1
|
Ramsey A, Akana L, Miyajima E, Douglas S, Gray J, Rowland A, Sharma KD, Xu J, Xie JY, Zhou GL. CAP1 (cyclase-associated protein 1) mediates the cyclic AMP signals that activate Rap1 in stimulating matrix adhesion of colon cancer cells. Cell Signal 2023; 104:110589. [PMID: 36621727 PMCID: PMC9908859 DOI: 10.1016/j.cellsig.2023.110589] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 12/12/2022] [Accepted: 01/03/2023] [Indexed: 01/07/2023]
Abstract
We previously reported that CAP1 (Cyclase-Associated Protein 1) regulates matrix adhesion in mammalian cells through FAK (Focal Adhesion Kinase). More recently, we discovered a phosphor-regulation mechanism for CAP1 through the Ser307/Ser309 tandem site that is of critical importance for all CAP1 functions. However, molecular mechanisms underlying the CAP1 function in adhesion and its regulation remain largely unknown. Here we report that Rap1 also facilitates the CAP1 function in adhesion, and more importantly, we identify a novel signaling pathway where CAP1 mediates the cAMP signals, through the cAMP effectors Epac (Exchange proteins directly activated by cAMP) and PKA (Protein Kinase A), to activate Rap1 in stimulating matrix adhesion in colon cancer cells. Knockdown of CAP1 led to opposite adhesion phenotypes in SW480 and HCT116 colon cancer cells, with reduced matrix adhesion and reduced FAK and Rap1 activities in SW480 cells while it stimulated matrix adhesion as well as FAK and Rap1 activities in HCT116 cells. Importantly, depletion of CAP1 abolished the stimulatory effects of the cAMP activators forskolin and isoproterenol, as well as that of Epac and PKA, on matrix adhesion in both cell types. Our results consistently support a required role for CAP1 in the cAMP activation of Rap1. Identification of the key role for CAP1 in linking the major second messenger cAMP to activation of Rap1 in stimulating adhesion, which may potentially also regulate proliferation in other cell types, not only vertically extends our knowledge on CAP biology, but also carries important translational potential for targeting CAP1 in cancer therapeutics.
Collapse
Affiliation(s)
- Auburn Ramsey
- Department of Biological Sciences, Arkansas State University, State University, AR 72467, USA
| | - Lokesh Akana
- Department of Biological Sciences, Arkansas State University, State University, AR 72467, USA
| | - Erina Miyajima
- Department of Biological Sciences, Arkansas State University, State University, AR 72467, USA
| | - Spencer Douglas
- Department of Biological Sciences, Arkansas State University, State University, AR 72467, USA
| | - Joshua Gray
- Department of Biological Sciences, Arkansas State University, State University, AR 72467, USA
| | - Alyssa Rowland
- Department of Biological Sciences, Arkansas State University, State University, AR 72467, USA
| | - Krishna Deo Sharma
- Molecular Biosciences Graduate Program, Arkansas State University, State University, AR 72467, USA
| | - Jianfeng Xu
- Molecular Biosciences Graduate Program, Arkansas State University, State University, AR 72467, USA; Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72401, USA; College of Agriculture, Arkansas State University, State University, AR 72467, USA
| | - Jennifer Y Xie
- Molecular Biosciences Graduate Program, Arkansas State University, State University, AR 72467, USA; Department of Basic Sciences, New York Institute of Technology College of Osteopathic Medicine at Arkansas State University, Jonesboro, AR 72401, USA
| | - Guo-Lei Zhou
- Department of Biological Sciences, Arkansas State University, State University, AR 72467, USA; Molecular Biosciences Graduate Program, Arkansas State University, State University, AR 72467, USA.
| |
Collapse
|
2
|
A Cdc42-mediated supracellular network drives polarized forces and Drosophila egg chamber extension. Nat Commun 2020; 11:1921. [PMID: 32317641 PMCID: PMC7174421 DOI: 10.1038/s41467-020-15593-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 03/13/2020] [Indexed: 01/09/2023] Open
Abstract
Actomyosin supracellular networks emerge during development and tissue repair. These cytoskeletal structures are able to generate large scale forces that can extensively remodel epithelia driving tissue buckling, closure and extension. How supracellular networks emerge, are controlled and mechanically work still remain elusive. During Drosophila oogenesis, the egg chamber elongates along the anterior-posterior axis. Here we show that a dorsal-ventral polarized supracellular F-actin network, running around the egg chamber on the basal side of follicle cells, emerges from polarized intercellular filopodia that radiate from basal stress fibers and extend penetrating neighboring cell cortexes. Filopodia can be mechanosensitive and function as cell-cell anchoring sites. The small GTPase Cdc42 governs the formation and distribution of intercellular filopodia and stress fibers in follicle cells. Finally, our study shows that a Cdc42-dependent supracellular cytoskeletal network provides a scaffold integrating local oscillatory actomyosin contractions at the tissue scale to drive global polarized forces and tissue elongation. During development, organs undergo large scale forces driven by the cytoskeleton but the precise molecular regulation of cytoskeletal networks remains unclear. Here, the authors report a Cdc42-dependent supracellular cytoskeletal network integrates local actomyosin contraction at tissue scale and drives global tissue elongation.
Collapse
|
3
|
Tian X, Yan H, Li J, Wu S, Wang J, Fan L. Neurotrophin Promotes Neurite Outgrowth by Inhibiting Rif GTPase Activation Downstream of MAPKs and PI3K Signaling. Int J Mol Sci 2017; 18:E148. [PMID: 28098758 PMCID: PMC5297781 DOI: 10.3390/ijms18010148] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 01/01/2017] [Accepted: 01/06/2017] [Indexed: 12/16/2022] Open
Abstract
Members of the well-known semaphorin family of proteins can induce both repulsive and attractive signaling in neural network formation and their cytoskeletal effects are mediated in part by small guanosine 5'-triphosphatase (GTPases). The aim of this study was to investigate the cellular role of Rif GTPase in the neurotrophin-induced neurite outgrowth. By using PC12 cells which are known to cease dividing and begin to show neurite outgrowth responding to nerve growth factor (NGF), we found that semaphorin 6A was as effective as nerve growth factor at stimulating neurite outgrowth in PC12 cells, and that its neurotrophic effect was transmitted through signaling by mitogen-activated protein kinases (MAPKs) and phosphatidylinositol-3-kinase (PI3K). We further found that neurotrophin-induced neurite formation in PC12 cells could be partially mediated by inhibition of Rif GTPase activity downstream of MAPKs and PI3K signaling. In conclusion, we newly identified Rif as a regulator of the cytoskeletal rearrangement mediated by semaphorins.
Collapse
Affiliation(s)
- Xiaoxia Tian
- School of Life Sciences, Inner Mongolia University, Hohhot 010021, China.
| | - Huijuan Yan
- School of Life Sciences, Inner Mongolia University, Hohhot 010021, China.
| | - Jiayi Li
- School of Life Sciences, Inner Mongolia University, Hohhot 010021, China.
| | - Shuang Wu
- School of Life Sciences, Inner Mongolia University, Hohhot 010021, China.
| | - Junyu Wang
- School of Life Sciences, Inner Mongolia University, Hohhot 010021, China.
| | - Lifei Fan
- School of Life Sciences, Inner Mongolia University, Hohhot 010021, China.
| |
Collapse
|
4
|
Okada T, Lee AY, Qin LX, Agaram N, Mimae T, Shen Y, O'Connor R, López-Lago MA, Craig A, Miller ML, Agius P, Molinelli E, Socci ND, Crago AM, Shima F, Sander C, Singer S. Integrin-α10 Dependency Identifies RAC and RICTOR as Therapeutic Targets in High-Grade Myxofibrosarcoma. Cancer Discov 2016; 6:1148-1165. [PMID: 27577794 PMCID: PMC5050162 DOI: 10.1158/2159-8290.cd-15-1481] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 08/25/2016] [Indexed: 12/31/2022]
Abstract
Myxofibrosarcoma is a common mesenchymal malignancy with complex genomics and heterogeneous clinical outcomes. Through gene-expression profiling of 64 primary high-grade myxofibrosarcomas, we defined an expression signature associated with clinical outcome. The gene most significantly associated with disease-specific death and distant metastasis was ITGA10 (integrin-α10). Functional studies revealed that myxofibrosarcoma cells strongly depended on integrin-α10, whereas normal mesenchymal cells did not. Integrin-α10 transmitted its tumor-specific signal via TRIO and RICTOR, two oncoproteins that are frequently co-overexpressed through gene amplification on chromosome 5p. TRIO and RICTOR activated RAC/PAK and AKT/mTOR to promote sarcoma cell survival. Inhibition of these proteins with EHop-016 (RAC inhibitor) and INK128 (mTOR inhibitor) had antitumor effects in tumor-derived cell lines and mouse xenografts, and combining the drugs enhanced the effects. Our results demonstrate the importance of integrin-α10/TRIO/RICTOR signaling for driving myxofibrosarcoma progression and provide the basis for promising targeted treatment strategies for patients with high-risk disease. SIGNIFICANCE Identifying the molecular pathogenesis for myxofibrosarcoma progression has proven challenging given the highly complex genomic alterations in this tumor type. We found that integrin-α10 promotes tumor cell survival through activation of TRIO-RAC-RICTOR-mTOR signaling, and that inhibitors of RAC and mTOR have antitumor effects in vivo, thus identifying a potential treatment strategy for patients with high-risk myxofibrosarcoma. Cancer Discov; 6(10); 1148-65. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 1069.
Collapse
Affiliation(s)
- Tomoyo Okada
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York.
| | - Ann Y Lee
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Li-Xuan Qin
- Department of Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Narasimhan Agaram
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Takahiro Mimae
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Yawei Shen
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Rachael O'Connor
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Miguel A López-Lago
- Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Amanda Craig
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Martin L Miller
- Computational Biology Center, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Phaedra Agius
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Evan Molinelli
- Computational Biology Center, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Nicholas D Socci
- Computational Biology Center, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Aimee M Crago
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York. Department of Surgery, Weill Cornell Medical College, New York, New York
| | - Fumi Shima
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan
| | - Chris Sander
- Computational Biology Center, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Samuel Singer
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York. Department of Surgery, Weill Cornell Medical College, New York, New York.
| |
Collapse
|
5
|
Liu A, Zhou Z, Dang R, Zhu Y, Qi J, He G, Leung C, Pak D, Jia Z, Xie W. Neuroligin 1 regulates spines and synaptic plasticity via LIMK1/cofilin-mediated actin reorganization. J Cell Biol 2016; 212:449-63. [PMID: 26880202 PMCID: PMC4754719 DOI: 10.1083/jcb.201509023] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The C-terminal domain of NLG1 is sufficient to enhance spine and synapse number and to modulate synaptic plasticity, and it exerts these effects via its interaction with SPAR and the subsequent activation of LIMK1/cofilin-mediated actin reorganization. Neuroligin (NLG) 1 is important for synapse development and function, but the underlying mechanisms remain unclear. It is known that at least some aspects of NLG1 function are independent of the presynaptic neurexin, suggesting that the C-terminal domain (CTD) of NLG1 may be sufficient for synaptic regulation. In addition, NLG1 is subjected to activity-dependent proteolytic cleavage, generating a cytosolic CTD fragment, but the significance of this process remains unknown. In this study, we show that the CTD of NLG1 is sufficient to (a) enhance spine and synapse number, (b) modulate synaptic plasticity, and (c) exert these effects via its interaction with spine-associated Rap guanosine triphosphatase–activating protein and subsequent activation of LIM-domain protein kinase 1/cofilin–mediated actin reorganization. Our results provide a novel postsynaptic mechanism by which NLG1 regulates synapse development and function.
Collapse
Affiliation(s)
- An Liu
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing 210096, China
| | - Zikai Zhou
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing 210096, China Institute of Life Sciences, The Collaborative Innovation Center for Brain Science, Southeast University, Nanjing 210096, China
| | - Rui Dang
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing 210096, China
| | - Yuehua Zhu
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing 210096, China
| | - Junxia Qi
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing 210096, China
| | - Guiqin He
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing 210096, China
| | - Celeste Leung
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Daniel Pak
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC 20007
| | - Zhengping Jia
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Wei Xie
- The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing 210096, China Institute of Life Sciences, The Collaborative Innovation Center for Brain Science, Southeast University, Nanjing 210096, China
| |
Collapse
|
6
|
Jean L, Yang L, Majumdar D, Gao Y, Shi M, Brewer BM, Li D, Webb DJ. The Rho family GEF Asef2 regulates cell migration in three dimensional (3D) collagen matrices through myosin II. Cell Adh Migr 2015; 8:460-7. [PMID: 25517435 DOI: 10.4161/19336918.2014.983778] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cell migration is fundamental to a variety of physiological processes, including tissue development, homeostasis, and regeneration. Migration has been extensively studied with cells on 2-dimensional (2D) substrates, but much less is known about cell migration in 3D environments. Tissues and organs are 3D, which is the native environment of cells in vivo, pointing to a need to understand migration and the mechanisms that regulate it in 3D environments. To investigate cell migration in 3D environments, we developed microfluidic devices that afford a controlled, reproducible platform for generating 3D matrices. Using these devices, we show that the Rho family guanine nucleotide exchange factor (GEF) Asef2 inhibits cell migration in 3D type I collagen (collagen I) matrices. Treatment of cells with the myosin II (MyoII) inhibitor blebbistatin abolished the decrease in migration by Asef2. Moreover, Asef2 enhanced MyoII activity as shown by increased phosphorylation of serine 19 (S19). Furthermore, Asef2 increased activation of Rac, which is a Rho family small GTPase, in 3D collagen I matrices. Inhibition of Rac activity by treatment with the Rac-specific inhibitor NSC23766 abrogated the Asef2-promoted increase in S19 MyoII phosphorylation. Thus, our results indicate that Asef2 regulates cell migration in 3D collagen I matrices through a Rac-MyoII-dependent mechanism.
Collapse
Key Words
- 2D, 2-dimensional
- 3D, 3-dimensional
- Collagen I, type I collagen
- DMEM, Dulbecco's Modified Eagle Medium
- ECM, extracellular matrix
- GEF, guanine nucleotide exchange factor
- MyoII, non-muscle myosin II
- PAK, p21-activated kinase
- PBD, p21-binding domain
- PBS, phosphate buffer saline
- PDMS, polydimethylsiloxane
- Rac
- Rho family GTPases
- UV, ultra-violet
- guanine nucleotide exchange factor
- microfluidics
- myosin II
- type I collagen
Collapse
Affiliation(s)
- Léolène Jean
- a Department of Biological Sciences and Vanderbilt Kennedy Center for Research on Human Development ; Vanderbilt University ; Nashville , TN USA
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Aznar N, Midde KK, Dunkel Y, Lopez-Sanchez I, Pavlova Y, Marivin A, Barbazán J, Murray F, Nitsche U, Janssen KP, Willert K, Goel A, Abal M, Garcia-Marcos M, Ghosh P. Daple is a novel non-receptor GEF required for trimeric G protein activation in Wnt signaling. eLife 2015; 4:e07091. [PMID: 26126266 PMCID: PMC4484057 DOI: 10.7554/elife.07091] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 06/01/2015] [Indexed: 12/17/2022] Open
Abstract
Wnt signaling is essential for tissue homeostasis and its dysregulation causes cancer. Wnt ligands trigger signaling by activating Frizzled receptors (FZDRs), which belong to the G-protein coupled receptor superfamily. However, the mechanisms of G protein activation in Wnt signaling remain controversial. In this study, we demonstrate that FZDRs activate G proteins and trigger non-canonical Wnt signaling via the Dishevelled-binding protein, Daple. Daple contains a Gα-binding and activating (GBA) motif, which activates Gαi proteins and an adjacent domain that directly binds FZDRs, thereby linking Wnt stimulation to G protein activation. This triggers non-canonical Wnt responses, that is, suppresses the β-catenin/TCF/LEF pathway and tumorigenesis, but enhances PI3K-Akt and Rac1 signals and tumor cell invasiveness. In colorectal cancers, Daple is suppressed during adenoma-to-carcinoma transformation and expressed later in metastasized tumor cells. Thus, Daple activates Gαi and enhances non-canonical Wnt signaling by FZDRs, and its dysregulation can impact both tumor initiation and progression to metastasis.
Collapse
Affiliation(s)
- Nicolas Aznar
- Department of Medicine, University of California, San Diego, San Diego, United States
| | - Krishna K Midde
- Department of Medicine, University of California, San Diego, San Diego, United States
| | - Ying Dunkel
- Department of Medicine, University of California, San Diego, San Diego, United States
| | | | - Yelena Pavlova
- Department of Medicine, University of California, San Diego, San Diego, United States
| | - Arthur Marivin
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Jorge Barbazán
- Translational Medical Oncology Laboratory, Health Research Institute of Santiago, Servizo Galego de Saúde, Santiago de Compostela, Spain
| | - Fiona Murray
- Department of Medicine, University of California, San Diego, San Diego, United States
| | - Ulrich Nitsche
- Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Klaus-Peter Janssen
- Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Karl Willert
- Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, California, United States
| | - Ajay Goel
- Division of Gastroenterology, Department of Internal Medicine and Charles A Sammons Cancer Center and Baylor Research Institute, Baylor University Medical Center, Dallas, Texas, United States
| | - Miguel Abal
- Translational Medical Oncology Laboratory, Health Research Institute of Santiago, Servizo Galego de Saúde, Santiago de Compostela, Spain
| | - Mikel Garcia-Marcos
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Pradipta Ghosh
- Department of Medicine, University of California, San Diego, San Diego, United States
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Zhang CC, Li R, Jiang H, Lin S, Rogalski JC, Liu K, Kast J. Development and application of a quantitative multiplexed small GTPase activity assay using targeted proteomics. J Proteome Res 2015; 14:967-76. [PMID: 25569337 DOI: 10.1021/pr501010v] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Small GTPases are a family of key signaling molecules that are ubiquitously expressed in various types of cells. Their activity is often analyzed by western blot, which is limited by its multiplexing capability, the quality of isoform-specific antibodies, and the accuracy of quantification. To overcome these issues, a quantitative multiplexed small GTPase activity assay has been developed. Using four different binding domains, this assay allows the binding of up to 12 active small GTPase isoforms simultaneously in a single experiment. To accurately quantify the closely related small GTPase isoforms, a targeted proteomic approach, i.e., selected/multiple reaction monitoring, was developed, and its functionality and reproducibility were validated. This assay was successfully applied to human platelets and revealed time-resolved coactivation of multiple small GTPase isoforms in response to agonists and differential activation of these isoforms in response to inhibitor treatment. This widely applicable approach can be used for signaling pathway studies and inhibitor screening in many cellular systems.
Collapse
Affiliation(s)
- Cheng-Cheng Zhang
- The Biomedical Research Centre, ∥The Centre for Blood Research, University of British Columbia , Vancouver, BC V6T 1Z3, Canada
| | | | | | | | | | | | | |
Collapse
|
10
|
Morrison AR, Yarovinsky TO, Young BD, Moraes F, Ross TD, Ceneri N, Zhang J, Zhuang ZW, Sinusas AJ, Pardi R, Schwartz MA, Simons M, Bender JR. Chemokine-coupled β2 integrin-induced macrophage Rac2-Myosin IIA interaction regulates VEGF-A mRNA stability and arteriogenesis. J Exp Med 2014; 211:1957-68. [PMID: 25180062 PMCID: PMC4172219 DOI: 10.1084/jem.20132130] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 08/01/2014] [Indexed: 12/14/2022] Open
Abstract
Myeloid cells are important contributors to arteriogenesis, but their key molecular triggers and cellular effectors are largely unknown. We report, in inflammatory monocytes, that the combination of chemokine receptor (CCR2) and adhesion receptor (β2 integrin) engagement leads to an interaction between activated Rac2 and Myosin 9 (Myh9), the heavy chain of Myosin IIA, resulting in augmented vascular endothelial growth factor A (VEGF-A) expression and induction of arteriogenesis. In human monocytes, CCL2 stimulation coupled to ICAM-1 adhesion led to rapid nuclear-to-cytosolic translocation of the RNA-binding protein HuR. This activation of HuR and its stabilization of VEGF-A mRNA were Rac2-dependent, and proteomic analysis for Rac2 interactors identified the 226 kD protein Myh9. The level of induced Rac2-Myh9 interaction strongly correlated with the degree of HuR translocation. CCL2-coupled ICAM-1 adhesion-driven HuR translocation and consequent VEGF-A mRNA stabilization were absent in Myh9(-/-) macrophages. Macrophage VEGF-A production, ischemic tissue VEGF-A levels, and flow recovery to hind limb ischemia were impaired in myeloid-specific Myh9(-/-) mice, despite preserved macrophage recruitment to the ischemic muscle. Micro-CT arteriography determined the impairment to be defective induced arteriogenesis, whereas developmental vasculogenesis was unaffected. These results place the macrophage at the center of ischemia-induced arteriogenesis, and they establish a novel role for Myosin IIA in signal transduction events modulating VEGF-A expression in tissue.
Collapse
Affiliation(s)
- Alan R Morrison
- Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511
| | - Timur O Yarovinsky
- Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511
| | - Bryan D Young
- Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511
| | - Filipa Moraes
- Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511
| | - Tyler D Ross
- Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511
| | - Nicolle Ceneri
- Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511
| | - Jiasheng Zhang
- Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511
| | - Zhen W Zhuang
- Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511
| | - Albert J Sinusas
- Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511
| | - Ruggero Pardi
- Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, 20123 Milan, Italy
| | - Martin A Schwartz
- Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511
| | - Michael Simons
- Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511
| | - Jeffrey R Bender
- Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511 Section of Cardiovascular Medicine, Department of Internal Medicine and the Yale Cardiovascular Research Center, Department of Immunobiology, Department of Cell Biology, and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511
| |
Collapse
|
11
|
Evans JC, Hines KM, Forsythe JG, Erdogan B, Shi M, Hill S, Rose KL, McLean JA, Webb DJ. Phosphorylation of serine 106 in Asef2 regulates cell migration and adhesion turnover. J Proteome Res 2014; 13:3303-13. [PMID: 24874604 PMCID: PMC4084842 DOI: 10.1021/pr5001384] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Asef2, a 652-amino acid protein,
is a guanine nucleotide exchange
factor (GEF) that regulates cell migration and other processes via
activation of Rho family GTPases, including Rac. Binding of the tumor
suppressor adenomatous polyposis coli (APC) to Asef2 is known to induce
its GEF activity; however, little is currently known about other modes
of Asef2 regulation. Here, we investigated the role of phosphorylation
in regulating Asef2 activity and function. Using high-resolution mass
spectrometry (MS) and tandem mass spectrometry (MS/MS), we obtained
complete coverage of all phosphorylatable residues and identified
six phosphorylation sites. One of these, serine 106 (S106), was particularly
intriguing as a potential regulator of Asef2 activity because of its
location within the APC-binding domain. Interestingly, mutation of
this serine to alanine (S106A), a non-phosphorylatable analogue, greatly
diminished the ability of Asef2 to activate Rac, while a phosphomimetic
mutation (serine to aspartic acid, S106D) enhanced Rac activation.
Furthermore, expression of these mutants in HT1080 cells demonstrated
that phosphorylation of S106 is critical for Asef2-promoted migration
and for cell-matrix adhesion assembly and disassembly (adhesion turnover),
which is a process that facilitates efficient migration. Collectively,
our results show that phosphorylation of S106 modulates Asef2 GEF
activity and Asef2-mediated cell migration and adhesion turnover.
Collapse
Affiliation(s)
- J Corey Evans
- Department of Biological Sciences and Vanderbilt Kennedy Center for Research on Human Development, ‡Department of Chemistry, §Vanderbilt Institute for Chemical Biology (VICB), ∥Vanderbilt Institute for Integrative Biosystems Research and Education (VIIBRE), ⊥Mass Spectrometry Research Center, #Department of Biochemistry, and ●Department of Cancer Biology, Vanderbilt University , Nashville, Tennessee 37235, United States
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Sun S, Zhang H, Liu J, Popugaeva E, Xu NJ, Feske S, White CL, Bezprozvanny I. Reduced synaptic STIM2 expression and impaired store-operated calcium entry cause destabilization of mature spines in mutant presenilin mice. Neuron 2014; 82:79-93. [PMID: 24698269 DOI: 10.1016/j.neuron.2014.02.019] [Citation(s) in RCA: 210] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2014] [Indexed: 12/14/2022]
Abstract
Mushroom dendritic spine structures are essential for memory storage, and the loss of mushroom spines may explain memory defects in Alzheimer's disease (AD). Here we show a significant reduction in the fraction of mushroom spines in hippocampal neurons from the presenilin-1 M146V knockin (KI) mouse model of familial AD (FAD). The stabilization of mushroom spines depends on STIM2-mediated neuronal store-operated calcium influx (nSOC) and continuous activity of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII). We demonstrate that STIM2-nSOC-CaMKII pathway is compromised in KI neurons, in aging neurons, and in sporadic AD brains due to downregulation of STIM2 protein. We further establish that overexpression of STIM2 rescues synaptic nSOC, CaMKII activity, and mushroom spine loss in KI neurons. Our results identify STIM2-nSOC-CaMKII synaptic maintenance pathway as a novel potential therapeutic target for treatment of AD and age-related memory decline.
Collapse
Affiliation(s)
- Suya Sun
- Department of Physiology, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Hua Zhang
- Department of Physiology, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Jie Liu
- Department of Physiology, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Elena Popugaeva
- Laboratory of Molecular Neurodegeneration, Saint Petersburg State Polytechnical University, Saint Petersburg, 195251, Russia
| | - Nan-Jie Xu
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Stefan Feske
- Department of Pathology, New York University Langone Medical Center, New York, NY 10016, USA
| | - Charles L White
- Department of Pathology, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Ilya Bezprozvanny
- Department of Physiology, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, USA; Laboratory of Molecular Neurodegeneration, Saint Petersburg State Polytechnical University, Saint Petersburg, 195251, Russia.
| |
Collapse
|
13
|
Monteiro AC, Luissint AC, Sumagin R, Lai C, Vielmuth F, Wolf MF, Laur O, Reiss K, Spindler V, Stehle T, Dermody TS, Nusrat A, Parkos CA. Trans-dimerization of JAM-A regulates Rap2 and is mediated by a domain that is distinct from the cis-dimerization interface. Mol Biol Cell 2014; 25:1574-85. [PMID: 24672055 PMCID: PMC4019489 DOI: 10.1091/mbc.e14-01-0018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Junctional adhesion molecule-A (JAM-A) is a tight junction–associated signaling protein that homodimerizes across cells at a unique motif to activate the small GTPase Rap2, previously implicated in the regulation of barrier function. JAM-A may therefore act as a barrier-inducing molecular switch that is activated when cells become confluent. Junctional adhesion molecule-A (JAM-A) is a tight junction–associated signaling protein that regulates epithelial cell proliferation, migration, and barrier function. JAM-A dimerization on a common cell surface (in cis) has been shown to regulate cell migration, and evidence suggests that JAM-A may form homodimers between cells (in trans). Indeed, transfection experiments revealed accumulation of JAM-A at sites between transfected cells, which was lost in cells expressing cis- or predicted trans-dimerization null mutants. Of importance, microspheres coated with JAM-A containing alanine substitutions to residues 43NNP45 (NNP-JAM-A) within the predicted trans-dimerization site did not aggregate. In contrast, beads coated with cis-null JAM-A demonstrated enhanced clustering similar to that observed with wild-type (WT) JAM-A. In addition, atomic force microscopy revealed decreased association forces in NNP-JAM-A compared with WT and cis-null JAM-A. Assessment of effects of JAM-A dimerization on cell signaling revealed that expression of trans- but not cis-null JAM-A mutants decreased Rap2 activity. Furthermore, confluent cells, which enable trans-dimerization, had enhanced Rap2 activity. Taken together, these results suggest that trans-dimerization of JAM-A occurs at a unique site and with different affinity compared with dimerization in cis. Trans-dimerization of JAM-A may thus act as a barrier-inducing molecular switch that is activated when cells become confluent.
Collapse
Affiliation(s)
- Ana C Monteiro
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Anny-Claude Luissint
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Ronen Sumagin
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Caroline Lai
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232Elizabeth B. Lamb Center for Pediatric Research, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Franziska Vielmuth
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians University, 80336 Munich, Germany
| | - Mattie F Wolf
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Oskar Laur
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Kerstin Reiss
- Interfaculty Institute of Biochemistry, University of Tübingen, D-72076 Tübingen, Germany
| | - Volker Spindler
- Institute of Anatomy and Cell Biology, Ludwig-Maximilians University, 80336 Munich, Germany
| | - Thilo Stehle
- Elizabeth B. Lamb Center for Pediatric Research, Vanderbilt University School of Medicine, Nashville, TN 37232Interfaculty Institute of Biochemistry, University of Tübingen, D-72076 Tübingen, Germany
| | - Terence S Dermody
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232Elizabeth B. Lamb Center for Pediatric Research, Vanderbilt University School of Medicine, Nashville, TN 37232Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Asma Nusrat
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Charles A Parkos
- Epithelial Pathobiology and Mucosal Inflammation Research Unit, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| |
Collapse
|
14
|
Monteiro AC, Sumagin R, Rankin CR, Leoni G, Mina MJ, Reiter DM, Stehle T, Dermody TS, Schaefer SA, Hall RA, Nusrat A, Parkos CA. JAM-A associates with ZO-2, afadin, and PDZ-GEF1 to activate Rap2c and regulate epithelial barrier function. Mol Biol Cell 2013; 24:2849-60. [PMID: 23885123 PMCID: PMC3771947 DOI: 10.1091/mbc.e13-06-0298] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Intestinal barrier function is regulated by epithelial tight junctions, structures that control paracellular permeability. JAM-A regulates epithelial permeability through association with ZO-2, afadin, and PDZ-GEF1 to activate Rap2c and control contraction of the apical cytoskeleton. Intestinal barrier function is regulated by epithelial tight junctions (TJs), structures that control paracellular permeability. Junctional adhesion molecule-A (JAM-A) is a TJ-associated protein that regulates barrier; however, mechanisms linking JAM-A to epithelial permeability are poorly understood. Here we report that JAM-A associates directly with ZO-2 and indirectly with afadin, and this complex, along with PDZ-GEF1, activates the small GTPase Rap2c. Supporting a functional link, small interfering RNA–mediated down-regulation of the foregoing regulatory proteins results in enhanced permeability similar to that observed after JAM-A loss. JAM-A–deficient mice and cultured epithelial cells demonstrate enhanced paracellular permeability to large molecules, revealing a potential role of JAM-A in controlling perijunctional actin cytoskeleton in addition to its previously reported role in regulating claudin proteins and small-molecule permeability. Further experiments suggest that JAM-A does not regulate actin turnover but modulates activity of RhoA and phosphorylation of nonmuscle myosin, both implicated in actomyosin contraction. These results suggest that JAM-A regulates epithelial permeability via association with ZO-2, afadin, and PDZ-GEF1 to activate Rap2c and control contraction of the apical cytoskeleton.
Collapse
Affiliation(s)
- Ana C Monteiro
- Department of Pathology, Emory University School of Medicine, Atlanta, GA 30306 Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30306 Emory Rollins School of Public Health, Atlanta, GA 30306 Interfaculty Institute of Biochemistry, University of Tübingen, D-72076 Tübingen, Germany Department of Pediatrics and Pathology, Vanderbilt University School of Medicine, Nashville, TN 37230 Departments of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37230 Elizabeth B. Lamb Center for Pediatric Research, Vanderbilt University School of Medicine, Nashville, TN 37230
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Niebel B, Weiche B, Mueller AL, Li DY, Karnowski N, Famulok M. A luminescent oxygen channeling biosensor that measures small GTPase activation. Chem Commun (Camb) 2011; 47:7521-3. [PMID: 21625685 DOI: 10.1039/c1cc11944c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We established a homogeneous luminescent oxygen channeling sensor for measuring activation states of small GTPases. The assay quantifies activated GTPases in cell lysates, can be applied to different GTPases, and can be used for multiplex screening. The study will provide guidelines for determining activation states of diverse GTPases in various biological contexts.
Collapse
Affiliation(s)
- Björn Niebel
- LIMES Institute, Chemical Biology & Medicinal Chemistry Unit, University of Bonn, 53121 Bonn, Germany
| | | | | | | | | | | |
Collapse
|
16
|
Zhang N, Liang J, Tian Y, Yuan L, Wu L, Miao S, Zong S, Wang L. A novel testis-specific GTPase serves as a link to proteasome biogenesis: functional characterization of RhoS/RSA-14-44 in spermatogenesis. Mol Biol Cell 2010; 21:4312-24. [PMID: 20980621 PMCID: PMC3002385 DOI: 10.1091/mbc.e10-04-0310] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
We functionally characterized RhoS/RSA-14-44 as a new member of Rho GTPase subfamily in spermatogenesis, which provides a direct link between Rho family GTPase and the proteasome biogenesis. Most Rho family GTPases serve as key molecular switches in a wide spectrum of biological processes. An increasing number of studies have expanded their roles to the spermatogenesis. Several members of Rho family have been confirmed to be essential for mammalian spermatogenesis, but the precise roles of this family in male reproduction have not been well studied yet. Here we report a surprising function of an atypical and testis-specific Rho GTPase, RSA-14-44 in spermatogenesis. Featured by unique structural and expressional patterns, RSA-14-44 is distinguished from three canonical members of Rho cluster. Thus, we define RSA-14-44 as a new member of Rho GTPases family and rename it RhoS (Rho in spermatogenic cells). RhoS associates with PSMB5, a catalytic subunit of the proteasome, in a series of stage-specific spermatogenic cells. More importantly, RhoS does not directly modulate the cellular proteasome activity, but participates in regulating the stability of “unincorporated” PSMB5 precursors. Meanwhile, our data demonstrate that the activation of RhoS is prerequisite for negatively regulating the stability of PSMB5 precursors. Therefore, our finding uncovers a direct and functional connection between the Rho GTPase family and the pathway of proteasome biogenesis and provide new clues for deciphering the secrets of spermatogenesis.
Collapse
Affiliation(s)
- Ning Zhang
- Chinese Academy of Medical Sciences, Peking Union Medical College, Tsinghua University, Beijing, China
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Nini L, Dagnino L. Accurate and reproducible measurements of RhoA activation in small samples of primary cells. Anal Biochem 2010; 398:135-7. [DOI: 10.1016/j.ab.2009.11.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 10/31/2009] [Accepted: 11/11/2009] [Indexed: 11/17/2022]
|
18
|
Torres VA, Mielgo A, Barbero S, Hsiao R, Wilkins JA, Stupack DG. Rab5 mediates caspase-8-promoted cell motility and metastasis. Mol Biol Cell 2009; 21:369-76. [PMID: 19923319 PMCID: PMC2808229 DOI: 10.1091/mbc.e09-09-0769] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Integrins signaling promotes nonapoptotic functions of caspase-8 via activation of small GTPases from the Rab and Rac families. Integrin ligation promotes Rab5 activity, which mediates subsequent activation of Rac1, cytoskeletal remodeling, and enhanced cell motility. Caspase-8 is a key apical sensory protein that governs cell responses to environmental cues, alternatively promoting apoptosis, proliferation, and cell migration. The proteins responsible for integration of these pathways, however, have remained elusive. Here, we reveal that Rab5 regulates caspase-8–dependent signaling from integrins. Integrin ligation leads to Rab5 activation, association with integrins, and activation of Rac, in a caspase-8–dependent manner. Rab5 activation promotes colocalization and coprecipitation of integrins with caspase-8, concomitant with Rab5 recruitment to integrin-rich regions such as focal adhesions and membrane ruffles. Moreover, caspase-8 expression promotes Rab5-mediated internalization and the recycling of β1 integrins, increasing cell migration independently of caspase catalytic activity. Conversely, Rab5 knockdown prevented caspase-8–mediated integrin signaling for Rac activation, cell migration, and apoptotic signaling, respectively. Similarly, Rab5 was critical for caspase-8–driven cell migration in vivo, because knockdown of Rab5 compromised the ability of caspase-8 to promote metastasis under nonapoptotic conditions. These studies identify Rab5 as a key integrator of caspase-8–mediated signal transduction downstream of integrins, regulating cell survival and migration in vivo and in vitro.
Collapse
Affiliation(s)
- Vicente A Torres
- Department of Pathology, University of California San Diego, School of Medicine, La Jolla, CA 92093, USA
| | | | | | | | | | | |
Collapse
|
19
|
Manukyan M, Nalbant P, Luxen S, Hahn KM, Knaus UG. RhoA GTPase activation by TLR2 and TLR3 ligands: connecting via Src to NF-kappa B. THE JOURNAL OF IMMUNOLOGY 2009; 182:3522-9. [PMID: 19265130 DOI: 10.4049/jimmunol.0802280] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Rho GTPases are essential regulators of signaling networks emanating from many receptors involved in innate or adaptive immunity. The Rho family member RhoA controls cytoskeletal processes as well as the activity of transcription factors such as NF-kappaB, C/EBP, and serum response factor. The multifaceted host cell activation triggered by TLRs in response to soluble and particulate microbial structures includes rapid stimulation of RhoA activity. RhoA acts downstream of TLR2 in HEK-TLR2 and monocytic THP-1 cells, but the signaling pathway connecting TLR2 and RhoA is still unknown. It is also not clear if RhoA activation is dependent on a certain TLR adapter. Using lung epithelial cells, we demonstrate TLR2- and TLR3-triggered recruitment and activation of RhoA at receptor-proximal cellular compartments. RhoA activity was dependent on TLR-mediated stimulation of Src family kinases. Both Src family kinases and RhoA were required for NF-kappaB activation, whereas RhoA was dispensable for type I IFN generation. These results suggest that RhoA plays a role downstream of MyD88-dependent and -independent TLR signaling and acts as a molecular switch downstream of TLR-Src-initiated pathways.
Collapse
Affiliation(s)
- Maria Manukyan
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | | | | | | | |
Collapse
|
20
|
Lung epithelial injury by B. anthracis lethal toxin is caused by MKK-dependent loss of cytoskeletal integrity. PLoS One 2009; 4:e4755. [PMID: 19270742 PMCID: PMC2649448 DOI: 10.1371/journal.pone.0004755] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Accepted: 01/22/2009] [Indexed: 11/25/2022] Open
Abstract
Bacillus anthracis lethal toxin (LT) is a key virulence factor of anthrax and contributes significantly to the in vivo pathology. The enzymatically active component is a Zn2+-dependent metalloprotease that cleaves most isoforms of mitogen-activated protein kinase kinases (MKKs). Using ex vivo differentiated human lung epithelium we report that LT destroys lung epithelial barrier function and wound healing responses by immobilizing the actin and microtubule network. Long-term exposure to the toxin generated a unique cellular phenotype characterized by increased actin filament assembly, microtubule stabilization, and changes in junction complexes and focal adhesions. LT-exposed cells displayed randomly oriented, highly dynamic protrusions, polarization defects and impaired cell migration. Reconstitution of MAPK pathways revealed that this LT-induced phenotype was primarily dependent on the coordinated loss of MKK1 and MKK2 signaling. Thus, MKKs control fundamental aspects of cytoskeletal dynamics and cell motility. Even though LT disabled repair mechanisms, agents such as keratinocyte growth factor or dexamethasone improved epithelial barrier integrity by reducing cell death. These results suggest that co-administration of anti-cytotoxic drugs may be of benefit when treating inhalational anthrax.
Collapse
|