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Singh A, Thale S, Leibner T, Lamparter L, Ricker A, Nüsse H, Klingauf J, Galic M, Ohlberger M, Matis M. Dynamic interplay of microtubule and actomyosin forces drive tissue extension. Nat Commun 2024; 15:3198. [PMID: 38609383 PMCID: PMC11014958 DOI: 10.1038/s41467-024-47596-8] [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: 08/25/2023] [Accepted: 04/04/2024] [Indexed: 04/14/2024] Open
Abstract
In order to shape a tissue, individual cell-based mechanical forces have to be integrated into a global force pattern. Over the last decades, the importance of actomyosin contractile arrays, which are the key constituents of various morphogenetic processes, has been established for many tissues. Recent studies have demonstrated that the microtubule cytoskeleton mediates folding and elongation of the epithelial sheet during Drosophila morphogenesis, placing microtubule mechanics on par with actin-based processes. While these studies establish the importance of both cytoskeletal systems during cell and tissue rearrangements, a mechanistic understanding of their functional hierarchy is currently missing. Here, we dissect the individual roles of these two key generators of mechanical forces during epithelium elongation in the developing Drosophila wing. We show that wing extension, which entails columnar-to-cuboidal cell shape remodeling in a cell-autonomous manner, is driven by anisotropic cell expansion caused by the remodeling of the microtubule cytoskeleton from apico-basal to planarly polarized. Importantly, cell and tissue elongation is not associated with Myosin activity. Instead, Myosin II exhibits a homeostatic role, as actomyosin contraction balances polarized microtubule-based forces to determine the final cell shape. Using a reductionist model, we confirm that pairing microtubule and actomyosin-based forces is sufficient to recapitulate cell elongation and the final cell shape. These results support a hierarchical mechanism whereby microtubule-based forces in some epithelial systems prime actomyosin-generated forces.
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Affiliation(s)
- Amrita Singh
- Institute of Cell Biology, Medical Faculty, University of Münster, Münster, Germany
- Cells in Motion' Interfaculty Centre, University of Münster, Münster, Germany
| | - Sameedha Thale
- Institute of Cell Biology, Medical Faculty, University of Münster, Münster, Germany
- Cells in Motion' Interfaculty Centre, University of Münster, Münster, Germany
| | - Tobias Leibner
- Applied Mathematics, Institute for Analysis and Numerics, Faculty of Mathematics and Computer science, University of Münster, Münster, Germany
| | - Lucas Lamparter
- Cells in Motion' Interfaculty Centre, University of Münster, Münster, Germany
- Institute of Medical Physics and Biophysics, Medical Faculty, University of Münster, Münster, Germany
| | - Andrea Ricker
- Institute of Medical Physics and Biophysics, Medical Faculty, University of Münster, Münster, Germany
| | - Harald Nüsse
- Institute of Medical Physics and Biophysics, Medical Faculty, University of Münster, Münster, Germany
| | - Jürgen Klingauf
- Cells in Motion' Interfaculty Centre, University of Münster, Münster, Germany
- Institute of Medical Physics and Biophysics, Medical Faculty, University of Münster, Münster, Germany
| | - Milos Galic
- Cells in Motion' Interfaculty Centre, University of Münster, Münster, Germany
- Institute of Medical Physics and Biophysics, Medical Faculty, University of Münster, Münster, Germany
| | - Mario Ohlberger
- Applied Mathematics, Institute for Analysis and Numerics, Faculty of Mathematics and Computer science, University of Münster, Münster, Germany
| | - Maja Matis
- Institute of Cell Biology, Medical Faculty, University of Münster, Münster, Germany.
- Cells in Motion' Interfaculty Centre, University of Münster, Münster, Germany.
- Institute of Medical Physics and Biophysics, Medical Faculty, University of Münster, Münster, Germany.
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Gujar MR, Gao Y, Teng X, Ding WY, Lin J, Tan YS, Chew LY, Toyama Y, Wang H. Patronin/CAMSAP promotes reactivation and regeneration of Drosophila quiescent neural stem cells. EMBO Rep 2023; 24:e56624. [PMID: 37440685 PMCID: PMC10481672 DOI: 10.15252/embr.202256624] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 06/06/2023] [Accepted: 06/26/2023] [Indexed: 07/15/2023] Open
Abstract
The ability of stem cells to switch between quiescent and proliferative states is crucial for maintaining tissue homeostasis and regeneration. Drosophila quiescent neural stem cells (qNSCs) extend a primary protrusion that is enriched in acentrosomal microtubules and can be regenerated upon injury. Arf1 promotes microtubule growth, reactivation (exit from quiescence), and regeneration of qNSC protrusions upon injury. However, how Arf1 is regulated in qNSCs remains elusive. Here, we show that the microtubule minus-end binding protein Patronin/CAMSAP promotes acentrosomal microtubule growth and quiescent NSC reactivation. Patronin is important for the localization of Arf1 at Golgi and physically associates with Arf1, preferentially with its GDP-bound form. Patronin is also required for the regeneration of qNSC protrusion, likely via the regulation of microtubule growth. Finally, Patronin functions upstream of Arf1 and its effector Msps/XMAP215 to target the cell adhesion molecule E-cadherin to NSC-neuropil contact sites during NSC reactivation. Our findings reveal a novel link between Patronin/CAMSAP and Arf1 in the regulation of microtubule growth and NSC reactivation. A similar mechanism might apply to various microtubule-dependent systems in mammals.
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Affiliation(s)
- Mahekta R Gujar
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
| | - Yang Gao
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
| | - Xiang Teng
- Mechanobiology InstituteSingaporeSingapore
| | - Wei Yung Ding
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
| | - Jiaen Lin
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
| | - Ye Sing Tan
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
| | - Liang Yuh Chew
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
- Present address:
Temasek LifeSciences LaboratorySingaporeSingapore
| | - Yusuke Toyama
- Mechanobiology InstituteSingaporeSingapore
- Department of Biological SciencesNational University of SingaporeSingaporeSingapore
| | - Hongyan Wang
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
- Department of Physiology, Yong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
- Integrative Sciences and Engineering ProgrammeNational University of SingaporeSingaporeSingapore
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Sustar AE, Strand LG, Zimmerman SG, Berg CA. Imaginal disk growth factors are Drosophila chitinase-like proteins with roles in morphogenesis and CO2 response. Genetics 2023; 223:iyac185. [PMID: 36576887 PMCID: PMC9910413 DOI: 10.1093/genetics/iyac185] [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: 07/18/2022] [Revised: 07/18/2022] [Accepted: 11/16/2022] [Indexed: 12/29/2022] Open
Abstract
Chitinase-like proteins (CLPs) are members of the family 18 glycosyl hydrolases, which include chitinases and the enzymatically inactive CLPs. A mutation in the enzyme's catalytic site, conserved in vertebrates and invertebrates, allowed CLPs to evolve independently with functions that do not require chitinase activity. CLPs normally function during inflammatory responses, wound healing, and host defense, but when they persist at excessive levels at sites of chronic inflammation and in tissue-remodeling disorders, they correlate positively with disease progression and poor prognosis. Little is known, however, about their physiological function. Drosophila melanogaster has 6 CLPs, termed Imaginal disk growth factors (Idgfs), encoded by Idgf1, Idgf2, Idgf3, Idgf4, Idgf5, and Idgf6. In this study, we developed tools to facilitate characterization of the physiological roles of the Idgfs by deleting each of the Idgf genes using the CRISPR/Cas9 system and assessing loss-of-function phenotypes. Using null lines, we showed that loss of function for all 6 Idgf proteins significantly lowers viability and fertility. We also showed that Idgfs play roles in epithelial morphogenesis, maintaining proper epithelial architecture and cell shape, regulating E-cadherin and cortical actin, and remarkably, protecting these tissues against CO2 exposure. Defining the normal molecular mechanisms of CLPs is a key to understanding how deviations tip the balance from a physiological to a pathological state.
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Affiliation(s)
- Anne E Sustar
- Department of Genome Sciences, University of Washington, Foege Bldg. S-250, 3720 15th Ave NE, Seattle, WA 98195-5065, USA
| | - Liesl G Strand
- Department of Genome Sciences, University of Washington, Foege Bldg. S-250, 3720 15th Ave NE, Seattle, WA 98195-5065, USA
| | - Sandra G Zimmerman
- Department of Genome Sciences, University of Washington, Foege Bldg. S-250, 3720 15th Ave NE, Seattle, WA 98195-5065, USA
| | - Celeste A Berg
- Department of Genome Sciences, University of Washington, Foege Bldg. S-250, 3720 15th Ave NE, Seattle, WA 98195-5065, USA
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Vineethakumari C, Lüders J. Microtubule Anchoring: Attaching Dynamic Polymers to Cellular Structures. Front Cell Dev Biol 2022; 10:867870. [PMID: 35309944 PMCID: PMC8927778 DOI: 10.3389/fcell.2022.867870] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 02/11/2022] [Indexed: 01/01/2023] Open
Abstract
Microtubules are dynamic, filamentous polymers composed of α- and β-tubulin. Arrays of microtubules that have a specific polarity and distribution mediate essential processes such as intracellular transport and mitotic chromosome segregation. Microtubule arrays are generated with the help of microtubule organizing centers (MTOC). MTOCs typically combine two principal activities, the de novo formation of microtubules, termed nucleation, and the immobilization of one of the two ends of microtubules, termed anchoring. Nucleation is mediated by the γ-tubulin ring complex (γTuRC), which, in cooperation with its recruitment and activation factors, provides a template for α- and β-tubulin assembly, facilitating formation of microtubule polymer. In contrast, the molecules and mechanisms that anchor newly formed microtubules at MTOCs are less well characterized. Here we discuss the mechanistic challenges underlying microtubule anchoring, how this is linked with the molecular activities of known and proposed anchoring factors, and what consequences defective microtubule anchoring has at the cellular and organismal level.
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