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Anandachar MS, Roy S, Sinha S, Boadi A, Katkar GD, Ghosh P. Diverse gut pathogens exploit the host engulfment pathway via a conserved mechanism. J Biol Chem 2023; 299:105390. [PMID: 37890785 PMCID: PMC10696401 DOI: 10.1016/j.jbc.2023.105390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/22/2023] [Accepted: 10/15/2023] [Indexed: 10/29/2023] Open
Abstract
Macrophages clear infections by engulfing and digesting pathogens within phagolysosomes. Pathogens escape this fate by engaging in a molecular arms race; they use WxxxE motif-containing "effector" proteins to subvert the host cells they invade and seek refuge within protective vacuoles. Here, we define the host component of the molecular arms race as an evolutionarily conserved polar "hot spot" on the PH domain of ELMO1 (Engulfment and Cell Motility protein 1), which is targeted by diverse WxxxE effectors. Using homology modeling and site-directed mutagenesis, we show that a lysine triad within the "patch" directly binds all WxxxE effectors tested: SifA (Salmonella), IpgB1 and IpgB2 (Shigella), and Map (enteropathogenic Escherichia coli). Using an integrated SifA-host protein-protein interaction network, in silico network perturbation, and functional studies, we show that the major consequences of preventing SifA-ELMO1 interaction are reduced Rac1 activity and microbial invasion. That multiple effectors of diverse structure, function, and sequence bind the same hot spot on ELMO1 suggests that the WxxxE effector(s)-ELMO1 interface is a convergence point of intrusion detection and/or host vulnerability. We conclude that the interface may represent the fault line in coevolved molecular adaptations between pathogens and the host, and its disruption may serve as a therapeutic strategy.
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Affiliation(s)
- Mahitha Shree Anandachar
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, USA; Department of Pathology, University of California San Diego, San Diego, California, USA
| | - Suchismita Roy
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, USA
| | - Saptarshi Sinha
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, USA
| | - Agyekum Boadi
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, USA
| | - Gajanan D Katkar
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, USA.
| | - Pradipta Ghosh
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, USA; Department of Medicine, University of California San Diego, San Diego, California, USA.
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Lee YJ, Choi YS, Kim S, Heo JY, Kim DS, Kim KD, Nam SM, Nam HS, Lee SH, Choi D, Cho MK. Overexpression of Dock180 and Elmo1 in Melanoma is Associated with Cell Survival and Migration. Ann Dermatol 2023; 35:439-450. [PMID: 38086358 PMCID: PMC10733078 DOI: 10.5021/ad.23.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/30/2023] [Accepted: 07/10/2023] [Indexed: 12/22/2023] Open
Abstract
BACKGROUND Melanoma is one of the most aggressive and metastatic skin cancers. Although overexpression of Dock180 and Elmo1 has been identified in various cancers, including glioma, ovarian cancer, and breast cancer, their expression and functions in melanoma remain unknown. OBJECTIVE This study aims to confirm the expression of Dock180 and Elmo1, their underlying mechanisms, and roles in melanoma. METHODS Both immunohistochemical staining and Western blotting were used to confirm expression of Dock180 and Elmo1 in human melanoma. To identify roles of Dock180 and Elmo1 in cell survival, apoptosis and migration, downregulation of Dock180 or Elmo1 in melanoma cells with small interfering RNA (siRNA) was performed. RESULTS We identified overexpression of Dock180 and Elmo1 in human melanoma compared to normal skin ex vivo. Inhibition of Dock180 or Elmo1 following siRNA in melanoma cells reduced cell viability and increased apoptosis as supported by increased proportion of cells with Annexin V-PE (+) staining and sub-G0/G1 peak in cell cycle analysis. Moreover, inhibition of Dock180 or Elmo1 regulated apoptosis-related proteins, showing downregulation of Bcl-2, caspase-3, and PARP and upregulation of Bax, PUMA, cleaved caspase-3, and cleaved PARP. Furthermore, knockdown of Dock180 and Elmo1 in melanoma cells reduced cell migration and changed cellular signaling pathways including ERK and AKT. Vemurafenib decreased cell viability in concentration-dependent manner, while transfection with Dock180- or Elmo1-specific siRNA in melanoma cells significantly reduced cell viability. CONCLUSION Our results suggest that both Dock180 and Elmo1 may be associated with cancer progression, and can be potential targets for treatment of melanoma.
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Affiliation(s)
- Yoon Jin Lee
- Department of Biochemistry, Soonchunhyang University College of Medicine, Cheonan, Korea
| | - Yu Sung Choi
- Department of Dermatology, Soonchunhyang University Seoul Hospital, Seoul, Korea
| | - Sooyoung Kim
- Department of Dermatology, Soonchunhyang University Seoul Hospital, Seoul, Korea
| | - Jae Young Heo
- Department of Dermatology, Soonchunhyang University Seoul Hospital, Seoul, Korea
| | - Dong Sung Kim
- Department of Dermatology, Soonchunhyang University Seoul Hospital, Seoul, Korea
| | - Ki Dam Kim
- Department of Dermatology, Soonchunhyang University Seoul Hospital, Seoul, Korea
| | - Seung Min Nam
- Department of Plastic and Reconstructive Surgery, Soonchunhyang University Bucheon Hospital, Bucheon, Korea
| | - Hae Seon Nam
- Division of Molecular Cancer Research, Soonchunhyang Medical Research Institute, Soonchunhyang University, Cheonan, Korea
| | - Sang Han Lee
- Department of Biochemistry, Soonchunhyang University College of Medicine, Cheonan, Korea
| | - Dongsic Choi
- Department of Biochemistry, Soonchunhyang University College of Medicine, Cheonan, Korea
| | - Moon Kyun Cho
- Department of Dermatology, Soonchunhyang University Seoul Hospital, Seoul, Korea.
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Kim JL, Kim SG, Natsagdorj E, Chung H, Cho SJ. Helicobacter pylori Eradication Can Reverse Rho GTPase Expression in Gastric Carcinogenesis. Gut Liver 2023; 17:741-752. [PMID: 36718103 PMCID: PMC10502497 DOI: 10.5009/gnl220301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/13/2022] [Accepted: 11/23/2022] [Indexed: 02/01/2023] Open
Abstract
Background/Aims Altered DNA methylation is a key mechanism of epigenetic modification in gastric cancer (GC). This study aimed to evaluate the changes in epigenetic and genetic expression of multiple Rho GTPases in Helicobacter pylori-related gastric carcinogenesis by comparing H. pylori-positive GCs and negative controls. Methods The messenger RNA expression and methylation of Rho GTPases (RhoA, Rac1, DOCK180, ELMO1, and CDC42) were evaluated in H. pylori-negative (control) human gastric tissues and H. pylori-positive GCs by using real-time reverse transcription-polymerase chain reaction and the quantitative MethyLight assay, respectively. Changes in expression and methylation levels of the genes were also compared between H. pylori-eradicated and -persistent GCs at 1-year follow-up. Results In GCs, the methylation and expression levels of DOCK180 and ELMO1 were higher than in controls, while RhoA and Rac1 had lower levels than controls. CDC42 had the same expression pattern as DOCK180 and ELMO1 without DNA methylation. Although methylation levels of DOCK180 and ELMO1 had no difference between H. pylori-eradicated and -persistent GCs at the index endoscopic resection, those of H. pylori-persistent GCs increased and H. pylori-eradicated GCs decreased for 1 year. The expression levels of DOCK180, ELMO1, and CDC42 in H. pylori-persistent GCs were higher than those in H. pylori-eradicated GCs over 1 year, unlike those of RhoA and Rac1. The methylation levels at index and the degrees of change over time of RhoA and Rac1 had no difference between H. pylori-persistent and -eradicated GCs. Conclusions Epigenetic alterations of DOCK180 and ELMO1 are involved in H. pylori-related gastric carcinogenesis. This epigenetic field could be improved by H. pylori eradication.
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Affiliation(s)
- Jue Lie Kim
- Department of Internal Medicine, Health Promotion Center, Seoul National University Hospital, Seoul, Korea
| | - Sang Gyun Kim
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Enerelt Natsagdorj
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Hyunsoo Chung
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Soo-Jeong Cho
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
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Anandachar MS, Roy S, Sinha S, Agyekum B, Ibeawuchi SR, Gementera H, Amamoto A, Katkar GD, Ghosh P. Diverse Gut Pathogens Exploit the Host Engulfment Pathway via a Conserved Mechanism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.09.536168. [PMID: 37066267 PMCID: PMC10104235 DOI: 10.1101/2023.04.09.536168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Macrophages clear infections by engulfing and digesting pathogens within phagolysosomes. Pathogens escape this fate by engaging in a molecular arms race; they use WxxxE motif-containing effector proteins to subvert the host cells they invade and seek refuge within protective vacuoles. Here we define the host component of the molecular arms race as an evolutionarily conserved polar hotspot on the PH-domain of ELMO1 (Engulfment and Cell Motility1), which is targeted by diverse WxxxE-effectors. Using homology modeling and site-directed mutagenesis, we show that a lysine triad within the patch directly binds all WxxxE-effectors tested: SifA (Salmonella), IpgB1 and IpgB2 (Shigella), and Map (enteropathogenic E. coli). Using an integrated SifA-host protein-protein interaction (PPI) network, in-silico network perturbation, and functional studies we show that the major consequences of preventing SifA-ELMO1 interaction are reduced Rac1 activity and microbial invasion. That multiple effectors of diverse structure, function, and sequence bind the same hotpot on ELMO1 suggests that the WxxxE-effector(s)-ELMO1 interface is a convergence point of intrusion detection and/or host vulnerability. We conclude that the interface may represent the fault line in co-evolved molecular adaptations between pathogens and the host and its disruption may serve as a therapeutic strategy.
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Variable Distribution of DOCK-D Proteins between Cytosol and Nucleoplasm in Cell Lines, Effect of Interleukin-4 on DOCK10 in B-Cell Lymphoid Neoplasms, and Validation of a New DOCK10 Antiserum for Immunofluorescence Studies. Antibodies (Basel) 2021; 10:antib10030033. [PMID: 34449554 PMCID: PMC8395434 DOI: 10.3390/antib10030033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/28/2021] [Accepted: 08/16/2021] [Indexed: 11/16/2022] Open
Abstract
Dedicator-of-cytokinesis (DOCK), a family of guanine-nucleotide exchange factors (GEFs), comprises four subfamilies, named from A to D. DOCK-D comprises DOCK9, DOCK10, and DOCK11. The GEF activity involves translocation from the cytoplasm to the plasma membrane (PM), as assessed by the transfection of tagged proteins. However, the cellular localization of endogenous DOCK proteins is poorly understood. In this paper, to gain a better understanding of the role of the DOCK-D proteins, we studied their distribution between cytosol and nucleoplasm in 11 cell lines. DOCK-D proteins were distributed with variable cytosolic or nuclear predominance, although the latter was common for DOCK9 and DOCK11. These results suggest that the DOCK-D proteins may perform new nuclear functions, which remain to be discovered. Furthermore, we found that DOCK10 levels are increased by interleukin-4 (IL-4) in B-cell lymphoid neoplasms other than chronic lymphocytic leukemia (CLL) such as mantle cell lymphoma and diffuse large B-cell lymphoma. We also found evidence for an induction of the cytosolic levels of DOCK10 by IL-4 in CLL. Finally, we obtained a valid DOCK10 antiserum for immunofluorescence (IF) microscopy that, as an antibody against the hemagglutinin (HA) tag, marked PM ruffles and filopodia in HeLa cells with inducible expression of HA-DOCK10.
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Kotelevets L, Chastre E. Rac1 Signaling: From Intestinal Homeostasis to Colorectal Cancer Metastasis. Cancers (Basel) 2020; 12:cancers12030665. [PMID: 32178475 PMCID: PMC7140047 DOI: 10.3390/cancers12030665] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/06/2020] [Accepted: 03/08/2020] [Indexed: 12/14/2022] Open
Abstract
The small GTPase Rac1 has been implicated in a variety of dynamic cell biological processes, including cell proliferation, cell survival, cell-cell contacts, epithelial mesenchymal transition (EMT), cell motility, and invasiveness. These processes are orchestrated through the fine tuning of Rac1 activity by upstream cell surface receptors and effectors that regulate the cycling Rac1-GDP (off state)/Rac1-GTP (on state), but also through the tuning of Rac1 accumulation, activity, and subcellular localization by post translational modifications or recruitment into molecular scaffolds. Another level of regulation involves Rac1 transcripts stability and splicing. Downstream, Rac1 initiates a series of signaling networks, including regulatory complex of actin cytoskeleton remodeling, activation of protein kinases (PAKs, MAPKs) and transcription factors (NFkB, Wnt/β-catenin/TCF, STAT3, Snail), production of reactive oxygen species (NADPH oxidase holoenzymes, mitochondrial ROS). Thus, this GTPase, its regulators, and effector systems might be involved at different steps of the neoplastic progression from dysplasia to the metastatic cascade. After briefly placing Rac1 and its effector systems in the more general context of intestinal homeostasis and in wound healing after intestinal injury, the present review mainly focuses on the several levels of Rac1 signaling pathway dysregulation in colorectal carcinogenesis, their biological significance, and their clinical impact.
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Affiliation(s)
- Larissa Kotelevets
- Institut National de la Santé et de la Recherche Médicale, UMR S 938, Centre de Recherche Saint-Antoine, 75012 Paris, France
- Sorbonne Université, Hôpital Saint-Antoine, Site Bâtiment Kourilsky, 75012 Paris, France
- Correspondence: (L.K.); (E.C.)
| | - Eric Chastre
- Institut National de la Santé et de la Recherche Médicale, UMR S 938, Centre de Recherche Saint-Antoine, 75012 Paris, France
- Sorbonne Université, Hôpital Saint-Antoine, Site Bâtiment Kourilsky, 75012 Paris, France
- Correspondence: (L.K.); (E.C.)
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Abdrabou A, Wang Z. Post-Translational Modification and Subcellular Distribution of Rac1: An Update. Cells 2018; 7:cells7120263. [PMID: 30544910 PMCID: PMC6316090 DOI: 10.3390/cells7120263] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/06/2018] [Accepted: 12/10/2018] [Indexed: 12/27/2022] Open
Abstract
Rac1 is a small GTPase that belongs to the Rho family. The Rho family of small GTPases is a subfamily of the Ras superfamily. The Rho family of GTPases mediate a plethora of cellular effects, including regulation of cytoarchitecture, cell size, cell adhesion, cell polarity, cell motility, proliferation, apoptosis/survival, and membrane trafficking. The cycling of Rac1 between the GTP (guanosine triphosphate)- and GDP (guanosine diphosphate)-bound states is essential for effective signal flow to elicit downstream biological functions. The cycle between inactive and active forms is controlled by three classes of regulatory proteins: Guanine nucleotide exchange factors (GEFs), GTPase-activating proteins (GAPs), and guanine-nucleotide-dissociation inhibitors (GDIs). Other modifications include RNA splicing and microRNAs; various post-translational modifications have also been shown to regulate the activity and function of Rac1. The reported post-translational modifications include lipidation, ubiquitination, phosphorylation, and adenylylation, which have all been shown to play important roles in the regulation of Rac1 and other Rho GTPases. Moreover, the Rac1 activity and function are regulated by its subcellular distribution and translocation. This review focused on the most recent progress in Rac1 research, especially in the area of post-translational modification and subcellular distribution and translocation.
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Affiliation(s)
- Abdalla Abdrabou
- Department of Medical Genetics, and Signal Transduction Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
| | - Zhixiang Wang
- Department of Medical Genetics, and Signal Transduction Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
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Cetinkaya A, Xiong J, Vargel İ, Kösemehmetoğlu K, Canter H, Gerdan Ö, Longo N, Alzahrani A, Camps M, Taskiran E, Laupheimer S, Botto L, Paramalingam E, Gormez Z, Uz E, Yuksel B, Ruacan Ş, Sağıroğlu M, Takahashi T, Reversade B, Akarsu N. Loss-of-Function Mutations in ELMO2 Cause Intraosseous Vascular Malformation by Impeding RAC1 Signaling. Am J Hum Genet 2016; 99:299-317. [PMID: 27476657 DOI: 10.1016/j.ajhg.2016.06.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 06/09/2016] [Indexed: 12/16/2022] Open
Abstract
Vascular malformations are non-neoplastic expansions of blood vessels that arise due to errors during angiogenesis. They are a heterogeneous group of sporadic or inherited vascular disorders characterized by localized lesions of arteriovenous, capillary, or lymphatic origin. Vascular malformations that occur inside bone tissue are rare. Herein, we report loss-of-function mutations in ELMO2 (which translates extracellular signals into cellular movements) that are causative for autosomal-recessive intraosseous vascular malformation (VMOS) in five different families. Individuals with VMOS suffer from life-threatening progressive expansion of the jaw, craniofacial, and other intramembranous bones caused by malformed blood vessels that lack a mature vascular smooth muscle layer. Analysis of primary fibroblasts from an affected individual showed that absence of ELMO2 correlated with a significant downregulation of binding partner DOCK1, resulting in deficient RAC1-dependent cell migration. Unexpectedly, elmo2-knockout zebrafish appeared phenotypically normal, suggesting that there might be human-specific ELMO2 requirements in bone vasculature homeostasis or genetic compensation by related genes. Comparative phylogenetic analysis indicated that elmo2 originated upon the appearance of intramembranous bones and the jaw in ancestral vertebrates, implying that elmo2 might have been involved in the evolution of these novel traits. The present findings highlight the necessity of ELMO2 for maintaining vascular integrity, specifically in intramembranous bones.
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Touaitahuata H, Morel A, Urbach S, Mateos-Langerak J, de Rossi S, Blangy A. Tensin 3 is a new partner of Dock5 that controls osteoclast podosome organization and activity. J Cell Sci 2016; 129:3449-61. [PMID: 27505886 DOI: 10.1242/jcs.184622] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 07/25/2016] [Indexed: 12/23/2022] Open
Abstract
Bone resorption by osteoclasts is mediated by a typical adhesion structure called the sealing zone or actin ring, whose architecture is based on a belt of podosomes. The molecular mechanisms driving podosome organization into superstructures remain poorly understood to date, in particular at the osteoclast podosome belt. We performed proteomic analyses in osteoclasts and found that the adaptor protein tensin 3 is a partner of Dock5, a Rac exchange factor necessary for podosome belt formation and bone resorption. Expression of tensin 3 and Dock5 concomitantly increase during osteoclast differentiation. These proteins associate with the osteoclast podosome belt but not with individual podosomes, in contrast to vinculin. Super-resolution microscopy revealed that, even if they colocalize in the x-y plane of the podosome belt, Dock5 and tensin 3 differentially localize relative to vinculin in the z-axis. Tensin 3 increases Dock5 exchange activity towards Rac, and suppression of tensin 3 in osteoclasts destabilizes podosome organization, leading to delocalization of Dock5 and a severe reduction in osteoclast activity. Our results suggest that Dock5 and tensin 3 cooperate for osteoclast activity, to ensure the correct organization of podosomes.
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Affiliation(s)
- Heiani Touaitahuata
- CRBM, Centre de Recherche de Biochimie Macromoléculaire, CNRS UMR 5237, 34000 Montpellier, France Montpellier University, 34000 Montpellier, France
| | - Anne Morel
- CRBM, Centre de Recherche de Biochimie Macromoléculaire, CNRS UMR 5237, 34000 Montpellier, France Montpellier University, 34000 Montpellier, France
| | - Serge Urbach
- Montpellier University, 34000 Montpellier, France Functional Proteomics Platform, Institut de Génomique Fonctionnelle, CNRS UMR 5203, 34000 Montpellier, France
| | - Julio Mateos-Langerak
- Montpellier University, 34000 Montpellier, France Montpellier RIO Imaging, Biocampus UMS3426 CNRS, 34000 Montpellier, France
| | - Sylvain de Rossi
- Montpellier University, 34000 Montpellier, France Montpellier RIO Imaging, Biocampus UMS3426 CNRS, 34000 Montpellier, France
| | - Anne Blangy
- CRBM, Centre de Recherche de Biochimie Macromoléculaire, CNRS UMR 5237, 34000 Montpellier, France Montpellier University, 34000 Montpellier, France
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Valente TS, Baldi F, Sant’Anna AC, Albuquerque LG, Paranhos da Costa MJR. Genome-Wide Association Study between Single Nucleotide Polymorphisms and Flight Speed in Nellore Cattle. PLoS One 2016; 11:e0156956. [PMID: 27300296 PMCID: PMC4907449 DOI: 10.1371/journal.pone.0156956] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 05/23/2016] [Indexed: 12/17/2022] Open
Abstract
Introduction Cattle temperament is an important factor that affects the profitability of beef cattle enterprises, due to its relationship with productivity traits, animal welfare and labor safety. Temperament is a complex phenotype often assessed by measuring a series of behavioral traits, which result from the effects of multiple environmental and genetic factors, and their interactions. The aims of this study were to perform a genome-wide association study and detect genomic regions, potential candidate genes and their biological mechanisms underlying temperament, measured by flight speed (FS) test in Nellore cattle. Materials and Methods The genome-wide association study (GWAS) was performed using a single-step procedure (ssGBLUP) which combined simultaneously all 16,600 phenotypes from genotyped and non-genotyped animals, full pedigree information of 162,645 animals and 1,384 genotyped animals in one step. The animals were genotyped with High Density Bovine SNP BeadChip which contains 777,962 SNP markers. After quality control (QC) a total of 455,374 SNPs remained. Results Heritability estimated for FS was 0.21 ± 0.02. Consecutive SNPs explaining 1% or more of the total additive genetic variance were considered as windows associated with FS. Nine candidate regions located on eight different Bos taurus chromosomes (BTA) (1 at 73 Mb, 2 at 65 Mb, 5 at 22 Mb and 119 Mb, 9 at 98 Mb, 11 at 67 Mb, 15 at 16 Mb, 17 at 63 Kb, and 26 at 47 Mb) were identified. The candidate genes identified in these regions were NCKAP5 (BTA2), PARK2 (BTA9), ANTXR1 (BTA11), GUCY1A2 (BTA15), CPE (BTA17) and DOCK1 (BTA26). Among these genes PARK2, GUCY1A2, CPE and DOCK1 are related to dopaminergic system, memory formation, biosynthesis of peptide hormone and neurotransmitter and brain development, respectively. Conclusions Our findings allowed us to identify nine genomic regions (SNP windows) associated with beef cattle temperament, measured by FS test. Within these windows, six promising candidate genes and their biological functions were identified. These results may contribute to a better comprehension into the genetic control of temperament expression in Nellore cattle.
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Affiliation(s)
- Tiago Silva Valente
- Universidade Estadual Paulista (Unesp), Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia, Via de Acesso Professor Paulo Donato Castellane, Jaboticabal, SP 14.884-900, Brazil
| | - Fernando Baldi
- Universidade Estadual Paulista (Unesp), Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia, Via de Acesso Professor Paulo Donato Castellane, Jaboticabal, SP 14.884-900, Brazil
| | - Aline Cristina Sant’Anna
- Universidade Federal de Juiz de Fora (UFJF), Instituto de Ciências Biológicas, Departamento de Zoologia, Rua José Lourenço Kelmer, Juiz de Fora, MG 36.036-900, Brazil
| | - Lucia Galvão Albuquerque
- Universidade Estadual Paulista (Unesp), Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia, Via de Acesso Professor Paulo Donato Castellane, Jaboticabal, SP 14.884-900, Brazil
| | - Mateus José Rodrigues Paranhos da Costa
- Universidade Estadual Paulista (Unesp), Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia, Via de Acesso Professor Paulo Donato Castellane, Jaboticabal, SP 14.884-900, Brazil
- * E-mail:
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Lee J, Moon B, Lee DH, Lee G, Park D. Identification of a novel protein interaction between Elmo1 and Cdc27. Biochem Biophys Res Commun 2016; 471:497-502. [PMID: 26882976 DOI: 10.1016/j.bbrc.2016.02.046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 02/12/2016] [Indexed: 11/24/2022]
Abstract
Elmo has no intrinsic catalytic activity but coordinate multiple cellular processes via their interactions with other proteins. Studies thus have been focused on identifying Elmo binding partners, but the number of characterized Elmo-interacting proteins remains limited. Here, we report Cdc27 as a novel Elmo1-interacting protein. In yeast and mammalian cells, Cdc27 specifically interacted with the C-terminal region of Elmo1 essential for Dock1 association and function. The interaction of Elmo1 with Dock1 abrogated binding between Elmo1 and Cdc27, but the Dock1-Elmo1 interaction was unaffected by Cdc27. Similarly, cellular phagocytotic functions mediated by the Elmo1-Dock1-Rac module were unaffected by Cdc27 levels. In summary, a novel binding partner, Cdc27, was identified for Elmo1 and they appear to be independent of Elmo-Dock1-Rac-mediated processes.
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Affiliation(s)
- Juyeon Lee
- School of Life Sciences and Bio Imaging Research Center, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea; Research Center for Cellular Homeostasis, Ewha Womans University, Seoul 120-750, Republic of Korea
| | - Byeongjin Moon
- School of Life Sciences and Bio Imaging Research Center, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Dae-Hee Lee
- Department of Surgery and Pharmacology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Gwangrog Lee
- School of Life Sciences and Bio Imaging Research Center, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Daeho Park
- School of Life Sciences and Bio Imaging Research Center, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea; Research Center for Cellular Homeostasis, Ewha Womans University, Seoul 120-750, Republic of Korea.
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Makino Y, Tsuda M, Ohba Y, Nishihara H, Sawa H, Nagashima K, Tanaka S. Tyr724 phosphorylation of ELMO1 by Src is involved in cell spreading and migration via Rac1 activation. Cell Commun Signal 2015. [PMID: 26205662 PMCID: PMC4513707 DOI: 10.1186/s12964-015-0113-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The complex of Dock180/ELMO1 that functions as a bipartite guanine nucleotide exchange factor for Rac is essential for diverse physiological and pathological processes of cells such as cell migration, phagocytosis, and invasion of cancer cells. Among the Src-family tyrosine kinases (SFKs), it has been reported that Hck directly phosphorylates ELMO1, regulating phagocytosis by promoting activation of Rac1; however, the involvement of other SFKs in ELMO1 phosphorylation has remained unknown. Here, we identified novel tyrosine (Y) residues of ELMO1 phosphorylated by SFKs, and examined the effects on Rac1 activity, cell adhesion, spreading, and cell motility on extracellular matrix (ECM). RESULTS In this study, we unveiled that Src and Fyn can induce tyrosine phosphorylation of ELMO1 in in vivo and in vitro phosphorylation assays. Mutational analyses identified both Y720 and Y724 residues of ELMO1 as Src-mediated phosphorylation sites, preferentially on Y724. Single substitution of Y724 to Phe abrogated Rac1 activation triggered by Src. To elucidate the biological function of pY724, we established NIH3T3 cells stably expressing wild-type ELMO1 or its Y724F mutant together with Dock180. Among them, Y724-deficient cells exhibited a depletion of Rac1 activity with diminished phosphorylation of ELMO1 even upon the ECM-stimulation. It is noteworthy that NIH3T3 cells with ELMO1 Y724F were strikingly defective to promote cell spreading on fibronectin-coated dish, concomitantly exhibiting immature assemblies of actin stress fibers and focal adhesions. Eventually, ELMO1 Y724F significantly impaired cell migration. CONCLUSION These results define that Src-mediated Y724 phosphorylation in ELMO1 plays a critical role for cell spreading via activation of Rac1, leading to promotion of cell migration. As the overexpression and/or hyperactivation of Src have been shown in a wide variety of human cancers, Src-mediated phosphorylation of Y724 in ELMO1 may regulate cancer cell adhesion to the ECM, invasion into surrounding tissues, and subsequent distant metastasis.
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Affiliation(s)
- Yoshinori Makino
- Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, 060-8638, Japan. .,Laboratory of Pathology and Development, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.
| | - Masumi Tsuda
- Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, 060-8638, Japan.
| | - Yusuke Ohba
- Department of Cell Physiology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, 060-8638, Japan.
| | - Hiroshi Nishihara
- Department of Translational Pathology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, 060-8638, Japan.
| | - Hirofumi Sawa
- Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, 060-8638, Japan. .,Hokkaido University Research Center for Zoonosis Control, Sapporo, 001-0020, Japan.
| | - Kazuo Nagashima
- Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, 060-8638, Japan. .,Sapporo Higashi Tokushukai Hospital, Sapporo, 065-0033, Japan.
| | - Shinya Tanaka
- Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, 060-8638, Japan. .,Department of Translational Pathology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, 060-8638, Japan.
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Schäker K, Bartsch S, Patry C, Stoll SJ, Hillebrands JL, Wieland T, Kroll J. The bipartite rac1 Guanine nucleotide exchange factor engulfment and cell motility 1/dedicator of cytokinesis 180 (elmo1/dock180) protects endothelial cells from apoptosis in blood vessel development. J Biol Chem 2015; 290:6408-18. [PMID: 25586182 DOI: 10.1074/jbc.m114.633701] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Engulfment and cell motility 1/dedicator of cytokinesis 180 (Elmo1/Dock180) is a bipartite guanine nucleotide exchange factor for the monomeric GTPase Ras-related C3 botulinum toxin substrate 1 (Rac1). Elmo1/Dock180 regulates Rac1 activity in a specific spatiotemporal manner in endothelial cells (ECs) during zebrafish development and acts downstream of the Netrin-1/Unc5-homolog B (Unc5B) signaling cascade. However, mechanistic details on the pathways by which Elmo1/Dock180 regulates endothelial function and vascular development remained elusive. In this study, we aimed to analyze the vascular function of Elmo1 and Dock180 in human ECs and during vascular development in zebrafish embryos. In vitro overexpression of Elmo1 and Dock180 in ECs reduced caspase-3/7 activity and annexin V-positive cell number upon induction of apoptosis. This protective effect of Elmo1 and Dock180 is mediated by activation of Rac1, p21-activated kinase (PAK) and AKT/protein kinase B (AKT) signaling. In zebrafish, Elmo1 and Dock180 overexpression reduced the total apoptotic cell and apoptotic EC number and promoted the formation of blood vessels during embryogenesis. In conclusion, Elmo1 and Dock180 protect ECs from apoptosis by the activation of the Rac1/PAK/AKT signaling cascade in vitro and in vivo. Thus, Elmo1 and Dock180 facilitate blood vessel formation by stabilization of the endothelium during angiogenesis.
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Affiliation(s)
- Kathrin Schäker
- From the Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM) and Division of Vascular Oncology and Metastasis, German Cancer Research Center (DKFZ-ZMBH Alliance), 69120 Heidelberg, Germany, and
| | - Susanne Bartsch
- From the Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM) and
| | - Christian Patry
- From the Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM) and
| | - Sandra J Stoll
- From the Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM) and
| | - Jan-Luuk Hillebrands
- Department of Pathology and Medical Biology, Division of Pathology, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
| | - Thomas Wieland
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim of Heidelberg University, 68167 Mannheim, Germany
| | - Jens Kroll
- From the Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM) and Division of Vascular Oncology and Metastasis, German Cancer Research Center (DKFZ-ZMBH Alliance), 69120 Heidelberg, Germany, and
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Elmo1 helps dock180 to regulate Rac1 activity and cell migration of ovarian cancer. Int J Gynecol Cancer 2015; 24:844-50. [PMID: 24819662 DOI: 10.1097/igc.0000000000000137] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE Engulfment and cell motility 1 (Elmo1) has been reported to cooperate with dedicator of cytokinesis 1 (Dock180) and to be linked to the invasive phenotype of cancer cells through activating small G-protein Rac. We aimed to study the role of Elmo1 in the malignant migration of ovarian cancer. METHODS Engulfment and cell motility 1 expression was evaluated in specimens from 93 patients with serous ovarian cancer (SOC) by immunohistochemical staining. Next, Elmo1-RNAi cells were established by validated small interference RNAs. Cell proliferation and cell motility were observed and compared with Dock180-RNAi cells. To confirm their synergetic contribution to forming focal adhesion and activating Rac1, Rac1-GTP level was measured by GST pull-down assay and immunofluorescence was used to observe focal adhesion formation both in Elmo1-RNAi and Dock180-RNAi cells. RESULTS Engulfment and cell motility 1 was mainly overexpressed in high-grade SOC tissues. Western blot analysis demonstrated that both Elmo1 and Dock180 expressions were hampered in Elmo1-RNAi cells. Compared with the negative control, decreased colony formation and cell invasion were observed in Elmo1-RNAi cells and Dock180-RNAi cells. Consistently, both exhibited reduced Rac1-GTP level and inhibited focal adhesion formation. CONCLUSIONS Engulfment and cell motility 1 presents with synergetic action in helping Dock180 to activate Rac1 and promote cell motility, and thus promote untoward expansion and aggressiveness of SOC.
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Namekata K, Kimura A, Kawamura K, Harada C, Harada T. Dock GEFs and their therapeutic potential: neuroprotection and axon regeneration. Prog Retin Eye Res 2014; 43:1-16. [PMID: 25016980 DOI: 10.1016/j.preteyeres.2014.06.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 06/26/2014] [Accepted: 06/30/2014] [Indexed: 12/17/2022]
Abstract
The dedicator of cytokinesis (Dock) family is composed of atypical guanine exchange factors (GEFs) that activate the Rho GTPases Rac1 and Cdc42. Rho GTPases are best documented for their roles in actin polymerization and they regulate important cellular functions, including morphogenesis, migration, neuronal development, and cell division and adhesion. To date, 11 Dock family members have been identified and their roles have been reported in diverse contexts. There has been increasing interest in elucidating the roles of Dock proteins in recent years and studies have revealed that they are potential therapeutic targets for various diseases, including glaucoma, Alzheimer's disease, cancer, attention deficit hyperactivity disorder and combined immunodeficiency. Among the Dock proteins, Dock3 is predominantly expressed in the central nervous system and recent studies have revealed that Dock3 plays a role in protecting retinal ganglion cells from neurotoxicity and oxidative stress as well as in promoting optic nerve regeneration. In this review, we discuss the current understanding of the 11 Dock GEFs and their therapeutic potential, with a particular focus on Dock3 as a novel target for the treatment of glaucoma and other neurodegenerative diseases.
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Affiliation(s)
- Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Atsuko Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Kazuto Kawamura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Chikako Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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16
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Stevenson C, de la Rosa G, Anderson CS, Murphy PS, Capece T, Kim M, Elliott MR. Essential role of Elmo1 in Dock2-dependent lymphocyte migration. THE JOURNAL OF IMMUNOLOGY 2014; 192:6062-70. [PMID: 24821968 DOI: 10.4049/jimmunol.1303348] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Elmo1 and Elmo2 are highly homologous cytoplasmic adaptor proteins that interact with Dock family guanine nucleotide exchange factors to promote activation of the small GTPase Rac. In T lymphocytes, Dock2 is essential for CCR7- and CXCR4-dependent Rac activation and chemotaxis, but the role of Elmo proteins in regulating Dock2 function in primary T cells is not known. In this article, we show that endogenous Elmo1, but not Elmo2, interacts constitutively with Dock2 in mouse and human primary T cells. CD4(+) T cells from Elmo1(-/-) mice were profoundly impaired in polarization, Rac activation, and chemotaxis in response to CCR7 and CXCR4 stimulation. Transfection of full-length Elmo1, but not Elmo2 or a Dock2-binding mutant of Elmo1, rescued defective migration of Elmo1(-/-) T cells. Interestingly, Dock2 protein levels were reduced by 4-fold in Elmo1(-/-) lymphocytes despite normal levels of Dock2 mRNA. Dock2 polyubiquitination was increased in Elmo1(-/-) T cells, and treatment with proteasome inhibitors partially restored Dock2 levels in Elmo1(-/-) T cells. Finally, we show that Dock2 is directly ubiquitinated in CD4(+) T cells and that Elmo1 expression in heterologous cells inhibits ubiquitination of Dock2. Taken together, these findings reveal a previously unknown, nonredundant role for Elmo1 in controlling Dock2 levels and Dock2-dependent T cell migration in primary lymphocytes. Inhibition of Dock2 has therapeutic potential as a means to control recruitment of pathogenic lymphocytes in diseased tissues. This work provides valuable insights into the molecular regulation of Dock2 by Elmo1 that can be used to design improved inhibitors that target the Elmo-Dock-Rac signaling complex.
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Affiliation(s)
- Catherine Stevenson
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642; and David H. Smith Center for Vaccine Biology and Imunology, University of Rochester Medical Center, Rochester, NY 14642
| | - Gonzalo de la Rosa
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642; and David H. Smith Center for Vaccine Biology and Imunology, University of Rochester Medical Center, Rochester, NY 14642
| | - Christopher S Anderson
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642; and David H. Smith Center for Vaccine Biology and Imunology, University of Rochester Medical Center, Rochester, NY 14642
| | - Patrick S Murphy
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642; and David H. Smith Center for Vaccine Biology and Imunology, University of Rochester Medical Center, Rochester, NY 14642
| | - Tara Capece
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642; and David H. Smith Center for Vaccine Biology and Imunology, University of Rochester Medical Center, Rochester, NY 14642
| | - Minsoo Kim
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642; and David H. Smith Center for Vaccine Biology and Imunology, University of Rochester Medical Center, Rochester, NY 14642
| | - Michael R Elliott
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642; and David H. Smith Center for Vaccine Biology and Imunology, University of Rochester Medical Center, Rochester, NY 14642
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17
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Mauldin JP, Lu M, Das S, Park D, Ernst PB, Ravichandran KS. A link between the cytoplasmic engulfment protein Elmo1 and the Mediator complex subunit Med31. Curr Biol 2012; 23:162-7. [PMID: 23273896 DOI: 10.1016/j.cub.2012.11.049] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 10/29/2012] [Accepted: 11/26/2012] [Indexed: 01/06/2023]
Abstract
The cytoplasmic Elmo1:Dock180 complex acts as a guanine nucleotide exchange factor (GEF) for the small GTPase Rac and functions downstream of the phagocytic receptor BAI1 during apoptotic cell clearance, and in the entry of Salmonella and Shigella into cells. We discovered an unexpected binding between Elmo1 and the Mediator complex subunit Med31. The Mediator complex is a regulatory hub for nearly all gene transcription via RNA polymerase II, bridging the general transcription machinery with gene-specific regulatory proteins. Med31 is the smallest and the most evolutionarily conserved Mediator subunit, and knockout of Med31 results in embryonic lethality in mice; however, Med31 function in specific biological contexts is poorly understood. We observed that in primary macrophages, during Salmonella infection, Elmo1 and Med31 specifically affected expression of the cytokine genes Il10 and Il33 among the >25 genes monitored. Although endogenous Med31 is predominantly nuclear localized, Elmo1 increased the cytoplasmic localization of Med31. We identify ubiquitination as a novel posttranslational modification of Med31, with the cytoplasmic monoubiquitinated form of Med31 being enhanced by Elmo1. These data identify Elmo1 as a novel regulator of Med31, revealing a previously unrecognized link between cytoplasmic signaling proteins and the Mediator complex.
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Affiliation(s)
- Joshua P Mauldin
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, USA
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18
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Abstract
The dynamics of the actin cytoskeleton and its regulation by Rho GTPases are essential to maintain cell shape, to allow cell motility and are also critical during cell cycle progression and mitosis. Rho GTPases and their effectors are involved in cell rounding at mitosis onset, in chromosomes alignment and are required for contraction of the actomyosin ring that separates daughter cells at the end of mitosis. Recent studies have revealed how a number of nucleotide exchange factors and GTPase-activating proteins regulate the activity of Rho GTPases during these processes. This review will focus on how the cell cycle machinery, in turn, regulates expression of proteins in the Rho signaling pathways through transcriptional activation, ubiquitylation and proteasomal degradation and modulates their activity through phosphorylation by mitotic kinases.
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Affiliation(s)
- Muriel David
- Inserm U749, Institut Gustave Roussy, Villejuif, France
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19
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Zhao F, Siu MKY, Jiang L, Tam KF, Ngan HYS, Le XF, Wong OGW, Wong ESY, Chan HY, Cheung ANY. Overexpression of dedicator of cytokinesis I (Dock180) in ovarian cancer correlated with aggressive phenotype and poor patient survival. Histopathology 2011; 59:1163-72. [DOI: 10.1111/j.1365-2559.2011.04045.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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20
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Patel M, Pelletier A, Côté JF. Opening up on ELMO regulation: New insights into the control of Rac signaling by the DOCK180/ELMO complex. Small GTPases 2011; 2:268-275. [PMID: 22292130 DOI: 10.4161/sgtp.2.5.17716] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 08/12/2011] [Indexed: 11/19/2022] Open
Abstract
GTPases are central hubs for directing cytoskeletal reorganization and cell migration. The DOCK family enforces positive regulation of certain GTPases, leading to their activation in discrete areas of the cell. ELMO, a well-known DOCK180 binding partner, has been cast with the role of potentiating DOCK180-mediated Rac activation. Exactly how ELMO contributes to Rac signaling is only beginning to be understood. Here, we discuss our most recent research investigating ELMO regulation of the DOCK180/Rac pathway. Interestingly, we found that ELMO is autoinhibited via intramolecular contacts at basal levels and we explore the novel domains that we identified at the heart of the auto-regulatory switch. We propose that the closed ELMO molecule masks protein-protein interfaces or domains with novel uncharacterized function; cell stimulation and GTPase binding to ELMO is proposed to activate (open) the protein and/or target the ELMO/DOCK180 complex to the cell membrane. In this manner, promiscuous signaling/activity downstream of ELMO/DOCK180 can be controlled for both spatially and temporally. Additionally, we report new data highlighting that DOCK proteins can form heterodimers, and we discuss possible mechanisms that could be implicated in controlling the ELMO activation state.
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Affiliation(s)
- Manishha Patel
- Institut de Recherches Cliniques de Montréal (IRCM); Montréal, Canada
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21
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Biersmith B, Liu Z, Bauman K, Geisbrecht ER. The DOCK protein sponge binds to ELMO and functions in Drosophila embryonic CNS development. PLoS One 2011; 6:e16120. [PMID: 21283588 PMCID: PMC3026809 DOI: 10.1371/journal.pone.0016120] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2010] [Accepted: 12/08/2010] [Indexed: 12/15/2022] Open
Abstract
Cell morphogenesis, which requires rearrangement of the actin cytoskeleton, is
essential to coordinate the development of tissues such as the musculature and
nervous system during normal embryonic development. One class of signaling
proteins that regulate actin cytoskeletal rearrangement is the evolutionarily
conserved CDM (C. elegansCed-5, human DOCK180,
DrosophilaMyoblast city, or Mbc) family of proteins, which function
as unconventional guanine nucleotide exchange factors for the small GTPase Rac.
This CDM-Rac protein complex is sufficient for Rac activation, but is enhanced
upon the association of CDM proteins with the ELMO/Ced-12 family of proteins. We
identified and characterized the role of Drosophila Sponge
(Spg), the vertebrate DOCK3/DOCK4 counterpart as an ELMO-interacting protein.
Our analysis shows Spg mRNA and protein is expressed in the visceral musculature
and developing nervous system, suggesting a role for Spg in later embryogenesis.
As maternal null mutants of spg die early in development, we
utilized genetic interaction analysis to uncover the role of Spg in central
nervous system (CNS) development. Consistent with its role in ELMO-dependent
pathways, we found genetic interactions with spg and
elmo mutants exhibited aberrant axonal defects. In
addition, our data suggests Ncad may be responsible for recruiting Spg to the
membrane, possibly in CNS development. Our findings not only characterize the
role of a new DOCK family member, but help to further understand the role of
signaling downstream of N-cadherin in neuronal development.
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Affiliation(s)
- Bridget Biersmith
- Division of Cell Biology and Biophysics, School of Biological Sciences,
University of Missouri, Kansas City, Missouri, United States of
America
- Ph.D. Program, School of Biological Sciences, University of Missouri,
Kansas City, Missouri, United States of America
| | - Ze Liu
- Division of Cell Biology and Biophysics, School of Biological Sciences,
University of Missouri, Kansas City, Missouri, United States of
America
- Ph.D. Program, School of Biological Sciences, University of Missouri,
Kansas City, Missouri, United States of America
| | - Kenneth Bauman
- Division of Cell Biology and Biophysics, School of Biological Sciences,
University of Missouri, Kansas City, Missouri, United States of
America
| | - Erika R. Geisbrecht
- Division of Cell Biology and Biophysics, School of Biological Sciences,
University of Missouri, Kansas City, Missouri, United States of
America
- * E-mail:
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22
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Koivusalo M, Welch C, Hayashi H, Scott CC, Kim M, Alexander T, Touret N, Hahn KM, Grinstein S. Amiloride inhibits macropinocytosis by lowering submembranous pH and preventing Rac1 and Cdc42 signaling. ACTA ACUST UNITED AC 2010; 188:547-63. [PMID: 20156964 PMCID: PMC2828922 DOI: 10.1083/jcb.200908086] [Citation(s) in RCA: 646] [Impact Index Per Article: 46.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Inhibitors of Na+/H+ exchange proteins block macropinocytosis by lowering the pH near the plasma membrane, which in turn inhibits actin remodeling by Rho family GTPases. Macropinocytosis is differentiated from other types of endocytosis by its unique susceptibility to inhibitors of Na+/H+ exchange. Yet, the functional relationship between Na+/H+ exchange and macropinosome formation remains obscure. In A431 cells, stimulation by EGF simultaneously activated macropinocytosis and Na+/H+ exchange, elevating cytosolic pH and stimulating Na+ influx. Remarkably, although inhibition of Na+/H+ exchange by amiloride or HOE-694 obliterated macropinocytosis, neither cytosolic alkalinization nor Na+ influx were required. Instead, using novel probes of submembranous pH, we detected the accumulation of metabolically generated acid at sites of macropinocytosis, an effect counteracted by Na+/H+ exchange and greatly magnified when amiloride or HOE-694 were present. The acidification observed in the presence of the inhibitors did not alter receptor engagement or phosphorylation, nor did it significantly depress phosphatidylinositol-3-kinase stimulation. However, activation of the GTPases that promote actin remodelling was found to be exquisitely sensitive to the submembranous pH. This sensitivity confers to macropinocytosis its unique susceptibility to inhibitors of Na+/H+ exchange.
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Affiliation(s)
- Mirkka Koivusalo
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
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Miyamoto Y, Yamauchi J. Cellular signaling of Dock family proteins in neural function. Cell Signal 2009; 22:175-82. [PMID: 19796679 DOI: 10.1016/j.cellsig.2009.09.036] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 08/24/2009] [Accepted: 09/13/2009] [Indexed: 12/11/2022]
Abstract
Dock180-related proteins are genetically conserved from Drosophila and C. elegans to mammals and are atypical types of guanine-nucleotide exchange factors (GEFs) for Rac and/or Cdc42 of small GTPases of the Rho family. Eleven members of the family occur in mammalian cells, each playing key roles in many aspects of essential cellular functions such as regulation of cytoskeletal organization, phagocytosis, cell migration, polarity formation, and differentiation. This review will summarize the newly accumulated findings concerning the Dock180-related proteins' molecular and cellular functions, emphasizing the roles of these proteins in neuronal cells and glial cells as well as their interactions in the central and peripheral nervous systems.
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Affiliation(s)
- Yuki Miyamoto
- Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo, Japan
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Kiyokawa E, Matsuda M. Regulation of focal adhesion and cell migration by ANKRD28-DOCK180 interaction. Cell Adh Migr 2009; 3:281-4. [PMID: 19458477 DOI: 10.4161/cam.3.3.8857] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
DOCK180 is an atypical guanine nucleotide exchange factor of Rac1 identified originally as one of the two major proteins bound to the SH3 domain of the Crk adaptor protein. DOCK180 induces tyrosine phosphorylation of p130(Cas), and recruits the Crk-p130(Cas) complex to focal adhesions. Recently, we searched for DOCK180-binding proteins with a nano-LC/MS/MS system, and found that ANKRD28, a protein with twenty-six ankyrin domain-repeats, interacts with the SH3 domain of DOCK180. Knockdown of ANKRD28 reduced the migration velocity and altered the distribution of focal adhesion proteins such as Crk, paxillin and p130(Cas). On the other hand, the expression of ANKRD28, p130(Cas), Crk and DOCK180 induced hyper-phosphorylation of p130(Cas), which paralleled the induction of multiple long cellular processes. Depletion of ELMO, another protein bound to the SH3 domain of DOCK180, also retarded cell migration, but its expression together with p130(Cas), Crk and DOCK180 induced extensive lamellipodial protrusion around the entire circumference without 130(Cas) hyperphosphorylation. These data suggest the dual modes of DOCK180-Rac regulation for cell migration.
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Affiliation(s)
- Etsuko Kiyokawa
- Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan.
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Watanabe T, Tsuda M, Makino Y, Konstantinou T, Nishihara H, Majima T, Minami A, Feller SM, Tanaka S. Crk adaptor protein-induced phosphorylation of Gab1 on tyrosine 307 via Src is important for organization of focal adhesions and enhanced cell migration. Cell Res 2009; 19:638-50. [PMID: 19350053 DOI: 10.1038/cr.2009.40] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Upon growth factor stimulation, the scaffold protein, Gab1, is tyrosine phosphorylated and subsequently the adaptor protein, Crk, transmits signals from Gab1. We have previously shown that Crk overexpression, which is detectable in various human cancers, induces tyrosine phosphorylation of Gab1 without extracellular stimuli. In the present study, the underlying mechanisms were further investigated. Mutational analyses of CrkII demonstrated that the SH2 domain, but not the SH3(N) or the regulatory Y221 residue of CrkII, is critical for the induction of Gab1-Y307 phosphorylation. SH2 mutation of CrkII also decreased the interaction with Gab1. In GST pull-down assay, Crk-SH2 bound to wild-type Gab1, whereas Crk-SH3(N) interacted with the Gab1 mutant, which lacks the clustered tyrosine region (residues 242-410). Tyrosine phosphorylation of Gab1 was induced by all Crk family proteins, but not other SH2-containing signalling adaptors. Src-family kinase inhibitor, PP2, abrogates Crk-induced tyrosine phosphorylations of Gab1. Y307 phosphorylation was undetectable in fibroblasts lacking Src, Yes, and Fyn, even upon overexpression of Crk, whereas cells lacking only Yes and Fyn still contained Gab1 with phosphorylated Y307. Furthermore, Crk induced the phosphorylation of Src-Y416; accordingly the interaction between Crk and Csk was increased. The Gab1-Y307F mutant failed to localize near the plasma membrane even upon HGF stimulation and decreased cell migration. Moreover, Gab1-Y307F disturbed the localization of Crk, FAK, and paxillin, which are the typical components of focal adhesions. Taken together, these results indicate that Crk facilitates tyrosine phosphorylation of Gab1-Y307 through Src, contributing to the organization of focal adhesions and enhanced cell migration, thereby possibly promoting human cancer development.
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Affiliation(s)
- Takuya Watanabe
- Laboratory of Molecular and Cellular Pathology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo 060-8638, Japan
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26
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Birge RB, Kalodimos C, Inagaki F, Tanaka S. Crk and CrkL adaptor proteins: networks for physiological and pathological signaling. Cell Commun Signal 2009; 7:13. [PMID: 19426560 PMCID: PMC2689226 DOI: 10.1186/1478-811x-7-13] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Accepted: 05/10/2009] [Indexed: 01/24/2023] Open
Abstract
The Crk adaptor proteins (Crk and CrkL) constitute an integral part of a network of essential signal transduction pathways in humans and other organisms that act as major convergence points in tyrosine kinase signaling. Crk proteins integrate signals from a wide variety of sources, including growth factors, extracellular matrix molecules, bacterial pathogens, and apoptotic cells. Mounting evidence indicates that dysregulation of Crk proteins is associated with human diseases, including cancer and susceptibility to pathogen infections. Recent structural work has identified new and unusual insights into the regulation of Crk proteins, providing a rationale for how Crk can sense diverse signals and produce a myriad of biological responses.
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Affiliation(s)
- Raymond B Birge
- Department of Biochemistry & Molecular Biology, UMDNJ-New Jersey Medical School, 185 South Orange Ave, Newark, NJ 07103, USA.
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27
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Ueda S, Fujimoto S, Hiramoto K, Negishi M, Katoh H. Dock4 regulates dendritic development in hippocampal neurons. J Neurosci Res 2009; 86:3052-61. [PMID: 18615735 DOI: 10.1002/jnr.21763] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Dendrite development is required for establishing proper neuronal connectivity. Rho-family small GTPases have been reported to play important roles in the regulation of dendritic growth and morphology. However, the molecular mechanisms that control the activities of Rho GTPases in developing dendrites are not well understood. In the present study we found Dock4, an activator of the small GTPase Rac, to have a role in regulating dendritic growth and branching in rat hippocampal neurons. Dock4 is highly expressed in the developing rat brain, predominantly in hippocampal neurons. In dissociated cultured hippocampal neurons, the expression of Dock4 protein is up-regulated after between 3 and 8 days in culture, when dendrites begin to grow. Knockdown of endogenous Dock4 results in reduced dendritic growth and branching. Conversely, overexpression of Dock4 with its binding partner ELMO2 enhances the numbers of dendrites and dendritic branches. These morphological effects elicited by Dock4 and ELMO2 require Rac activation and the C-terminal Crk-binding region of Dock4. Indeed, Dock4 forms a complex with ELMO2 and CrkII in hippocampal neurons. These findings demonstrate a new function of the Rac activator Dock4 in dendritic morphogenesis in hippocampal neurons.
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Affiliation(s)
- Shuhei Ueda
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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28
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Tachibana M, Kiyokawa E, Hara S, Iemura SI, Natsume T, Manabe T, Matsuda M. Ankyrin repeat domain 28 (ANKRD28), a novel binding partner of DOCK180, promotes cell migration by regulating focal adhesion formation. Exp Cell Res 2008; 315:863-76. [PMID: 19118547 DOI: 10.1016/j.yexcr.2008.12.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 12/01/2008] [Accepted: 12/03/2008] [Indexed: 01/17/2023]
Abstract
DOCK180 is a guanine exchange factor of Rac1 originally identified as a protein bound to an SH3 domain of the Crk adaptor protein. DOCK180 induces tyrosine phosphorylation of p130(Cas), and recruits the Crk-p130(Cas) complex to focal adhesions. To understand the role of DOCK180 in cell adhesion and migration, we searched for DOCK180-binding proteins with a nano-LC/MS/MS system, and identified ANKRD28, a protein that contains twenty-six ankyrin domain repeats. Knockdown of ANKRD28 by RNA interference reduced the velocity of migration of HeLa cells, suggesting that this protein plays a physiologic role in the DOCK180-Rac1 signaling pathway. Furthermore, knockdown of ANKRD28 was found to alter the distribution of focal adhesion proteins such as Crk, paxillin, and p130(Cas). On the other hand, expression of ANKRD28, p130(Cas), Crk, and DOCK180 induced hyper-phosphorylation of p130(Cas), and impaired detachment of the cell membrane during migration. Consequently, cells expressing ANKRD28 exhibited multiple long cellular processes. ANKRD28 associated with DOCK180 in an SH3-dependent manner and competed with ELMO, another protein bound to the SH3 domain of DOCK180. In striking contrast to ANKRD28, overexpression of ELMO induced extensive lamellipodial protrusion around the entire circumference. These data suggest that ANKRD28 specifies the localization and the activity of the DOCK180-Rac1 pathway.
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Affiliation(s)
- Mitsuhiro Tachibana
- Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
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29
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Elliott MR, Ravichandran KS. Pallbearer and friends: lending a hand in apoptotic cell clearance. Trends Cell Biol 2008; 18:95-7. [PMID: 18280734 DOI: 10.1016/j.tcb.2007.12.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Revised: 12/19/2007] [Accepted: 12/20/2007] [Indexed: 10/22/2022]
Abstract
Engulfment and prompt removal of apoptotic cells occurs from embryogenesis throughout the lifespan of multicellular organisms. A new player, Pallbearer, has recently been identified in Drosophila as being important for efficient engulfment by macrophages. Pallbearer is a component of the SCF E3 ubiquitin ligase complex involved in the ubiquitylation of proteins targeted for proteasomal degradation. This work provides the first link between the cellular processes of ubiquitylation/proteasomal degradation and the ability to clear apoptotic cells efficiently.
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Affiliation(s)
- Michael R Elliott
- Carter Immunology Center and the Department of Microbiology, University of Virginia, Charlottesville, VA 22908, USA
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30
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Geisbrecht ER, Haralalka S, Swanson SK, Florens L, Washburn MP, Abmayr SM. Drosophila ELMO/CED-12 interacts with Myoblast city to direct myoblast fusion and ommatidial organization. Dev Biol 2008; 314:137-49. [PMID: 18163987 PMCID: PMC2697615 DOI: 10.1016/j.ydbio.2007.11.022] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2007] [Revised: 11/07/2007] [Accepted: 11/17/2007] [Indexed: 10/22/2022]
Abstract
Members of the CDM (CED-5, Dock180, Myoblast city) superfamily of guanine nucleotide exchange factors function in diverse processes that include cell migration and myoblast fusion. Previous studies have shown that the SH3, DHR1 and DHR2 domains of Myoblast city (MBC) are essential for it to direct myoblast fusion in the Drosophila embryo, while the conserved DCrk-binding proline rich region is expendable. Herein, we describe the isolation of Drosophila ELMO/CED-12, an approximately 82 kDa protein with a pleckstrin homology (PH) and proline-rich domain, by interaction with the MBC SH3 domain. Mass spectrometry confirms the presence of an MBC/ELMO complex within the embryonic musculature at the time of myoblast fusion and embryos maternally and/or zygotically mutant for elmo exhibit defects in myoblast fusion. Overexpression of MBC and ELMO in the embryonic mesoderm causes defects in myoblast fusion reminiscent of those seen with constitutively-activated Rac1, supporting the previous finding that both the absence of and an excess of Rac activity are deleterious to myoblast fusion. Overexpression of MBC and ELMO/CED-12 in the eye causes perturbations in ommatidial organization that are suppressed by mutations in Rac1 and Rac2, demonstrating genetically that MBC and ELMO/CED-12 cooperate to activate these small GTPases in Drosophila.
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Affiliation(s)
- Erika R. Geisbrecht
- Stowers Institute for Medical Research, 1000 E. 50 St, Kansas City, MO 64110 USA
| | - Shruti Haralalka
- Stowers Institute for Medical Research, 1000 E. 50 St, Kansas City, MO 64110 USA
| | - Selene K. Swanson
- Proteomics core facility, Stowers Institute for Medical Research, 1000 E. 50 St, Kansas City, MO 64110 USA
| | - Laurence Florens
- Proteomics core facility, Stowers Institute for Medical Research, 1000 E. 50 St, Kansas City, MO 64110 USA
| | - Mike P. Washburn
- Proteomics core facility, Stowers Institute for Medical Research, 1000 E. 50 St, Kansas City, MO 64110 USA
| | - Susan M. Abmayr
- Stowers Institute for Medical Research, 1000 E. 50 St, Kansas City, MO 64110 USA
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31
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Ravichandran KS, Lorenz U. Engulfment of apoptotic cells: signals for a good meal. Nat Rev Immunol 2007; 7:964-74. [PMID: 18037898 DOI: 10.1038/nri2214] [Citation(s) in RCA: 491] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The clearance of apoptotic cells by phagocytes is an integral component of normal life, and defects in this process can have significant implications for self tolerance and autoimmunity. Recent studies have provided new insights into the engulfment process, including how phagocytes seek apoptotic cells, how they recognize and ingest these targets and how they maintain cellular homeostasis after the 'meal'. Several new factors that regulate engulfment have been identified, whereas the roles of some of the older players require revision. This Review focuses on these recent developments and attempts to highlight some of the important questions in this field.
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Affiliation(s)
- Kodi S Ravichandran
- Carter Immunology Center and the Department of Microbiology, University of Virginia, Charlottesville, Virginia, 22908, USA.
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32
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Kinchen JM, Ravichandran KS. Journey to the grave: signaling events regulating removal of apoptotic cells. J Cell Sci 2007; 120:2143-9. [PMID: 17591687 DOI: 10.1242/jcs.03463] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Programmed cell death is critical both for organ formation during development and during adult life, when billions of cells must be removed every day. The culmination of the apoptotic process is the specific recognition and engulfment of the apoptotic cell by a phagocyte. A number of recent studies have revealed a series of evolutionarily conserved proteins that link corpse recognition to membrane movement, facilitating the internalization of the target and its subsequent degradation. Two potential signaling modules have been identified: one involving the CED-12/ELMO and CED-5/Dock180 proteins, which function as a bipartite guanine nucleotide exchange factor (GEF) for Rac1, and a second involving CED-1/LRP1 (a potential engulfment receptor) and the adaptor protein CED-6/GULP. Recognition of the apoptotic cell modulates cytokine secretion by the phagocyte, resulting in an anti-inflammatory state distinct from that induced by necrotic cells. The recent molecular delineation of the phagocytic process and the identification of novel signaling proteins involved in engulfment have provided an exciting new platform for future studies into this biologically important process.
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Affiliation(s)
- Jason M Kinchen
- Beirne Carter Center for Immunology Research, University of Virginia, Charlottesville, VA 22908, USA
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33
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Jarzynka MJ, Hu B, Hui KM, Bar-Joseph I, Gu W, Hirose T, Haney LB, Ravichandran KS, Nishikawa R, Cheng SY. ELMO1 and Dock180, a bipartite Rac1 guanine nucleotide exchange factor, promote human glioma cell invasion. Cancer Res 2007; 67:7203-11. [PMID: 17671188 PMCID: PMC2867339 DOI: 10.1158/0008-5472.can-07-0473] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A distinct feature of malignant gliomas is the intrinsic ability of single tumor cells to disperse throughout the brain, contributing to the failure of existing therapies to alter the progression and recurrence of these deadly brain tumors. Regrettably, the mechanisms underlying the inherent invasiveness of glioma cells are poorly understood. Here, we report for the first time that engulfment and cell motility 1 (ELMO1) and dedicator of cytokinesis 1 (Dock180), a bipartite Rac1 guanine nucleotide exchange factor (GEF), are evidently linked to the invasive phenotype of glioma cells. Immunohistochemical analysis of primary human glioma specimens showed high expression levels of ELMO1 and Dock180 in actively invading tumor cells in the invasive areas, but not in the central regions of these tumors. Elevated expression of ELMO1 and Dock180 was also found in various human glioma cell lines compared with normal human astrocytes. Inhibition of endogenous ELMO1 and Dock180 expression significantly impeded glioma cell invasion in vitro and in brain tissue slices with a concomitant reduction in Rac1 activation. Conversely, exogenous expression of ELMO1 and Dock180 in glioma cells with low level endogenous expression increased their migratory and invasive capacity in vitro and in brain tissue. These data suggest that the bipartite GEF, ELMO1 and Dock180, play an important role in promoting cancer cell invasion and could be potential therapeutic targets for the treatment of diffuse malignant gliomas.
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Affiliation(s)
- Michael J. Jarzynka
- Cancer Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Bo Hu
- Cancer Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Kwok-Min Hui
- Cancer Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Ifat Bar-Joseph
- Cancer Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Weisong Gu
- Ohio Supercomputer Center-Springfield, Springfield, Ohio
| | - Takanori Hirose
- Department of Pathology, Saitama Medical University, Moroyama-machi, Iruma-gun, Saitama, Japan
| | - Lisa B. Haney
- Beirne Carter Center for Immunology Research and Department of Microbiology, University of Virginia, Charlottesville, Virginia
| | - Kodi S. Ravichandran
- Beirne Carter Center for Immunology Research and Department of Microbiology, University of Virginia, Charlottesville, Virginia
| | - Ryo Nishikawa
- Department of Neurosurgery, Saitama Medical University, Moroyama-machi, Iruma-gun, Saitama, Japan
| | - Shi-Yuan Cheng
- Cancer Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
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34
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Côté JF, Vuori K. GEF what? Dock180 and related proteins help Rac to polarize cells in new ways. Trends Cell Biol 2007; 17:383-93. [PMID: 17765544 PMCID: PMC2887429 DOI: 10.1016/j.tcb.2007.05.001] [Citation(s) in RCA: 252] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Revised: 05/23/2007] [Accepted: 05/23/2007] [Indexed: 11/21/2022]
Abstract
Rho GTPase activation, which is mediated by guanine nucleotide exchange factors (GEFs), is tightly regulated in time and space. Although Rho GTPases have a significant role in many biological events, they are best known for their ability to restructure the actin cytoskeleton profoundly through the activation of specific downstream effectors. Two distinct families of GEFs for Rho GTPases have been reported so far, based on the features of their catalytic domains: firstly, the classical GEFs, which contain a Dbl homology-pleckstrin homology domain module with GEF activity, and secondly, the Dock180-related GEFs, which contain a Dock homology region-2 domain that catalyzes guanine nucleotide exchange on Rho GTPases. Recent exciting data suggest key roles for the DHR-2 domain-containing GEFs in a wide variety of fundamentally important biological functions, including cell migration, phagocytosis of apoptotic cells, myoblast fusion and neuronal polarization.
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Affiliation(s)
- Jean-François Côté
- Cytoskeletal Organization and Cell Migration Laboratory, Institut de Recherches Cliniques de Montréal, Université de Montréal, 110 Pine Avenue West, Montréal, PQ H2W1R7, Canada.
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