1
|
Cisterna BA, Skruber K, Jane ML, Camesi CI, Nguyen ID, Liu TM, Warp PV, Black JB, Butler MT, Bear JE, Mor DE, Read TA, Vitriol EA. Prolonged depletion of profilin 1 or F-actin causes an adaptive response in microtubules. J Cell Biol 2024; 223:e202309097. [PMID: 38722279 PMCID: PMC11082369 DOI: 10.1083/jcb.202309097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 03/06/2024] [Accepted: 04/05/2024] [Indexed: 05/12/2024] Open
Abstract
In addition to its well-established role in actin assembly, profilin 1 (PFN1) has been shown to bind to tubulin and alter microtubule growth. However, whether PFN1's predominant control over microtubules in cells occurs through direct regulation of tubulin or indirectly through the polymerization of actin has yet to be determined. Here, we manipulated PFN1 expression, actin filament assembly, and actomyosin contractility and showed that reducing any of these parameters for extended periods of time caused an adaptive response in the microtubule cytoskeleton, with the effect being significantly more pronounced in neuronal processes. All the observed changes to microtubules were reversible if actomyosin was restored, arguing that PFN1's regulation of microtubules occurs principally through actin. Moreover, the cytoskeletal modifications resulting from PFN1 depletion in neuronal processes affected microtubule-based transport and mimicked phenotypes that are linked to neurodegenerative disease. This demonstrates how defects in actin can cause compensatory responses in other cytoskeleton components, which in turn significantly alter cellular function.
Collapse
Affiliation(s)
- Bruno A. Cisterna
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Kristen Skruber
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - Makenzie L. Jane
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Caleb I. Camesi
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Ivan D. Nguyen
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Tatiana M. Liu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Peyton V. Warp
- University of Miami Miller School of Medicine, Miami, FL, USA
| | - Joseph B. Black
- Division of Urologic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Mitchell T. Butler
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - James E. Bear
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Danielle E. Mor
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Tracy-Ann Read
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Eric A. Vitriol
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| |
Collapse
|
2
|
Read TA, Cisterna BA, Skruber K, Ahmadieh S, Lindamood HL, Vitriol JA, Shi Y, Lefebvre AE, Black JB, Butler MT, Bear JE, Cherezova A, Ilatovskaya DV, Weintraub NL, Vitriol EA. The actin binding protein profilin 1 is critical for mitochondria function. bioRxiv 2023:2023.08.07.552354. [PMID: 37609280 PMCID: PMC10441311 DOI: 10.1101/2023.08.07.552354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Profilin 1 (PFN1) is an actin binding protein that is vital for the polymerization of monomeric actin into filaments. Here we screened knockout cells for novel functions of PFN1 and discovered that mitophagy, a type of selective autophagy that removes defective or damaged mitochondria from the cell, was significantly upregulated in the absence of PFN1. Despite successful autophagosome formation and fusion with the lysosome, and activation of additional mitochondrial quality control pathways, PFN1 knockout cells still accumulate damaged, dysfunctional mitochondria. Subsequent imaging and functional assays showed that loss of PFN1 significantly affects mitochondria morphology, dynamics, and respiration. Further experiments revealed that PFN1 is located to the mitochondria matrix and is likely regulating mitochondria function from within rather than through polymerizing actin at the mitochondria surface. Finally, PFN1 mutants associated with amyotrophic lateral sclerosis (ALS) fail to rescue PFN1 knockout mitochondrial phenotypes and form aggregates within mitochondria, further perturbing them. Together, these results suggest a novel function for PFN1 in regulating mitochondria and identify a potential pathogenic mechanism of ALS-linked PFN1 variants.
Collapse
Affiliation(s)
- Tracy-Ann Read
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Bruno A. Cisterna
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Kristen Skruber
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - Samah Ahmadieh
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Halli L. Lindamood
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Josefine A. Vitriol
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Yang Shi
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
- Department of Population Health Sciences, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | | | - Joseph B. Black
- Division of Urologic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Mitchell T. Butler
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - James E. Bear
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Alena Cherezova
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Daria V. Ilatovskaya
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Neil L. Weintraub
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Eric A. Vitriol
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| |
Collapse
|
3
|
Appalabhotla R, Butler MT, Bear JE, Haugh JM. G-actin diffusion is insufficient to achieve F-actin assembly in fast-treadmilling protrusions. Biophys J 2023; 122:3816-3829. [PMID: 37644720 PMCID: PMC10541494 DOI: 10.1016/j.bpj.2023.08.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 07/07/2023] [Accepted: 08/25/2023] [Indexed: 08/31/2023] Open
Abstract
To generate forces that drive migration of a eukaryotic cell, arrays of actin filaments (F-actin) are assembled at the cell's leading membrane edge. To maintain cell propulsion and respond to dynamic external cues, actin filaments must be disassembled to regenerate the actin monomers (G-actin), and transport of G-actin from sites of disassembly back to the leading edge completes the treadmilling cycle and limits the flux of F-actin assembly. Whether or not molecular diffusion is sufficient for G-actin transport has been a long-standing topic of debate, in part because the dynamic nature of cell motility and migration hinders the estimation of transport parameters. In this work, we applied an experimental system in which cells adopt an approximately constant and symmetrical shape; they cannot migrate but exhibit fast, steady treadmilling in the thin region protruding from the cell. Using fluorescence recovery after photobleaching, we quantified the relative concentrations and corresponding fluxes of F- and G-actin in this system. In conjunction with mathematical modeling, constrained by measured features of each region of interest, this approach revealed that diffusion alone cannot account for the transport of G-actin to the leading edge. Although G-actin diffusion and vectorial transport might vary with position in the protruding region, good agreement with the fluorescence recovery after photobleaching measurements was achieved by a model with constant G-actin diffusivity ∼2 μm2/s and anterograde G-actin velocity less than 1 μm/s.
Collapse
Affiliation(s)
- Ravikanth Appalabhotla
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina
| | - Mitchell T Butler
- Department of Cell Biology and Physiology, UNC Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - James E Bear
- Department of Cell Biology and Physiology, UNC Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina.
| | - Jason M Haugh
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina.
| |
Collapse
|
4
|
Cisterna BA, Skruber K, Jane ML, Camesi CI, Nguyen ID, Warp PV, Black JB, Butler MT, Bear JE, Tracy-Ann R, Vitriol EA. Cytoskeletal adaptation following long-term dysregulation of actomyosin in neuronal processes. bioRxiv 2023:2023.08.25.554891. [PMID: 37662186 PMCID: PMC10473725 DOI: 10.1101/2023.08.25.554891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Microtubules, intermediate filaments, and actin are cytoskeletal polymer networks found within the cell. While each has unique functions, all the cytoskeletal elements must work together for cellular mechanics to be fully operative. This is achieved through crosstalk mechanisms whereby the different networks influence each other through signaling pathways and direct interactions. Because crosstalk can be complex, it is possible for perturbations in one cytoskeletal element to affect the others in ways that are difficult to predict. Here we investigated how long-term changes to the actin cytoskeleton affect microtubules and intermediate filaments. Reducing F-actin or actomyosin contractility increased acetylated microtubules and intermediate filament expression, with the effect being significantly more pronounced in neuronal processes. Changes to microtubules were completely reversible if F-actin and myosin activity is restored. Moreover, the altered microtubules in neuronal processes resulting from F-actin depletion caused significant changes to microtubule-based transport, mimicking phenotypes that are linked to neurodegenerative disease. Thus, defects in actin dynamics cause a compensatory response in other cytoskeleton components which profoundly alters cellular function.
Collapse
Affiliation(s)
- Bruno A. Cisterna
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Kristen Skruber
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - Makenzie L. Jane
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Caleb I. Camesi
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Ivan D. Nguyen
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Peyton V. Warp
- University of Miami Miller School of Medicine, Miami, FL, USA
| | - Joseph B. Black
- Division of Urologic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Mitchell T. Butler
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - James E. Bear
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Read Tracy-Ann
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Eric A. Vitriol
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| |
Collapse
|
5
|
Hakeem RM, Subramanian BC, Hockenberry MA, King ZT, Butler MT, Legant WR, Bear JE. A Photopolymerized Hydrogel System with Dual Stiffness Gradients Reveals Distinct Actomyosin-Based Mechano-Responses in Fibroblast Durotaxis. ACS Nano 2023; 17:197-211. [PMID: 36475639 PMCID: PMC9839609 DOI: 10.1021/acsnano.2c05941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Durotaxis, migration of cells directed by a stiffness gradient, is critical in development and disease. To distinguish durotaxis-specific migration mechanisms from those on uniform substrate stiffnesses, we engineered an all-in-one photopolymerized hydrogel system containing areas of stiffness gradients with dual slopes (steep and shallow), adjacent to uniform stiffness (soft and stiff) regions. While fibroblasts rely on nonmuscle myosin II (NMII) activity and the LIM-domain protein Zyxin, ROCK and the Arp2/3 complex are surprisingly dispensable for durotaxis on either stiffness gradient. Additionally, loss of either actin-elongator Formin-like 3 (FMNL3) or actin-bundler fascin has little impact on durotactic response on stiffness gradients. However, lack of Arp2/3 activity results in a filopodia-based durotactic migration that is equally as efficient as that of lamellipodia-based durotactic migration. Importantly, we uncover essential and specific roles for FMNL3 and fascin in the formation and asymmetric distribution of filopodia during filopodia-based durotaxis response to the stiffness gradients. Together, our tunable all-in-one hydrogel system serves to identify both conserved as well as distinct molecular mechanisms that underlie mechano-responses of cells experiencing altered slopes of stiffness gradients.
Collapse
Affiliation(s)
- Reem M Hakeem
- Department of Biochemistry and Biophysics, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
- UNC Lineberger Comprehensive Cancer Center, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Bhagawat C Subramanian
- UNC Lineberger Comprehensive Cancer Center, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Max A Hockenberry
- Department of Cell Biology and Physiology, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
- UNC Lineberger Comprehensive Cancer Center, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
- Department of Pharmacology, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Zayna T King
- Department of Cell Biology and Physiology, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
- UNC Lineberger Comprehensive Cancer Center, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Mitchell T Butler
- Department of Cell Biology and Physiology, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
- UNC Lineberger Comprehensive Cancer Center, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Wesley R Legant
- Department of Pharmacology, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - James E Bear
- Department of Cell Biology and Physiology, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
- UNC Lineberger Comprehensive Cancer Center, UNC-Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| |
Collapse
|
6
|
King ZT, Butler MT, Hockenberry MA, Subramanian BC, Siesser PF, Graham DM, Legant WR, Bear JE. Coro1B and Coro1C regulate lamellipodia dynamics and cell motility by tuning branched actin turnover. J Cell Biol 2022; 221:e202111126. [PMID: 35657370 PMCID: PMC9170525 DOI: 10.1083/jcb.202111126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 04/01/2022] [Accepted: 05/18/2022] [Indexed: 02/03/2023] Open
Abstract
Actin filament dynamics must be precisely controlled in cells to execute behaviors such as vesicular trafficking, cytokinesis, and migration. Coronins are conserved actin-binding proteins that regulate several actin-dependent subcellular processes. Here, we describe a new conditional knockout cell line for two ubiquitous coronins, Coro1B and Coro1C. These coronins, which strongly co-localize with Arp2/3-branched actin, require Arp2/3 activity for proper subcellular localization. Coronin null cells have altered lamellipodial protrusion dynamics due to increased branched actin density and reduced actin turnover within lamellipodia, leading to defective haptotaxis. Surprisingly, excessive cofilin accumulates in coronin null lamellipodia, a result that is inconsistent with the current models of coronin-cofilin functional interaction. However, consistent with coronins playing a pro-cofilin role, coronin null cells have increased F-actin levels. Lastly, we demonstrate that the loss of coronins increases accompanied by an increase in cellular contractility. Together, our observations reveal that coronins are critical for proper turnover of branched actin networks and that decreased actin turnover leads to increased cellular contractility.
Collapse
Affiliation(s)
- Zayna T. King
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - Mitchell T. Butler
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - Max A. Hockenberry
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- Department of Pharmacology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - Bhagawat C. Subramanian
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - Priscila F. Siesser
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - David M. Graham
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - Wesley R. Legant
- Department of Pharmacology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - James E. Bear
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- Department of Pharmacology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| |
Collapse
|
7
|
Chandra A, Butler MT, Bear JE, Haugh JM. Modeling cell protrusion predicts how myosin II and actin turnover affect adhesion-based signaling. Biophys J 2022; 121:102-118. [PMID: 34861242 PMCID: PMC8758409 DOI: 10.1016/j.bpj.2021.11.2889] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/03/2021] [Accepted: 11/29/2021] [Indexed: 01/07/2023] Open
Abstract
Orchestration of cell migration is essential for development, tissue regeneration, and the immune response. This dynamic process integrates adhesion, signaling, and cytoskeletal subprocesses across spatial and temporal scales. In mesenchymal cells, adhesion complexes bound to extracellular matrix mediate both biochemical signal transduction and physical interaction with the F-actin cytoskeleton. Here, we present a mathematical model that offers insight into both aspects, considering spatiotemporal dynamics of nascent adhesions, active signaling molecules, mechanical clutching, actin treadmilling, and nonmuscle myosin II contractility. At the core of the model is a positive feedback loop, whereby adhesion-based signaling promotes generation of barbed ends at, and protrusion of, the cell's leading edge, which in turn promotes formation and stabilization of nascent adhesions. The model predicts a switch-like transition and optimality of membrane protrusion, determined by the balance of actin polymerization and retrograde flow, with respect to extracellular matrix density. The model, together with new experimental measurements, explains how protrusion can be modulated by mechanical effects (nonmuscle myosin II contractility and adhesive bond stiffness) and F-actin turnover.
Collapse
Affiliation(s)
- Ankit Chandra
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina
| | - Mitchell T. Butler
- Department of Cell Biology and Physiology, UNC Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - James E. Bear
- Department of Cell Biology and Physiology, UNC Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Jason M. Haugh
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina,Corresponding author
| |
Collapse
|
8
|
Abstract
Planar cell polarity (PCP) controls convergent extension and axis elongation in all vertebrates. Although asymmetric localization of PCP proteins is central to their function, we understand little about PCP protein localization during convergent extension. Here, we use quantitative live imaging to simultaneously monitor cell intercalation behaviors and PCP protein dynamics in the Xenopus laevis neural plate epithelium. We observed asymmetric enrichment of PCP proteins, but more interestingly, we observed tight correlation of PCP protein enrichment with actomyosin-driven contractile behavior of cell-cell junctions. Moreover, we found that the turnover rates of junctional PCP proteins also correlated with the contractile behavior of individual junctions. All these dynamic relationships were disrupted when PCP signaling was manipulated. Together, these results provide a dynamic and quantitative view of PCP protein localization during convergent extension and suggest a complex and intimate link between the dynamic localization of core PCP proteins, actomyosin assembly, and polarized junction shrinking during cell intercalation in the closing vertebrate neural tube.
Collapse
Affiliation(s)
- Mitchell T Butler
- Department of Molecular Biosciences, University of Texas at Austin, Austin, United States
| | - John B Wallingford
- Department of Molecular Biosciences, University of Texas at Austin, Austin, United States
| |
Collapse
|
9
|
Abstract
Planar cell polarity (PCP) is an essential feature of animal tissues, whereby distinct polarity is established within the plane of a cell sheet. Tissue-wide establishment of PCP is driven by multiple global cues, including gradients of gene expression, gradients of secreted WNT ligands and anisotropic tissue strain. These cues guide the dynamic, subcellular enrichment of PCP proteins, which can self-assemble into mutually exclusive complexes at opposite sides of a cell. Endocytosis, endosomal trafficking and degradation dynamics of PCP components further regulate planar tissue patterning. This polarization propagates throughout the whole tissue, providing a polarity axis that governs collective morphogenetic events such as the orientation of subcellular structures and cell rearrangements. Reflecting the necessity of polarized cellular behaviours for proper development and function of diverse organs, defects in PCP have been implicated in human pathologies, most notably in severe birth defects.
Collapse
Affiliation(s)
- Mitchell T Butler
- Department of Molecular Biosciences, Patterson Labs, 2401 Speedway, The University of Texas at Austin, Austin, Texas 78712, USA
| | - John B Wallingford
- Department of Molecular Biosciences, Patterson Labs, 2401 Speedway, The University of Texas at Austin, Austin, Texas 78712, USA
| |
Collapse
|
10
|
Butler MT, Wallingford JB. Control of vertebrate core planar cell polarity protein localization and dynamics by Prickle 2. Development 2015; 142:3429-39. [PMID: 26293301 PMCID: PMC4631750 DOI: 10.1242/dev.121384] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 08/12/2015] [Indexed: 01/21/2023]
Abstract
Planar cell polarity (PCP) is a ubiquitous property of animal tissues and is essential for morphogenesis and homeostasis. In most cases, this fundamental property is governed by a deeply conserved set of 'core PCP' proteins, which includes the transmembrane proteins Van Gogh-like (Vangl) and Frizzled (Fzd), as well as the cytoplasmic effectors Prickle (Pk) and Dishevelled (Dvl). Asymmetric localization of these proteins is thought to be central to their function, and understanding the dynamics of these proteins is an important challenge in developmental biology. Among the processes that are organized by the core PCP proteins is the directional beating of cilia, such as those in the vertebrate node, airway and brain. Here, we exploit the live imaging capabilities of Xenopus to chart the progressive asymmetric localization of fluorescent reporters of Dvl1, Pk2 and Vangl1 in a planar polarized ciliated epithelium. Using this system, we also characterize the influence of Pk2 on the asymmetric dynamics of Vangl1 at the cell cortex, and we define regions of Pk2 that control its own localization and those impacting Vangl1. Finally, our data reveal a striking uncoupling of Vangl1 and Dvl1 asymmetry. This study advances our understanding of conserved PCP protein functions and also establishes a rapid, tractable platform to facilitate future in vivo studies of vertebrate PCP protein dynamics.
Collapse
Affiliation(s)
- Mitchell T Butler
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, USA
| | - John B Wallingford
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, USA Howard Hughes Medical Institute, University of Texas at Austin, Austin, Texas 78712, USA
| |
Collapse
|
11
|
Lazova MD, Butler MT, Shimizu TS, Harshey RM. Salmonella chemoreceptors McpB and McpC mediate a repellent response to L-cystine: a potential mechanism to avoid oxidative conditions. Mol Microbiol 2012; 84:697-711. [PMID: 22486902 DOI: 10.1111/j.1365-2958.2012.08051.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chemoreceptors McpB and McpC in Salmonella enterica have been reported to promote chemotaxis in LB motility-plate assays. Of the chemicals tested as potential effectors of these receptors, the only response was towards L-cysteine and its oxidized form, L-cystine. Although enhanced radial migration in plates suggested positive chemotaxis to both amino acids, capillary assays failed to show an attractant response to either, in cells expressing only these two chemoreceptors. In vivo fluorescence resonance energy transfer (FRET) measurements of kinase activity revealed that in wild-type bacteria, cysteine and cystine are chemoeffectors of opposing sign, the reduced form being a chemoattractant and the oxidized form a repellent. The attractant response to cysteine was mediated primarily by Tsr, as reported earlier for Escherichia coli. The repellent response to cystine was mediated by McpB/C. Adaptive recovery upon cystine exposure required the methyl-transferase/-esterase pair, CheR/CheB, but restoration of kinase activity was never complete (i.e. imperfect adaptation). We provide a plausible explanation for the attractant-like responses to both cystine and cysteine in motility plates, and speculate that the opposing signs of response to this redox pair might afford Salmonella a mechanism to gauge and avoid oxidative environments.
Collapse
Affiliation(s)
- Milena D Lazova
- FOM Institute for Atomic and Molecular Physics, 1098 XG Amsterdam, the Netherlands
| | | | | | | |
Collapse
|
12
|
Abstract
BACKGROUND Minimally invasive techniques to harvest the saphenous vein for coronary artery bypass grafting continue to improve and evolve. Smaller cutaneous incisions have been shown to decrease postoperative discomfort and improve healing. We describe a technique involving carbon dioxide insufflation and endoscopic dissection to allow easier and atraumatic dissection. METHODS The VasoView endoscope system (Origin Medsystems, Inc) was used to harvest the saphenous vein for coronary artery bypass grafting in 27 patients. This group was compared with 24 patients having traditional saphenous vein harvesting. Wounds were examined for complications daily. Pain and postoperative mobility were quantified independently by physical therapists. RESULTS Comparison of patients in the two groups revealed greater edema in the legs with traditional harvesting. Patients with endoscopic removal also had less pain and increased mobility postoperatively. On average, minimally invasive harvesting allowed patients to ambulate to a predischarge goal of 300 ft 2 days earlier. CONCLUSIONS Minimally invasive harvesting of the saphenous vein by insufflation techniques is safe, effective, and atraumatic to the conduit. Discomfort is minimized, promoting earlier and improved ambulation.
Collapse
Affiliation(s)
- R J Morris
- Department of Cardiothoracic Surgery, Allegheny University Hospitals-Hahnemann, Philadelphia, Pennsylvania 19102, USA
| | | | | |
Collapse
|