, 94305, CA, USA.
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Raiders S, Black EC, Bae A, MacFarlane S, Klein M, Shaham S, Singhvi A. Glia actively sculpt sensory neurons by controlled phagocytosis to tune animal behavior. eLife 2021; 10:63532. [PMID: 33759761 PMCID: PMC8079151 DOI: 10.7554/elife.63532] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 03/23/2021] [Indexed: 02/07/2023] Open
Abstract
Glia in the central nervous system engulf neuron fragments to remodel synapses and recycle photoreceptor outer segments. Whether glia passively clear shed neuronal debris or actively prune neuron fragments is unknown. How pruning of single-neuron endings impacts animal behavior is also unclear. Here, we report our discovery of glia-directed neuron pruning in Caenorhabditis elegans. Adult C. elegans AMsh glia engulf sensory endings of the AFD thermosensory neuron by repurposing components of the conserved apoptotic corpse phagocytosis machinery. The phosphatidylserine (PS) flippase TAT-1/ATP8A functions with glial PS-receptor PSR-1/PSR and PAT-2/α-integrin to initiate engulfment. This activates glial CED-10/Rac1 GTPase through the ternary GEF complex of CED-2/CrkII, CED-5/DOCK180, CED-12/ELMO. Execution of phagocytosis uses the actin-remodeler WSP-1/nWASp. This process dynamically tracks AFD activity and is regulated by temperature, the AFD sensory input. Importantly, glial CED-10 levels regulate engulfment rates downstream of neuron activity, and engulfment-defective mutants exhibit altered AFD-ending shape and thermosensory behavior. Our findings reveal a molecular pathway underlying glia-dependent engulfment in a peripheral sense-organ and demonstrate that glia actively engulf neuron fragments, with profound consequences on neuron shape and animal sensory behavior. Neurons are tree-shaped cells that receive information through endings connected to neighbouring cells or the environment. Controlling the size, number and location of these endings is necessary to ensure that circuits of neurons get precisely the right amount of input from their surroundings. Glial cells form a large portion of the nervous system, and they are tasked with supporting, cleaning and protecting neurons. In humans, part of their duties is to ‘eat’ (or prune) unnecessary neuron endings. In fact, this role is so important that defects in glial pruning are associated with conditions such as Alzheimer’s disease. Yet it is still unknown how pruning takes place, and in particular whether it is the neuron or the glial cell that initiates the process. To investigate this question, Raiders et al. enlisted the common laboratory animal Caenorhabditis elegans, a tiny worm with a simple nervous system where each neuron has been meticulously mapped out. First, the experiments showed that glial cells in C. elegans actually prune the endings of sensory neurons. Focusing on a single glia-neuron pair then revealed that the glial cell could trim the endings of a living neuron by redeploying the same molecular machinery it uses to clear dead cell debris. Compared to this debris-clearing activity, however, the glial cell takes a more nuanced approach to pruning: specifically, it can adjust the amount of trimming based on the activity load of the neuron. When Raiders et al. disrupted the glial pruning for a single temperature-sensing neuron, the worm lost its normal temperature preferences; this demonstrated how the pruning activity of a single glial cell can be linked to behavior. Taken together the experiments showcase how C. elegans can be used to study glial pruning. Further work using this model could help to understand how disease emerges when glial cells cannot perform their role, and to spot the genetic factors that put certain individuals at increased risk for neurological and sensory disorders.
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Affiliation(s)
- Stephan Raiders
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States.,Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, United States
| | - Erik Calvin Black
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States
| | - Andrea Bae
- Laboratory of Developmental Genetics, The Rockefeller University, New York, United States.,Cellular Imaging Shared Resources, Fred Hutchinson Cancer Research Center, Seattle, United States
| | - Stephen MacFarlane
- Department of Physics and Department of Biology, University of Miami, Coral Gables, United States
| | - Mason Klein
- Department of Physics and Department of Biology, University of Miami, Coral Gables, United States
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, New York, United States
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States.,Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, United States.,Department of Biological Structure, University of Washington School of Medicine, Seattle, United States.,Brotman Baty Institute for Precision Medicine, Seattle, United States
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50
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Abrams J, Nance J. A polarity pathway for exocyst-dependent intracellular tube extension. eLife 2021; 10:65169. [PMID: 33687331 PMCID: PMC8021397 DOI: 10.7554/elife.65169] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/08/2021] [Indexed: 12/25/2022] Open
Abstract
Lumen extension in intracellular tubes can occur when vesicles fuse with an invading apical membrane. Within the Caenorhabditis elegans excretory cell, which forms an intracellular tube, the exocyst vesicle-tethering complex is enriched at the lumenal membrane and is required for its outgrowth, suggesting that exocyst-targeted vesicles extend the lumen. Here, we identify a pathway that promotes intracellular tube extension by enriching the exocyst at the lumenal membrane. We show that PAR-6 and PKC-3/aPKC concentrate at the lumenal membrane and promote lumen extension. Using acute protein depletion, we find that PAR-6 is required for exocyst membrane recruitment, whereas PAR-3, which can recruit the exocyst in mammals, appears dispensable for exocyst localization and lumen extension. Finally, we show that CDC-42 and RhoGEF EXC-5/FGD regulate lumen extension by recruiting PAR-6 and PKC-3 to the lumenal membrane. Our findings reveal a pathway that connects CDC-42, PAR proteins, and the exocyst to extend intracellular tubes.
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Affiliation(s)
- Joshua Abrams
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, United States
| | - Jeremy Nance
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, United States.,Department of Cell Biology, NYU Grossman School of Medicine, New York, United States
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