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Cebecauer M. Role of Lipids in Morphogenesis of T-Cell Microvilli. Front Immunol 2021; 12:613591. [PMID: 33790891 PMCID: PMC8006438 DOI: 10.3389/fimmu.2021.613591] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 01/13/2021] [Indexed: 11/13/2022] Open
Abstract
T cells communicate with the environment via surface receptors. Cooperation of surface receptors regulates T-cell responses to diverse stimuli. Recently, finger-like membrane protrusions, microvilli, have been demonstrated to play a role in the organization of receptors and, hence, T-cell activation. However, little is known about the morphogenesis of dynamic microvilli, especially in the cells of immune system. In this review, I focus on the potential role of lipids and lipid domains in morphogenesis of microvilli. Discussed is the option that clustering of sphingolipids with phosphoinositides at the plasma membrane results in dimpling (curved) domains. Such domains can attract phosphoinositide-binding proteins and stimulate actin cytoskeleton reorganization. This process triggers cortical actin opening and bundling of actin fibres to support the growing of microvilli. Critical regulators of microvilli morphogenesis in T cells are unknown. At the end, I suggest several candidates with a potential to organize proteins and lipids in these structures.
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Affiliation(s)
- Marek Cebecauer
- Department of Biophysical Chemistry, J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences (CAS), Prague, Czechia
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2
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Zhang Y, Huang J, Li Q, Chen K, Liang Y, Zhan Z, Ye F, Ni W, Chen L, Ding Y. Histone methyltransferase SETDB1 promotes cells proliferation and migration by interacting withTiam1 in hepatocellular carcinoma. BMC Cancer 2018; 18:539. [PMID: 29739365 PMCID: PMC5941371 DOI: 10.1186/s12885-018-4464-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 04/30/2018] [Indexed: 11/24/2022] Open
Abstract
Background SETDB1 is a histone H3K9 methyltransferase, which plays a significant role in the occurrence and progression of tumors. Previous studies have confirmed that T-lymphom invasion and metastasis gene (Tiam1) is a protein associated with the metastasis of hepatocellular carcinoma (HCC); however, we have not yet been successful in elucidating the specific mechanism of HCC. Methods Yeast two-hybrid test was conducted to screen proteins that interacted with Tiam1 gene. Glutathione-S-transferase (GST) pull-down and crosslinking-immunoprecipitation (CLIP) assays were performed to determine whether SETDB1 can interact with Tiam1 gene. A series of related experiments were performed to explore role of SETDB1 on cell proliferation, migration, and invasion in HCC. Recovery experiment was performed to investigate the effect of Tiam1 knockdown on cell proliferation and migration, which was caused by SETDB1 overexpression in HCC cells. The expression of SETDB1 was frequently upregulated in HCC tissues and positively correlated with Tiam1. Results GST pull-down and CLIP assays were performed to elucidate the interaction between SETDB1 and Tiam1. Cell proliferation, migration, and epithelial mesenchymal transformation (EMT) in HCC cells was promoted with the overexpression of SETDB1. Following the knockdown of Tiam1 gene, the effect of SETDB1 on cell proliferation and migration was reversed in HCC cells. The expression of SETDB1 was frequently up-regulated in HCC tissues, and it was positively correlated with Tiam1 gene. Conclusions Ours is the first study to prove that SETDB1 promotes the proliferation and migration of cells by forming SETDB1-Tiam1 compounds. We found that SETDB1-Tiam1 compounds were involved in a novel pathway, which regulated epigenetic modification of gene expression in HCC samples. Electronic supplementary material The online version of this article (10.1186/s12885-018-4464-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yuqin Zhang
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Jing Huang
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Qisheng Li
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Keli Chen
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Yonghao Liang
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Zetao Zhan
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Feng Ye
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Wen Ni
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Longhua Chen
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China.
| | - Yi Ding
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China.
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3
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Acevedo A, González-Billault C. Crosstalk between Rac1-mediated actin regulation and ROS production. Free Radic Biol Med 2018; 116:101-113. [PMID: 29330095 DOI: 10.1016/j.freeradbiomed.2018.01.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 01/03/2018] [Accepted: 01/05/2018] [Indexed: 02/08/2023]
Abstract
The small RhoGTPase Rac1 is implicated in a variety of events related to actin cytoskeleton rearrangement. Remarkably, another event that is completely different from those related to actin regulation has the same relevance; the Rac1-mediated production of reactive oxygen species (ROS) through NADPH oxidases (NOX). Each outcome involves different Rac1 downstream effectors; on one hand, events related to the actin cytoskeleton require Rac1 to bind to WAVEs proteins and PAKs that ultimately promote actin branching and turnover, on the other, NOX-derived ROS production demands active Rac1 to be bound to a cytosolic activator of NOX. How Rac1-mediated signaling ends up promoting actin-related events, NOX-derived ROS, or both is poorly understood. Rac1 regulators, including scaffold proteins, are known to exert tight control over its functions. Hence, evidence of Rac1 regulatory events leading to both actin remodeling and NOX-mediated ROS generation are discussed. Moreover, cellular functions linked to physiological and pathological conditions that exhibit crosstalk between Rac1 outcomes are analyzed, while plausible roles in neuronal functions (and dysfunctions) are highlighted. Together, discussed evidence shed light on cellular mechanisms which requires Rac1 to direct either actin- and/or ROS-related events, helping to understand crucial roles of Rac1 dual functionality.
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Affiliation(s)
- Alejandro Acevedo
- FONDAP Geroscience Center for Brain Health and Metabolism, Santiago, Chile.
| | - Christian González-Billault
- FONDAP Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Department of Biology, Faculty of Sciences, Universidad de Chile, 7800024, Chile; The Buck Institute for Research on Aging, Novato, USA.
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4
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Lawson CD, Ridley AJ. Rho GTPase signaling complexes in cell migration and invasion. J Cell Biol 2018; 217:447-457. [PMID: 29233866 PMCID: PMC5800797 DOI: 10.1083/jcb.201612069] [Citation(s) in RCA: 324] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/23/2017] [Accepted: 11/17/2017] [Indexed: 12/02/2022] Open
Abstract
Cell migration is dependent on the dynamic formation and disassembly of actin filament-based structures, including lamellipodia, filopodia, invadopodia, and membrane blebs, as well as on cell-cell and cell-extracellular matrix adhesions. These processes all involve Rho family small guanosine triphosphatases (GTPases), which are regulated by the opposing actions of guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Rho GTPase activity needs to be precisely tuned at distinct cellular locations to enable cells to move in response to different environments and stimuli. In this review, we focus on the ability of RhoGEFs and RhoGAPs to form complexes with diverse binding partners, and describe how this influences their ability to control localized GTPase activity in the context of migration and invasion.
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Affiliation(s)
- Campbell D Lawson
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, England, UK
| | - Anne J Ridley
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, England, UK
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Osteopontin at the Crossroads of Inflammation and Tumor Progression. Mediators Inflamm 2017; 2017:4049098. [PMID: 28769537 PMCID: PMC5523273 DOI: 10.1155/2017/4049098] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 06/04/2017] [Indexed: 12/13/2022] Open
Abstract
Complex interactions between tumor and host cells regulate systemic tumor dissemination, a process that begins early at the primary tumor site and goes on until tumor cells detach themselves from the tumor mass and start migrating into the blood or lymphatic vessels. Metastatic cells colonize the target organs and are capable of surviving and growing at distant sites. In this context, osteopontin (OPN) appears to be a key determinant of the crosstalk between cancer cells and the host microenvironment, which in turn modulates immune evasion. OPN is overexpressed in several human carcinomas and has been implicated in inflammation, tumor progression, and metastasis. Thus, it represents one of the most attracting targets for cancer therapy. Within the tumor mass, OPN is secreted in various forms either by the tumor itself or by stroma cells, and it can exert either pro- or antitumorigenic effects according to the cell type and tumor microenvironment. Thus, targeting OPN for therapeutic purposes needs to take into account the heterogeneous functions of the multiple OPN forms with regard to cancer formation and progression. In this review, we will describe the role of systemic, tumor-derived, and stroma-derived OPN, highlighting its pivotal role at the crossroads of inflammation and tumor progression.
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Marei H, Malliri A. Rac1 in human diseases: The therapeutic potential of targeting Rac1 signaling regulatory mechanisms. Small GTPases 2017; 8:139-163. [PMID: 27442895 PMCID: PMC5584733 DOI: 10.1080/21541248.2016.1211398] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 07/05/2016] [Accepted: 07/05/2016] [Indexed: 12/11/2022] Open
Abstract
Abnormal Rac1 signaling is linked to a number of debilitating human diseases, including cancer, cardiovascular diseases and neurodegenerative disorders. As such, Rac1 represents an attractive therapeutic target, yet the search for effective Rac1 inhibitors is still underway. Given the adverse effects associated with Rac1 signaling perturbation, cells have evolved several mechanisms to ensure the tight regulation of Rac1 signaling. Thus, characterizing these mechanisms can provide invaluable information regarding major cellular events that lead to aberrant Rac1 signaling. Importantly, this information can be utilized to further facilitate the development of effective pharmacological modulators that can restore normal Rac1 signaling. In this review, we focus on the pathological role of Rac1 signaling, highlighting the benefits and potential drawbacks of targeting Rac1 in a clinical setting. Additionally, we provide an overview of available compounds that target key Rac1 regulatory mechanisms and discuss future therapeutic avenues arising from our understanding of these mechanisms.
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Affiliation(s)
- Hadir Marei
- Cell Signaling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, UK
| | - Angeliki Malliri
- Cell Signaling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, UK
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Marei H, Malliri A. GEFs: Dual regulation of Rac1 signaling. Small GTPases 2017; 8:90-99. [PMID: 27314616 PMCID: PMC5464116 DOI: 10.1080/21541248.2016.1202635] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/10/2016] [Accepted: 06/10/2016] [Indexed: 12/15/2022] Open
Abstract
GEFs play a critical role in regulating Rac1 signaling. They serve as signaling nodes converting upstream signals into downstream Rac1-driven cellular responses. Through associating with membrane-bound Rac1, GEFs facilitate the exchange of GDP for GTP, thereby activating Rac1. As a result, Rac1 undergoes conformational changes that mediate its interaction with downstream effectors, linking Rac1 to a multitude of physiological and pathological processes. Interestingly, there are at least 20 GEFs involved in Rac1 activation, suggesting a more complex role of GEFs in regulating Rac1 signaling apart from promoting the exchange of GDP for GTP. Indeed, accumulating evidence implicates GEFs in directing the specificity of Rac1-driven signaling cascades, although the underlying mechanisms were poorly defined. Recently, through conducting a comparative study, we highlighted the role of 2 Rac-specific GEFs, Tiam1 and P-Rex1, in dictating the biological outcome downstream of Rac1. Importantly, further proteomic analysis uncovered a GEF activity-independent function for both GEFs in modulating the Rac1 interactome, which results in the stimulation of GEF-specific signaling cascades. Here, we provide an overview of our recent findings and discuss the role of GEFs as master regulators of Rac1 signaling with a particular focus on GEF-mediated modulation of cell migration following Rac1 activation.
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Affiliation(s)
- Hadir Marei
- Cell Signaling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, UK
| | - Angeliki Malliri
- Cell Signaling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, UK
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8
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Marei H, Carpy A, Macek B, Malliri A. Proteomic analysis of Rac1 signaling regulation by guanine nucleotide exchange factors. Cell Cycle 2016; 15:1961-74. [PMID: 27152953 PMCID: PMC4968972 DOI: 10.1080/15384101.2016.1183852] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 04/13/2016] [Accepted: 04/22/2016] [Indexed: 10/30/2022] Open
Abstract
The small GTPase Rac1 is implicated in various cellular processes that are essential for normal cell function. Deregulation of Rac1 signaling has also been linked to a number of diseases, including cancer. The diversity of Rac1 functioning in cells is mainly attributed to its ability to bind to a multitude of downstream effectors following activation by Guanine nucleotide Exchange Factors (GEFs). Despite the identification of a large number of Rac1 binding partners, factors influencing downstream specificity are poorly defined, thus hindering the detailed understanding of both Rac1's normal and pathological functions. In a recent study, we demonstrated a role for 2 Rac-specific GEFs, Tiam1 and P-Rex1, in mediating Rac1 anti- versus pro-migratory effects, respectively. Importantly, via conducting a quantitative proteomic screen, we identified distinct changes in the Rac1 interactome following activation by either GEF, indicating that these opposing effects are mediated through GEF modulation of the Rac1 interactome. Here, we present the full list of identified Rac1 interactors together with functional annotation of the differentially regulated Rac1 binding partners. In light of this data, we also provide additional insights into known and novel signaling cascades that might account for the GEF-mediated Rac1-driven cellular effects.
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Affiliation(s)
- Hadir Marei
- Cell Signaling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, UK
| | - Alejandro Carpy
- Proteome Center Tuebingen, Interfaculty Institute for Cell Biology, University of Tuebingen, Tuebingen, Germany
| | - Boris Macek
- Proteome Center Tuebingen, Interfaculty Institute for Cell Biology, University of Tuebingen, Tuebingen, Germany
| | - Angeliki Malliri
- Cell Signaling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, UK
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9
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Marei H, Carpy A, Woroniuk A, Vennin C, White G, Timpson P, Macek B, Malliri A. Differential Rac1 signalling by guanine nucleotide exchange factors implicates FLII in regulating Rac1-driven cell migration. Nat Commun 2016; 7:10664. [PMID: 26887924 PMCID: PMC4759627 DOI: 10.1038/ncomms10664] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 01/08/2016] [Indexed: 01/22/2023] Open
Abstract
The small GTPase Rac1 has been implicated in the formation and dissemination of tumours. Upon activation by guanine nucleotide exchange factors (GEFs), Rac1 associates with a variety of proteins in the cell thereby regulating various functions, including cell migration. However, activation of Rac1 can lead to opposing migratory phenotypes raising the possibility of exacerbating tumour progression when targeting Rac1 in a clinical setting. This calls for the identification of factors that influence Rac1-driven cell motility. Here we show that Tiam1 and P-Rex1, two Rac GEFs, promote Rac1 anti- and pro-migratory signalling cascades, respectively, through regulating the Rac1 interactome. In particular, we demonstrate that P-Rex1 stimulates migration through enhancing the interaction between Rac1 and the actin-remodelling protein flightless-1 homologue, to modulate cell contraction in a RhoA-ROCK-independent manner.
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Affiliation(s)
- Hadir Marei
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M204BX, UK
| | - Alejandro Carpy
- Proteome Center Tuebingen, Interfaculty Institute for Cell Biology, University of Tuebingen, Tuebingen 72026, Germany
| | - Anna Woroniuk
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M204BX, UK
| | - Claire Vennin
- Invasion and Metastasis Group, Garvan Institute of Medical Research, The Kinghorn Cancer Centre, Faculty of Medicine, St Vincent's Clinical School, University of New South Wales, Darlinghurst, New South Wales 2010, Australia
| | - Gavin White
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M204BX, UK
| | - Paul Timpson
- Invasion and Metastasis Group, Garvan Institute of Medical Research, The Kinghorn Cancer Centre, Faculty of Medicine, St Vincent's Clinical School, University of New South Wales, Darlinghurst, New South Wales 2010, Australia
| | - Boris Macek
- Proteome Center Tuebingen, Interfaculty Institute for Cell Biology, University of Tuebingen, Tuebingen 72026, Germany
| | - Angeliki Malliri
- Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M204BX, UK
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Xu K, Tian X, Oh SY, Movassaghi M, Naber SP, Kuperwasser C, Buchsbaum RJ. The fibroblast Tiam1-osteopontin pathway modulates breast cancer invasion and metastasis. Breast Cancer Res 2016; 18:14. [PMID: 26821678 PMCID: PMC4730665 DOI: 10.1186/s13058-016-0674-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 12/30/2015] [Indexed: 12/21/2022] Open
Abstract
Background The tumor microenvironment has complex effects in cancer pathophysiology that are not fully understood. Most cancer therapies are directed against malignant cells specifically, leaving pro-malignant signals from the microenvironment unaddressed. Defining specific mechanisms by which the tumor microenvironment contributes to breast cancer metastasis may lead to new therapeutic approaches against advanced breast cancer. Methods We use a novel method for manipulating three-dimensional mixed cell co-cultures, along with studies in mouse xenograft models of human breast cancer and a histologic study of human breast cancer samples, to investigate how breast cancer-associated fibroblasts affect the malignant behaviors of breast cancer cells. Results Altering fibroblast Tiam1 expression induces changes in invasion, migration, epithelial-mesenchymal transition, and cancer stem cell characteristics in associated breast cancer cells. These changes are both dependent on fibroblast secretion of osteopontin and also long-lasting even after cancer cell dissociation from the fibroblasts, indicating a novel Tiam1-osteopontin pathway in breast cancer-associated fibroblasts. Notably, inhibition of fibroblast osteopontin with low doses of a novel small molecule prevents lung metastasis in a mouse model of human breast cancer metastasis. Moreover, fibroblast expression patterns of Tiam1 and osteopontin in human breast cancers show converse changes correlating with invasion, supporting the hypothesis that this pathway in tumor-associated fibroblasts regulates breast cancer invasiveness in human disease and is thus clinically relevant. Conclusions These findings suggest a new therapeutic paradigm for preventing breast cancer metastasis. Pro-malignant signals from the tumor microenvironment with long-lasting effects on associated cancer cells may perpetuate the metastatic potential of developing cancers. Inhibition of these microenvironment signals represents a new therapeutic strategy against cancer metastasis that enables targeting of stromal cells with less genetic plasticity than associated cancer cells and opens new avenues for investigation of novel therapeutic targets and agents. Electronic supplementary material The online version of this article (doi:10.1186/s13058-016-0674-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kun Xu
- Molecular Oncology Research Institute, Tufts Medical Center, 75 Kneeland Street, Boston, MA, 02111, USA.
| | - Xuejun Tian
- Department of Pathology, Tufts Medical Center, 800 Washington Street, Boston, MA, 02111, USA.
| | - Sun Y Oh
- Molecular Oncology Research Institute, Tufts Medical Center, 75 Kneeland Street, Boston, MA, 02111, USA. .,Department of Medicine, Tufts Medical Center, 800 Washington Street, Boston, MA, 02111, USA.
| | - Mohammad Movassaghi
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
| | - Stephen P Naber
- Department of Pathology, Tufts Medical Center, 800 Washington Street, Boston, MA, 02111, USA.
| | - Charlotte Kuperwasser
- Molecular Oncology Research Institute, Tufts Medical Center, 75 Kneeland Street, Boston, MA, 02111, USA. .,Developmental, Molecular, and Chemical Biology Department, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA, 02111, USA.
| | - Rachel J Buchsbaum
- Molecular Oncology Research Institute, Tufts Medical Center, 75 Kneeland Street, Boston, MA, 02111, USA. .,Department of Medicine, Tufts Medical Center, 800 Washington Street, Boston, MA, 02111, USA.
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Chang C, Niu Z, Gu N, Zhao W, Wang G, Jia Y, Li D, Xu C. Analysis of the ways and methods of signaling pathways in regulating cell cycle of NIH3T3 at transcriptional level. BMC Cell Biol 2015; 16:25. [PMID: 26511608 PMCID: PMC4625951 DOI: 10.1186/s12860-015-0071-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 10/19/2015] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND To analyze the ways and methods of signaling pathways in regulating cell cycle progression of NIH3T3 at transcriptional level, we modeled cell cycle of NIH3T3 and found that G1 phase of NIH3T3 cell cycle was at 5-15 h after synchronization, S phase at 15-21 h, G2 phase at 21-22 h, M phase at 22-25 h. RESULTS Mouse Genome 430 2.0 microarray was used to detect the gene expression profiles of the model, and results showed remarkable changes in the expressions of 64 cell cycle genes and 960 genes associated with other physiological activity during the cell cycle of NIH3T3. For the next step, IPA software was used to analyze the physiological activities, cell cycle genes-associated signal transduction activities and their regulatory roles of these genes in cell cycle progression, and our results indicated that the reported genes were involved in 17 signaling pathways in the regulation of cell cycle progression. Newfound genes such as PKC, RAS, PP2A, NGR and PI3K etc. belong to the functional category of molecular mechanism of cancer, cyclins and cell cycle regulation HER-2 signaling in breast cancer signaling pathways. These newfound genes could promote DNA damage repairment and DNA replication progress, regulate the metabolism of protein, and maintain the cell cycle progression of NIH3T3 modulating the reported genes CCND1 and C-FOS. CONCLUSION All of the aforementioned signaling pathways interacted with the cell cycle network, indicating that NIH3T3 cell cycle was regulated by a number of signaling pathways.
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Affiliation(s)
- Cuifang Chang
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Zhipeng Niu
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Ningning Gu
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Weiming Zhao
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Gaiping Wang
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Yifeng Jia
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Deming Li
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Cunshuan Xu
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
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Donnelly SK, Bravo-Cordero JJ, Hodgson L. Rho GTPase isoforms in cell motility: Don't fret, we have FRET. Cell Adh Migr 2015; 8:526-34. [PMID: 25482645 PMCID: PMC4594258 DOI: 10.4161/cam.29712] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The Rho-family of p21 small GTPases are directly linked to the regulation of actin-based motile machinery and play a key role in the control of cell migration. Aside from the original and most well-characterized canonical Rho GTPases RhoA, Rac1, and Cdc42, numerous isoforms of these key proteins have been identified and shown to have specific roles in regulating various cellular motility processes. The major difficulty in addressing these isoform-specific effects is that isoforms typically contain highly similar primary amino acid sequences and thus are able to interact with the same upstream regulators and the downstream effector targets. Here, we will introduce the major members of each GTPase subfamily and discuss recent advances in the design and application of fluorescent resonance energy transfer-based probes, which are at the forefront of the technologies available to directly probe the differential, spatiotemporal activation dynamics of these proteins in live single cells. Currently, it is possible to specifically detect the activation status of RhoA vs. RhoC isoforms, as well as Cdc42 vs. TC-10 isoforms in living cells. Clearly, additional efforts are still required to produce biosensor systems capable of detecting other isoforms of Rho GTPases including RhoB, Rac2/3, RhoG, etc. Through such efforts, we will uncover the isoform-specific roles of these near-identical proteins in living cells, clearly an important area of the Rho GTPase biology that is not yet fully appreciated.
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Affiliation(s)
- Sara K Donnelly
- a Department of Anatomy and Structural Biology ; Albert Einstein College of Medicine of Yeshiva University ; Bronx , NY USA
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Duman JG, Mulherkar S, Tu YK, X Cheng J, Tolias KF. Mechanisms for spatiotemporal regulation of Rho-GTPase signaling at synapses. Neurosci Lett 2015; 601:4-10. [PMID: 26003445 DOI: 10.1016/j.neulet.2015.05.034] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 05/16/2015] [Accepted: 05/18/2015] [Indexed: 01/16/2023]
Abstract
Synapses mediate information flow between neurons and undergo plastic changes in response to experience, which is critical for learning and memory. Conversely, synaptic defects impair information processing and underlie many brain pathologies. Rho-family GTPases control synaptogenesis by transducing signals from extracellular stimuli to the cytoskeleton and nucleus. The Rho-GTPases Rac1 and Cdc42 promote synapse development and the growth of axons and dendrites, while RhoA antagonizes these processes. Despite its importance, many aspects of Rho-GTPase signaling remain relatively unknown. Rho-GTPases are activated by guanine nucleotide exchange factors (GEFs) and inhibited by GTPase-activating proteins (GAPs). Though the number of both GEFs and GAPs greatly exceeds that of Rho-GTPases, loss of even a single GEF or GAP often has profound effects on cognition and behavior. Here, we explore how the actions of specific GEFs and GAPs give rise to the precise spatiotemporal activation patterns of Rho-GTPases in neurons. We consider the effects of coupling GEFs and GAPs targeting the same Rho-GTPase and the modular pathways that connect specific cellular stimuli with a given Rho-GTPase via different GEFs. We discuss how the creation of sharp borders between Rho-GTPase activation zones is achieved by pairing a GEF for one Rho-GTPase with a GAP for another and the extensive crosstalk between different Rho-GTPases. Given the importance of synapses for cognition and the fundamental roles that Rho-GTPases play in regulating them, a detailed understanding of Rho-GTPase signaling is essential to the progress of neuroscience.
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Affiliation(s)
- Joseph G Duman
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Shalaka Mulherkar
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Yen-Kuei Tu
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Integrative Molecular and Biomedical Sciences Program,Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Jinxuan X Cheng
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Kimberley F Tolias
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Integrative Molecular and Biomedical Sciences Program,Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
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14
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Evans JC, Robinson CM, Shi M, Webb DJ. The guanine nucleotide exchange factor (GEF) Asef2 promotes dendritic spine formation via Rac activation and spinophilin-dependent targeting. J Biol Chem 2015; 290:10295-308. [PMID: 25750125 DOI: 10.1074/jbc.m114.605543] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Indexed: 11/06/2022] Open
Abstract
Dendritic spines are actin-rich protrusions that establish excitatory synaptic contacts with surrounding neurons. Reorganization of the actin cytoskeleton is critical for the development and plasticity of dendritic spines, which is the basis for learning and memory. Rho family GTPases are emerging as important modulators of spines and synapses, predominantly through their ability to regulate actin dynamics. Much less is known, however, about the function of guanine nucleotide exchange factors (GEFs), which activate these GTPases, in spine and synapse development. In this study we show that the Rho family GEF Asef2 is found at synaptic sites, where it promotes dendritic spine and synapse formation. Knockdown of endogenous Asef2 with shRNAs impairs spine and synapse formation, whereas exogenous expression of Asef2 causes an increase in spine and synapse density. This effect of Asef2 on spines and synapses is abrogated by expression of GEF activity-deficient Asef2 mutants or by knockdown of Rac, suggesting that Asef2-Rac signaling mediates spine development. Because Asef2 interacts with the F-actin-binding protein spinophilin, which localizes to spines, we investigated the role of spinophilin in Asef2-promoted spine formation. Spinophilin recruits Asef2 to spines, and knockdown of spinophilin hinders spine and synapse formation in Asef2-expressing neurons. Furthermore, inhibition of N-methyl-d-aspartate receptor (NMDA) activity blocks spinophilin-mediated localization of Asef2 to spines. These results collectively point to spinophilin-Asef2-Rac signaling as a novel mechanism for the development of dendritic spines and synapses.
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Affiliation(s)
- J Corey Evans
- From the Department of Biological Sciences and the Kennedy Center for Research on Human Development and
| | - Cristina M Robinson
- From the Department of Biological Sciences and the Kennedy Center for Research on Human Development and
| | - Mingjian Shi
- From the Department of Biological Sciences and the Kennedy Center for Research on Human Development and
| | - Donna J Webb
- From the Department of Biological Sciences and the Kennedy Center for Research on Human Development and the Department of Cancer Biology, Vanderbilt University, Nashville, Tennessee 37235
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15
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Johnsson AKE, Dai Y, Nobis M, Baker MJ, McGhee EJ, Walker S, Schwarz JP, Kadir S, Morton JP, Myant KB, Huels DJ, Segonds-Pichon A, Sansom OJ, Anderson KI, Timpson P, Welch HCE. The Rac-FRET mouse reveals tight spatiotemporal control of Rac activity in primary cells and tissues. Cell Rep 2014; 6:1153-1164. [PMID: 24630994 PMCID: PMC3988842 DOI: 10.1016/j.celrep.2014.02.024] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 02/05/2014] [Accepted: 02/15/2014] [Indexed: 01/19/2023] Open
Abstract
The small G protein family Rac has numerous regulators that integrate extracellular signals into tight spatiotemporal maps of its activity to promote specific cell morphologies and responses. Here, we have generated a mouse strain, Rac-FRET, which ubiquitously expresses the Raichu-Rac biosensor. It enables FRET imaging and quantification of Rac activity in live tissues and primary cells without affecting cell properties and responses. We assessed Rac activity in chemotaxing Rac-FRET neutrophils and found enrichment in leading-edge protrusions and unexpected longitudinal shifts and oscillations during protruding and stalling phases of migration. We monitored Rac activity in normal or disease states of intestinal, liver, mammary, pancreatic, and skin tissue, in response to stimulation or inhibition and upon genetic manipulation of upstream regulators, revealing unexpected insights into Rac signaling during disease development. The Rac-FRET strain is a resource that promises to fundamentally advance our understanding of Rac-dependent responses in primary cells and native environments.
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Affiliation(s)
- Anna-Karin E Johnsson
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Yanfeng Dai
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Max Nobis
- Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Martin J Baker
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Ewan J McGhee
- Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Simon Walker
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Juliane P Schwarz
- Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Shereen Kadir
- Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Jennifer P Morton
- Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Kevin B Myant
- Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - David J Huels
- Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Anne Segonds-Pichon
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Owen J Sansom
- Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Kurt I Anderson
- Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Paul Timpson
- Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK; Garvan Institute of Medical Research and Kinghorn Cancer Centre, Cancer Research Program, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, NSW, 2010 Sydney, Australia.
| | - Heidi C E Welch
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
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16
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The guanine nucleotide exchange factor Tiam1: A Janus-faced molecule in cellular signaling. Cell Signal 2014; 26:483-91. [DOI: 10.1016/j.cellsig.2013.11.034] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 11/26/2013] [Indexed: 11/22/2022]
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17
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Joshi M, Gakhar L, Fuentes EJ. High-resolution structure of the Tiam1 PHn-CC-Ex domain. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:744-52. [PMID: 23832200 PMCID: PMC3702317 DOI: 10.1107/s1744309113014206] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 05/22/2013] [Indexed: 01/22/2023]
Abstract
The T-lymphoma and metastasis gene 1 (TIAM1) encodes a guanine nucleotide-exchange factor protein (Tiam1) that is specific for the Rho-family GTPase Rac1 and is important for cell polarity, migration and adhesion. Tiam1 is a large multi-domain protein that contains several protein-protein binding domains that are important for regulating cellular function. The PHn-CC-Ex domain is critical for plasma-membrane association and interactions with protein-scaffold proteins (e.g. Par3b, spinophilin, IRSp53 and JIP2) that direct Tiam1-Rac1 signaling specificity. It was determined that the coiled-coil domain of Par3b binds the PHn-CC-Ex domain with a dissociation constant of ≈ 30 µM. Moreover, the structures of two variants of the Tiam1 PHn-CC-Ex domain were solved at resolutions of 1.98 and 2.15 Å, respectively. The structures indicate that the PHn, CC and Ex regions form independent subdomains that together provide an integrated platform for binding partner proteins. Small-angle X-ray scattering (SAXS) data indicate that the Tiam1 PHn-CC-Ex domain is monomeric in solution and that the solution and crystal structures are very similar. Together, these data provide the foundation necessary to elucidate the structural mechanism of the PHn-CC-Ex/scaffold interactions that are critical for Tiam1-Rac1 signaling specificity.
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Affiliation(s)
- Monika Joshi
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Lokesh Gakhar
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
- Protein Crystallography Facility, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Ernesto J. Fuentes
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
- Holden Comprehensive Cancer Center, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
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18
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The adhesion-GPCR BAI1 regulates synaptogenesis by controlling the recruitment of the Par3/Tiam1 polarity complex to synaptic sites. J Neurosci 2013; 33:6964-78. [PMID: 23595754 DOI: 10.1523/jneurosci.3978-12.2013] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Excitatory synapses are polarized structures that primarily reside on dendritic spines in the brain. The small GTPase Rac1 regulates the development and plasticity of synapses and spines by modulating actin dynamics. By restricting the Rac1-guanine nucleotide exchange factor Tiam1 to spines, the polarity protein Par3 promotes synapse development by spatially controlling Rac1 activation. However, the mechanism for recruiting Par3 to spines is unknown. Here, we identify brain-specific angiogenesis inhibitor 1 (BAI1) as a synaptic adhesion GPCR that is required for spinogenesis and synaptogenesis in mice and rats. We show that BAI1 interacts with Par3/Tiam1 and recruits these proteins to synaptic sites. BAI1 knockdown results in Par3/Tiam1 mislocalization and loss of activated Rac1 and filamentous actin from spines. Interestingly, BAI1 also mediates Rac-dependent engulfment in professional phagocytes through its interaction with a different Rac1-guanine nucleotide exchange factor module, ELMO/DOCK180. However, this interaction is dispensable for BAI1's role in synapse development because a BAI1 mutant that cannot interact with ELMO/DOCK180 rescues spine defects in BAI1-knockdown neurons, whereas a mutant that cannot interact with Par3/Tiam1 rescues neither spine defects nor Par3 localization. Further, overexpression of Tiam1 rescues BAI1 knockdown spine phenotypes. These results indicate that BAI1 plays an important role in synaptogenesis that is mechanistically distinct from its role in phagocytosis. Furthermore, our results provide the first example of a cell surface receptor that targets members of the PAR polarity complex to synapses.
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19
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Liu Y, Collins C, Kiosses WB, Murray AM, Joshi M, Shepherd TR, Fuentes EJ, Tzima E. A novel pathway spatiotemporally activates Rac1 and redox signaling in response to fluid shear stress. ACTA ACUST UNITED AC 2013; 201:863-73. [PMID: 23733346 PMCID: PMC3678169 DOI: 10.1083/jcb.201207115] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The GEF Tiam1 acts as a novel molecular link to the VE-cadherin–p67phox–Par3 polarity complex, leading to localized activation of Rac1 and NADPH oxidase in response to fluid flow. Hemodynamic forces regulate embryonic organ development, hematopoiesis, vascular remodeling, and atherogenesis. The mechanosensory stimulus of blood flow initiates a complex network of intracellular pathways, including activation of Rac1 GTPase, establishment of endothelial cell (EC) polarity, and redox signaling. The activity of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase can be modulated by the GTP/GDP state of Rac1; however, the molecular mechanisms of Rac1 activation by flow are poorly understood. Here, we identify a novel polarity complex that directs localized Rac1 activation required for downstream reactive oxygen species (ROS) production. Vav2 is required for Rac1 GTP loading, whereas, surprisingly, Tiam1 functions as an adaptor in a VE-cadherin–p67phox–Par3 polarity complex that directs localized activation of Rac1. Furthermore, loss of Tiam1 led to the disruption of redox signaling both in vitro and in vivo. Our results describe a novel molecular cascade that regulates redox signaling by the coordinated regulation of Rac1 and by linking components of the polarity complex to the NADPH oxidase.
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Affiliation(s)
- Yunhao Liu
- Department of Cell Biology and Physiology, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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20
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Abstract
Small GTPases use GDP/GTP alternation to actuate a variety of functional switches that are pivotal for cell dynamics. The GTPase switch is turned on by GEFs, which stimulate dissociation of the tightly bound GDP, and turned off by GAPs, which accelerate the intrinsically sluggish hydrolysis of GTP. For Ras, Rho, and Rab GTPases, this switch incorporates a membrane/cytosol alternation regulated by GDIs and GDI-like proteins. The structures and core mechanisms of representative members of small GTPase regulators from most families have now been elucidated, illuminating their general traits combined with scores of unique features. Recent studies reveal that small GTPase regulators have themselves unexpectedly sophisticated regulatory mechanisms, by which they process cellular signals and build up specific cell responses. These mechanisms include multilayered autoinhibition with stepwise release, feedback loops mediated by the activated GTPase, feed-forward signaling flow between regulators and effectors, and a phosphorylation code for RhoGDIs. The flipside of these highly integrated functions is that they make small GTPase regulators susceptible to biochemical abnormalities that are directly correlated with diseases, notably a striking number of missense mutations in congenital diseases, and susceptible to bacterial mimics of GEFs, GAPs, and GDIs that take command of small GTPases in infections. This review presents an overview of the current knowledge of these many facets of small GTPase regulation.
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Affiliation(s)
- Jacqueline Cherfils
- Laboratoire d’Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique, Centre deRecherche de Gif, Gif-sur-Yvette, France
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21
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Csépányi-Kömi R, Lévay M, Ligeti E. Small G proteins and their regulators in cellular signalling. Mol Cell Endocrinol 2012; 353:10-20. [PMID: 22108439 DOI: 10.1016/j.mce.2011.11.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 09/27/2011] [Accepted: 11/07/2011] [Indexed: 01/04/2023]
Abstract
Small molecular weight GTPases (small G proteins) are essential in the transduction of signals from different plasma membrane receptors. Due to their endogenous GTP-hydrolyzing activity, these proteins function as time-dependent biological switches controlling diverse cellular functions including cell shape and migration, cell proliferation, gene transcription, vesicular transport and membrane-trafficking. This review focuses on endocrine diseases linked to small G proteins. We provide examples for the regulation of the activity of small G proteins by various mechanisms such as posttranslational modifications, guanine nucleotide exchange factors (GEFs), GTPase activating proteins (GAPs) or guanine nucleotide dissociation inhibitors (GDIs). Finally we summarize endocrine diseases where small G proteins or their regulatory proteins have been revealed as the cause.
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Affiliation(s)
- Roland Csépányi-Kömi
- Department of Physiology, Semmelweis University, Tűzoltó u. 37-47, 1094 Budapest, Hungary
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22
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Liu J, Xu K, Chase M, Ji Y, Logan JK, Buchsbaum RJ. Tiam1-regulated osteopontin in senescent fibroblasts contributes to the migration and invasion of associated epithelial cells. J Cell Sci 2012; 125:376-86. [PMID: 22302986 DOI: 10.1242/jcs.089466] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The tumor microenvironment undergoes changes concurrent with neoplastic progression. Cancer incidence increases with aging and is associated with tissue accumulation of senescent cells. Senescent fibroblasts are thought to contribute to tumor development in aging tissues. We have shown that fibroblasts deficient in the Rac exchange factor Tiam1 promote invasion and metastasis of associated epithelial tumor cells. Here, we use a three-dimensional culture model of cellular invasiveness to outline several steps underlying this effect. We find that stress-induced senescence induces decreased fibroblast Tiam1 protein levels and increased osteopontin levels, and that senescent fibroblast lysates induce Tiam1 protein degradation in a calcium- and calpain-dependent fashion. Changes in fibroblast Tiam1 protein levels induce converse changes in osteopontin mRNA and protein. Senescent fibroblasts induce increased invasion and migration in co-cultured mammary epithelial cells. These effects in epithelial cells are ameliorated by either increasing fibroblast Tiam1 or decreasing fibroblast osteopontin. Finally, in seeded cell migration assays we find that either senescent or Tiam1-deficient fibroblasts induce increased epithelial cell migration that is dependent on fibroblast secretion of osteopontin. These findings indicate that one mechanism by which senescent fibroblasts promote neoplastic progression in associated tumors is through degradation of fibroblast Tiam1 protein and the consequent increase in secretion of osteopontin by fibroblasts.
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Affiliation(s)
- Jiewei Liu
- Molecular Oncology Research Institute, Tufts Medical Center Boston, MA 02111, USA
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23
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Grönholm M, Jahan F, Marchesan S, Karvonen U, Aatonen M, Narumanchi S, Gahmberg CG. TCR-induced activation of LFA-1 involves signaling through Tiam1. THE JOURNAL OF IMMUNOLOGY 2011; 187:3613-9. [PMID: 21876037 DOI: 10.4049/jimmunol.1100704] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Adhesion is pivotal for most leukocyte functions, and the β(2) integrin family of adhesion molecules plays a central role. The integrins need activation to become functional, but the molecular events resulting in adhesion have remained incompletely understood. In human T cells, activation through the TCR results in specific phosphorylation of the T758 on the β(2) chain of LFA-1. We now show that this phosphorylation leads to downstream binding of 14-3-3 proteins, followed by engagement of the guanine nucleotide exchange factor protein Tiam1 and Rac1 activation. Downregulation of the signaling molecules inhibits LFA-1 activity. Activation by the chemokine stromal cell-derived factor-1α also results in T758 phosphorylation and integrin activation. Thus, TCR and chemokine activation converges on LFA-1 phosphorylation, followed by similar downstream events affecting adhesion.
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Affiliation(s)
- Mikaela Grönholm
- Division of Biochemistry and Biotechnology, Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland.
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24
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Liu S, Qu YH, Yan WH. Clinicopathological significance of Tiam1 and Rac1 protein expression in esophageal squamous cell carcinoma. Shijie Huaren Xiaohua Zazhi 2010; 18:3869-3873. [DOI: 10.11569/wcjd.v18.i36.3869] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To detect the expression of T-cell lymphoma invasion and metastasis factor1 (Tiam1) and Rac GTPase activating protein 1 (Rac1) proteins in esophageal squamous cell carcinoma (ESCC) and to analyze their correlation with the development, progression, invasion and metastasis of ESCC.
METHODS: The expression of TIAM1 and Rac1 proteins was detected by immunohistochemistry in 62 ESCC specimens, 20 tumor-adjacent atypical hyperplastic epithelial specimens, and 20 normal esophageal epithelial specimens.
RESULTS: The expression of Tiam1 protein was closely correlated with tumor grade, infiltration, lymph node metastasis, and TNM grade in ESCC (χ2 = 8.779, 7.680, 4.502 and 4.987, all P < 0.05). There is a significant difference in the positive rate of Tiam1 protein expression among normal esophageal epithelium, tumor-adjacent atypical hyperplastic epithelium and carcinoma [15.0% (3/20), 55.0% (11/20) and 72.6% (45/62), respectively; χ2 = 20.643, P < 0.05]. The expression of Rac1 protein was closely correlated with tumor grade, infiltration, lymph node metastasis, and TNM grade in ESCC (χ2 = 8.652, 6.884, 8.276 and 6.371, all P < 0.05). There is a significant difference in the positive rate of Rac1 protein expression among normal esophageal epithelium, adjacent atypical hyperplastic epithelium and carcinoma [25.0% (5/20), 70.0% (14/20) and 70.0% (44/62), respectively; χ2 = 57.621, P < 0.01]. There is a positive correlation between the expression of Tiam1 and Rac1 proteins (γp = 0.642, P < 0.05).
CONCLUSION: Combined detection of Tiam1 and Rac1 expression can be used for early diagnosis and prognostic evaluation of ESCC.
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Xu K, Rajagopal S, Klebba I, Dong S, Ji Y, Liu J, Kuperwasser C, Garlick JA, Naber SP, Buchsbaum RJ. The role of fibroblast Tiam1 in tumor cell invasion and metastasis. Oncogene 2010; 29:6533-42. [PMID: 20802514 PMCID: PMC2997941 DOI: 10.1038/onc.2010.385] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The co-evolution of tumors and their microenvironment involves bidirectional communication between tumor cells and tumor-associated stroma. Various cell types are present in tumor-associated stroma, of which fibroblasts are the most abundant. The Rac exchange factor Tiam1 is implicated in multiple signaling pathways in epithelial tumor cells and lack of Tiam1 in tumor cells retards tumor growth in Tiam1 knock-out mouse models. Conversely, tumors arising in Tiam1 knock-out mice have increased invasiveness. We have investigated the role of Tiam1 in tumor-associated fibroblasts as a modulator of tumor cell invasion and metastasis, using retroviral delivery of short hairpin RNA to suppress Tiam1 levels in three different experimental models. In spheroid co-culture of mammary epithelial cells and fibroblasts, Tiam1 silencing in fibroblasts led to increased epithelial cell outgrowth into matrix. In tissue-engineered human skin, Tiam1 silencing in dermal fibroblasts led to increased invasiveness of epidermal keratinocytes with premalignant features. In a model of human breast cancer in mice, co-implantation of mammary fibroblasts inhibited tumor invasion and metastasis, which was reversed by Tiam1 silencing in co-injected fibroblasts. These results suggest that stromal Tiam1 may play a role in modulating the effects of the tumor microenvironment on malignant cell invasion and metastasis. This suggests a set of pathways for further investigation, with implications for future therapeutic targets.
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Affiliation(s)
- K Xu
- Molecular Oncology Research Institute, Tufts Medical Center, Tufts University, Boston, MA 02111, USA
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