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Nishizawa K, Lin SZ, Chardès C, Rupprecht JF, Lenne PF. Two-point optical manipulation reveals mechanosensitive remodeling of cell-cell contacts in vivo. Proc Natl Acad Sci U S A 2023; 120:e2212389120. [PMID: 36947511 PMCID: PMC10068846 DOI: 10.1073/pnas.2212389120] [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: 07/19/2022] [Accepted: 01/17/2023] [Indexed: 03/23/2023] Open
Abstract
Biological tissues acquire reproducible shapes during development through dynamic cell behaviors. Most of these behaviors involve the remodeling of cell-cell contacts. During epithelial morphogenesis, contractile actomyosin networks remodel cell-cell contacts by shrinking and extending junctions between lateral cell surfaces. However, actomyosin networks not only generate mechanical stresses but also respond to them, confounding our understanding of how mechanical stresses remodel cell-cell contacts. Here, we develop a two-point optical manipulation method to impose different stress patterns on cell-cell contacts in the early epithelium of the Drosophila embryo. The technique allows us to produce junction extension and shrinkage through different push and pull manipulations at the edges of junctions. We use these observations to expand classical vertex-based models of tissue mechanics, incorporating negative and positive mechanosensitive feedback depending on the type of remodeling. In particular, we show that Myosin-II activity responds to junction strain rate and facilitates full junction shrinkage. Altogether our work provides insight into how stress produces efficient deformation of cell-cell contacts in vivo and identifies unanticipated mechanosensitive features of their remodeling.
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Affiliation(s)
- Kenji Nishizawa
- Aix Marseille Univ, CNRS, IBDM, Turing Centre for Living systems, Marseille UMR 7288, France
| | - Shao-Zhen Lin
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, Turing Centre for Living systems, Marseille UMR 7332, France
| | - Claire Chardès
- Aix Marseille Univ, CNRS, IBDM, Turing Centre for Living systems, Marseille UMR 7288, France
| | - Jean-François Rupprecht
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, Turing Centre for Living systems, Marseille UMR 7332, France
| | - Pierre-François Lenne
- Aix Marseille Univ, CNRS, IBDM, Turing Centre for Living systems, Marseille UMR 7288, France
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Tang G, Chen Y, Xu JR, Kistler HC, Ma Z. The fungal myosin I is essential for Fusarium toxisome formation. PLoS Pathog 2018; 14:e1006827. [PMID: 29357387 PMCID: PMC5794197 DOI: 10.1371/journal.ppat.1006827] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 02/01/2018] [Accepted: 12/18/2017] [Indexed: 01/12/2023] Open
Abstract
Myosin-I molecular motors are proposed to function as linkers between membranes and the actin cytoskeleton in several cellular processes, but their role in the biosynthesis of fungal secondary metabolites remain elusive. Here, we found that the myosin I of Fusarium graminearum (FgMyo1), the causal agent of Fusarium head blight, plays critical roles in mycotoxin biosynthesis. Inhibition of myosin I by the small molecule phenamacril leads to marked reduction in deoxynivalenol (DON) biosynthesis. FgMyo1 also governs translation of the DON biosynthetic enzyme Tri1 by interacting with the ribosome-associated protein FgAsc1. Disruption of the ATPase activity of FgMyo1 either by the mutation E420K, down-regulation of FgMyo1 expression or deletion of FgAsc1 results in reduced Tri1 translation. The DON biosynthetic enzymes Tri1 and Tri4 are mainly localized to subcellular structures known as toxisomes in response to mycotoxin induction and the FgMyo1-interacting protein, actin, participates in toxisome formation. The actin polymerization disruptor latrunculin A inhibits toxisome assembly. Consistent with this observation, deletion of the actin-associated proteins FgPrk1 and FgEnd3 also results in reduced toxisome formation. Unexpectedly, the FgMyo1-actin cytoskeleton is not involved in biosynthesis of another secondary metabolite tested. Taken together, this study uncovers a novel function of myosin I in regulating mycotoxin biosynthesis in filamentous fungi. The mycotoxin deoxynivalenol (DON) is the most frequently detected secondary metabolite produced by Fusarium graminearum and other Fusarium spp. To date, relatively few studies have addressed how mycotoxin biosynthesis occurs in fungal cells. Here we found that myosin I governs translation of DON biosynthetic enzyme Tri1 via interacting with the ribosome-associated protein FgAsc1. Moreover, the key DON biosynthetic enzymes Tri1 and Tri4 are mainly localized to the toxisomes derived from endoplasmic reticulum under toxin inducing conditions. We further found that the FgMyo1-actin cytoskeleton was involved in toxisome formation but not for the biosynthesis of another secondary metabolite tested. Taken together, these results indicate for the first time that myosin I plays critical roles in mycotoxin biosynthesis.
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Affiliation(s)
- Guangfei Tang
- Institute of Biotechnology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, China
| | - Yun Chen
- Institute of Biotechnology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, China
| | - Jin-Rong Xu
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
| | - H. Corby Kistler
- Department of Plant Pathology, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Zhonghua Ma
- Institute of Biotechnology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, China
- State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou, China
- * E-mail:
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3
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Hallengren E, Almgren P, Engström G, Persson M, Melander O. Analysis of Low Frequency Protein Truncating Stop-Codon Variants and Fasting Concentration of Growth Hormone. PLoS One 2015; 10:e0128348. [PMID: 26086970 PMCID: PMC4472854 DOI: 10.1371/journal.pone.0128348] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/24/2015] [Indexed: 01/22/2023] Open
Abstract
Background The genetic background of Growth Hormone (GH) secretion is not well understood. Mutations giving rise to a stop codon have a high likelihood of affecting protein function. Objectives To analyze likely functional stop codon mutations that are associated with fasting plasma concentration of Growth Hormone. Methods We analyzed stop codon mutations in 5451 individuals in the Malmö Diet and Cancer study by genotyping the Illumina Exome Chip. To enrich for stop codon mutations with likely functional effects on protein function, we focused on those disrupting >80% of the predicted amino acid sequence, which were carried by ≥10 individuals. Such mutations were related to GH concentration, measured with a high sensitivity assay (hs-GH) and, if nominally significant, to GH related phenotypes, using linear regression analysis. Results Two stop codon mutations were associated with the fasting concentration of hs-GH. rs121909305 (NP_005370.1:p.R93*) [Minor Allele Frequency (MAF) = 0.8%] in the Myosin 1A gene (MYO1A) was associated with a 0.36 (95%CI, 0.04 to 0.54; p=0.02) increment of the standardized value of the natural logarithm of hs-GH per 1 minor allele and rs35699176 (NP_067040.1:p.Q100*) in the Zink Finger protein 77 gene (ZNF77) (MAF = 4.8%) was associated with a 0.12 (95%CI, 0.02 to 0.22; p = 0.02) increase of hs-GH. The mutated high hs-GH associated allele of MYO1A was related to lower BMI (β-coefficient, -0.22; p = 0.05), waist (β-coefficient, -0.22; p = 0.04), body fat percentage (β-coefficient, -0.23; p = 0.03) and with higher HDL (β-coefficient, 0.23; p = 0.04). The ZNF77 stop codon was associated with height (β-coefficient, 0.11; p = 0.02) but not with cardiometabolic risk factors. Conclusion We here suggest that a stop codon of MYO1A, disrupting 91% of the predicted amino acid sequence, is associated with higher hs-GH and GH-related traits suggesting that MYO1A is involved in GH metabolism and possibly body fat distribution. However, our results are preliminary and need replication in independent populations.
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Affiliation(s)
- Erik Hallengren
- Department of Clinical Sciences, Lund University, Malmö, Sweden
- Department of Internal Medicine, Skåne University Hospital, Malmö, Sweden
- * E-mail:
| | - Peter Almgren
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Gunnar Engström
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Margaretha Persson
- Department of Clinical Sciences, Lund University, Malmö, Sweden
- Department of Internal Medicine, Skåne University Hospital, Malmö, Sweden
| | - Olle Melander
- Department of Clinical Sciences, Lund University, Malmö, Sweden
- Department of Internal Medicine, Skåne University Hospital, Malmö, Sweden
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Mazzolini R, Dopeso H, Mateo-Lozano S, Chang W, Rodrigues P, Bazzocco S, Alazzouzi H, Landolfi S, Hernández-Losa J, Andretta E, Alhopuro P, Espín E, Armengol M, Tabernero J, Ramón y Cajal S, Kloor M, Gebert J, Mariadason JM, Schwartz S, Aaltonen LA, Mooseker MS, Arango D. Brush border myosin Ia has tumor suppressor activity in the intestine. Proc Natl Acad Sci U S A 2012; 109:1530-5. [PMID: 22307608 PMCID: PMC3277176 DOI: 10.1073/pnas.1108411109] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [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: 12/31/2022] Open
Abstract
The loss of the epithelial architecture and cell polarity/differentiation is known to be important during the tumorigenic process. Here we demonstrate that the brush border protein Myosin Ia (MYO1A) is important for polarization and differentiation of colon cancer cells and is frequently inactivated in colorectal tumors by genetic and epigenetic mechanisms. MYO1A frame-shift mutations were observed in 32% (37 of 116) of the colorectal tumors with microsatellite instability analyzed, and evidence of promoter methylation was observed in a significant proportion of colon cancer cell lines and primary colorectal tumors. The loss of polarization/differentiation resulting from MYO1A inactivation is associated with higher tumor growth in soft agar and in a xenograft model. In addition, the progression of genetically and carcinogen-initiated intestinal tumors was significantly accelerated in Myo1a knockout mice compared with Myo1a wild-type animals. Moreover, MYO1A tumor expression was found to be an independent prognostic factor for colorectal cancer patients. Patients with low MYO1A tumor protein levels had significantly shorter disease-free and overall survival compared with patients with high tumoral MYO1A (logrank test P = 0.004 and P = 0.009, respectively). The median time-to-disease recurrence in patients with low MYO1A was 1 y, compared with >9 y in the group of patients with high MYO1A. These results identify MYO1A as a unique tumor-suppressor gene in colorectal cancer and demonstrate that the loss of structural brush border proteins involved in cell polarity are important for tumor development.
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Affiliation(s)
- Rocco Mazzolini
- Group of Molecular Oncology, and
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina, 50018 Zaragoza, Spain
| | - Higinio Dopeso
- Group of Molecular Oncology, and
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina, 50018 Zaragoza, Spain
| | - Silvia Mateo-Lozano
- Group of Molecular Oncology, and
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina, 50018 Zaragoza, Spain
| | - Wakam Chang
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, 06520-8103 CT
| | - Paulo Rodrigues
- Group of Molecular Oncology, and
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina, 50018 Zaragoza, Spain
| | | | | | | | | | - Elena Andretta
- Group of Molecular Oncology, and
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina, 50018 Zaragoza, Spain
| | - Pia Alhopuro
- Department of Medical Genetics, Genome-Scale Biology Research Program, Biomedicum Helsinki, University of Helsinki, 00014 Helsinki, Finland
| | | | | | - Josep Tabernero
- Department of Medical Oncology, Vall d'Hebron University Hospital, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
| | | | - Matthias Kloor
- Department of Applied Tumor Biology, Institute of Pathology, University Hospital Heidelberg, 69120 Heidelberg, Germany; and
| | - Johannes Gebert
- Department of Applied Tumor Biology, Institute of Pathology, University Hospital Heidelberg, 69120 Heidelberg, Germany; and
| | - John M. Mariadason
- Ludwig Institute for Cancer Research, Melbourne Centre for Clinical Sciences, Austin Health, Heidelberg, Victoria 3084, Australia
| | - Simo Schwartz
- Group of Drug Delivery and Targeting, Centro de Investigaciones en Bioquímica y Biología Molecular-Nanomedicine, Vall d'Hebron University Hospital Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina, 50018 Zaragoza, Spain
| | - Lauri A. Aaltonen
- Department of Medical Genetics, Genome-Scale Biology Research Program, Biomedicum Helsinki, University of Helsinki, 00014 Helsinki, Finland
| | - Mark S. Mooseker
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, 06520-8103 CT
| | - Diego Arango
- Group of Molecular Oncology, and
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina, 50018 Zaragoza, Spain
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5
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Steinberg T, Ziegler N, Alonso A, Kohl A, Müssig E, Proksch S, Schulz S, Tomakidi P. Strain response in fibroblasts indicates a possible role of the Ca(2+)-dependent nuclear transcription factor NM1 in RNA synthesis. Cell Calcium 2011; 49:259-71. [PMID: 21470675 DOI: 10.1016/j.ceca.2011.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Revised: 02/08/2011] [Accepted: 03/07/2011] [Indexed: 11/15/2022]
Abstract
On the mechanistic level, response of periodontal fibroblasts permanently exposed to mechanical strain forces in vivo still lacks in clarity. Therefore, we first investigated putative strain modulation of proteins by combined 1D gel electrophoresis-based protein profiling and electrospray tandem mass spectrometry (ESI-MS). Thereafter, the exponential-modified protein abundance index (emPAI) identified strain modulation of cytoskeleton-associated molecules, including decrease in talin and microtubule-associated protein 4 (MAP4), and significant increase in myosin IC (Myo IC), the latter ones regulated by Ca(2+). These findings were corroborated by western blotting (WB) and indirect immunofluorescence (IIF). Regarding the dual function of Myo IC as actin-based cytoplasmic motor protein and nuclear transcription factor NM1, WB and IIF revealed inverse correlation for Myo IC and NM1. During strain application, cytoplasmic increase of Myo IC was counteracted by nuclear NM1 deprivation, the latter coinciding with a decline in RNA quantity. Independent on strain, cytoplasmic Myo IC and nuclear NM1 abundance could be abrogated by the Ca(2+) channel blocker nifedipine, suggesting Ca(2+) dependency of cytoplasmic and/or nuclear Myo IC/NM1 expression. Mechanistically, we conclude that, application of strain appears as causative for the decline in RNA by impacting NM1, thereby indicating the possible role of NM1 in RNA synthesis.
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Affiliation(s)
- Thorsten Steinberg
- Department of Oral Biotechnology, Dental School, University Hospital Freiburg, Hugstetterstrasse 55, 79106 Freiburg, Germany.
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6
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Abstract
The ability to sense molecular tension is crucial for a wide array of cellular processes, including the detection of auditory stimuli, control of cell shape, and internalization and transport of membranes. We show that myosin I, a motor protein that has been implicated in powering key steps in these processes, dramatically alters its motile properties in response to tension. We measured the displacement generated by single myosin I molecules, and we determined the actin-attachment kinetics with varying tensions using an optical trap. The rate of myosin I detachment from actin decreases >75-fold under tension of 2 piconewtons or less, resulting in myosin I transitioning from a low (<0.2) to a high (>0.9) duty-ratio motor. This impressive tension sensitivity supports a role for myosin I as a molecular force sensor.
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Affiliation(s)
- Joseph M Laakso
- Pennsylvania Muscle Institute and Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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7
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Maeda R, Hozumi S, Taniguchi K, Okumura T, Matsuno K. [Genetic analysis of left-right asymmetry in Drosophila melanogaster]. Seikagaku 2007; 79:1131-1134. [PMID: 18203452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Affiliation(s)
- Reo Maeda
- Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
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8
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Hozumi S, Maeda R, Taniguchi K, Matsuno K. [Mechanisms to establish left-right asymmetry in invertebrates]. Tanpakushitsu Kakusan Koso 2007; 52:227-35. [PMID: 17352187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
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9
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Abstract
In this issue of Developmental Cell, Sokac et al. (2006) describe an intriguing new role for an actin-based motor protein in restraining actin polymerization during endocytosis in Xenopus oocytes.
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Affiliation(s)
- Margaret A Titus
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455, USA
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10
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Sokac AM, Schietroma C, Gundersen CB, Bement WM. Myosin-1c couples assembling actin to membranes to drive compensatory endocytosis. Dev Cell 2007; 11:629-40. [PMID: 17084356 PMCID: PMC2826358 DOI: 10.1016/j.devcel.2006.09.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [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: 03/09/2004] [Revised: 07/31/2006] [Accepted: 09/05/2006] [Indexed: 10/23/2022]
Abstract
Compensatory endocytosis follows regulated exocytosis in cells ranging from eggs to neurons, but the means by which it is accomplished are unclear. In Xenopus eggs, compensatory endocytosis is driven by dynamic coats of assembling actin that surround and compress exocytosing cortical granules (CGs). We have identified Xenopus laevis myosin-1c (XlMyo1c) as a myosin that is upregulated by polyadenylation during meiotic maturation, the developmental interval that prepares eggs for fertilization and regulated CG exocytosis. Upon calcium-induced exocytosis, XlMyo1c is recruited to exocytosing CG membranes where actin coats then assemble. When XlMyo1c function is disrupted, actin coats assemble, but dynamic actin filaments are uncoupled from the exocytosing CG membranes such that coats do not compress, and compensatory endocytosis fails. Remarkably, there is also an increase in polymerized actin at membranes throughout the cell. We conclude that XlMyo1c couples polymerizing actin to membranes and so mediates force production during compensatory endocytosis.
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Affiliation(s)
- Anna M. Sokac
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, Madison, Wisconsin 53706
- Department of Zoology, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Cataldo Schietroma
- Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - Cameron B. Gundersen
- Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - William M. Bement
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, Madison, Wisconsin 53706
- Department of Zoology, University of Wisconsin-Madison, Madison, Wisconsin 53706
- Correspondence:
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11
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Abstract
Myosins are actin-based molecular motors that are found in almost all eukaryotes. Phylogenetic analysis allows the discrimination of 37 different types of myosins, most with unknown functions. Recent work in Drosophila has revealed a crucial role for type ID unconventional myosin in left-right asymmetry. Mutations in Myosin ID completely reverse the left-right axis (situs inversus), a phenotype that is dependent on an intact actin cytoskeleton. How this myosin might orient the left-right axis has began to be elucidated by showing that it interacts directly with beta-catenin, suggesting that myosin ID interacts with the adherens junction to control the direction of organ looping. This is the first demonstration of a role of a myosin in body patterning.
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Affiliation(s)
- Pauline Spéder
- Institute of Signalling, Developmental Biology & Cancer, CNRS - UMR 6543, University of Nice Sophia-Antipolis, Parc Valrose, 06108 Nice cedex 2, France
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12
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Kim SV, Mehal WZ, Dong X, Heinrich V, Pypaert M, Mellman I, Dembo M, Mooseker MS, Wu D, Flavell RA. Modulation of cell adhesion and motility in the immune system by Myo1f. Science 2006; 314:136-9. [PMID: 17023661 DOI: 10.1126/science.1131920] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Although class I myosins are known to play a wide range of roles, the physiological function of long-tailed class I myosins in vertebrates remains elusive. We demonstrated that one of these proteins, Myo1f, is expressed predominantly in the mammalian immune system. Cells from Myo1f-deficient mice exhibited abnormally increased adhesion and reduced motility, resulting from augmented exocytosis of beta2 integrin-containing granules. Also, the cortical actin that co-localizes with Myo1f was reduced in Myo1f-deficient cells. In vivo, Myo1f-deficient mice showed increased susceptibility to infection by Listeria monocytogenes and an impaired neutrophil response. Thus, Myo1f directs immune cell motility and innate host defense against infection.
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Affiliation(s)
- Sangwon V Kim
- Section of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA
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13
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Sumoza-Toledo A, Gillespie PG, Romero-Ramirez H, Ferreira-Ishikawa HC, Larson RE, Santos-Argumedo L. Differential localization of unconventional myosin I and nonmuscle myosin II during B cell spreading. Exp Cell Res 2006; 312:3312-22. [PMID: 16919270 DOI: 10.1016/j.yexcr.2006.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Revised: 07/01/2006] [Accepted: 07/07/2006] [Indexed: 02/06/2023]
Abstract
Cross-linking of CD44 in vitro promotes chemokinesis and actin-based dendrite formation in T and B cells. However, the mechanisms by which the adhesion molecule CD44 induces cytoskeleton activation in lymphocytes are still poorly understood. In this study, we have investigated whether myosin isoforms are involved in CD44-dependent dendrite formation in activated B cells. Pharmacological inhibition of myosin with 2,3-butanedione monoxime strongly affected spreading and dendrite formation, suggesting that these cellular motors may participate in these phenomena. Furthermore, immunofluorescence analysis showed differences in subcellular localization of class I and class II myosin during B cell spreading. In response to CD44 cross-linking, myosin-1c was polarized to lamellipodia, where F-actin was high. In contrast, the distribution of cytosplasmic nonmuscle class II myosin was not altered. Expressions of myosin-1c and II were also demonstrated in B cells by Western blot. Although the inhibition of PLCgamma, PI3K and MEK-1 activation affected the spreading and dendrite formation in activated B cells, only PLCgamma and MEK-1 inhibition correlated with absence of myosin-1c polarization. Additionally, myosin-1c polarization was observed upon cross-linking of other surface molecules, suggesting a common mechanism for B cell spreading. This work shows that class I and class II myosin are expressed in B cells, are differentially distributed, and may participate in the morphological changes of these cells.
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Affiliation(s)
- Adriana Sumoza-Toledo
- Department of Molecular Biomedicine, Centro de Investigación y Estudios Avanzados, Av. IPN #2508. Col. Zacatenco. CP 07360, México, D.F., México
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14
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Sun Y, Martin AC, Drubin DG. Endocytic internalization in budding yeast requires coordinated actin nucleation and myosin motor activity. Dev Cell 2006; 11:33-46. [PMID: 16824951 DOI: 10.1016/j.devcel.2006.05.008] [Citation(s) in RCA: 197] [Impact Index Per Article: 10.9] [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: 11/29/2005] [Revised: 05/03/2006] [Accepted: 05/16/2006] [Indexed: 10/24/2022]
Abstract
Actin polymerization essential for endocytic internalization in budding yeast is controlled by four nucleation promoting factors (NPFs) that each exhibits a unique dynamic behavior at endocytic sites. How each NPF functions and is regulated to restrict actin assembly to late stages of endocytic internalization is not known. Quantitative analysis of NPF biochemical activities, and genetic analysis of recruitment and regulatory mechanisms, defined a linear pathway in which protein composition changes at endocytic sites control actin assembly and function. We show that yeast WASP initiates actin assembly at endocytic sites and that this assembly and the recruitment of a yeast WIP-like protein by WASP recruit a type I myosin with both NPF and motor activities. Importantly, type I myosin motor and NPF activities are separable, and both contribute to endocytic coat inward movement, which likely represents membrane invagination. These results reveal a mechanism in which actin nucleation and myosin motor activity cooperate to promote endocytic internalization.
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Affiliation(s)
- Yidi Sun
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
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15
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Hofmann WA, Johnson T, Klapczynski M, Fan JL, de Lanerolle P. From transcription to transport: emerging roles for nuclear myosin IThis paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process. Biochem Cell Biol 2006; 84:418-26. [PMID: 16936815 DOI: 10.1139/o06-069] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Myosins are a superfamily of actin-activated ATPases that, in the cytoplasm, work together with actin as molecular motors. The presence of actin in the nucleus has been known for many years. The demonstration of a nuclear isoform of a myosin, nuclear myosin I (NMI), stimulated a great deal of interest in possible intranuclear motor functions of an acto–NMI complex. NMI has been shown to be involved in transcription by RNA polymerases I and II. In both cases, NMI interacts with the respective polymerase and is critically involved in the basic process of transcription. A recent study on intranuclear long-range chromosome movement has now demonstrated a role for NMI in the translocation of chromosome regions as well. Moreover, this movement is based on an active and directed process that is facilitated by an acto–NMI complex, establishing for the first time a functional role for a motor complex consisting of actin and a myosin in the nucleus.
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Affiliation(s)
- Wilma A Hofmann
- Department of Physiology and Biophysics, University of IL at Chicago, 835 S. Wolcott, Chicago, IL 60612, USA
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16
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Abstract
Despite being bilaterally symmetric, most Metazoa exhibit clear, genetically determined left-right differences. In several animals, microtubule-based structures are thought to be the source of chiral information used to establish handedness. Now, two new studies in Drosophila identify a role for unconventional myosin motors in this process.
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Affiliation(s)
- Buzz Baum
- Ludwig Institute for Cancer Research, 91 Riding House Street, London W1W 7BS, UK.
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D'Agostino JL, Goode BL. Dissection of Arp2/3 complex actin nucleation mechanism and distinct roles for its nucleation-promoting factors in Saccharomyces cerevisiae. Genetics 2005; 171:35-47. [PMID: 16183906 PMCID: PMC1456526 DOI: 10.1534/genetics.105.040634] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [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: 01/08/2005] [Accepted: 05/31/2005] [Indexed: 11/18/2022] Open
Abstract
Actin nucleation by the Arp2/3 complex is under tight control, remaining inactive until stimulation by nucleation-promoting factors (NPFs). Although multiple NPFs are expressed in most cell types, little is known about how they are coordinated and whether they perform similar or distinct functions. We examined genetic relationships among the four S. cerevisiae NPFs. Combining las17delta with pan1-101 or myo3delta myo5delta was lethal at all temperatures, whereas combining pan1-101 with myo3delta myo5delta showed no genetic interaction and abp1delta partially suppressed las17delta. These data suggest that NPFs have distinct and overlapping functions in vivo. We also tested genetic interactions between each NPF mutant and seven different temperature-sensitive arp2 alleles and purified mutant Arp2/3 complexes to compare their activities. Two arp2 alleles with mutations at the barbed end were severely impaired in nucleation, providing the first experimental evidence that Arp2 nucleates actin at its barbed end in vitro and in vivo. Another arp2 allele caused partially unregulated ("leaky") nucleation in the absence of NPFs. Combining this mutant with a partially unregulated allele in a different subunit of Arp2/3 complex was lethal, suggesting that cells cannot tolerate high levels of unregulated activity. Genetic interactions between arp2 alleles and NPF mutants point to Abp1 having an antagonistic role with respect to other NPFs, possibly serving to attenuate their stronger activities. In support of this model, Abp1 binds strongly to Arp2/3 complex, yet has notably weak nucleation-promoting activity and inhibits Las17 activity on Arp2/3 complex in a dose-responsive manner.
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Barylko B, Jung G, Albanesi JP. Structure, function, and regulation of myosin 1C. Acta Biochim Pol 2005; 52:373-80. [PMID: 15933767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2005] [Revised: 05/05/2005] [Accepted: 05/06/2005] [Indexed: 05/02/2023]
Abstract
Myosin 1C, the first mammalian single-headed myosin to be purified, cloned, and sequenced, has been implicated in the translocation of plasma membrane channels and transporters. Like other forms of myosin I (of which eight exist in humans) myosin 1C consists of motor, neck, and tail domains. The neck domain binds calmodulins more tightly in the absence than in the presence of Ca(2+). Release of calmodulins exposes binding sites for anionic lipids, particularly phosphoinositides. The tail domain, which has an isoelectic point of 10.5, interacts with anionic lipid headgroups. When both neck and tail lipid binding sites are engaged, the myosin associates essentially irreversibly with membranes. Despite this tight membrane binding, it is widely believed that myosin 1C docking proteins are necessary for targeting the enzyme to specific subcellular location. The search for these putative myosin 1C receptors is an active area of research.
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Affiliation(s)
- Barbara Barylko
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Abstract
Slow-twitch soleus, a weight-bearing hindlimb muscle, predominantly expresses the type I myosin heavy chain (MHC) isoform. However, under unloading conditions, a transition in MHC expression occurs from slow type I toward the fast-type isoforms. Transcriptional processes are believed to be involved in this adaptation. To test the hypothesis that the downregulation of MHC1 in soleus muscle following unloading is controlled through cis element(s) in the proximal region of the promoter, the MHC1 promoter was injected into soleus muscles of control rats and those subjected to 7 days of hindlimb suspension. Mutation analyses of six putative regulatory elements within the -408-bp region demonstrated that three elements, an A/T-rich, the proximal muscle-type CAT (betae3), and an E-box (-63 bp), play an important role in the basal level of MHC1 gene activity in the control soleus and function as unloading-responsive elements. Gel mobility shift assays revealed a diminished level of complex formation of the betae3 and E-box probes with nuclear extract from hindlimb suspension soleus compared with control soleus. Supershift assays indicated that transcriptional enhancer factor 1 and myogenin factors bind the betae3 and E-box elements, respectively, in the control soleus. Western blots showed that the relative concentrations of the transcriptional enhancer factor 1 and myogenin factors were significantly attenuated in the unloaded soleus compared with the control muscle. We conclude that the downregulation of MHC1 in response to unloading is due, in part, to a significant decrease in the concentration of these transcription factors available for binding the positive regulatory elements.
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Affiliation(s)
- Julia M Giger
- Dept. of Physiology and Biophysics, Univ. of California-Irvine, D-346, Med Sci I, Irvine, CA 92697, USA
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Stafford WF, Walker ML, Trinick JA, Coluccio LM. Mammalian class I myosin, Myo1b, is monomeric and cross-links actin filaments as determined by hydrodynamic studies and electron microscopy. Biophys J 2004; 88:384-91. [PMID: 15475577 PMCID: PMC1305015 DOI: 10.1529/biophysj.104.045245] [Citation(s) in RCA: 25] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The class I myosin, Myo1b, is a calmodulin- and actin-associated molecular motor widely expressed in mammalian tissues. Analytical ultracentrifugation studies indicate that Myo1b purified from rat liver has a Stokes radius of 6.7 nm and a sedimentation coefficient, s(20,w), of 7.0 S with a predicted molar mass of 213 kg/mol. These results indicate that Myo1b is monomeric and consists primarily of a splice variant having five associated calmodulins. Molecular modeling based on the analytical ultracentrifugation studies are supported by electron microscopy studies that depict Myo1b as a single-headed, tadpole-shaped molecule with outer dimensions of 27.9 x 4.0 nm. Above a certain Myo1b/actin ratio, Myo1b bundles actin filaments presumably by virtue of a second actin-binding site. These studies provide new information regarding the oligomeric state and morphology of Myo1b and support a model in which Myo1b cross-links actin through a cryptic actin-binding site.
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Affiliation(s)
- Walter F. Stafford
- Boston Biomedical Research Institute, Watertown, Massachusetts; and Asbury Centre for Structural Molecular Biology and School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Matt L. Walker
- Boston Biomedical Research Institute, Watertown, Massachusetts; and Asbury Centre for Structural Molecular Biology and School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - John A. Trinick
- Boston Biomedical Research Institute, Watertown, Massachusetts; and Asbury Centre for Structural Molecular Biology and School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Lynne M. Coluccio
- Boston Biomedical Research Institute, Watertown, Massachusetts; and Asbury Centre for Structural Molecular Biology and School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
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Larsson B, Andersen JL, Kadi F, Björk J, Gerdle B. Myosin heavy chain isoforms influence surface EMG parameters: a study of the trapezius muscle in cleaners with and without myalgia and in healthy teachers. Eur J Appl Physiol 2002; 87:481-8. [PMID: 12355186 DOI: 10.1007/s00421-002-0667-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2002] [Indexed: 11/30/2022]
Abstract
The present study had two aims: (1) to investigate potential differences in proportion of myosin heavy chain isoforms in the trapezius muscle between female cleaners with and without trapezius myalgia and healthy teachers, and (2) to elucidate if myosin heavy chain composition and surface electromyogram (EMG) during an isokinetic endurance test of shoulder flexors are significantly related. The subjects were divided into three groups: (1) 25 female cleaners with diagnosed work-related trapezius myalgia; (2) 25 female cleaners without work-related trapezius myalgia; (3) a control group of 21 healthy female teachers who were not exposed to repetitive or static muscle work. All subjects performed a test involving150 forward flexions using an isokinetic dynamometer. During the test surface EMG was recorded from the trapezius muscle. Muscle samples were obtained from the descending part of the trapezius muscle. The fibre type area percentage based on ATPase staining and the proportions of different MHC isoforms as determined by gel electrophoresis. The trapezius was dominated by MHC I (71%), followed by MHC IIA (22-24%), and MHC IIX (5-7%); no significant differences between the three groups of subjects were found. The proportion of MHC I correlated negatively with MHC IIA ( r=-0.78; P<0.001) and MHC IIX ( r=-0.53; P<0.001). Significant correlations existed between the proportion of the MHC isoforms and the corresponding proportion of the fibre type area; 27-45% of the variance was explained. The multivariate analysis of the three groups of subjects revealed that MHC variables showed intercorrelations with EMG (both amplitude and frequency variables). However, the directions of the relationships differed among the three groups; the cleaners with myalgia and the teachers showed the greatest similarities in patterns. Intrinsic muscle properties appear to influence the frequency content of the EMG, which is in contrast to some of the theoretical models of the EMG. Our data could suggest that monotonous work such as professional cleaning can change the relationships between muscle structure and the frequency content of the EMG.
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Affiliation(s)
- Britt Larsson
- Department of Occupational and Environmental Medicine, University Hospital, Lund, Sweden.
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Pollard TD. A conversation with Thomas D. Pollard. Interview by K. Noelle Gracy. Biochem Biophys Res Commun 2002; 297:6-9. [PMID: 12220500 DOI: 10.1016/s0006-291x(02)02012-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Abstract
The pathogenic yeast Candida albicans can undergo a dramatic change in morphology from round yeast cells to long filamentous cells called hyphae. We have cloned the CaMYO5 gene encoding the only myosin I in C. albicans. A strain with a deletion of both copies of CaMYO5 is viable but cannot form hyphae under all hypha-inducing conditions tested. This mutant exhibits a higher frequency of random budding and a depolarized distribution of cortical actin patches relative to the wild-type strain. We found that polar budding, polarized localization of cortical actin patches, and hypha formation are dependent on a specific phosphorylation site on myosin I, called the "TEDS-rule" site. Mutation of this serine 366 to alanine gives rise to the null mutant phenotype, while a S366D mutation, the product of which mimics a phosphorylated serine, allows hypha formation. However, the S366D mutation still causes a depolarized distribution of cortical actin patches in budding cells, similar to that in the null mutant. The localization of CaMyo5-GFP together with cortical actin patches at the bud and hyphal tips is also dependent on serine 366. Intriguingly, the cortical actin patches in the majority of the hyphae of the mutant expressing Camyo5(S366D) were depolarized, suggesting that although their distribution is dependent on myosin I localization, polarized cortical actin patches may not be required for hypha formation.
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Affiliation(s)
- U Oberholzer
- Genetics Division, Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec H4P 2R2, Canada.
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Affiliation(s)
- Thein Z Win
- Department of Biology, University College London, London, United Kingdom
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Abstract
While human masseter muscle is known to have unusual co-expression of myosin heavy-chain proteins, cellular kinetics of individual fibers has not yet been tested. Here we examine if myosin heavy-chain protein content is closely correlated to fiber-shortening speed, as previously reported in other human muscles, or if these proteins do not correlate well to shortening speeds, as has been demonstrated previously in rat muscle. Slack-test recordings of single, skinned human masseter fibers at 15 degrees C revealed maximum shortening velocities generally slower and much more variable than those recorded in human limb muscle. The slowest fiber recorded had a maximum shortening velocity (V0) value of 0.027 muscle lengths x s(-1), several times slower than the slowest type I fibers previously measured in humans. By contrast, human limb muscle controls produced V0 measurements comparable with previously published results. Analysis by gel electrophoresis found 63% of masseter fibers to contain pure type I MyHC and the remainder to co-express mostly type I in various combinations with IIA and IIX isoforms. V0 in masseter fibers forms a continuum in which no clear relationship to MyHC isoform content is apparent.
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Affiliation(s)
- T. J. Morris
- The Department of Orthodontics & Dentofacial Orthopedics, University of Pittsburgh, 3501 Terrace Street, Pittsburgh, PA 15261-1932
| | - C. A. Brandon
- The Department of Orthodontics & Dentofacial Orthopedics, University of Pittsburgh, 3501 Terrace Street, Pittsburgh, PA 15261-1932
| | - M. J. Horton
- The Department of Orthodontics & Dentofacial Orthopedics, University of Pittsburgh, 3501 Terrace Street, Pittsburgh, PA 15261-1932
| | - D. S. Carlson
- Baylor College of Dentistry, Texas A&M University System Health Science Center
| | - J. J. Sciote
- The Department of Orthodontics & Dentofacial Orthopedics, University of Pittsburgh, 3501 Terrace Street, Pittsburgh, PA 15261-1932
- corresponding author,
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