1
|
Banerjee B, Das D. Effects of bursty synthesis in organelle biogenesis. Math Biosci 2024; 370:109156. [PMID: 38346665 DOI: 10.1016/j.mbs.2024.109156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 01/31/2024] [Accepted: 02/03/2024] [Indexed: 02/16/2024]
Abstract
A fundamental question of cell biology is how cells control the number of organelles. The processes of organelle biogenesis, namely de novo synthesis, fission, fusion, and decay, are inherently stochastic, producing cell-to-cell variability in organelle abundance. In addition, experiments suggest that the synthesis of some organelles can be bursty. We thus ask how bursty synthesis impacts intracellular organelle number distribution. We develop an organelle biogenesis model with bursty de novo synthesis by considering geometrically distributed burst sizes. We analytically solve the model in biologically relevant limits and provide exact expressions for the steady-state organelle number distributions and their means and variances. We also present approximate solutions for the whole model, complementing with exact stochastic simulations. We show that bursts generally increase the noise in organelle numbers, producing distinct signatures in noise profiles depending on different mechanisms of organelle biogenesis. We also find different shapes of organelle number distributions, including bimodal distributions in some parameter regimes. Notably, bursty synthesis broadens the parameter regime of observing bimodality compared to the 'non-bursty' case. Together, our framework utilizes number fluctuations to elucidate the role of bursty synthesis in producing organelle number heterogeneity in cells.
Collapse
Affiliation(s)
- Binayak Banerjee
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Nadia 741 246, West Bengal, India
| | - Dipjyoti Das
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Nadia 741 246, West Bengal, India.
| |
Collapse
|
2
|
Chou WH, Molaei M, Wu H, Oakes PW, Beach JR, Gardel ML. Limiting pool and actin architecture controls myosin cluster sizes in adherent cells. Biophys J 2024; 123:157-171. [PMID: 38062704 PMCID: PMC10808045 DOI: 10.1016/j.bpj.2023.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 09/11/2023] [Accepted: 12/04/2023] [Indexed: 12/19/2023] Open
Abstract
The actomyosin cytoskeleton generates mechanical forces that power important cellular processes, such as cell migration, cell division, and mechanosensing. Actomyosin self-assembles into contractile networks and bundles that underlie force generation and transmission in cells. A central step is the assembly of the myosin II filament from myosin monomers, regulation of which has been extensively studied. However, myosin filaments are almost always found as clusters within the cell cortex. While recent studies characterized cluster nucleation dynamics at the cell periphery, how myosin clusters grow on stress fibers remains poorly characterized. Here, we utilize a U2OS osteosarcoma cell line with endogenously tagged myosin II to measure the myosin cluster size distribution in the lamella of adherent cells. We find that myosin clusters can grow with Rho-kinase (ROCK) activity alone in the absence of myosin motor activity. Time-lapse imaging reveals that myosin clusters grow via increased myosin association to existing clusters, which is potentiated by ROCK-dependent myosin filament assembly. Enabling myosin motor activity allows further myosin cluster growth through myosin association that is dependent on F-actin architecture. Using a toy model, we show that myosin self-affinity is sufficient to recapitulate the experimentally observed myosin cluster size distribution, and that myosin cluster sizes are determined by the pool of myosin available for cluster growth. Together, our findings provide new insights into the regulation of myosin cluster sizes within the lamellar actomyosin cytoskeleton.
Collapse
Affiliation(s)
- Wen-Hung Chou
- Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, Illinois; Institute of Biophysical Dynamics, The University of Chicago, Chicago, Illinois
| | - Mehdi Molaei
- Institute of Biophysical Dynamics, The University of Chicago, Chicago, Illinois; Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois
| | - Huini Wu
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Chicago, Illinois
| | - Patrick W Oakes
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Chicago, Illinois
| | - Jordan R Beach
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Chicago, Illinois
| | - Margaret L Gardel
- Institute of Biophysical Dynamics, The University of Chicago, Chicago, Illinois; Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois; James Franck Institute, The University of Chicago, Chicago, Illinois; Department of Physics, The University of Chicago, Chicago, Illinois.
| |
Collapse
|
3
|
Williamson D, Tasker-Brown W, Murray JAH, Jones AR, Band LR. Modelling how plant cell-cycle progression leads to cell size regulation. PLoS Comput Biol 2023; 19:e1011503. [PMID: 37862377 PMCID: PMC10653611 DOI: 10.1371/journal.pcbi.1011503] [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: 03/06/2023] [Revised: 11/16/2023] [Accepted: 09/07/2023] [Indexed: 10/22/2023] Open
Abstract
Populations of cells typically maintain a consistent size, despite cell division rarely being precisely symmetrical. Therefore, cells must possess a mechanism of "size control", whereby the cell volume at birth affects cell-cycle progression. While size control mechanisms have been elucidated in a number of other organisms, it is not yet clear how this mechanism functions in plants. Here, we present a mathematical model of the key interactions in the plant cell cycle. Model simulations reveal that the network of interactions exhibits limit-cycle solutions, with biological switches underpinning both the G1/S and G2/M cell-cycle transitions. Embedding this network model within growing cells, we test hypotheses as to how cell-cycle progression can depend on cell size. We investigate two different mechanisms at both the G1/S and G2/M transitions: (i) differential expression of cell-cycle activator and inhibitor proteins (with synthesis of inhibitor proteins being independent of cell size), and (ii) equal inheritance of inhibitor proteins after cell division. The model demonstrates that both these mechanisms can lead to larger daughter cells progressing through the cell cycle more rapidly, and can thus contribute to cell-size control. To test how these features enable size homeostasis over multiple generations, we then simulated these mechanisms in a cell-population model with multiple rounds of cell division. These simulations suggested that integration of size-control mechanisms at both G1/S and G2/M provides long-term cell-size homeostasis. We concluded that while both size independence and equal inheritance of inhibitor proteins can reduce variations in cell size across individual cell-cycle phases, combining size-control mechanisms at both G1/S and G2/M is essential to maintain size homeostasis over multiple generations. Thus, our study reveals how features of the cell-cycle network enable cell-cycle progression to depend on cell size, and provides a mechanistic understanding of how plant cell populations maintain consistent size over generations.
Collapse
Affiliation(s)
- Daniel Williamson
- Centre for Mathematical Medicine and Biology, School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - William Tasker-Brown
- Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, United Kingdom
| | - James A. H. Murray
- Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, United Kingdom
| | - Angharad R. Jones
- Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, United Kingdom
| | - Leah R. Band
- Centre for Mathematical Medicine and Biology, School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, United Kingdom
| |
Collapse
|
4
|
Hickey K, Nazarov T, Smertenko A. Organellomic gradients in the fourth dimension. PLANT PHYSIOLOGY 2023; 193:98-111. [PMID: 37243543 DOI: 10.1093/plphys/kiad310] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 05/11/2023] [Indexed: 05/29/2023]
Abstract
Organelles function as hubs of cellular metabolism and elements of cellular architecture. In addition to 3 spatial dimensions that describe the morphology and localization of each organelle, the time dimension describes complexity of the organelle life cycle, comprising formation, maturation, functioning, decay, and degradation. Thus, structurally identical organelles could be biochemically different. All organelles present in a biological system at a given moment of time constitute the organellome. The homeostasis of the organellome is maintained by complex feedback and feedforward interactions between cellular chemical reactions and by the energy demands. Synchronized changes of organelle structure, activity, and abundance in response to environmental cues generate the fourth dimension of plant polarity. Temporal variability of the organellome highlights the importance of organellomic parameters for understanding plant phenotypic plasticity and environmental resiliency. Organellomics involves experimental approaches for characterizing structural diversity and quantifying the abundance of organelles in individual cells, tissues, or organs. Expanding the arsenal of appropriate organellomics tools and determining parameters of the organellome complexity would complement existing -omics approaches in comprehending the phenomenon of plant polarity. To highlight the importance of the fourth dimension, this review provides examples of organellome plasticity during different developmental or environmental situations.
Collapse
Affiliation(s)
- Kathleen Hickey
- Institute of Biological Chemistry, College of Agricultural, Human, and Natural Resources Sciences, Washington State University, Pullman, 99164 WA, USA
| | - Taras Nazarov
- Institute of Biological Chemistry, College of Agricultural, Human, and Natural Resources Sciences, Washington State University, Pullman, 99164 WA, USA
| | - Andrei Smertenko
- Institute of Biological Chemistry, College of Agricultural, Human, and Natural Resources Sciences, Washington State University, Pullman, 99164 WA, USA
| |
Collapse
|
5
|
Chou WH, Molaei M, Wu H, Oakes PW, Beach JR, Gardel ML. Limiting Pool and Actin Architecture Controls Myosin Cluster Sizes in Adherent Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.07.544121. [PMID: 37333106 PMCID: PMC10274763 DOI: 10.1101/2023.06.07.544121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
The actomyosin cytoskeleton generates mechanical forces that power important cellular processes, such as cell migration, cell division, and mechanosensing. Actomyosin self-assembles into contractile networks and bundles that underlie force generation and transmission in cells. A central step is the assembly of the myosin II filament from myosin monomers, regulation of which has been extensively studied. However, myosin filaments are almost always found as clusters within the cell cortex. While recent studies characterized cluster nucleation dynamics at the cell periphery, how myosin clusters grow on stress fibers remains poorly characterized. Here, we utilize a U2OS osteosarcoma cell line with endogenously tagged myosin II to measure the myosin cluster size distribution in the lamella of adherent cells. We find that myosin clusters can grow with Rho-kinase (ROCK) activity alone in the absence of myosin motor activity. Time-lapse imaging reveals that myosin clusters grow via increased myosin association to existing clusters, which is potentiated by ROCK-dependent myosin filament assembly. Enabling myosin motor activity allows further myosin cluster growth through myosin association that is dependent on F-actin architecture. Using a toy model, we show that myosin self-affinity is sufficient to recapitulate the experimentally observed myosin cluster size distribution, and that myosin cluster sizes are determined by the pool of myosin available for cluster growth. Together, our findings provide new insights into the regulation of myosin cluster sizes within the lamellar actomyosin cytoskeleton.
Collapse
|
6
|
Marshall WF. The flagellar length control system: exploring the physical biology of organelle size. Phys Biol 2023; 20:10.1088/1478-3975/acb18d. [PMID: 36623317 PMCID: PMC9877179 DOI: 10.1088/1478-3975/acb18d] [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: 10/27/2022] [Accepted: 01/09/2023] [Indexed: 01/11/2023]
Abstract
How cells build and maintain dynamic structures of defined size is currently an important unsolved problem in quantitative cell biology. The flagella of the unicellular green algaChlamydomonasprovide a highly tractable model system to investigate this general question, but while the powerful genetics of this organism have revealed numerous genes required for proper flagellar length, in most cases we do not understand their mechanistic role in length control. Flagellar length can be viewed as the steady state solution of a dynamical system involving assembly and disassembly of axonemal microtubules, with assembly depending on an active transport process known as intraflagellar transport (IFT). The inherent length dependence of IFT gives rise to a family of simple models for length regulation that can account for many previously described phenomena such as the ability of flagella to maintain equal lengths. But these models requires that the cell has a way to measure flagellar length in order to adjust IFT rates accordingly. Several models for length sensing have been modeled theoretically and evaluated experimentally, allowing them to be ruled out. Current data support a model in which the diffusive return of the kinesin motor driving IFT provides a length dependence that ultimately is the basis for length regulation. By combining models of length sensing with a more detailed representation of cargo transport and availability, it is now becoming possible to formulate concrete hypotheses to explain length altering mutants.
Collapse
Affiliation(s)
- Wallace F Marshall
- Department Biochemistry & Biophysics, University of California San Francisco, San Francisco, CA, United States of America
| |
Collapse
|
7
|
Amiri KP, Kalish A, Mukherji S. Robustness and Universality in Organelle Size Control. PHYSICAL REVIEW LETTERS 2023; 130:018401. [PMID: 36669211 PMCID: PMC10316456 DOI: 10.1103/physrevlett.130.018401] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 11/07/2022] [Indexed: 06/15/2023]
Abstract
One of the grand challenges in cellular biophysics is understanding the precision with which cells assemble and maintain subcellular structures. Organelle sizes, for example, must be flexible enough to allow cells to grow or shrink them as environments demand yet be maintained within homeostatic limits. Despite identification of molecular factors that regulate organelle sizes we lack insight into the quantitative principles underlying organelle size control. Here we show experimentally that cells can robustly control average fluctuations in organelle size. By demonstrating that organelle sizes obey a universal scaling relationship we predict theoretically, our framework suggests that organelles grow in random bursts from a limiting pool of building blocks. Burstlike growth provides a general biophysical mechanism by which cells can maintain on average reliable yet plastic organelle sizes.
Collapse
Affiliation(s)
| | - Asa Kalish
- Department of Physics, Washington University in St. Louis
| | | |
Collapse
|
8
|
Mahjoub MR, Nanjundappa R, Harvey MN. Development of a multiciliated cell. Curr Opin Cell Biol 2022; 77:102105. [PMID: 35716530 DOI: 10.1016/j.ceb.2022.102105] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 05/09/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022]
Abstract
Multiciliated cells (MCC) are evolutionary conserved, highly specialized cell types that contain dozens to hundreds of motile cilia that they use to propel fluid directionally. To template these cilia, each MCC produces between 30 and 500 basal bodies via a process termed centriole amplification. Much progress has been made in recent years in understanding the pathways involved in MCC fate determination, differentiation, and ciliogenesis. Recent studies using mammalian cell culture systems, mice, Xenopus, and other model organisms have started to uncover the mechanisms involved in centriole and cilia biogenesis. Yet, how MCC progenitor cells regulate the precise number of centrioles and cilia during their differentiation remains largely unknown. In this review, we will examine recent findings that address this fundamental question.
Collapse
Affiliation(s)
- Moe R Mahjoub
- Department of Medicine (Nephrology Division), Washington University, St Louis, MO, USA; Department of Cell Biology and Physiology, Washington University, St Louis, MO, USA.
| | - Rashmi Nanjundappa
- Department of Medicine (Nephrology Division), Washington University, St Louis, MO, USA
| | - Megan N Harvey
- Department of Medicine (Nephrology Division), Washington University, St Louis, MO, USA
| |
Collapse
|
9
|
Effects of length-dependent positive feedback on length distributions of microtubules undergoing hydrolysis. J Biosci 2022. [DOI: 10.1007/s12038-022-00255-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
10
|
Effects of random hydrolysis on biofilament length distributions in a shared subunit pool. Biophys J 2022; 121:502-514. [PMID: 34954156 PMCID: PMC8822617 DOI: 10.1016/j.bpj.2021.12.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 08/15/2021] [Accepted: 12/20/2021] [Indexed: 02/03/2023] Open
Abstract
The sizes of filamentous structures in a cell are often regulated for many physiological processes. A key question in cell biology is how such size control is achieved. Here, we theoretically study the length distributions of multiple filaments, growing by stochastic assembly and disassembly of subunits from a limiting subunit pool. Importantly, we consider a chemical switching of subunits (hydrolysis) prevalent in many biofilaments like microtubules (MTs). We show by simulations of different models that hydrolysis leads to a skewed unimodal length distribution for a single MT. In contrast, hydrolysis can lead to bimodal distributions of individual lengths for two MTs, where individual filaments toggle stochastically between bigger and smaller sizes. For more than two MTs, length distributions are also bimodal, although the bimodality becomes less prominent. We further show that this collective phenomenon is connected with the nonequilibrium nature of hydrolysis, and the bimodality disappears for reversible dynamics. Consistent with earlier theoretical studies, a homogeneous subunit pool, without hydrolysis, cannot control filament lengths. We thus elucidate the role of hydrolysis as a control mechanism on MT length diversity.
Collapse
|
11
|
Global asymptotic stability of the active disassembly model of flagellar length control. J Math Biol 2021; 84:8. [PMID: 34970717 PMCID: PMC8802998 DOI: 10.1007/s00285-021-01709-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 09/10/2021] [Accepted: 12/10/2021] [Indexed: 01/01/2023]
Abstract
Organelle size control is a fundamental question in biology that demonstrates the fascinating ability of cells to maintain homeostasis within their highly variable environments. Theoretical models describing cellular dynamics have the potential to help elucidate the principles underlying size control. Here, we perform a detailed study of the active disassembly model proposed in Fai et al. (elife 8:e42599, 2019). We construct a hybrid system which is shown to be well-behaved throughout the domain. We rule out the possibility of oscillations arising in the model and prove global asymptotic stability in the case of two flagella by the construction of a suitable Lyapunov function. Finally, we generalize the model to the case of arbitrary flagellar number in order to study olfactory sensory neurons, which have up to twenty cilia per cell. We show that our theoretical results may be extended to this case and explore the implications of this universal mechanism of size control.
Collapse
|
12
|
Pereira SG, Dias Louro MA, Bettencourt-Dias M. Biophysical and Quantitative Principles of Centrosome Biogenesis and Structure. Annu Rev Cell Dev Biol 2021; 37:43-63. [PMID: 34314592 DOI: 10.1146/annurev-cellbio-120219-051400] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The centrosome is a main orchestrator of the animal cellular microtubule cytoskeleton. Dissecting its structure and assembly mechanisms has been a goal of cell biologists for over a century. In the last two decades, a good understanding of the molecular constituents of centrosomes has been achieved. Moreover, recent breakthroughs in electron and light microscopy techniques have enabled the inspection of the centrosome and the mapping of its components with unprecedented detail. However, we now need a profound and dynamic understanding of how these constituents interact in space and time. Here, we review the latest findings on the structural and molecular architecture of the centrosome and how its biogenesis is regulated, highlighting how biophysical techniques and principles as well as quantitative modeling are changing our understanding of this enigmatic cellular organelle. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Collapse
|
13
|
Castillo-Badillo JA, Gautam N. An optogenetic model reveals cell shape regulation through FAK and fascin. J Cell Sci 2021; 134:269115. [PMID: 34114634 DOI: 10.1242/jcs.258321] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 06/01/2021] [Indexed: 12/17/2022] Open
Abstract
Cell shape regulation is important, but the mechanisms that govern shape are not fully understood, in part due to limited experimental models in which cell shape changes and underlying molecular processes can be rapidly and non-invasively monitored in real time. Here, we used an optogenetic tool to activate RhoA in the middle of mononucleated macrophages to induce contraction, resulting in a side with the nucleus that retained its shape and a non-nucleated side that was unable to maintain its shape and collapsed. In cells overexpressing focal adhesion kinase (FAK; also known as PTK2), the non-nucleated side exhibited a wide flat morphology and was similar in adhesion area to the nucleated side. In cells overexpressing fascin, an actin-bundling protein, the non-nucleated side assumed a spherical shape and was similar in height to the nucleated side. This effect of fascin was also observed in fibroblasts even without inducing furrow formation. Based on these results, we conclude that FAK and fascin work together to maintain cell shape by regulating adhesion area and height, respectively, in different cell types. This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Jean A Castillo-Badillo
- Department of Anesthesiology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - N Gautam
- Department of Anesthesiology, Washington University School of Medicine, St Louis, MO 63110, USA.,Department of Genetics, Washington University School of Medicine, St Louis, MO 63110, USA
| |
Collapse
|
14
|
Kulkarni S, Marquez J, Date P, Ventrella R, Mitchell BJ, Khokha MK. Mechanical stretch scales centriole number to apical area via Piezo1 in multiciliated cells. eLife 2021; 10:66076. [PMID: 34184636 PMCID: PMC8270640 DOI: 10.7554/elife.66076] [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: 12/30/2020] [Accepted: 06/28/2021] [Indexed: 01/01/2023] Open
Abstract
How cells count and regulate organelle number is a fundamental question in cell biology. For example, most cells restrict centrioles to two in number and assemble one cilium; however, multiciliated cells (MCCs) synthesize hundreds of centrioles to assemble multiple cilia. Aberration in centriole/cilia number impairs MCC function and can lead to pathological outcomes. Yet how MCCs control centriole number remains unknown. Using Xenopus, we demonstrate that centriole number scales with apical area over a remarkable 40-fold change in size. We find that tensile forces that shape the apical area also trigger centriole amplification based on both cell stretching experiments and disruption of embryonic elongation. Unexpectedly, Piezo1, a mechanosensitive ion channel, localizes near each centriole suggesting a potential role in centriole amplification. Indeed, depletion of Piezo1 affects centriole amplification and disrupts its correlation with the apical area in a tension-dependent manner. Thus, mechanical forces calibrate cilia/centriole number to the MCC apical area via Piezo1. Our results provide new perspectives to study organelle number control essential for optimal cell function.
Collapse
Affiliation(s)
- Saurabh Kulkarni
- Pediatric Genomics Discovery Program, Department of Pediatrics and Genetics, Yale University School of Medicine, New Haven, United States
| | - Jonathan Marquez
- Pediatric Genomics Discovery Program, Department of Pediatrics and Genetics, Yale University School of Medicine, New Haven, United States
| | - Priya Date
- Pediatric Genomics Discovery Program, Department of Pediatrics and Genetics, Yale University School of Medicine, New Haven, United States
| | - Rosa Ventrella
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Brian J Mitchell
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Mustafa K Khokha
- Pediatric Genomics Discovery Program, Department of Pediatrics and Genetics, Yale University School of Medicine, New Haven, United States
| |
Collapse
|
15
|
D'Ario M, Tavares R, Schiessl K, Desvoyes B, Gutierrez C, Howard M, Sablowski R. Cell size controlled in plants using DNA content as an internal scale. Science 2021; 372:1176-1181. [PMID: 34112688 DOI: 10.1126/science.abb4348] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 03/16/2021] [Accepted: 05/06/2021] [Indexed: 12/11/2022]
Abstract
How eukaryotic cells assess and maintain sizes specific for their species and cell type remains unclear. We show that in the Arabidopsis shoot stem cell niche, cell size variability caused by asymmetric divisions is corrected by adjusting the growth period before DNA synthesis. KIP-related protein 4 (KRP4) inhibits progression to DNA synthesis and associates with mitotic chromosomes. The F BOX-LIKE 17 (FBL17) protein removes excess KRP4. Consequently, daughter cells are born with comparable amounts of KRP4. Inhibitor dilution models predicted that KRP4 inherited through chromatin would robustly regulate size, whereas inheritance of excess free KRP4 would disrupt size homeostasis, as confirmed by mutant analyses. We propose that a cell cycle regulator, stabilized by association with mitotic chromosomes, reads DNA content as a cell size-independent scale.
Collapse
Affiliation(s)
- Marco D'Ario
- Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Rafael Tavares
- Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK
| | | | - Bénédicte Desvoyes
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Cantoblanco, 28049 Madrid, Spain
| | - Crisanto Gutierrez
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Cantoblanco, 28049 Madrid, Spain
| | - Martin Howard
- Computational and Systems Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Robert Sablowski
- Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK.
| |
Collapse
|
16
|
Dias Louro MA, Bettencourt-Dias M, Carneiro J. A first-takes-all model of centriole copy number control based on cartwheel elongation. PLoS Comput Biol 2021; 17:e1008359. [PMID: 33970906 PMCID: PMC8136855 DOI: 10.1371/journal.pcbi.1008359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 05/20/2021] [Accepted: 04/06/2021] [Indexed: 11/18/2022] Open
Abstract
How cells control the numbers of subcellular components is a fundamental question in biology. Given that biosynthetic processes are fundamentally stochastic it is utterly puzzling that some structures display no copy number variation within a cell population. Centriole biogenesis, with each centriole being duplicated once and only once per cell cycle, stands out due to its remarkable fidelity. This is a highly controlled process, which depends on low-abundance rate-limiting factors. How can exactly one centriole copy be produced given the variation in the concentration of these key factors? Hitherto, tentative explanations of this control evoked lateral inhibition- or phase separation-like mechanisms emerging from the dynamics of these rate-limiting factors but how strict centriole number is regulated remains unsolved. Here, a novel solution to centriole copy number control is proposed based on the assembly of a centriolar scaffold, the cartwheel. We assume that cartwheel building blocks accumulate around the mother centriole at supercritical concentrations, sufficient to assemble one or more cartwheels. Our key postulate is that once the first cartwheel is formed it continues to elongate by stacking the intermediate building blocks that would otherwise form supernumerary cartwheels. Using stochastic models and simulations, we show that this mechanism may ensure formation of one and only one cartwheel robustly over a wide range of parameter values. By comparison to alternative models, we conclude that the distinctive signatures of this novel mechanism are an increasing assembly time with cartwheel numbers and the translation of stochasticity in building block concentrations into variation in cartwheel numbers or length.
Collapse
Affiliation(s)
| | | | - Jorge Carneiro
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova, Oeiras, Portugal
| |
Collapse
|
17
|
Wang N, Liu J, Ricci WA, Gent JI, Dawe RK. Maize centromeric chromatin scales with changes in genome size. Genetics 2021; 217:iyab020. [PMID: 33857306 PMCID: PMC8049547 DOI: 10.1093/genetics/iyab020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 01/30/2021] [Indexed: 11/14/2022] Open
Abstract
Centromeres are defined by the location of Centromeric Histone H3 (CENP-A/CENH3) which interacts with DNA to define the locations and sizes of functional centromeres. An analysis of 26 maize genomes including 110 fully assembled centromeric regions revealed positive relationships between centromere size and genome size. These effects are independent of variation in the amounts of the major centromeric satellite sequence CentC. We also backcrossed known centromeres into two different lines with larger genomes and observed consistent increases in functional centromere sizes for multiple centromeres. Although changes in centromere size involve changes in bound CENH3, we could not mimic the effect by overexpressing CENH3 by threefold. Literature from other fields demonstrate that changes in genome size affect protein levels, organelle size and cell size. Our data demonstrate that centromere size is among these scalable features, and that multiple limiting factors together contribute to a stable centromere size equilibrium.
Collapse
Affiliation(s)
- Na Wang
- Department of Plant Biology, University of Georgia, Athens GA 30602, USA
| | - Jianing Liu
- Department of Genetics, University of Georgia, Athens GA 30602, USA
| | - William A Ricci
- Department of Plant Biology, University of Georgia, Athens GA 30602, USA
| | - Jonathan I Gent
- Department of Plant Biology, University of Georgia, Athens GA 30602, USA
| | - R Kelly Dawe
- Department of Plant Biology, University of Georgia, Athens GA 30602, USA
- Department of Genetics, University of Georgia, Athens GA 30602, USA
| |
Collapse
|
18
|
Mast FD, Rachubinski RA, Aitchison JD. Peroxisome prognostications: Exploring the birth, life, and death of an organelle. J Cell Biol 2020; 219:133827. [PMID: 32211898 PMCID: PMC7054992 DOI: 10.1083/jcb.201912100] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/30/2020] [Accepted: 01/31/2020] [Indexed: 02/07/2023] Open
Abstract
Peroxisomes play a central role in human health and have biochemical properties that promote their use in many biotechnology settings. With a primary role in lipid metabolism, peroxisomes share a niche with lipid droplets within the endomembrane-secretory system. Notably, factors in the ER required for the biogenesis of peroxisomes also impact the formation of lipid droplets. The dynamic interface between peroxisomes and lipid droplets, and also between these organelles and the ER and mitochondria, controls their metabolic flux and their dynamics. Here, we review our understanding of peroxisome biogenesis to propose and reframe models for understanding how peroxisomes are formed in cells. To more fully understand the roles of peroxisomes and to take advantage of their many properties that may prove useful in novel therapeutics or biotechnology applications, we recast mechanisms controlling peroxisome biogenesis in a framework that integrates inference from these models with experimental data.
Collapse
Affiliation(s)
- Fred D Mast
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle WA
| | | | - John D Aitchison
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle WA.,Department of Pediatrics, University of Washington, Seattle, WA
| |
Collapse
|
19
|
Li W, Zhang S, Yang G. Dynamic organization of intracellular organelle networks. WIREs Mech Dis 2020; 13:e1505. [PMID: 32865347 DOI: 10.1002/wsbm.1505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 06/06/2020] [Accepted: 07/09/2020] [Indexed: 01/07/2023]
Abstract
Intracellular organelles are membrane-bound and biochemically distinct compartments constructed to serve specialized functions in eukaryotic cells. Through extensive interactions, they form networks to coordinate and integrate their specialized functions for cell physiology. A fundamental property of these organelle networks is that they constantly undergo dynamic organization via membrane fusion and fission to remodel their internal connections and to mediate direct material exchange between compartments. The dynamic organization not only enables them to serve critical physiological functions adaptively but also differentiates them from many other biological networks such as gene regulatory networks and cell signaling networks. This review examines this fundamental property of the organelle networks from a systems point of view. The focus is exclusively on homotypic networks formed by mitochondria, lysosomes, endosomes, and the endoplasmic reticulum, respectively. First, key mechanisms that drive the dynamic organization of these networks are summarized. Then, several distinct organizational properties of these networks are highlighted. Next, spatial properties of the dynamic organization of these networks are emphasized, and their functional implications are examined. Finally, some representative molecular machineries that mediate the dynamic organization of these networks are surveyed. Overall, the dynamic organization of intracellular organelle networks is emerging as a fundamental and unifying paradigm in the internal organization of eukaryotic cells. This article is categorized under: Metabolic Diseases > Molecular and Cellular Physiology.
Collapse
Affiliation(s)
- Wenjing Li
- Laboratory of Computational Biology and Machine Intelligence, School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, China.,National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Shuhao Zhang
- Laboratory of Computational Biology and Machine Intelligence, School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, China.,National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, Nankai University, Tianjin, China
| | - Ge Yang
- Laboratory of Computational Biology and Machine Intelligence, School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, China.,National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China.,Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA.,Department of Computational Biology, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
20
|
Dobbelaere J, Schmidt Cernohorska M, Huranova M, Slade D, Dammermann A. Cep97 Is Required for Centriole Structural Integrity and Cilia Formation in Drosophila. Curr Biol 2020; 30:3045-3056.e7. [DOI: 10.1016/j.cub.2020.05.078] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 02/25/2020] [Accepted: 05/26/2020] [Indexed: 01/19/2023]
|
21
|
Aydogan MG, Steinacker TL, Mofatteh M, Wilmott ZM, Zhou FY, Gartenmann L, Wainman A, Saurya S, Novak ZA, Wong SS, Goriely A, Boemo MA, Raff JW. An Autonomous Oscillation Times and Executes Centriole Biogenesis. Cell 2020; 181:1566-1581.e27. [PMID: 32531200 PMCID: PMC7327525 DOI: 10.1016/j.cell.2020.05.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 12/19/2019] [Accepted: 05/08/2020] [Indexed: 01/18/2023]
Abstract
The accurate timing and execution of organelle biogenesis is crucial for cell physiology. Centriole biogenesis is regulated by Polo-like kinase 4 (Plk4) and initiates in S-phase when a daughter centriole grows from the side of a pre-existing mother. Here, we show that a Plk4 oscillation at the base of the growing centriole initiates and times centriole biogenesis to ensure that centrioles grow at the right time and to the right size. The Plk4 oscillation is normally entrained to the cell-cycle oscillator but can run autonomously of it-potentially explaining why centrioles can duplicate independently of cell-cycle progression. Mathematical modeling indicates that the Plk4 oscillation can be generated by a time-delayed negative feedback loop in which Plk4 inactivates the interaction with its centriolar receptor through multiple rounds of phosphorylation. We hypothesize that similar organelle-specific oscillations could regulate the timing and execution of organelle biogenesis more generally.
Collapse
Affiliation(s)
- Mustafa G Aydogan
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK.
| | - Thomas L Steinacker
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Mohammad Mofatteh
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Zachary M Wilmott
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK; Mathematical Institute, University of Oxford, Oxford OX2 6GG, UK
| | - Felix Y Zhou
- Ludwig Institute for Cancer Research, University of Oxford, Oxford OX3 7DQ, UK
| | - Lisa Gartenmann
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Alan Wainman
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Saroj Saurya
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Zsofia A Novak
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Siu-Shing Wong
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Alain Goriely
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, UK
| | - Michael A Boemo
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK.
| | - Jordan W Raff
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK.
| |
Collapse
|
22
|
Rana PS, Kurokawa M, Model MA. Evidence for macromolecular crowding as a direct apoptotic stimulus. J Cell Sci 2020; 133:jcs243931. [PMID: 32393677 PMCID: PMC7240305 DOI: 10.1242/jcs.243931] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 03/13/2020] [Indexed: 12/13/2022] Open
Abstract
Potassium loss and persistent shrinkage have both been implicated in apoptosis but their relationship and respective roles remain controversial. We approached this problem by clamping intracellular sodium and potassium in HeLa or MDCK cells using a combination of ionophores. Although ionophore treatment caused significant cell swelling, the initial volume could be restored and further reduced by application of sucrose. The swollen cells treated with ionophores remained viable for at least 8 h without any signs of apoptosis. Application of sucrose and the resulting shrinkage caused volume-dependent intrinsic apoptosis with all its classical features: inversion of phosphatidylserine, caspase activation and Bcl-2-dependent release of cytochrome c from mitochondria. In other experiments, apoptosis was induced by addition of the protein kinase inhibitor staurosporine at various degrees of swelling. Our results show that: (1) persistent shrinkage can cause apoptosis regardless of intracellular sodium or potassium composition or of the state of actin cytoskeleton; (2) strong potassium dependence of caspase activation is only observed in swollen cells with a reduced density of cytosolic proteins. We conclude that macromolecular crowding can be an important factor in determining the transition of cells to apoptosis.
Collapse
Affiliation(s)
- Priyanka S Rana
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Manabu Kurokawa
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Michael A Model
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| |
Collapse
|
23
|
Choubey S, Das D, Majumdar S. Cell-to-cell variability in organelle abundance reveals mechanisms of organelle biogenesis. Phys Rev E 2020; 100:022405. [PMID: 31574672 DOI: 10.1103/physreve.100.022405] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Indexed: 12/20/2022]
Abstract
How cells regulate the number of organelles is a fundamental question in cell biology. While decades of experimental work have uncovered four fundamental processes that regulate organelle biogenesis, namely, de novo synthesis, fission, fusion, and decay, a comprehensive understanding of how these processes together control organelle abundance remains elusive. Recent fluorescence microscopy experiments allow for the counting of organelles at the single-cell level. These measurements provide information about the cell-to-cell variability in organelle abundance in addition to the mean level. Motivated by such measurements, we build upon a recent study and analyze a general stochastic model of organelle biogenesis. We compute the exact analytical expressions for the probability distribution of organelle numbers, their mean, and variance across a population of single cells. It is shown that different mechanisms of organelle biogenesis lead to distinct signatures in the distribution of organelle numbers which allow us to discriminate between these various mechanisms. By comparing our theory against published data for peroxisome abundance measurements in yeast, we show that a widely believed model of peroxisome biogenesis that involves de novo synthesis, fission, and decay is inadequate in explaining the data. Also, our theory predicts bimodality in certain limits of the model. Overall, the framework developed here can be harnessed to gain mechanistic insights into the process of organelle biogenesis.
Collapse
Affiliation(s)
- Sandeep Choubey
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzerstraße 38, 01187 Dresden, Germany
| | - Dipjyoti Das
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06511, USA
| | - Saptarshi Majumdar
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzerstraße 38, 01187 Dresden, Germany
| |
Collapse
|
24
|
Wesley CC, Mishra S, Levy DL. Organelle size scaling over embryonic development. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 9:e376. [PMID: 32003549 DOI: 10.1002/wdev.376] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/19/2019] [Accepted: 01/08/2020] [Indexed: 12/13/2022]
Abstract
Cell division without growth results in progressive cell size reductions during early embryonic development. How do the sizes of intracellular structures and organelles scale with cell size and what are the functional implications of such scaling relationships? Model organisms, in particular Caenorhabditis elegans worms, Drosophila melanogaster flies, Xenopus laevis frogs, and Mus musculus mice, have provided insights into developmental size scaling of the nucleus, mitotic spindle, and chromosomes. Nuclear size is regulated by nucleocytoplasmic transport, nuclear envelope proteins, and the cytoskeleton. Regulators of microtubule dynamics and chromatin compaction modulate spindle and mitotic chromosome size scaling, respectively. Developmental scaling relationships for membrane-bound organelles, like the endoplasmic reticulum, Golgi, mitochondria, and lysosomes, have been less studied, although new imaging approaches promise to rectify this deficiency. While models that invoke limiting components and dynamic regulation of assembly and disassembly can account for some size scaling relationships in early embryos, it will be exciting to investigate the contribution of newer concepts in cell biology such as phase separation and interorganellar contacts. With a growing understanding of the underlying mechanisms of organelle size scaling, future studies promise to uncover the significance of proper scaling for cell function and embryonic development, as well as how aberrant scaling contributes to disease. This article is categorized under: Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing Early Embryonic Development > Fertilization to Gastrulation Comparative Development and Evolution > Model Systems.
Collapse
Affiliation(s)
- Chase C Wesley
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
| | - Sampada Mishra
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
| | - Daniel L Levy
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
| |
Collapse
|
25
|
Pollard LW, Garabedian MV, Alioto SL, Shekhar S, Goode BL. Genetically inspired in vitro reconstitution of Saccharomyces cerevisiae actin cables from seven purified proteins. Mol Biol Cell 2020; 31:335-347. [PMID: 31913750 PMCID: PMC7183793 DOI: 10.1091/mbc.e19-10-0576] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A major goal of synthetic biology is to define the minimal cellular machinery required to assemble a biological structure in its simplest form. Here, we focused on Saccharomyces cerevisiae actin cables, which provide polarized tracks for intracellular transport and maintain defined lengths while continuously undergoing rapid assembly and turnover. Guided by the genetic requirements for proper cable assembly and dynamics, we show that seven evolutionarily conserved S. cerevisiae proteins (actin, formin, profilin, tropomyosin, capping protein, cofilin, and AIP1) are sufficient to reconstitute the formation of cables that undergo polarized turnover and maintain steady-state lengths similar to actin cables in vivo. Further, the removal of individual proteins from this simple in vitro reconstitution system leads to cable defects that closely approximate in vivo cable phenotypes caused by disrupting the corresponding genes. Thus, a limited set of molecular components is capable of self-organizing into dynamic, micron-scale actin structures with features similar to cables in living cells.
Collapse
Affiliation(s)
| | | | | | | | - Bruce L Goode
- Department of Biology, Brandeis University, Waltham, MA 02454
| |
Collapse
|
26
|
Vuaridel‐Thurre G, Vuaridel AR, Dhar N, McKinney JD. Computational Analysis of the Mutual Constraints between Single‐Cell Growth and Division Control Models. ACTA ACUST UNITED AC 2019; 4:e1900103. [DOI: 10.1002/adbi.201900103] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 11/05/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Gaëlle Vuaridel‐Thurre
- School of Life SciencesSwiss Federal Institute of Technology in Lausanne (EPFL) CH‐1015 Lausanne Switzerland
| | - Ambroise R. Vuaridel
- School of Life SciencesSwiss Federal Institute of Technology in Lausanne (EPFL) CH‐1015 Lausanne Switzerland
| | - Neeraj Dhar
- School of Life SciencesSwiss Federal Institute of Technology in Lausanne (EPFL) CH‐1015 Lausanne Switzerland
| | - John D. McKinney
- School of Life SciencesSwiss Federal Institute of Technology in Lausanne (EPFL) CH‐1015 Lausanne Switzerland
| |
Collapse
|
27
|
Abstract
The genetic control of the characteristic cell sizes of different species and tissues is a long-standing enigma. Plants are convenient for studying this question in a multicellular context, as their cells do not move and are easily tracked and measured from organ initiation in the meristems to subsequent morphogenesis and differentiation. In this article, we discuss cell size control in plants compared with other organisms. As seen from yeast cells to mammalian cells, size homeostasis is maintained cell autonomously in the shoot meristem. In developing organs, vacuolization contributes to cell size heterogeneity and may resolve conflicts between growth control at the cellular and organ levels. Molecular mechanisms for cell size control have implications for how cell size responds to changes in ploidy, which are particularly important in plant development and evolution. We also discuss comparatively the functional consequences of cell size and their potential repercussions at higher scales, including genome evolution.
Collapse
Affiliation(s)
- Marco D'Ario
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Robert Sablowski
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| |
Collapse
|
28
|
Senger F, Pitaval A, Ennomani H, Kurzawa L, Blanchoin L, Théry M. Spatial integration of mechanical forces by α-actinin establishes actin network symmetry. J Cell Sci 2019; 132:jcs.236604. [PMID: 31615968 DOI: 10.1242/jcs.236604] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/08/2019] [Indexed: 12/15/2022] Open
Abstract
Cell and tissue morphogenesis depend on the production and spatial organization of tensional forces in the actin cytoskeleton. Actin network architecture is made of distinct modules characterized by specific filament organizations. The assembly of these modules are well described, but their integration in a cellular network is less understood. Here, we investigated the mechanism regulating the interplay between network architecture and the geometry of the extracellular environment of the cell. We found that α-actinin, a filament crosslinker, is essential for network symmetry to be consistent with extracellular microenvironment symmetry. It is required for the interconnection of transverse arcs with radial fibres to ensure an appropriate balance between forces at cell adhesions and across the actin network. Furthermore, this connectivity appeared necessary for the ability of the cell to integrate and to adapt to complex patterns of extracellular cues as they migrate. Our study has unveiled a role of actin filament crosslinking in the spatial integration of mechanical forces that ensures the adaptation of intracellular symmetry axes in accordance with the geometry of extracellular cues.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Fabrice Senger
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorphoLab, 3800, Grenoble, France
| | - Amandine Pitaval
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorphoLab, 3800, Grenoble, France.,Université Grenoble-Alpes, CEA, INRA, CNRS, UMR5168, Interdisciplinary Research Institute of Grenoble, Biomics Lab, 38000 Grenoble, France
| | - Hajer Ennomani
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorphoLab, 3800, Grenoble, France
| | - Laetitia Kurzawa
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorphoLab, 3800, Grenoble, France
| | - Laurent Blanchoin
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorphoLab, 3800, Grenoble, France .,Université Paris Diderot, INSERM, CEA, Hôpital Saint Louis, Institut Universitaire d'Hematologie, UMRS 1160, CytoMorphoLab, 75010 Paris, France
| | - Manuel Théry
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorphoLab, 3800, Grenoble, France .,Université Paris Diderot, INSERM, CEA, Hôpital Saint Louis, Institut Universitaire d'Hematologie, UMRS 1160, CytoMorphoLab, 75010 Paris, France
| |
Collapse
|
29
|
Fai TG, Mohapatra L, Kar P, Kondev J, Amir A. Length regulation of multiple flagella that self-assemble from a shared pool of components. eLife 2019; 8:e42599. [PMID: 31596235 PMCID: PMC6863624 DOI: 10.7554/elife.42599] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 10/08/2019] [Indexed: 11/24/2022] Open
Abstract
The single-celled green algae Chlamydomonas reinhardtii with its two flagella-microtubule-based structures of equal and constant lengths-is the canonical model organism for studying size control of organelles. Experiments have identified motor-driven transport of tubulin to the flagella tips as a key component of their length control. Here we consider a class of models whose key assumption is that proteins responsible for the intraflagellar transport (IFT) of tubulin are present in limiting amounts. We show that the limiting-pool assumption is insufficient to describe the results of severing experiments, in which a flagellum is regenerated after it has been severed. Next, we consider an extension of the limiting-pool model that incorporates proteins that depolymerize microtubules. We show that this 'active disassembly' model of flagellar length control explains in quantitative detail the results of severing experiments and use it to make predictions that can be tested in experiments.
Collapse
Affiliation(s)
- Thomas G Fai
- Department of MathematicsBrandeis UniversityWalthamUnited States
| | | | - Prathitha Kar
- Paulson School of Engineering and Applied SciencesHarvard UniversityCambridgeUnited States
| | - Jane Kondev
- Department of PhysicsBrandeis UniversityWalthamUnited States
| | - Ariel Amir
- Paulson School of Engineering and Applied SciencesHarvard UniversityCambridgeUnited States
| |
Collapse
|
30
|
Mohapatra L, Lagny TJ, Harbage D, Jelenkovic PR, Kondev J. The Limiting-Pool Mechanism Fails to Control the Size of Multiple Organelles. Cell Syst 2019; 4:559-567.e14. [PMID: 28544883 DOI: 10.1016/j.cels.2017.04.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 01/31/2017] [Accepted: 04/26/2017] [Indexed: 10/24/2022]
Abstract
How the size of micrometer-scale cellular structures such as the mitotic spindle, cytoskeletal filaments, the nucleus, the nucleolus, and other non-membrane bound organelles is controlled despite a constant turnover of their constituent parts is a central problem in biology. Experiments have implicated the limiting-pool mechanism: structures grow by stochastic addition of molecular subunits from a finite pool until the rates of subunit addition and removal are balanced, producing a structure of well-defined size. Here, we consider these dynamics when multiple filamentous structures are assembled stochastically from a shared pool of subunits. Using analytical calculations and computer simulations, we show that robust size control can be achieved only when a single filament is assembled. When multiple filaments compete for monomers, filament lengths exhibit large fluctuations. These results extend to three-dimensional structures and reveal the physical limitations of the limiting-pool mechanism of size control when multiple organelles are assembled from a shared pool of subunits.
Collapse
Affiliation(s)
| | - Thibaut J Lagny
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, 75005 Paris, France; Institut Curie, PSL Research University, CNRS, UMR 144, 75005 Paris, France
| | - David Harbage
- Department of Physics, Brandeis University, Waltham, MA 02454, USA
| | - Predrag R Jelenkovic
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
| | - Jane Kondev
- Department of Physics, Brandeis University, Waltham, MA 02454, USA
| |
Collapse
|
31
|
Nanjundappa R, Kong D, Shim K, Stearns T, Brody SL, Loncarek J, Mahjoub MR. Regulation of cilia abundance in multiciliated cells. eLife 2019; 8:e44039. [PMID: 31025935 PMCID: PMC6504233 DOI: 10.7554/elife.44039] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/25/2019] [Indexed: 12/14/2022] Open
Abstract
Multiciliated cells (MCC) contain hundreds of motile cilia used to propel fluid over their surface. To template these cilia, each MCC produces between 100-600 centrioles by a process termed centriole amplification. Yet, how MCC regulate the precise number of centrioles and cilia remains unknown. Airway progenitor cells contain two parental centrioles (PC) and form structures called deuterosomes that nucleate centrioles during amplification. Using an ex vivo airway culture model, we show that ablation of PC does not perturb deuterosome formation and centriole amplification. In contrast, loss of PC caused an increase in deuterosome and centriole abundance, highlighting the presence of a compensatory mechanism. Quantification of centriole abundance in vitro and in vivo identified a linear relationship between surface area and centriole number. By manipulating cell size, we discovered that centriole number scales with surface area. Our results demonstrate that a cell-intrinsic surface area-dependent mechanism controls centriole and cilia abundance in multiciliated cells.
Collapse
Affiliation(s)
- Rashmi Nanjundappa
- Nephrology Division, Department of MedicineWashington UniversitySt LouisUnited States
| | - Dong Kong
- Center for Cancer Research, National Cancer InstituteFrederickUnited States
| | - Kyuhwan Shim
- Nephrology Division, Department of MedicineWashington UniversitySt LouisUnited States
| | - Tim Stearns
- Department of BiologyStanford UniversityStanfordUnited States
| | - Steven L Brody
- Pulmonary Division, Department of MedicineWashington UniversitySt LouisUnited States
| | - Jadranka Loncarek
- Center for Cancer Research, National Cancer InstituteFrederickUnited States
| | - Moe R Mahjoub
- Nephrology Division, Department of MedicineWashington UniversitySt LouisUnited States
- Department of Cell Biology and PhysiologyWashington UniversitySt LouisUnited States
| |
Collapse
|
32
|
Yang Y, Wu M. Rhythmicity and waves in the cortex of single cells. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0116. [PMID: 29632268 PMCID: PMC5904302 DOI: 10.1098/rstb.2017.0116] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/30/2017] [Indexed: 12/15/2022] Open
Abstract
Emergence of dynamic patterns in the form of oscillations and waves on the cortex of single cells is a fascinating and enigmatic phenomenon. Here we outline various theoretical frameworks used to model pattern formation with the goal of reducing complex, heterogeneous patterns into key parameters that are biologically tractable. We also review progress made in recent years on the quantitative and molecular definitions of these terms, which we believe have begun to transform single-cell dynamic patterns from a purely observational and descriptive subject to more mechanistic studies. Specifically, we focus on the nature of local excitable and oscillation events, their spatial couplings leading to propagating waves and the role of active membrane. Instead of arguing for their functional importance, we prefer to consider such patterns as basic properties of dynamic systems. We discuss how knowledge of these patterns could be used to dissect the structure of cellular organization and how the network-centric view could help define cellular functions as transitions between different dynamical states. Last, we speculate on how these patterns could encode temporal and spatial information. This article is part of the theme issue ‘Self-organization in cell biology’.
Collapse
Affiliation(s)
- Yang Yang
- Department of Biological Sciences, Centre for Bioimaging Sciences, Mechanobiology Institute, National University of Singapore, Singapore
| | - Min Wu
- Department of Biological Sciences, Centre for Bioimaging Sciences, Mechanobiology Institute, National University of Singapore, Singapore
| |
Collapse
|
33
|
Björklund M. Cell size homeostasis: Metabolic control of growth and cell division. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:409-417. [PMID: 30315834 DOI: 10.1016/j.bbamcr.2018.10.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 09/25/2018] [Accepted: 10/03/2018] [Indexed: 12/14/2022]
Abstract
Joint regulation of growth rate and cell division rate determines cell size. Here we discuss how animal cells achieve cell size homeostasis potentially involving multiple signaling pathways converging at metabolic regulation of growth rate and cell cycle progression. While several models have been developed to explain cell size control, comparison of the two predominant models shows that size homeostasis is dependent on the ability to adjust cellular growth rate based on cell size. Consequently, maintenance of size homeostasis requires that larger cells can grow slower than small cells in relative terms. We review recent experimental evidence showing that such size adjustment occurs primarily at or immediately before the G1/S transition of the cell cycle. We further propose that bidirectional feedback between growth rate and size results in cell size sensing and discuss potential mechanisms how this may be accomplished.
Collapse
Affiliation(s)
- Mikael Björklund
- Zhejiang University-University of Edinburgh (ZJU-UoE) Institute, Zhejiang University School of Medicine, International Campus, 718 East Haizhou Rd., Haining, Zhejiang 314400, PR China.
| |
Collapse
|
34
|
Nigg EA, Holland AJ. Once and only once: mechanisms of centriole duplication and their deregulation in disease. Nat Rev Mol Cell Biol 2018; 19:297-312. [PMID: 29363672 PMCID: PMC5969912 DOI: 10.1038/nrm.2017.127] [Citation(s) in RCA: 306] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Centrioles are conserved microtubule-based organelles that form the core of the centrosome and act as templates for the formation of cilia and flagella. Centrioles have important roles in most microtubule-related processes, including motility, cell division and cell signalling. To coordinate these diverse cellular processes, centriole number must be tightly controlled. In cycling cells, one new centriole is formed next to each pre-existing centriole in every cell cycle. Advances in imaging, proteomics, structural biology and genome editing have revealed new insights into centriole biogenesis, how centriole numbers are controlled and how alterations in these processes contribute to diseases such as cancer and neurodevelopmental disorders. Moreover, recent work has uncovered the existence of surveillance pathways that limit the proliferation of cells with numerical centriole aberrations. Owing to this progress, we now have a better understanding of the molecular mechanisms governing centriole biogenesis, opening up new possibilities for targeting these pathways in the context of human disease.
Collapse
Affiliation(s)
- Erich A. Nigg
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Andrew J. Holland
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| |
Collapse
|
35
|
Aydogan MG, Wainman A, Saurya S, Steinacker TL, Caballe A, Novak ZA, Baumbach J, Muschalik N, Raff JW. A homeostatic clock sets daughter centriole size in flies. J Cell Biol 2018; 217:1233-1248. [PMID: 29500190 PMCID: PMC5881511 DOI: 10.1083/jcb.201801014] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 01/23/2018] [Accepted: 01/26/2018] [Indexed: 12/13/2022] Open
Abstract
Centrioles are highly structured organelles whose size is remarkably consistent within any given cell type. New centrioles are born when Polo-like kinase 4 (Plk4) recruits Ana2/STIL and Sas-6 to the side of an existing "mother" centriole. These two proteins then assemble into a cartwheel, which grows outwards to form the structural core of a new daughter. Here, we show that in early Drosophila melanogaster embryos, daughter centrioles grow at a linear rate during early S-phase and abruptly stop growing when they reach their correct size in mid- to late S-phase. Unexpectedly, the cartwheel grows from its proximal end, and Plk4 determines both the rate and period of centriole growth: the more active the centriolar Plk4, the faster centrioles grow, but the faster centriolar Plk4 is inactivated and growth ceases. Thus, Plk4 functions as a homeostatic clock, establishing an inverse relationship between growth rate and period to ensure that daughter centrioles grow to the correct size.
Collapse
Affiliation(s)
- Mustafa G Aydogan
- Sir William Dunn School of Pathology, University of Oxford, Oxford, England, UK
| | - Alan Wainman
- Sir William Dunn School of Pathology, University of Oxford, Oxford, England, UK
- Micron Oxford Advanced Bioimaging Unit, Department of Biochemistry, University of Oxford, Oxford, England, UK
| | - Saroj Saurya
- Sir William Dunn School of Pathology, University of Oxford, Oxford, England, UK
| | - Thomas L Steinacker
- Sir William Dunn School of Pathology, University of Oxford, Oxford, England, UK
| | - Anna Caballe
- Sir William Dunn School of Pathology, University of Oxford, Oxford, England, UK
| | - Zsofia A Novak
- Sir William Dunn School of Pathology, University of Oxford, Oxford, England, UK
| | - Janina Baumbach
- Sir William Dunn School of Pathology, University of Oxford, Oxford, England, UK
| | - Nadine Muschalik
- Sir William Dunn School of Pathology, University of Oxford, Oxford, England, UK
| | - Jordan W Raff
- Sir William Dunn School of Pathology, University of Oxford, Oxford, England, UK
| |
Collapse
|
36
|
Xiao S, Tong C, Yang Y, Wu M. Mitotic Cortical Waves Predict Future Division Sites by Encoding Positional and Size Information. Dev Cell 2017; 43:493-506.e3. [DOI: 10.1016/j.devcel.2017.10.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 08/02/2017] [Accepted: 10/22/2017] [Indexed: 10/18/2022]
|
37
|
Chandler-Brown D, Schmoller KM, Winetraub Y, Skotheim JM. The Adder Phenomenon Emerges from Independent Control of Pre- and Post-Start Phases of the Budding Yeast Cell Cycle. Curr Biol 2017; 27:2774-2783.e3. [PMID: 28889980 DOI: 10.1016/j.cub.2017.08.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/16/2017] [Accepted: 08/04/2017] [Indexed: 12/26/2022]
Abstract
Although it has long been clear that cells actively regulate their size, the molecular mechanisms underlying this regulation have remained poorly understood. In budding yeast, cell size primarily modulates the duration of the cell-division cycle by controlling the G1/S transition known as Start. We have recently shown that the rate of progression through Start increases with cell size, because cell growth dilutes the cell-cycle inhibitor Whi5 in G1. Recent phenomenological studies in yeast and bacteria have shown that these cells add an approximately constant volume during each complete cell cycle, independent of their size at birth. These results seem to be in conflict, as the phenomenological studies suggest that cells measure the amount they grow, rather than their size, and that size control acts over the whole cell cycle, rather than specifically in G1. Here, we propose an integrated model that unifies the adder phenomenology with the molecular mechanism of G1/S cell-size control. We use single-cell microscopy to parameterize a full cell-cycle model based on independent control of pre- and post-Start cell-cycle periods. We find that our model predicts the size-independent amount of cell growth during the full cell cycle. This suggests that the adder phenomenon is an emergent property of the independent regulation of pre- and post-Start cell-cycle periods rather than the consequence of an underlying molecular mechanism measuring a fixed amount of growth.
Collapse
Affiliation(s)
| | - Kurt M Schmoller
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | | | - Jan M Skotheim
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
| |
Collapse
|
38
|
Zhang J, Gao G, Begum G, Wang J, Khanna AR, Shmukler BE, Daubner GM, de los Heros P, Davies P, Varghese J, Bhuiyan MIH, Duan J, Zhang J, Duran D, Alper SL, Sun D, Elledge SJ, Alessi DR, Kahle KT. Functional kinomics establishes a critical node of volume-sensitive cation-Cl - cotransporter regulation in the mammalian brain. Sci Rep 2016; 6:35986. [PMID: 27782176 PMCID: PMC5080614 DOI: 10.1038/srep35986] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 10/04/2016] [Indexed: 02/08/2023] Open
Abstract
Cell volume homeostasis requires the dynamically regulated transport of ions across the plasmalemma. While the ensemble of ion transport proteins involved in cell volume regulation is well established, the molecular coordinators of their activities remain poorly characterized. We utilized a functional kinomics approach including a kinome-wide siRNA-phosphoproteomic screen, a high-content kinase inhibitor screen, and a kinase trapping-Orbitrap mass spectroscopy screen to systematically identify essential kinase regulators of KCC3 Thr991/Thr1048 phosphorylation - a key signaling event in cell swelling-induced regulatory volume decrease (RVD). In the mammalian brain, we found the Cl--sensitive WNK3-SPAK kinase complex, required for cell shrinkage-induced regulatory volume decrease (RVI) via the stimulatory phosphorylation of NKCC1 (Thr203/Thr207/Thr212), is also essential for the inhibitory phosphorylation of KCC3 (Thr991/Thr1048). This is mediated in vivo by an interaction between the CCT domain in SPAK and RFXV/I domains in WNK3 and NKCC1/KCC3. Accordingly, genetic or pharmacologic WNK3-SPAK inhibition prevents cell swelling in response to osmotic stress and ameliorates post-ischemic brain swelling through a simultaneous inhibition of NKCC1-mediated Cl- uptake and stimulation of KCC3-mediated Cl- extrusion. We conclude that WNK3-SPAK is an integral component of the long-sought "Cl-/volume-sensitive kinase" of the cation-Cl- cotransporters, and functions as a molecular rheostat of cell volume in the mammalian brain.
Collapse
Affiliation(s)
- Jinwei Zhang
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
- Departments of Neurosurgery and Pediatrics, Yale School of Medicine, New Haven, CT 06511 USA
| | - Geng Gao
- Division of Genetics, Brigham and Women’s Hospital, Boston, MA 02115 USA
| | - Gulnaz Begum
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Jinhua Wang
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Department of Biological Chemistry & Molecular Pharmacology, Harvard Medical School, 250 Longwood Ave, SGM 628, Boston, MA 02115, USA
| | - Arjun R. Khanna
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Boris E. Shmukler
- Division of Nephrology and Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA -022154 USA
- Department of Medicine, Harvard Medical School, Boston, MA -022154, USA
| | - Gerrit M. Daubner
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
| | - Paola de los Heros
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
| | - Paul Davies
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
| | - Joby Varghese
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
| | | | - Jinjing Duan
- Departments of Neurosurgery and Pediatrics, Yale School of Medicine, New Haven, CT 06511 USA
- Department of Cardiology, Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts 02115, USA
| | - Jin Zhang
- Department of Cardiology, Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts 02115, USA
| | - Daniel Duran
- Departments of Neurosurgery and Pediatrics, Yale School of Medicine, New Haven, CT 06511 USA
| | - Seth L. Alper
- Division of Nephrology and Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA -022154 USA
- Department of Medicine, Harvard Medical School, Boston, MA -022154, USA
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
- Veterans Affairs Pittsburgh Health Care System, Geriatric Research, Educational and Clinical Center, Pittsburgh, PA, USA
| | - Stephen J. Elledge
- Department of Genetics, Harvard University Medical School, Howard Hughes Medical Institute, Boston, Massachusetts 02115 USA
| | - Dario R. Alessi
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
| | - Kristopher T. Kahle
- Departments of Pediatrics and Cellular & Molecular Physiology; Interdepartmental Neuroscience Program; and Centers for Mendelian Genomics, Yale School of Medicine, New Haven, CT 06511 USA
| |
Collapse
|