1
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Dean WF, Albert RM, Nawara TJ, Ubil M, Beggs RR, Mattheyses AL. Dsg2 ectodomain organization increases throughout desmosome assembly. Cell Adh Migr 2024; 18:1-13. [PMID: 38566311 PMCID: PMC10993919 DOI: 10.1080/19336918.2024.2333366] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 03/18/2024] [Indexed: 04/04/2024] Open
Abstract
Desmosomes are intercellular junctions that regulate mechanical integrity in epithelia and cardiac muscle. Dynamic desmosome remodeling is essential for wound healing and development, yet the mechanisms governing junction assembly remain elusive. While we and others have shown that cadherin ectodomains are highly organized, how this ordered architecture emerges during assembly is unknown. Using fluorescence polarization microscopy, we show that desmoglein 2 (Dsg2) ectodomain order gradually increases during 8 h of assembly, coinciding with increasing adhesive strength. In a scratch wound assay, we observed a similar increase in order in desmosomes assembling at the leading edge of migratory cells. Together, our findings indicate that cadherin organization is a hallmark of desmosome maturity and may play a role in conferring adhesive strength.
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Affiliation(s)
- William F. Dean
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rose M. Albert
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tomasz J. Nawara
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Melanie Ubil
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Reena R. Beggs
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexa L. Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
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2
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Nawara TJ, Sztul E, Mattheyses AL. Fluidic shear stress alters clathrin dynamics and vesicle formation in endothelial cells. bioRxiv 2024:2024.01.02.572628. [PMID: 38260513 PMCID: PMC10802377 DOI: 10.1101/2024.01.02.572628] [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: 01/24/2024]
Abstract
Endothelial cells (ECs) experience a variety of highly dynamic mechanical stresses. Among others, cyclic stretch and increased plasma membrane tension inhibit clathrin-mediated endocytosis (CME) in non-ECs cells. How ECs overcome such unfavorable, from biophysical perspective, conditions and maintain CME remains elusive. Previously, we have used simultaneous two-wavelength axial ratiometry (STAR) microscopy to show that endocytic dynamics are similar between statically cultured human umbilical vein endothelial cells (HUVECs) and fibroblast-like Cos-7 cells. Here we asked whether biophysical stresses generated by blood flow could favor one mechanism of clathrin-coated vesicle formation to overcome environment present in vasculature. We used our data processing platform - DrSTAR - to examine if clathrin dynamics are altered in HUVECs grown under fluidic sheer stress (FSS). Surprisingly, we found that FSS led to an increase in clathrin dynamics. In HUVECs grown under FSS we observed a 2.3-fold increase in clathrin-coated vesicle formation and a 1.9-fold increase in non-productive flat clathrin lattices compared to cells grown in static conditions. The curvature-positive events had significantly delayed curvature initiation in flow-stimulated cells, highlighting a shift toward flat-to-curved clathrin transitions in vesicle formation. Overall, our findings indicate that clathrin dynamics and CCV formation can be modulated by the local physiological environment and represents an important regulatory mechanism.
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Affiliation(s)
- Tomasz J. Nawara
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Elizabeth Sztul
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexa L. Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
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3
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Ankenbauer KE, Rao TC, Mattheyses AL, Bellis SL. Sialylation of EGFR by ST6GAL1 induces receptor activation and modulates trafficking dynamics. J Biol Chem 2023; 299:105217. [PMID: 37660914 PMCID: PMC10520885 DOI: 10.1016/j.jbc.2023.105217] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/06/2023] [Accepted: 08/17/2023] [Indexed: 09/05/2023] Open
Abstract
Aberrant glycosylation is a hallmark of a cancer cell. One prevalent alteration is an enrichment in α2,6-linked sialylation of N-glycosylated proteins, a modification directed by the ST6GAL1 sialyltransferase. ST6GAL1 is upregulated in many malignancies including ovarian cancer. Prior studies have shown that the addition of α2,6 sialic acid to the epidermal growth factor receptor (EGFR) activates this receptor, although the mechanism was largely unknown. To investigate the role of ST6GAL1 in EGFR activation, ST6GAL1 was overexpressed in the OV4 ovarian cancer line, which lacks endogenous ST6GAL1, or knocked-down in the OVCAR-3 and OVCAR-5 ovarian cancer lines, which have robust ST6GAL1 expression. Cells with high expression of ST6GAL1 displayed increased activation of EGFR and its downstream signaling targets, AKT and NFκB. Using biochemical and microscopy approaches, including total internal reflection fluorescence microscopy, we determined that the α2,6 sialylation of EGFR promoted its dimerization and higher order oligomerization. Additionally, ST6GAL1 activity was found to modulate EGFR trafficking dynamics following EGF-induced receptor activation. Specifically, EGFR sialylation enhanced receptor recycling to the cell surface following activation while simultaneously inhibiting lysosomal degradation. 3D widefield deconvolution microscopy confirmed that in cells with high ST6GAL1 expression, EGFR exhibited greater colocalization with Rab11 recycling endosomes and reduced colocalization with LAMP1-positive lysosomes. Collectively, our findings highlight a novel mechanism by which α2,6 sialylation promotes EGFR signaling by facilitating receptor oligomerization and recycling.
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Affiliation(s)
- Katherine E Ankenbauer
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Tejeshwar C Rao
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
| | - Susan L Bellis
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
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4
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Ankenbauer KE, Rao TC, Mattheyses AL, Bellis SL. Sialylation of EGFR by ST6GAL1 induces receptor activation and modulates trafficking dynamics. bioRxiv 2023:2023.06.03.543566. [PMID: 37398202 PMCID: PMC10312608 DOI: 10.1101/2023.06.03.543566] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Aberrant glycosylation is a hallmark of a cancer cell. One prevalent alteration is an enrichment in α2,6-linked sialylation of N-glycosylated proteins, a modification directed by the ST6GAL1 sialyltransferase. ST6GAL1 is upregulated in many malignancies including ovarian cancer. Prior studies have shown that the addition of α2,6 sialic acid to the Epidermal Growth Factor Receptor (EGFR) activates this receptor, although the mechanism was largely unknown. To investigate the role of ST6GAL1 in EGFR activation, ST6GAL1 was overexpressed in the OV4 ovarian cancer line, which lacks endogenous ST6GAL1, or knocked down in the OVCAR-3 and OVCAR-5 ovarian cancer lines, which have robust ST6GAL1 expression. Cells with high expression of ST6GAL1 displayed increased activation of EGFR and its downstream signaling targets, AKT and NFκB. Using biochemical and microscopy approaches, including Total Internal Reflection Fluorescence (TIRF) microscopy, we determined that the α2,6 sialylation of EGFR promoted its dimerization and higher order oligomerization. Additionally, ST6GAL1 activity was found to modulate EGFR trafficking dynamics following EGF-induced receptor activation. Specifically, EGFR sialylation enhanced receptor recycling to the cell surface following activation while simultaneously inhibiting lysosomal degradation. 3D widefield deconvolution microscopy confirmed that in cells with high ST6GAL1 expression, EGFR exhibited greater co-localization with Rab11 recycling endosomes and reduced co-localization with LAMP1-positive lysosomes. Collectively, our findings highlight a novel mechanism by which α2,6 sialylation promotes EGFR signaling by facilitating receptor oligomerization and recycling.
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Affiliation(s)
- Katherine E. Ankenbauer
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - Tejeshwar C. Rao
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - Alexa L. Mattheyses
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - Susan L. Bellis
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
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Nawara TJ, Mattheyses AL. Imaging nanoscale axial dynamics at the basal plasma membrane. Int J Biochem Cell Biol 2023; 156:106349. [PMID: 36566777 PMCID: PMC10634635 DOI: 10.1016/j.biocel.2022.106349] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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: 10/03/2022] [Revised: 12/16/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022]
Abstract
Understanding of how energetically unfavorable plasma membrane shapes form, especially in the context of dynamic processes in living cells or tissues like clathrin-mediated endocytosis is in its infancy. Even though cutting-edge microscopy techniques that bridge this gap exist, they remain underused in biomedical sciences. Here, we demystify the perceived complexity of these advanced microscopy approaches and demonstrate their power in resolving nanometer axial dynamics in living cells. Total internal reflection fluorescence microscopy based approaches are the main focus of this review. We present clathrin-mediated endocytosis as a model system when describing the principles, data acquisition requirements, data interpretation strategies, and limitations of the described techniques. We hope this standardized description will bring the approaches for measuring nanoscale axial dynamics closer to the potential users and help in choosing the right approach to the right question.
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Affiliation(s)
- Tomasz J Nawara
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
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6
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Nawara TJ, Dean WF, Mattheyses AL. DrSTAR: Tracking real-time nanometer axial changes. Biophys J 2023; 122:595-602. [PMID: 36659851 PMCID: PMC9989936 DOI: 10.1016/j.bpj.2023.01.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [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: 07/29/2022] [Revised: 11/23/2022] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
Protein interactions with the plasma membrane mediate processes critical for cell viability such as migration and endocytosis, yet our understanding of how recruitment of key proteins correlates with their ability to sense or induce energetically unfavorable plasma membrane shapes remains limited. Simultaneous two-wavelength axial ratiometry (STAR) microscopy provides millisecond time resolution and nanometer axial resolution of protein dynamics at the basal plasma membrane. However, STAR microscopy requires extensive and time-consuming quantitative data processing to access axial (Δz) information. Therefore, addressing questions about the influence of biological and biophysical factors on the interaction between the plasma membrane and protein of interest remains challenging. Here, we overcome the limitations in STAR data processing and present dynamic reference STAR (DrSTAR): a user-friendly, automated, open-source MATLAB-based package. DrSTAR enables processing multiple experimental conditions and biological replicates, employs a novel local background referencing algorithm, and accelerates processing time to facilitate broad adaptation of STAR for studying nanometer axial changes in protein distribution.
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Affiliation(s)
- Tomasz J Nawara
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - William F Dean
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama.
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7
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Dean WF, Nawara TJ, Albert RM, Mattheyses AL. OOPS: A GUI-based software package for object-oriented analysis of fluorescence polarization microscopy data. Biophys J 2023; 122:279a. [PMID: 36783380 DOI: 10.1016/j.bpj.2022.11.1588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- William F Dean
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tomasz J Nawara
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rose M Albert
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexa L Mattheyses
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
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8
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Rao TC, Patel M, Beggs RR, Ma R, Salaita K, Mattheyses AL. Activated EGFR-αVβ3 interactions directly drive integrin-mediated cell mechanics. Biophys J 2023; 122:267a. [PMID: 36783316 DOI: 10.1016/j.bpj.2022.11.1531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Tejeshwar C Rao
- Cell, Developmental, and Integrative Biology, University of Alabama Birmingham, Birmingham, AL, USA
| | - Monica Patel
- Cell, Developmental, and Integrative Biology, University of Alabama Birmingham, Birmingham, AL, USA
| | - Reena R Beggs
- Cell, Developmental, and Integrative Biology, University of Alabama Birmingham, Birmingham, AL, USA
| | - Rong Ma
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Alexa L Mattheyses
- Cell, Developmental, and Integrative Biology, University of Alabama Birmingham, Birmingham, AL, USA
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9
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Nawara TJ, Dean WF, Mattheyses AL. Shear stress shifts clathrin-coated vesicle formation to favor the flat-to-curved model in endothelial cells. Biophys J 2023; 122:460a. [PMID: 36784364 DOI: 10.1016/j.bpj.2022.11.2473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Tomasz J Nawara
- Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - William F Dean
- Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexa L Mattheyses
- Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
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10
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Williams YA, Nawara TJ, Yuan J, Mattheyses AL. Computational modeling of endocytic vesicle formation imaged by simultaneous two-wavelength axial ratiometry. Biophys J 2023; 122:514a. [PMID: 36784658 DOI: 10.1016/j.bpj.2022.11.2735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Yancey A Williams
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tomasz J Nawara
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jie Yuan
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
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11
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Rao TC, Patel MD, Beggs RR, Ma R, Salaita K, Mattheyses AL. RTK-integrin interactions universally modulate αVβ3 integrin-mediated cell adhesion. Biophys J 2023; 122:267a. [PMID: 36783317 DOI: 10.1016/j.bpj.2022.11.1532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Tejeshwar C Rao
- Cell, Developmental, and Integrative Biology, University of Alabama Birmingham, Birmingham, AL, USA
| | - Monica D Patel
- Cell, Developmental, and Integrative Biology, University of Alabama Birmingham, Birmingham, AL, USA
| | - Reena R Beggs
- Cell, Developmental, and Integrative Biology, University of Alabama Birmingham, Birmingham, AL, USA
| | - Rong Ma
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Alexa L Mattheyses
- Cell, Developmental, and Integrative Biology, University of Alabama Birmingham, Birmingham, AL, USA
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12
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Dean WF, Mattheyses AL. Defining domain-specific orientational order in the desmosomal cadherins. Biophys J 2022; 121:4325-4341. [PMID: 36225113 PMCID: PMC9703042 DOI: 10.1016/j.bpj.2022.10.009] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 09/12/2022] [Accepted: 10/06/2022] [Indexed: 01/25/2023] Open
Abstract
Desmosomes are large, macromolecular protein assemblies that mechanically couple the intermediate filament cytoskeleton to sites of cadherin-mediated cell adhesion, thereby providing structural integrity to tissues that routinely experience large forces. Proper desmosomal adhesion is necessary for the normal development and maintenance of vertebrate tissues, such as epithelia and cardiac muscle, while dysfunction can lead to severe disease of the heart and skin. Therefore, it is important to understand the relationship between desmosomal adhesion and the architecture of the molecules that form the adhesive interface, the desmosomal cadherins (DCs). However, desmosomes are embedded in two plasma membranes and are linked to the cytoskeletal networks of two cells, imposing extreme difficulty on traditional structural studies of DC architecture, which have yielded conflicting results. Consequently, the relationship between DC architecture and adhesive function remains unclear. To overcome these challenges, we utilized excitation-resolved fluorescence polarization microscopy to quantify the orientational order of the extracellular and intracellular domains of three DC isoforms: desmoglein 2, desmocollin 2, and desmoglein 3. We found that DC ectodomains were significantly more ordered than their cytoplasmic counterparts, indicating a drastic difference in DC architecture between opposing sides of the plasma membrane. This difference was conserved among all DCs tested, suggesting that it may be an important feature of desmosomal architecture. Moreover, our findings suggest that the organization of DC ectodomains is predominantly the result of extracellular adhesive interactions. We employed azimuthal orientation mapping to show that DC ectodomains are arranged with rotational symmetry about the membrane normal. Finally, we performed a series of mathematical simulations to test the feasibility of a recently proposed antiparallel arrangement of DC ectodomains, finding that it is supported by our experimental data. Importantly, the strategies employed here have the potential to elucidate molecular mechanisms for diseases that result from defective desmosome architecture.
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Affiliation(s)
- William F Dean
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama.
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13
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Nawara TJ, Williams YD, Rao TC, Hu Y, Sztul E, Salaita K, Mattheyses AL. Imaging vesicle formation dynamics supports the flexible model of clathrin-mediated endocytosis. Nat Commun 2022; 13:1732. [PMID: 35365614 PMCID: PMC8976038 DOI: 10.1038/s41467-022-29317-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 02/24/2022] [Indexed: 12/11/2022] Open
Abstract
Clathrin polymerization and changes in plasma membrane architecture are necessary steps in forming vesicles to internalize cargo during clathrin-mediated endocytosis (CME). Simultaneous analysis of clathrin dynamics and membrane structure is challenging due to the limited axial resolution of fluorescence microscopes and the heterogeneity of CME. This has fueled conflicting models of vesicle assembly and obscured the roles of flat clathrin assemblies. Here, using Simultaneous Two-wavelength Axial Ratiometry (STAR) microscopy, we bridge this critical knowledge gap by quantifying the nanoscale dynamics of clathrin-coat shape change during vesicle assembly. We find that de novo clathrin accumulations generate both flat and curved structures. High-throughput analysis reveals that the initiation of vesicle curvature does not directly correlate with clathrin accumulation. We show clathrin accumulation is preferentially simultaneous with curvature formation at shorter-lived clathrin-coated vesicles (CCVs), but favors a flat-to-curved transition at longer-lived CCVs. The broad spectrum of curvature initiation dynamics revealed by STAR microscopy supports multiple productive mechanisms of vesicle formation and advocates for the flexible model of CME. Despite decades of research, the dynamics of clathrin-coated vesicle formation is ambiguous. Here, authors use STAR microscopy to quantify the nanoscale dynamics of vesicle formation, supporting the flexible model of clathrin-mediated endocytosis.
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Affiliation(s)
- Tomasz J Nawara
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yancey D Williams
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tejeshwar C Rao
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yuesong Hu
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Elizabeth Sztul
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
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14
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Rao TC, Beggs RR, Ankenbauer KE, Hwang J, Ma VPY, Salaita K, Bellis SL, Mattheyses AL. ST6Gal-I-mediated sialylation of the epidermal growth factor receptor modulates cell mechanics and enhances invasion. J Biol Chem 2022; 298:101726. [PMID: 35157848 PMCID: PMC8956946 DOI: 10.1016/j.jbc.2022.101726] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 12/19/2022] Open
Abstract
Heterogeneity within the glycocalyx influences cell adhesion mechanics and signaling. However, the role of specific glycosylation subtypes in influencing cell mechanics via alterations of receptor function remains unexplored. It has been shown that the addition of sialic acid to terminal glycans impacts growth, development, and cancer progression. In addition, the sialyltransferase ST6Gal-I promotes epidermal growth factor receptor (EGFR) activity, and we have shown EGFR is an 'allosteric mechano-organizer' of integrin tension. Here, we investigated the impact of ST6Gal-I on cell mechanics. Using DNA-based tension gauge tether probes of variable thresholds, we found that high ST6Gal-I activity promotes increased integrin forces and spreading in Cos-7 and OVCAR3, OVCAR5, and OV4 cancer cells. Further, employing inhibitors and function-blocking antibodies against β1, β3, and β5 integrins and ST6Gal-I targets EGFR, tumor necrosis factor receptor, and Fas cell surface death receptor, we validated that the observed phenotypes are EGFR-specific. We found that while tension, contractility, and adhesion are extracellular-signal-regulated kinase pathway-dependent, spreading, proliferation, and invasion are phosphoinositide 3-kinase-Akt serine/threonine kinase dependent. Using total internal reflection fluorescence microscopy and flow cytometry, we also show that high ST6Gal-I activity leads to sustained EGFR membrane retention, making it a key regulator of cell mechanics. Our findings suggest a novel sialylation-dependent mechanism orchestrating cellular mechanics and enhancing cell motility via EGFR signaling.
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Affiliation(s)
- Tejeshwar C Rao
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Reena R Beggs
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Katherine E Ankenbauer
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jihye Hwang
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | | | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, Georgia, USA
| | - Susan L Bellis
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
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15
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Rao TC, Mattheyses AL. Tension Gauge Tether Probes for Quantifying Growth Factor Mediated Integrin Mechanics and Adhesion. J Vis Exp 2022. [PMID: 35225264 DOI: 10.3791/63529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Multicellular organisms rely on interactions between membrane receptors and cognate ligands in the surrounding extracellular matrix (ECM) to orchestrate multiple functions, including adhesion, proliferation, migration, and differentiation. Mechanical forces can be transmitted from the cell via the adhesion receptor integrin to ligands in the ECM. The amount and spatial organization of these cell-generated forces can be modulated by growth factor receptors, including epidermal growth factor receptor (EGFR). The tools currently available to quantify crosstalk-mediated changes in cell mechanics and relate them to focal adhesions, cellular morphology, and signaling are limited. DNA-based molecular force sensors known as tension gauge tethers (TGTs) have been employed to quantify these changes. TGT probes are unique in their ability to both modulate the underlying force threshold and report piconewton scale receptor forces across the entire adherent cell surface at diffraction-limited spatial resolution. The TGT probes used here rely on the irreversible dissociation of a DNA duplex by receptor-ligand forces that generate a fluorescent signal. This allows quantification of the cumulative integrin tension (force history) of the cell. This article describes a protocol employing TGTs to study the impact of EGFR on integrin mechanics and adhesion formation. The assembly of the TGT mechanical sensing platform is systematically detailed and the procedure to image forces, focal adhesions, and cell spreading is outlined. Overall, the ability to modulate the underlying force threshold of the probe, the adhesion ligand, and the type and concentration of growth factor employed for stimulation make this a robust platform for studying the interplay of diverse membrane receptors in regulating integrin-mediated forces.
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16
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Rao TC, Beggs RR, Ma R, Salaita K, Mattheyses AL. Direct RTK-integrin interactions universally modulate αvβ3 integrin-mediated cell adhesion. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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17
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Albert RM, Dean WF, Beggs RR, Mattheyses AL. Acquisition of cadherin order during desmosome assembly. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.2013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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18
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Abstract
Desmosomes are macromolecular cell-cell junctions critical for maintaining adhesion and resisting mechanical stress in epithelial tissue. Desmosome assembly and the relationship between maturity and molecular architecture are not well understood. To address this, we employed a calcium switch assay to synchronize assembly followed by quantification of desmosome nanoscale organization using direct Stochastic Optical Reconstruction Microscopy (dSTORM). We found that the organization of the desmoplakin rod/C-terminal junction changed over the course of maturation, as indicated by a decrease in the plaque-to-plaque distance, while the plaque length increased. In contrast, the desmoplakin N-terminal domain and plakoglobin organization (plaque-to-plaque distance) were constant throughout maturation. This structural rearrangement of desmoplakin was concurrent with desmosome maturation measured by E-cadherin exclusion and increased adhesive strength. Using two-color dSTORM, we showed that while the number of individual E-cadherin containing junctions went down with the increasing time in high Ca2+, they maintained a wider desmoplakin rod/C-terminal plaque-to-plaque distance. This indicates that the maturation state of individual desmosomes can be identified by their architectural organization. We confirmed these architectural changes in another model of desmosome assembly, cell migration. Desmosomes in migrating cells, closest to the scratch where they are assembling, were shorter, E-cadherin enriched, and had wider desmoplakin rod/C-terminal plaque-to-plaque distances compared to desmosomes away from the wound edge. Key results were demonstrated in three cell lines representing simple, transitional, and stratified epithelia. Together, these data suggest that there is a set of architectural programs for desmosome maturation, and we hypothesize that desmoplakin architecture may be a contributing mechanism to regulating adhesive strength.
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Affiliation(s)
- Reena R Beggs
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tejeshwar C Rao
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - William F Dean
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Andrew P Kowalczyk
- Departments of Dermatology and Cellular and Molecular Physiology, Pennsylvania State College of Medicine, Hershey, PA, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
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19
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Abstract
The establishment of apicobasal or planar cell polarity involves many events that occur at or near the plasma membrane including focal adhesion dynamics, endocytosis, exocytosis, and cytoskeletal reorganization. It is desirable to visualize these events without interference from other regions deeper within the cell. Total internal reflection fluorescence (TIRF) microscopy utilizes an elegant optical sectioning approach to visualize fluorophores near the sample-coverslip interface. TIRF provides high-contrast fluorescence images with limited background and virtually no out-of-focus light, ideal for visualizing and tracking dynamics near the plasma membrane. In this chapter, we present a general experimental and analysis TIRF pipeline for studying cell surface receptor endocytosis. The approach presented can be easily applied to study other dynamic biological processes at or near the plasma membrane using TIRF microscopy.
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Affiliation(s)
- Tejeshwar C Rao
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tomasz J Nawara
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
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20
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Kammerud SC, Metge BJ, Elhamamsy AR, Weeks SE, Alsheikh HA, Mattheyses AL, Shevde LA, Samant RS. Novel role of the dietary flavonoid fisetin in suppressing rRNA biogenesis. J Transl Med 2021; 101:1439-1448. [PMID: 34267320 PMCID: PMC8510891 DOI: 10.1038/s41374-021-00642-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/06/2021] [Accepted: 07/06/2021] [Indexed: 12/13/2022] Open
Abstract
The nucleolus of a cell is a critical cellular compartment that is responsible for ribosome biogenesis and plays a central role in tumor progression. Fisetin, a nutraceutical, is a naturally occurring flavonol from the flavonoid group of polyphenols that has anti-cancer effects. Fisetin negatively impacts several signaling pathways that support tumor progression. However, effect of fisetin on the nucleolus and its functions were unknown. We observed that fisetin is able to physically enter the nucleolus. In the nucleolus, RNA polymerase I (RNA Pol I) mediates the biogenesis of ribosomal RNA. Thus, we investigated the impacts of fisetin on the nucleolus. We observed that breast tumor cells treated with fisetin show a 20-30% decreased nucleolar abundance per cell and a 30-60% downregulation of RNA Pol I transcription activity, as well as a 50-70% reduction in nascent rRNA synthesis, depending on the cell line. Our studies show that fisetin negatively influences MAPK/ERK pathway to impair RNA Pol I activity and rRNA biogenesis. Functionally, we demonstrate that fisetin acts synergistically (CI = 0.4) with RNA Pol I inhibitor, BMH-21 and shows a noteworthy negative impact (60% decrease) on lung colonization of breast cancer cells. Overall, our findings highlight the potential of ribosomal RNA (rRNA) biogenesis as a target for secondary prevention and possible treatment of metastatic disease.
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Affiliation(s)
- Sarah C Kammerud
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brandon J Metge
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Amr R Elhamamsy
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Shannon E Weeks
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Heba A Alsheikh
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lalita A Shevde
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
- O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rajeev S Samant
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.
- O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA.
- Birmingham VA Medical Center, Birmingham, AL, USA.
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21
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Blanchard A, Combs JD, Brockman JM, Kellner AV, Glazier R, Su H, Bender RL, Bazrafshan AS, Chen W, Quach ME, Li R, Mattheyses AL, Salaita K. Turn-key mapping of cell receptor force orientation and magnitude using a commercial structured illumination microscope. Nat Commun 2021; 12:4693. [PMID: 34344862 PMCID: PMC8333341 DOI: 10.1038/s41467-021-24602-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 06/22/2021] [Indexed: 02/07/2023] Open
Abstract
Many cellular processes, including cell division, development, and cell migration require spatially and temporally coordinated forces transduced by cell-surface receptors. Nucleic acid-based molecular tension probes allow one to visualize the piconewton (pN) forces applied by these receptors. Building on this technology, we recently developed molecular force microscopy (MFM) which uses fluorescence polarization to map receptor force orientation with diffraction-limited resolution (~250 nm). Here, we show that structured illumination microscopy (SIM), a super-resolution technique, can be used to perform super-resolution MFM. Using SIM-MFM, we generate the highest resolution maps of both the magnitude and orientation of the pN traction forces applied by cells. We apply SIM-MFM to map platelet and fibroblast integrin forces, as well as T cell receptor forces. Using SIM-MFM, we show that platelet traction force alignment occurs on a longer timescale than adhesion. Importantly, SIM-MFM can be implemented on any standard SIM microscope without hardware modifications.
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Affiliation(s)
- Aaron Blanchard
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - J Dale Combs
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Joshua M Brockman
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Anna V Kellner
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Roxanne Glazier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Hanquan Su
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | | | | | - Wenchun Chen
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - M Edward Quach
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Renhao Li
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Khalid Salaita
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
- Department of Chemistry, Emory University, Atlanta, GA, USA.
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22
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Blanchard AT, Combs D, Aysha Rashid S, Brockman J, Duan Y, Mattheyses AL, Salaita K. Diffraction-Limited Mapping of Integrin Force Vector Fields with Valid-Mfm. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.2211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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23
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Brockman JM, Su H, Blanchard AT, Duan Y, Meyer T, Quach ME, Glazier R, Bazrafshan A, Bender RL, Kellner AV, Ogasawara H, Ma R, Schueder F, Petrich BG, Jungmann R, Li R, Mattheyses AL, Ke Y, Salaita K. Live-cell super-resolved PAINT imaging of piconewton cellular traction forces. Nat Methods 2020; 17:1018-1024. [PMID: 32929270 PMCID: PMC7574592 DOI: 10.1038/s41592-020-0929-2] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [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: 12/18/2019] [Accepted: 07/20/2020] [Indexed: 11/09/2022]
Abstract
Despite the vital role of mechanical forces in biology, it still remains a challenge to image cellular force with sub-100-nm resolution. Here, we present tension points accumulation for imaging in nanoscale topography (tPAINT), integrating molecular tension probes with the DNA points accumulation for imaging in nanoscale topography (DNA-PAINT) technique to map piconewton mechanical events with ~25-nm resolution. To perform live-cell dynamic tension imaging, we engineered reversible probes with a cryptic docking site revealed only when the probe experiences forces exceeding a defined mechanical threshold (~7-21 pN). Additionally, we report a second type of irreversible tPAINT probe that exposes its cryptic docking site permanently and thus integrates force history over time, offering improved spatial resolution in exchange for temporal dynamics. We applied both types of tPAINT probes to map integrin receptor forces in live human platelets and mouse embryonic fibroblasts. Importantly, tPAINT revealed a link between platelet forces at the leading edge of cells and the dynamic actin-rich ring nucleated by the Arp2/3 complex.
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Affiliation(s)
- Joshua M Brockman
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Hanquan Su
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Aaron T Blanchard
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Yuxin Duan
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Travis Meyer
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - M Edward Quach
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA, USA
| | - Roxanne Glazier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | | | | | - Anna V Kellner
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | | | - Rong Ma
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Florian Schueder
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Germany
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Brian G Petrich
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA, USA
| | - Ralf Jungmann
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Germany
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Renhao Li
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yonggang Ke
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Khalid Salaita
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
- Department of Chemistry, Emory University, Atlanta, GA, USA.
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24
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Rao TC, Ma VPY, Blanchard A, Urner TM, Grandhi S, Salaita K, Mattheyses AL. EGFR activation attenuates the mechanical threshold for integrin tension and focal adhesion formation. J Cell Sci 2020; 133:jcs238840. [PMID: 32546532 PMCID: PMC7358133 DOI: 10.1242/jcs.238840] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [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: 09/07/2019] [Accepted: 06/04/2020] [Indexed: 02/06/2023] Open
Abstract
Mechanical forces, growth factors and the extracellular matrix all play crucial roles in cell adhesion. To understand how epidermal growth factor receptor (EGFR) impacts the mechanics of adhesion, we employed tension gauge tether (TGT) probes displaying the integrin ligand cRGDfK and quantified integrin tension. EGF exposure significantly increased spread area, cell circularity, integrated integrin tension, mechanical rupture density, radial organization and size of focal adhesions in Cos-7 cells on TGT surfaces. These findings suggest that EGFR regulates integrin tension and the spatial organization of focal adhesions. Additionally, we found that the mechanical tension threshold for outside-in integrin activation is tunable by EGFR. Parallel genetic and pharmacologic strategies demonstrated that these phenotypes are driven by ligand-dependent EGFR signaling. Our results establish a novel mechanism whereby EGFR regulates integrin activation and cell adhesion, providing control over cellular responses to the environment.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Tejeshwar C Rao
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | | | - Aaron Blanchard
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30322, USA
| | - Tara M Urner
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Shreya Grandhi
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, GA 30322, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30322, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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25
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Bartle EI, Rao TC, Beggs RR, Dean WF, Urner TM, Kowalczyk AP, Mattheyses AL. Protein exchange is reduced in calcium-independent epithelial junctions. J Cell Biol 2020; 219:151763. [PMID: 32399559 PMCID: PMC7265307 DOI: 10.1083/jcb.201906153] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 01/29/2020] [Accepted: 03/11/2020] [Indexed: 12/29/2022] Open
Abstract
Desmosomes are cell–cell junctions that provide mechanical integrity to epithelial and cardiac tissues. Desmosomes have two distinct adhesive states, calcium-dependent and hyperadhesive, which balance tissue plasticity and strength. A highly ordered array of cadherins in the adhesive interface is hypothesized to drive hyperadhesion, but how desmosome structure confers adhesive state is still elusive. We employed fluorescence polarization microscopy to show that cadherin order is not required for hyperadhesion induced by pharmacologic and genetic approaches. FRAP experiments in cells treated with the PKCα inhibitor Gö6976 revealed that cadherins, plakoglobin, and desmoplakin have significantly reduced exchange in and out of hyperadhesive desmosomes. To test whether this was a result of enhanced keratin association, we used the desmoplakin mutant S2849G, which conferred reduced protein exchange. We propose that inside-out regulation of protein exchange modulates adhesive function, whereby proteins are “locked in” to hyperadhesive desmosomes while protein exchange confers plasticity on calcium-dependent desmosomes, thereby providing rapid control of adhesion.
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Affiliation(s)
- Emily I Bartle
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - Tejeshwar C Rao
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - Reena R Beggs
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - William F Dean
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - Tara M Urner
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - Andrew P Kowalczyk
- Departments of Cell Biology and Dermatology, Emory University, Atlanta, GA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
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26
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Blanchard AT, Brockman JM, Salaita K, Mattheyses AL. Variable incidence angle linear dichroism (VALiD): a technique for unique 3D orientation measurement of fluorescent ensembles. Opt Express 2020; 28:10039-10061. [PMID: 32225599 PMCID: PMC7340377 DOI: 10.1364/oe.381676] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/10/2020] [Accepted: 01/13/2020] [Indexed: 06/02/2023]
Abstract
A fundamental challenge with fluorophore orientation measurement is degeneracy, which is the inability to distinguish between multiple unique fluorophore orientations. Techniques exist for the non-degenerate measurement of the orientations of single, static fluorophores. However, such techniques are unsuitable for densely labeled and/or dynamic samples common to biological research. Accordingly, a rapid, widefield microscopy technique that can measure orientation parameters for ensembles of fluorophores in a non-degenerate manner is desirable. We propose that exciting samples with polarized light and multiple incidence angles could enable such a technique. We use Monte Carlo simulations to validate this approach for specific axially symmetric ensembles of fluorophores and obtain optimal experimental parameters for its future implementation.
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Affiliation(s)
- Aaron T. Blanchard
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Joshua M. Brockman
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Khalid Salaita
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Alexa L. Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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27
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Brockman JM, Su H, Mattheyses AL, Ke Y, Salaita K. Super-resolved Measurement of Piconewton Receptor Forces via Tension-PAINT. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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28
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Beggs RR, Rao TC, Dean WF, Albert RM, Mattheyses AL. Structural Changes to Desmosome Architecture during Assembly and Maturation. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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29
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Blanchard A, Combs D, Brockman J, Mattheyses AL, Salaita K. Superresolution Traction Force Mapping with Structured Illumination Molecular Force Microscopy. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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30
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Dean WF, Bartle EI, Mattheyses AL. Cadherin Organization in Desmosomes Probed using Fluorescence Polarization Microscopy. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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31
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Abstract
Desmosomes are cell-cell junctions responsible for mechanically integrating adjacent cells. Due to the small size of the junctions, their protein architecture cannot be elucidated using conventional fluorescence microscopy. Super-resolution microscopy techniques, including dSTORM, deliver higher-resolution images which can reveal the localization or arrangement of proteins within individual desmosomes. Herein we describe an imaging and analysis method to determine the nanoscale architecture of desmosomes using super-resolution dSTORM.
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Affiliation(s)
- Reena R Beggs
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - William F Dean
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
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32
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Henderson BW, Greathouse KM, Ramdas R, Walker CK, Rao TC, Bach SV, Curtis KA, Day JJ, Mattheyses AL, Herskowitz JH. Pharmacologic inhibition of LIMK1 provides dendritic spine resilience against β-amyloid. Sci Signal 2019; 12:eaaw9318. [PMID: 31239325 PMCID: PMC7088434 DOI: 10.1126/scisignal.aaw9318] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [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] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) therapies predominantly focus on β-amyloid (Aβ), but Aβ effects may be maximal before clinical symptoms appear. Downstream of Aβ, dendritic spine loss correlates most strongly with cognitive decline in AD. Rho-associated kinases (ROCK1 and ROCK2) regulate the actin cytoskeleton, and ROCK1 and ROCK2 protein abundances are increased in early AD. Here, we found that the increased abundance of ROCK1 in cultured primary rat hippocampal neurons reduced dendritic spine length through a myosin-based pathway, whereas the increased abundance of ROCK2 induced spine loss through the serine and threonine kinase LIMK1. Aβ42 oligomers can activate ROCKs. Here, using static imaging studies combined with multielectrode array analyses, we found that the ROCK2-LIMK1 pathway mediated Aβ42-induced spine degeneration and neuronal hyperexcitability. Live-cell microscopy revealed that pharmacologic inhibition of LIMK1 rendered dendritic spines resilient to Aβ42 oligomers. Treatment of hAPP mice with a LIMK1 inhibitor rescued Aβ-induced hippocampal spine loss and morphologic aberrations. Our data suggest that therapeutically targeting LIMK1 may provide dendritic spine resilience to Aβ and therefore may benefit cognitively normal patients that are at high risk for developing dementia.
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Affiliation(s)
- Benjamin W Henderson
- Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
- Department of Neurology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Kelsey M Greathouse
- Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
- Department of Neurology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Raksha Ramdas
- Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
- Department of Neurology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Courtney K Walker
- Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
- Department of Neurology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Tejeshwar C Rao
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Svitlana V Bach
- Department of Neurobiology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Kendall A Curtis
- Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
- Department of Neurology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Jeremy J Day
- Department of Neurobiology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Jeremy H Herskowitz
- Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA.
- Department of Neurology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
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33
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Lewis JD, Caldara AL, Zimmer SE, Stahley SN, Seybold A, Strong NL, Frangakis AS, Levental I, Wahl JK, Mattheyses AL, Sasaki T, Nakabayashi K, Hata K, Matsubara Y, Ishida-Yamamoto A, Amagai M, Kubo A, Kowalczyk AP. The desmosome is a mesoscale lipid raft-like membrane domain. Mol Biol Cell 2019; 30:1390-1405. [PMID: 30943110 PMCID: PMC6724694 DOI: 10.1091/mbc.e18-10-0649] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Desmogleins (Dsgs) are cadherin family adhesion molecules essential for epidermal integrity. Previous studies have shown that desmogleins associate with lipid rafts, but the significance of this association was not clear. Here, we report that the desmoglein transmembrane domain (TMD) is the primary determinant of raft association. Further, we identify a novel mutation in the DSG1 TMD (G562R) that causes severe dermatitis, multiple allergies, and metabolic wasting syndrome. Molecular modeling predicts that this G-to-R mutation shortens the DSG1 TMD, and experiments directly demonstrate that this mutation compromises both lipid raft association and desmosome incorporation. Finally, cryo-electron tomography indicates that the lipid bilayer within the desmosome is ∼10% thicker than adjacent regions of the plasma membrane. These findings suggest that differences in bilayer thickness influence the organization of adhesion molecules within the epithelial plasma membrane, with cadherin TMDs recruited to the desmosome via the establishment of a specialized mesoscale lipid raft-like membrane domain.
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Affiliation(s)
- Joshua D Lewis
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322.,Department of Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University School of Medicine, Atlanta, GA 30322
| | - Amber L Caldara
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322.,Department of Graduate Program in Cancer Biology, Emory University School of Medicine, Atlanta, GA 30322
| | - Stephanie E Zimmer
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322.,Department of Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University School of Medicine, Atlanta, GA 30322
| | - Sara N Stahley
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322.,Department of Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University School of Medicine, Atlanta, GA 30322
| | - Anna Seybold
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, 60323 Frankfurt, Germany.,Institute for Biophysics, Goethe University Frankfurt, 60323 Frankfurt, Germany
| | - Nicole L Strong
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
| | - Achilleas S Frangakis
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, 60323 Frankfurt, Germany.,Institute for Biophysics, Goethe University Frankfurt, 60323 Frankfurt, Germany
| | - Ilya Levental
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - James K Wahl
- Department of Oral Biology, College of Dentistry, University of Nebraska Medical Center, Lincoln, NE 68583
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Takashi Sasaki
- Center for Supercentenarian Medical Research, Keio University School of Medicine, Tokyo 160-8582, Japan
| | | | - Kenichiro Hata
- National Research Institute for Child Health and Development, Tokyo, Japan
| | - Yoichi Matsubara
- National Research Institute for Child Health and Development, Tokyo, Japan
| | - Akemi Ishida-Yamamoto
- Department of Dermatology, Asahikawa Medical University, Asahikawa, Hokkaido 078-8510, Japan
| | - Masayuki Amagai
- Department of Dermatology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Akiharu Kubo
- Department of Dermatology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Andrew P Kowalczyk
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322.,Department of Dermatology, Emory University School of Medicine, Atlanta, GA 30322.,Department of Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University School of Medicine, Atlanta, GA 30322.,Department of Graduate Program in Cancer Biology, Emory University School of Medicine, Atlanta, GA 30322
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Bartle EI, Urner TM, Rao TC, Kowalczyk AP, Mattheyses AL. Calcium Independence of Epithelial Junctions is Regulated by Protein Mobility. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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35
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Hamilton JA, Wu Q, Yang P, Luo B, Liu S, Li J, L Mattheyses A, Sanz I, Chatham WW, Hsu HC, Mountz JD. Cutting Edge: Intracellular IFN-β and Distinct Type I IFN Expression Patterns in Circulating Systemic Lupus Erythematosus B Cells. J Immunol 2018; 201:2203-2208. [PMID: 30201809 DOI: 10.4049/jimmunol.1800791] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 08/14/2018] [Indexed: 11/19/2022]
Abstract
In systemic lupus erythematosus (SLE), type I IFNs promote induction of type I IFN-stimulated genes (ISG) and can drive B cells to produce autoantibodies. Little is known about the expression of distinct type I IFNs in lupus, particularly high-affinity IFN-β. Single-cell analyses of transitional B cells isolated from SLE patients revealed distinct B cell subpopulations, including type I IFN producers, IFN responders, and mixed IFN producer/responder clusters. Anti-Ig plus TLR3 stimulation of SLE B cells induced release of bioactive type I IFNs that could stimulate HEK-Blue cells. Increased levels of IFN-β were detected in circulating B cells from SLE patients compared with controls and were significantly higher in African American patients with renal disease and in patients with autoantibodies. Together, the results identify type I IFN-producing and -responding subpopulations within the SLE B cell compartment and suggest that some patients may benefit from specific targeting of IFN-β.
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Affiliation(s)
- Jennie A Hamilton
- Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Qi Wu
- Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - PingAr Yang
- Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Bao Luo
- Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Shanrun Liu
- Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jun Li
- Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Ignacio Sanz
- Division of Rheumatology, Lowance Center for Human Immunology, Emory University School of Medicine, Atlanta, GA 30322; and
| | - W Winn Chatham
- Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Hui-Chen Hsu
- Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - John D Mountz
- Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294; .,Birmingham VA Medical Center, Birmingham, AL 35233
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Bartle EI, Rao TC, Urner TM, Mattheyses AL. Bridging the gap: Super-resolution microscopy of epithelial cell junctions. Tissue Barriers 2018; 6:e1404189. [PMID: 29420122 PMCID: PMC5823550 DOI: 10.1080/21688370.2017.1404189] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [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: 09/08/2017] [Revised: 10/26/2017] [Accepted: 10/30/2017] [Indexed: 02/02/2023] Open
Abstract
Cell junctions are critical for cell adhesion and communication in epithelial tissues. It is evident that the cellular distribution, size, and architecture of cell junctions play a vital role in regulating function. These details of junction architecture have been challenging to elucidate in part due to the complexity and size of cell junctions. A major challenge in understanding these features is attaining high resolution spatial information with molecular specificity. Fluorescence microscopy allows localization of specific proteins to junctions, but with a resolution on the same scale as junction size, rendering internal protein organization unobtainable. Super-resolution microscopy provides a bridge between fluorescence microscopy and nanoscale approaches, utilizing fluorescent tags to reveal protein organization below the resolution limit. Here we provide a brief introduction to super-resolution microscopy and discuss novel findings into the organization, structure and function of epithelial cell junctions.
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Affiliation(s)
- Emily I. Bartle
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tejeshwar C. Rao
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tara M. Urner
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexa L. Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
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Bartle EI, Urner TM, Raju SS, Mattheyses AL. Desmoglein 3 Order and Dynamics in Desmosomes Determined by Fluorescence Polarization Microscopy. Biophys J 2018; 113:2519-2529. [PMID: 29212005 DOI: 10.1016/j.bpj.2017.09.028] [Citation(s) in RCA: 8] [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] [Received: 06/13/2017] [Revised: 09/18/2017] [Accepted: 09/21/2017] [Indexed: 11/24/2022] Open
Abstract
Desmosomes are macromolecular cell-cell junctions that provide adhesive strength in epithelial tissue. Desmosome function is inseparably linked to structure, and it is hypothesized that the arrangement, or order, of desmosomal cadherins in the intercellular space is critical for adhesive strength. However, due to desmosome size, molecular complexity, and dynamics, the role that order plays in adhesion is challenging to study. Herein, we present an excitation resolved fluorescence polarization microscopy approach to measure the spatiotemporal dynamics of order and disorder of the desmosomal cadherin desmoglein 3 (Dsg3) in living cells. Simulations were used to establish order factor as a robust metric for quantifying the spatiotemporal dynamics of order and disorder. Order factor measurements in keratinocytes showed the Dsg3 extracellular domain is ordered at the individual desmosome, single cell, and cell population levels compared to a series of disordered controls. Desmosomal adhesion is Ca2+ dependent, and reduction of extracellular Ca2+ leads to a loss of adhesion measured by dispase fragmentation assay (λ = 15.1 min). Live cell imaging revealed Dsg3 order decreased more rapidly (λ = 5.5 min), indicating that cadherin order is not required for adhesion. Our results suggest that rapid disordering of cadherins can communicate a change in extracellular Ca2+ concentration to the cell, leading to a downstream loss of adhesion. Fluorescence polarization is an effective bridge between protein structure and complex dynamics and the approach presented here is broadly applicable to studying order in macromolecular structures.
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Affiliation(s)
- Emily I Bartle
- Department of Cell Biology, Emory University, Atlanta, Georgia
| | - Tara M Urner
- Department of Cell Biology, Emory University, Atlanta, Georgia
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Brockman JM, Blanchard AT, Pui-Yan V, Derricotte WD, Zhang Y, Fay ME, Lam WA, Evangelista FA, Mattheyses AL, Salaita K. Mapping the 3D orientation of piconewton integrin traction forces. Nat Methods 2017; 15:115-118. [PMID: 29256495 DOI: 10.1038/nmeth.4536] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 11/08/2017] [Indexed: 11/09/2022]
Abstract
Mechanical forces are integral to many biological processes; however, current techniques cannot map the magnitude and direction of piconewton molecular forces. Here, we describe molecular force microscopy, leveraging molecular tension probes and fluorescence polarization microscopy to measure the magnitude and 3D orientation of cellular forces. We mapped the orientation of integrin-based traction forces in mouse fibroblasts and human platelets, revealing alignment between the organization of force-bearing structures and their force orientations.
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Affiliation(s)
- Joshua M Brockman
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Aaron T Blanchard
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Victor Pui-Yan
- Department of Chemistry, Emory University, Atlanta, Georgia, USA
| | | | - Yun Zhang
- Department of Chemistry, Emory University, Atlanta, Georgia, USA
| | - Meredith E Fay
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Wilbur A Lam
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | | | - Alexa L Mattheyses
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Khalid Salaita
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA.,Department of Chemistry, Emory University, Atlanta, Georgia, USA
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39
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Sood C, Marin M, Chande A, Mattheyses AL, Salaita K, Pizzato M, Melikian G. SERINC5 Inhibits HIV Fusion through Inactivation of Env Glycoproteins and Interference with Productive Refolding of Env. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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40
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Stahley SN, Warren MF, Feldman RJ, Mattheyses AL, Kowalczyk AP. Super resolution microscopy reveals altered desmosome organization, endocytosis and desmosome splitting in pemphigus vulgaris epidermis. J Dermatol Sci 2016. [DOI: 10.1016/j.jdermsci.2016.08.086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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41
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Schlingmann B, Overgaard CE, Molina SA, Lynn KS, Mitchell LA, Dorsainvil White S, Mattheyses AL, Guidot DM, Capaldo CT, Koval M. Regulation of claudin/zonula occludens-1 complexes by hetero-claudin interactions. Nat Commun 2016; 7:12276. [PMID: 27452368 PMCID: PMC4962485 DOI: 10.1038/ncomms12276] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/15/2016] [Indexed: 01/06/2023] Open
Abstract
Claudins are tetraspan transmembrane tight-junction proteins that regulate epithelial barriers. In the distal airspaces of the lung, alveolar epithelial tight junctions are crucial to regulate airspace fluid. Chronic alcohol abuse weakens alveolar tight junctions, priming the lung for acute respiratory distress syndrome, a frequently lethal condition caused by airspace flooding. Here we demonstrate that in response to alcohol, increased claudin-5 paradoxically accompanies an increase in paracellular leak and rearrangement of alveolar tight junctions. Claudin-5 is necessary and sufficient to diminish alveolar epithelial barrier function by impairing the ability of claudin-18 to interact with a scaffold protein, zonula occludens 1 (ZO-1), demonstrating that one claudin affects the ability of another claudin to interact with the tight-junction scaffold. Critically, a claudin-5 peptide mimetic reverses the deleterious effects of alcohol on alveolar barrier function. Thus, claudin controlled claudin-scaffold protein interactions are a novel target to regulate tight-junction permeability.
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Affiliation(s)
- Barbara Schlingmann
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA
| | - Christian E Overgaard
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA
| | - Samuel A Molina
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA
| | - K Sabrina Lynn
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA
| | - Leslie A Mitchell
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA
| | - StevenClaude Dorsainvil White
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA
| | - Alexa L Mattheyses
- Department of Cell Biology, Emory University, Atlanta, Georgia 30322, USA
| | - David M Guidot
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA.,Atlanta Veterans Affairs Medical Center, Decatur, Georgia 30033, USA
| | - Christopher T Capaldo
- Department of Pathology; Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, 205 Whitehead Building, 615 Michael Street, Atlanta, Georgia 30322, USA.,Emory Alcohol and Lung Biology Center, Emory University, Atlanta, Georgia 30322, USA.,Department of Cell Biology, Emory University, Atlanta, Georgia 30322, USA
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42
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Stahley SN, Bartle EI, Atkinson CE, Kowalczyk AP, Mattheyses AL. Molecular organization of the desmosome as revealed by direct stochastic optical reconstruction microscopy. J Cell Sci 2016; 129:2897-904. [PMID: 27505428 DOI: 10.1242/jcs.185785] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 06/15/2016] [Indexed: 12/14/2022] Open
Abstract
Desmosomes are macromolecular junctions responsible for providing strong cell-cell adhesion. Because of their size and molecular complexity, the precise ultrastructural organization of desmosomes is challenging to study. Here, we used direct stochastic optical reconstruction microscopy (dSTORM) to resolve individual plaque pairs for inner and outer dense plaque proteins. Analysis methods based on desmosomal mirror symmetry were developed to measure plaque-to-plaque distances and create an integrated map. We quantified the organization of desmoglein 3, plakoglobin and desmoplakin (N-terminal, rod and C-terminal domains) in primary human keratinocytes. Longer desmosome lengths correlated with increasing plaque-to-plaque distance, suggesting that desmoplakin is arranged with its long axis at an angle within the plaque. We next examined whether plaque organization changed in different adhesive states. Plaque-to-plaque distance for the desmoplakin rod and C-terminal domains decreased in PKP-1-mediated hyperadhesive desmosomes, suggesting that protein reorganization correlates with function. Finally, in human epidermis we found a difference in plaque-to-plaque distance for the desmoplakin C-terminal domain, but not the desmoplakin rod domain or plakoglobin, between basal and suprabasal cells. Our data reveal the molecular organization of desmosomes in cultured keratinocytes and skin as defined by dSTORM.
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Affiliation(s)
- Sara N Stahley
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Emily I Bartle
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Claire E Atkinson
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Andrew P Kowalczyk
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA Department of Dermatology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Alexa L Mattheyses
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
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Stahley SN, Warren MF, Feldman RJ, Swerlick RA, Mattheyses AL, Kowalczyk AP. Super-Resolution Microscopy Reveals Altered Desmosomal Protein Organization in Tissue from Patients with Pemphigus Vulgaris. J Invest Dermatol 2016; 136:59-66. [PMID: 26763424 PMCID: PMC4730957 DOI: 10.1038/jid.2015.353] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 07/29/2015] [Accepted: 08/17/2015] [Indexed: 12/19/2022]
Abstract
Pemphigus vulgaris (PV) is an autoimmune epidermal blistering disease in which autoantibodies (IgG) are directed against the desmosomal cadherin desmoglein 3 (Dsg3). In order to better understand how PV IgG alters desmosome morphology and function in vivo, PV patient biopsies were analyzed by structured illumination microscopy (SIM), a form of super-resolution fluorescence microscopy. In patient tissue, desmosomal proteins were aberrantly clustered and localized to PV IgG-containing endocytic linear arrays. Patient IgG also colocalized with markers for lipid rafts and endosomes. Additionally, steady-state levels of Dsg3 were decreased and desmosomes were reduced in size in patient tissue. Desmosomes at blister sites were occasionally split, with PV IgG decorating the extracellular faces of split desmosomes. Desmosome splitting was recapitulated in vitro by exposing cultured keratinocytes both to PV IgG and to mechanical stress, demonstrating that splitting at the blister interface in patient tissue is due to compromised desmosomal adhesive function. These findings indicate that Dsg3 clustering and endocytosis are associated with reduced desmosome size and adhesion defects in PV patient tissue. Further, this study reveals that super-resolution optical imaging is powerful approach for studying epidermal adhesion structures in normal and diseased skin.
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Affiliation(s)
- Sara N Stahley
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA; Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Maxine F Warren
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Ron J Feldman
- Department of Dermatology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Robert A Swerlick
- Department of Dermatology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Alexa L Mattheyses
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Andrew P Kowalczyk
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA; Department of Dermatology, Emory University School of Medicine, Atlanta, Georgia, USA; Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia, USA.
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44
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Liu Z, Liu Y, Chang Y, Seyf HR, Henry A, Mattheyses AL, Yehl K, Zhang Y, Huang Z, Salaita K. Nanoscale optomechanical actuators for controlling mechanotransduction in living cells. Nat Methods 2016; 13:143-6. [PMID: 26657558 PMCID: PMC4732909 DOI: 10.1038/nmeth.3689] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [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: 02/27/2015] [Accepted: 11/04/2015] [Indexed: 11/09/2022]
Abstract
To control receptor tension optically at the cell surface, we developed an approach involving optomechanical actuator nanoparticles that are controlled with near-infrared light. Illumination leads to particle collapse, delivering piconewton forces to specific cell surface receptors with high spatial and temporal resolution. We demonstrate optomechanical actuation by controlling integrin-based focal adhesion formation, cell protrusion and migration, and T cell receptor activation.
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Affiliation(s)
- Zheng Liu
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Yang Liu
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Yuan Chang
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Hamid Reza Seyf
- Georgia Institute of Technology, George W. Woodruff School of Mechanical Engineering, Atlanta, GA, USA
| | - Asegun Henry
- Georgia Institute of Technology, George W. Woodruff School of Mechanical Engineering, Atlanta, GA, USA
- Georgia Institute of Technology, School of Materials Science and Engineering, Atlanta, GA, USA
| | - Alexa L. Mattheyses
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Kevin Yehl
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Yun Zhang
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | | | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, GA, USA
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45
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Swanger SA, Mattheyses AL, Gentry EG, Herskowitz JH. ROCK1 and ROCK2 inhibition alters dendritic spine morphology in hippocampal neurons. Cell Logist 2015; 5:e1133266. [PMID: 27054047 PMCID: PMC4820816 DOI: 10.1080/21592799.2015.1133266] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 12/07/2015] [Accepted: 12/10/2015] [Indexed: 10/22/2022]
Abstract
Communication among neurons is mediated through synaptic connections between axons and dendrites, and most excitatory synapses occur on actin-rich protrusions along dendrites called dendritic spines. Dendritic spines are structurally dynamic, and synapse strength is closely correlated with spine morphology. Abnormalities in the size, shape, and number of dendritic spines are prevalent in neurologic diseases, including autism spectrum disorders, schizophrenia, and Alzheimer disease. However, therapeutic targets that influence spine morphology are lacking. Rho-associated coiled-coil containing protein kinases (ROCK) 1 and ROCK2 are potent regulators of the actin cytoskeleton and highly promising drug targets for central nervous system disorders. In this report, we addressed how pharmacologic inhibition of ROCK1 and ROCK2 affects dendritic spine morphology. Hippocampal neurons were transfected with plasmids expressing fluorescently labeled Lifeact, a small actin binding peptide, and then incubated with or without Y-27632, an established pan-ROCK small molecule inhibitor. Using an automated 3D spine morphometry analysis method, we showed that inhibition of ROCK1 and ROCK2 significantly increased the mean protrusion density and significantly reduced the mean protrusion width. A trending increase in mean protrusion length was observed following Y-27632 treatment, and novel effects were observed among spine classes. Exposure to Y-27632 significantly increased the number of filopodia and thin spines, while the numbers of stubby and mushroom spines were similar to mock-treated samples. These findings support the hypothesis that pharmacologic inhibition of ROCK1 and ROCK2 may convey therapeutic benefit for neurologic disorders that feature dendritic spine loss or aberrant structural plasticity.
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Affiliation(s)
- Sharon A Swanger
- Department of Pharmacology; Emory University School of Medicine; Atlanta, GA USA
| | - Alexa L Mattheyses
- Department of Cell Biology; Emory University School of Medicine; Atlanta; GA USA
| | - Erik G Gentry
- Center for Neurodegeneration and Experimental Therapeutics; University of Alabama at Birmingham; Birmingham, AL USA
- Department of Neurology; University of Alabama at Birmingham; Birmingham, AL USA
| | - Jeremy H Herskowitz
- Center for Neurodegeneration and Experimental Therapeutics; University of Alabama at Birmingham; Birmingham, AL USA
- Department of Neurology; University of Alabama at Birmingham; Birmingham, AL USA
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Stabley DR, Oh T, Simon SM, Mattheyses AL, Salaita K. Real-time fluorescence imaging with 20 nm axial resolution. Nat Commun 2015; 6:8307. [PMID: 26392382 PMCID: PMC4595625 DOI: 10.1038/ncomms9307] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 08/07/2015] [Indexed: 11/09/2022] Open
Abstract
Measuring the nanoscale organization of protein structures near the plasma membrane of live cells is challenging, especially when the structure is dynamic. Here we present the development of a two-wavelength total internal reflection fluorescence method capable of real-time imaging of cellular structure height with nanometre resolution. The method employs a protein of interest tagged with two different fluorophores and imaged to obtain the ratio of emission in the two channels. We use this approach to visualize the nanoscale organization of microtubules and endocytosis of the epidermal growth factor receptor.
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Affiliation(s)
- Daniel R Stabley
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Thomas Oh
- Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York 10065, USA
| | - Sanford M Simon
- Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York 10065, USA
| | - Alexa L Mattheyses
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia 30322, USA
| | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
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Abstract
Förster or Fluorescence resonance energy transfer (FRET) can be used to detect protein-protein interactions. When combined with microscopy, FRET has high temporal and spatial resolution, allowing the interaction dynamics of proteins within specific subcellular compartments to be detected in cells. FRET microscopy has become a powerful technique to assay the direct binding interaction of two proteins in vivo. Here, we describe a sensitized emission method to determine the presence and dynamics of protein-protein interactions in living cells.
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Affiliation(s)
- Alexa L Mattheyses
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA,
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Johnson DS, Toledo-Crow R, Mattheyses AL, Simon SM. Polarization-controlled TIRFM with focal drift and spatial field intensity correction. Biophys J 2014; 106:1008-19. [PMID: 24606926 DOI: 10.1016/j.bpj.2013.12.043] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 12/20/2013] [Accepted: 12/31/2013] [Indexed: 10/25/2022] Open
Abstract
Total internal reflection fluorescence microscopy (TIRFM) is becoming an increasingly common methodology to narrow the illumination excitation thickness to study cellular process such as exocytosis, endocytosis, and membrane dynamics. It is also frequently used as a method to improve signal/noise in other techniques such as in vitro single-molecule imaging, stochastic optical reconstruction microscopy/photoactivated localization microscopy imaging, and fluorescence resonance energy transfer imaging. The unique illumination geometry of TIRFM also enables a distinct method to create an excitation field for selectively exciting fluorophores that are aligned either parallel or perpendicular to the optical axis. This selectivity has been used to study orientation of cell membranes and cellular proteins. Unfortunately, the coherent nature of laser light, the typical excitation source in TIRFM, often creates spatial interference fringes across the illuminated area. These fringes are particularly problematic when imaging large cellular areas or when accurate quantification is necessary. Methods have been developed to minimize these fringes by modulating the TIRFM field during a frame capture period; however, these approaches eliminate the possibility to simultaneously excite with a specific polarization. A new, to our knowledge, technique is presented, which compensates for spatial fringes while simultaneously permitting rapid image acquisition of both parallel and perpendicular excitation directions in ~25 ms. In addition, a back reflection detection scheme was developed that enables quick and accurate alignment of the excitation laser. The detector also facilitates focus drift compensation, a common problem in TIRFM due to the narrow excitation depth, particularly when imaging over long time courses or when using a perfusion flow chamber. The capabilities of this instrument were demonstrated by imaging membrane orientation using DiO on live cells and on lipid bilayers that were supported on a glass slide (supported lipid bilayer). The use of the approach to biological problems was illustrated by examining the temporal and spatial dynamics of exocytic vesicles.
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Affiliation(s)
- Daniel S Johnson
- Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York
| | - Ricardo Toledo-Crow
- Research Engineering Lab, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Alexa L Mattheyses
- Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York
| | - Sanford M Simon
- Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York.
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Alford LM, Mattheyses AL, Hunter EL, Lin H, Dutcher SK, Sale WS. The Chlamydomonas mutant pf27 reveals novel features of ciliary radial spoke assembly. Cytoskeleton (Hoboken) 2014; 70:804-18. [PMID: 24124175 DOI: 10.1002/cm.21144] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 09/10/2013] [Accepted: 09/12/2013] [Indexed: 01/05/2023]
Abstract
To address the mechanisms of ciliary radial spoke assembly, we took advantage of the Chlamydomonas pf27 mutant. The radial spokes that assemble in pf27 are localized to the proximal quarter of the axoneme, but otherwise are fully assembled into 20S radial spoke complexes competent to bind spokeless axonemes in vitro. Thus, pf27 is not defective in radial spoke assembly or docking to the axoneme. Rather, our results suggest that pf27 is defective in the transport of spoke complexes. During ciliary regeneration in pf27, radial spoke assembly occurs asynchronously from other axonemal components. In contrast, during ciliary regeneration in wild-type Chlamydomonas, radial spokes and other axonemal components assemble concurrently as the axoneme grows. Complementation in temporary dikaryons between wild-type and pf27 reveals rescue of radial spoke assembly that begins at the distal tip, allowing further assembly to proceed from tip to base of the axoneme. Notably, rescued assembly of radial spokes occurred independently of the established proximal radial spokes in pf27 axonemes in dikaryons. These results reveal that 20S radial spokes can assemble proximally in the pf27 cilium but as the cilium lengthens, spoke assembly requires transport. We postulate that PF27 encodes an adaptor or modifier protein required for radial spoke–IFT interaction.
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Newman LE, Zhou CJ, Mudigonda S, Mattheyses AL, Paradies E, Marobbio CMT, Kahn RA. The ARL2 GTPase is required for mitochondrial morphology, motility, and maintenance of ATP levels. PLoS One 2014; 9:e99270. [PMID: 24911211 PMCID: PMC4050054 DOI: 10.1371/journal.pone.0099270] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [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: 03/24/2014] [Accepted: 05/13/2014] [Indexed: 02/06/2023] Open
Abstract
ARF-like 2 (ARL2) is a member of the ARF family and RAS superfamily of regulatory GTPases, predicted to be present in the last eukaryotic common ancestor, and essential in a number of model genetic systems. Though best studied as a regulator of tubulin folding, we previously demonstrated that ARL2 partially localizes to mitochondria. Here, we show that ARL2 is essential to a number of mitochondrial functions, including mitochondrial morphology, motility, and maintenance of ATP levels. We compare phenotypes resulting from ARL2 depletion and expression of dominant negative mutants and use these to demonstrate that the mitochondrial roles of ARL2 are distinct from its roles in tubulin folding. Testing of current models for ARL2 actions at mitochondria failed to support them. Rather, we found that knockdown of the ARL2 GTPase activating protein (GAP) ELMOD2 phenocopies two of three phenotypes of ARL2 siRNA, making it a likely effector for these actions. These results add new layers of complexity to ARL2 signaling, highlighting the need to deconvolve these different cell functions. We hypothesize that ARL2 plays essential roles inside mitochondria along with other cellular functions, at least in part to provide coupling of regulation between these essential cell processes.
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Affiliation(s)
- Laura E. Newman
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Cheng-jing Zhou
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Samatha Mudigonda
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Alexa L. Mattheyses
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Eleonora Paradies
- Consiglio Nazionale delle Ricerche Institute of Biomembranes and Bioenergetics, Bari, Italy
| | | | - Richard A. Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States of America
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