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Wang C, Gu J, Li H, Zhao B, Yu T, Guo CL, Huang M, Jiang W, Ouyang Q. The Discovery of GIT1/β-Pix Inhibitors: Virtual Screening and Biological Evaluation of New Small-molecule Compounds with Anti-invasion Effect in Gastrointestinal Neoplasms. Drug Des Devel Ther 2024; 18:3075-3088. [PMID: 39050797 PMCID: PMC11268723 DOI: 10.2147/dddt.s461609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 06/13/2024] [Indexed: 07/27/2024] Open
Abstract
Background and Objective GIT1 (G-protein-coupled receptor kinase interacting protein-1) has been found to be highly related with cancer cell invasion and metastasis in many cancer types. β-Pix (p21-activated kinase-interacting exchange factor) is one of the proteins that interact with GIT1. Targeting GIT1/β-Pix complex might be a potential therapeutic strategy for interfering cancer metastasis. However, at present, no well-recognized small-molecule inhibitor targeting GIT1/β-Pix is available. Thus, we aim to discover novel GIT1/β-Pix inhibitors with simple scaffold, high activity and low toxicity to develop new therapeutic strategies to restrain cancer metastasis. Methods GIT1/β-Pix inhibitors were identified from ChemBridge by virtual screening. Briefly, the modeling of GIT1 was performed and the establishment of GIT1/β-Pix binding pocket enabled the virtual screening to identify the inhibitor. In addition, direct binding of the candidate molecules to GIT1 was detected by biolayer interferometry (BLI) to discover the hit compound. Furthermore, the inhibitory effect on invasion of stomach and colon cancer cells in vitro was carried out by the transwell assay and detection of epithelial-mesenchymal transition (EMT)-related proteins. Finally, the binding mode of hit compound to GIT1 was estimated by molecular dynamics simulation to analyze the key amino residues to guide further optimization. Results We selected the top 50 compounds from the ChemBridge library by virtual screening. Then, by skeleton similarity analysis nine compounds were selected for further study. Furthermore, the direct interaction of nine compounds to GIT1 was detected by BLI to obtain the best affinitive compound. Finally, 17302836 was successfully identified (KD = 84.1±2.0 μM). In vitro tests on 17302836 showed significant anti-invasion effect on gastric cancer and colorectal cancer. Conclusion We discovered a new GIT1/β-Pix inhibitor (17302836) against gastrointestinal cancer invasion and metastasis. This study provides a promising candidate for developing new GIT1/β-Pix inhibitors for tumor treatment.
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Affiliation(s)
- Chenkun Wang
- Department of Pharmacy, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, People’s Republic of China
- Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, Chongqing, People’s Republic of China
| | - Jing Gu
- Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, Chongqing, People’s Republic of China
| | - Hongwei Li
- Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, Chongqing, People’s Republic of China
| | - Bo Zhao
- Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, Chongqing, People’s Republic of China
| | - Tao Yu
- Department of Pharmacy, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, People’s Republic of China
- Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, Chongqing, People’s Republic of China
| | - Chun-Ling Guo
- Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, Chongqing, People’s Republic of China
| | - Mouxin Huang
- Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, Chongqing, People’s Republic of China
| | - Weiwei Jiang
- Department of Pharmacy, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, People’s Republic of China
| | - Qin Ouyang
- Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, Chongqing, People’s Republic of China
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Portela M, Mukherjee S, Paul S, La Marca JE, Parsons LM, Veraksa A, Richardson HE. The Drosophila tumour suppressor Lgl and Vap33 activate the Hippo pathway through a dual mechanism. J Cell Sci 2024; 137:jcs261917. [PMID: 38240353 PMCID: PMC10911279 DOI: 10.1242/jcs.261917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 01/10/2024] [Indexed: 02/12/2024] Open
Abstract
The tumour suppressor, Lethal (2) giant larvae [Lgl; also known as L(2)gl], is an evolutionarily conserved protein that was discovered in the vinegar fly Drosophila, where its depletion results in tissue overgrowth and loss of cell polarity. Lgl links cell polarity and tissue growth through regulation of the Notch and the Hippo signalling pathways. Lgl regulates the Notch pathway by inhibiting V-ATPase activity via Vap33. How Lgl regulates the Hippo pathway was unclear. In this current study, we show that V-ATPase activity inhibits the Hippo pathway, whereas Vap33 acts to activate Hippo signalling. Vap33 physically and genetically interacts with the actin cytoskeletal regulators RtGEF (Pix) and Git, which also bind to the Hippo protein (Hpo) and are involved in the activation of the Hippo pathway. Additionally, we show that the ADP ribosylation factor Arf79F (Arf1), which is a Hpo interactor, is involved in the inhibition of the Hippo pathway. Altogether, our data suggest that Lgl acts via Vap33 to activate the Hippo pathway by a dual mechanism: (1) through interaction with RtGEF, Git and Arf79F, and (2) through interaction and inhibition of the V-ATPase, thereby controlling epithelial tissue growth.
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Affiliation(s)
- Marta Portela
- Department of Biochemistry & Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, 3086, Australia
- Cell Cycle and Development Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria, 3002, Australia
| | - Swastik Mukherjee
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Sayantanee Paul
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - John E. La Marca
- Department of Biochemistry & Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, 3086, Australia
- Blood Cells and Blood Cancer Division, Water and Eliza Hall Institute, Melbourne, Victoria, 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, 3010, Australia
- Genome Engineering and Cancer Modelling Program, Olivia Newton-John Cancer Research Institute, Melbourne, Victoria, 3084, Australia
| | - Linda M. Parsons
- Cell Cycle and Development Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria, 3002, Australia
| | - Alexey Veraksa
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Helena E. Richardson
- Department of Biochemistry & Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, 3086, Australia
- Cell Cycle and Development Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria, 3002, Australia
- Sir Peter MacCallum Department of Oncology, Department of Anatomy and Neuroscience, Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Victoria, 3010, Australia
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3
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Sulimenko V, Sládková V, Sulimenko T, Dráberová E, Vosecká V, Dráberová L, Skalli O, Dráber P. Regulation of microtubule nucleation in mouse bone marrow-derived mast cells by ARF GTPase-activating protein GIT2. Front Immunol 2024; 15:1321321. [PMID: 38370406 PMCID: PMC10870779 DOI: 10.3389/fimmu.2024.1321321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 01/16/2024] [Indexed: 02/20/2024] Open
Abstract
Aggregation of high-affinity IgE receptors (FcϵRIs) on granulated mast cells triggers signaling pathways leading to a calcium response and release of inflammatory mediators from secretory granules. While microtubules play a role in the degranulation process, the complex molecular mechanisms regulating microtubule remodeling in activated mast cells are only partially understood. Here, we demonstrate that the activation of bone marrow mast cells induced by FcϵRI aggregation increases centrosomal microtubule nucleation, with G protein-coupled receptor kinase-interacting protein 2 (GIT2) playing a vital role in this process. Both endogenous and exogenous GIT2 were associated with centrosomes and γ-tubulin complex proteins. Depletion of GIT2 enhanced centrosomal microtubule nucleation, and phenotypic rescue experiments revealed that GIT2, unlike GIT1, acts as a negative regulator of microtubule nucleation in mast cells. GIT2 also participated in the regulation of antigen-induced degranulation and chemotaxis. Further experiments showed that phosphorylation affected the centrosomal localization of GIT2 and that during antigen-induced activation, GIT2 was phosphorylated by conventional protein kinase C, which promoted microtubule nucleation. We propose that GIT2 is a novel regulator of microtubule organization in activated mast cells by modulating centrosomal microtubule nucleation.
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Affiliation(s)
- Vadym Sulimenko
- Laboratory of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Vladimíra Sládková
- Laboratory of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Tetyana Sulimenko
- Laboratory of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Eduarda Dráberová
- Laboratory of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Věra Vosecká
- Laboratory of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Lubica Dráberová
- Laboratory of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Omar Skalli
- Department of Biological Sciences, The University of Memphis, Memphis, TN, United States
| | - Pavel Dráber
- Laboratory of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
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Lin L, Hu K. Macrophage Function Modulated by tPA Signaling in Mouse Experimental Kidney Disease Models. Int J Mol Sci 2023; 24:11067. [PMID: 37446244 DOI: 10.3390/ijms241311067] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 06/29/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023] Open
Abstract
Macrophage infiltration and accumulation is a hallmark of chronic kidney disease. Tissue plasminogen activator (tPA) is a serine protease regulating the homeostasis of blood coagulation, fibrinolysis, and matrix degradation, and has been shown to act as a cytokine to trigger various receptor-mediated intracellular signal pathways, modulating macrophage function in response to kidney injury. In this review, we discuss the current understanding of tPA-modulated macrophage function and underlying signaling mechanisms during kidney fibrosis and inflammation.
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Affiliation(s)
- Ling Lin
- Division of Nephrology, Department of Medicine, Penn State University College of Medicine, Hershey, PA 17033, USA
| | - Kebin Hu
- Division of Nephrology, Department of Medicine, Penn State University College of Medicine, Hershey, PA 17033, USA
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, PA 17033, USA
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5
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Zhang W, Wu Y, J Gunst S. Membrane adhesion junctions regulate airway smooth muscle phenotype and function. Physiol Rev 2023; 103:2321-2347. [PMID: 36796098 PMCID: PMC10243546 DOI: 10.1152/physrev.00020.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 02/09/2023] [Accepted: 02/15/2023] [Indexed: 02/18/2023] Open
Abstract
The local environment surrounding airway smooth muscle (ASM) cells has profound effects on the physiological and phenotypic properties of ASM tissues. ASM is continually subjected to the mechanical forces generated during breathing and to the constituents of its surrounding extracellular milieu. The smooth muscle cells within the airways continually modulate their properties to adapt to these changing environmental influences. Smooth muscle cells connect to the extracellular cell matrix (ECM) at membrane adhesion junctions that provide mechanical coupling between smooth muscle cells within the tissue. Membrane adhesion junctions also sense local environmental signals and transduce them to cytoplasmic and nuclear signaling pathways in the ASM cell. Adhesion junctions are composed of clusters of transmembrane integrin proteins that bind to ECM proteins outside the cell and to large multiprotein complexes in the submembranous cytoplasm. Physiological conditions and stimuli from the surrounding ECM are sensed by integrin proteins and transduced by submembranous adhesion complexes to signaling pathways to the cytoskeleton and nucleus. The transmission of information between the local environment of the cells and intracellular processes enables ASM cells to rapidly adapt their physiological properties to modulating influences in their extracellular environment: mechanical and physical forces that impinge on the cell, ECM constituents, local mediators, and metabolites. The structure and molecular organization of adhesion junction complexes and the actin cytoskeleton are dynamic and constantly changing in response to environmental influences. The ability of ASM to rapidly accommodate to the ever-changing conditions and fluctuating physical forces within its local environment is essential for its normal physiological function.
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Affiliation(s)
- Wenwu Zhang
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Yidi Wu
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Susan J Gunst
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States
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6
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Liu S, Premont RT, Park KH, Rockey DC. β-PIX cooperates with GIT1 to regulate endothelial nitric oxide synthase in sinusoidal endothelial cells. Am J Physiol Gastrointest Liver Physiol 2022; 323:G511-G522. [PMID: 36044673 PMCID: PMC9639759 DOI: 10.1152/ajpgi.00034.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 08/11/2022] [Accepted: 08/24/2022] [Indexed: 01/31/2023]
Abstract
Previous studies have demonstrated that G protein-coupled receptor kinase interacting-1 protein (GIT1) associates with endothelial nitric oxide synthase (eNOS) to regulate nitric oxide production in sinusoidal endothelial cells (SECs). Here, we hypothesized that GIT1's tightly associated binding partner, β-PIX (p21-activated kinase-interacting exchange factor β, ARHGEF7) is specifically important in the regulation of eNOS activity. We examined β-PIX expression in normal rat liver by immunohistochemistry and explored β-PIX protein-protein interactions using immunoprecipitation and immunoblotting. The role of β-PIX in regulating eNOS enzymatic activity was studied in GIT1-deficient SECs. Finally, structural analysis of interaction sites in GIT1 and β-PIX required to regulate eNOS activity were mapped. β-PIX was expressed primarily in SECs in normal liver and was either absent or expressed at extremely low levels in other liver cells (stellate cells, Kupffer cells, and hepatocytes). β-PIX interacted with GIT1 and eNOS to form a trimolecular signaling module in normal SECs and was important in stimulating eNOS activity. Of note, GIT1-β-PIX interaction led to synergistic enhancement of eNOS activity, and β-PIX-driven increase in eNOS activity was GIT1 dependent. Disruption of β-PIX or GIT1 in normal SECs using β-PIX siRNA or GIT1-deficient SECs led to reduced eNOS activity. Finally, specific GIT1 domains [Spa2 homology domain (SHD) and synaptic localization domain (SLD), aa 331-596] and the β-PIX COOH terminal (aa 496-555) appeared to be critical in the regulation eNOS activity. The data indicate that β-PIX regulates eNOS phosphorylation and function in normal SECs and highlight the importance of the GIT1/β-PIX/eNOS trimolecular complex in normal liver SEC function.NEW & NOTEWORTHY β-PIX is a multidomain protein known to be a GIT1 binding partner. We report here that in the normal liver, the distribution and cellular localization of β-PIX are restricted largely to sinusoidal endothelial cells. Furthermore, β-PIX interacts with eNOS and GIT1 promotes eNOS activity and NO production and therefore exerts a novel posttranslational regulatory function on eNOS activity in sinusoidal endothelial cells. We also have identified specific molecular domains important in GIT1 and β-PIX's interaction with eNOS, which may represent novel therapeutic targets in the control of sinusoidal blood flow and intrahepatic resistance.
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Affiliation(s)
- Songling Liu
- Digestive Disease Research Center, Medical University of South Carolina, Charleston, South Carolina
| | - Richard T Premont
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Ki-Hoon Park
- Digestive Disease Research Center, Medical University of South Carolina, Charleston, South Carolina
| | - Don C Rockey
- Digestive Disease Research Center, Medical University of South Carolina, Charleston, South Carolina
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7
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Keum S, Yang SJ, Park E, Kang T, Choi JH, Jeong J, Hwang YE, Kim JW, Park D, Rhee S. Beta-Pix-dynamin 2 complex promotes colorectal cancer progression by facilitating membrane dynamics. Cell Oncol (Dordr) 2021; 44:1287-1305. [PMID: 34582006 PMCID: PMC8648671 DOI: 10.1007/s13402-021-00637-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 09/14/2021] [Indexed: 12/24/2022] Open
Abstract
PURPOSE Spatiotemporal regulation of cell membrane dynamics is a major process that promotes cancer cell invasion by acting as a driving force for cell migration. Beta-Pix (βPix), a guanine nucleotide exchange factor for Rac1, has been reported to be involved in actin-mediated cellular processes, such as cell migration, by interacting with various proteins. As yet, however, the molecular mechanisms underlying βPix-mediated cancer cell invasion remain unclear. METHODS The clinical significance of βPix was analyzed in patients with colorectal cancer (CRC) using public clinical databases. Pull-down and immunoprecipitation assays were employed to identify novel binding partners for βPix. Additionally, various cell biological assays including immunocytochemistry and time-lapse video microscopy were performed to assess the effects of βPix on CRC progression. A βPix-SH3 antibody delivery system was used to determine the effects of the βPix-Dyn2 complex in CRC cells. RESULTS We found that the Src homology 3 (SH3) domain of βPix interacts with the proline-rich domain of Dynamin 2 (Dyn2), a large GTPase. The βPix-Dyn2 interaction promoted lamellipodia formation, along with plasma membrane localization of membrane-type 1 matrix metalloproteinase (MT1-MMP). Furthermore, we found that Src kinase-mediated phosphorylation of the tyrosine residue at position 442 of βPix enhanced βPix-Dyn2 complex formation. Disruption of the βPix-Dyn2 complex by βPix-SH3 antibodies targeting intracellular βPix inhibited CRC cell invasion. CONCLUSIONS Our data indicate that spatiotemporal regulation of the Src-βPix-Dyn2 axis is crucial for CRC cell invasion by promoting membrane dynamics and MT1-MMP recruitment into the leading edge. The development of inhibitors that disrupt the βPix-Dyn2 complex may be a useful therapeutic strategy for CRC.
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Affiliation(s)
- Seula Keum
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Soo Jung Yang
- Translational Research Program, Benaroya Research Institute at Virginia Mason, Seattle, WA, 98101, USA
| | - Esther Park
- School of Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - TaeIn Kang
- School of Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jee-Hye Choi
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Jangho Jeong
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Ye Eun Hwang
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Jung-Woong Kim
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Dongeun Park
- School of Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sangmyung Rhee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea.
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8
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Davidson A, Tyler J, Hume P, Singh V, Koronakis V. A kinase-independent function of PAK is crucial for pathogen-mediated actin remodelling. PLoS Pathog 2021; 17:e1009902. [PMID: 34460869 PMCID: PMC8432889 DOI: 10.1371/journal.ppat.1009902] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 09/10/2021] [Accepted: 08/17/2021] [Indexed: 02/02/2023] Open
Abstract
The p21-activated kinase (PAK) family regulate a multitude of cellular processes, including actin cytoskeleton remodelling. Numerous bacterial pathogens usurp host signalling pathways that regulate actin reorganisation in order to promote Infection. Salmonella and pathogenic Escherichia coli drive actin-dependent forced uptake and intimate attachment respectively. We demonstrate that the pathogen-driven generation of both these distinct actin structures relies on the recruitment and activation of PAK. We show that the PAK kinase domain is dispensable for this actin remodelling, which instead requires the GTPase-binding CRIB and the central poly-proline rich region. PAK interacts with and inhibits the guanine nucleotide exchange factor β-PIX, preventing it from exerting a negative effect on cytoskeleton reorganisation. This kinase-independent function of PAK may be usurped by other pathogens that modify host cytoskeleton signalling and helps us better understand how PAK functions in normal and diseased eukaryotic cells.
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Affiliation(s)
- Anthony Davidson
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Joe Tyler
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Peter Hume
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Vikash Singh
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Vassilis Koronakis
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
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Shin EY, Soung NK, Schwartz MA, Kim EG. Altered endocytosis in cellular senescence. Ageing Res Rev 2021; 68:101332. [PMID: 33753287 PMCID: PMC8131247 DOI: 10.1016/j.arr.2021.101332] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/02/2021] [Accepted: 03/15/2021] [Indexed: 01/10/2023]
Abstract
Cellular senescence occurs in response to diverse stresses (e.g., telomere shortening, DNA damage, oxidative stress, oncogene activation). A growing body of evidence indicates that alterations in multiple components of endocytic pathways contribute to cellular senescence. Clathrin-mediated endocytosis (CME) and caveolae-mediated endocytosis (CavME) represent major types of endocytosis that are implicated in senescence. More recent research has also identified a chromatin modifier and tumor suppressor that contributes to the induction of senescence via altered endocytosis. Here, molecular regulators of aberrant endocytosis-induced senescence are reviewed and discussed in the context of their capacity to serve as senescence-inducing stressors or modifiers.
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Affiliation(s)
- Eun-Young Shin
- Department of Biochemistry, Chungbuk National University College of Medicine, Cheongju, 28644, South Korea
| | - Nak-Kyun Soung
- World Class Institute, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Ochang-eup, Cheongju, 28116, South Korea
| | - Martin Alexander Schwartz
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, And Department of Cell Biology, Yale University School of Medicine, New Haven, CT, 06511, USA; Wellcome Trust Centre for Cell-matrix Research, University of Manchester, Manchester, UK.
| | - Eung-Gook Kim
- Department of Biochemistry, Chungbuk National University College of Medicine, Cheongju, 28644, South Korea.
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10
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Karlsson R, Dráber P. Profilin-A master coordinator of actin and microtubule organization in mammalian cells. J Cell Physiol 2021; 236:7256-7265. [PMID: 33821475 DOI: 10.1002/jcp.30379] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/08/2021] [Accepted: 03/12/2021] [Indexed: 12/17/2022]
Abstract
The last two decades have witnessed a tremendous increase in cell biology data. Not least is this true for studies of the dynamic organization of the microfilament and microtubule systems in animal cells where analyses of the molecular components and their interaction patterns have deepened our understanding of these complex force-generating machineries. Previous observations of a molecular cross-talk between the two systems have now led to the realization of the existence of several intricate mechanisms operating to maintain their coordinated cellular organization. In this short review, we relate to this development by discussing new results concerning the function of the actin regulator profilin 1 as a control component of microfilament-microtubule cross-talk.
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Affiliation(s)
- Roger Karlsson
- Department of Molecular Biosciences, WGI, Stockholm University, Stockholm, Sweden
| | - Pavel Dráber
- Department of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
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11
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Structural and functional analysis of LIM domain-dependent recruitment of paxillin to αvβ3 integrin-positive focal adhesions. Commun Biol 2021; 4:380. [PMID: 33782527 PMCID: PMC8007706 DOI: 10.1038/s42003-021-01886-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 02/11/2021] [Indexed: 02/06/2023] Open
Abstract
The LIM domain-dependent localization of the adapter protein paxillin to β3 integrin-positive focal adhesions (FAs) is not mechanistically understood. Here, by combining molecular biology, photoactivation and FA-isolation experiments, we demonstrate specific contributions of each LIM domain of paxillin and reveal multiple paxillin interactions in adhesion-complexes. Mutation of β3 integrin at a putative paxillin binding site (β3VE/YA) leads to rapidly inward-sliding FAs, correlating with actin retrograde flow and enhanced paxillin dissociation kinetics. Induced mechanical coupling of paxillin to β3VE/YA integrin arrests the FA-sliding, thereby disclosing an essential structural function of paxillin for the maturation of β3 integrin/talin clusters. Moreover, bimolecular fluorescence complementation unveils the spatial orientation of the paxillin LIM-array, juxtaposing the positive LIM4 to the plasma membrane and the β3 integrin-tail, while in vitro binding assays point to LIM1 and/or LIM2 interaction with talin-head domain. These data provide structural insights into the molecular organization of β3 integrin-FAs.
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12
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van Gastel J, Leysen H, Boddaert J, Vangenechten L, Luttrell LM, Martin B, Maudsley S. Aging-related modifications to G protein-coupled receptor signaling diversity. Pharmacol Ther 2020; 223:107793. [PMID: 33316288 DOI: 10.1016/j.pharmthera.2020.107793] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/26/2020] [Indexed: 02/06/2023]
Abstract
Aging is a highly complex molecular process, affecting nearly all tissue systems in humans and is the highest risk factor in developing neurodegenerative disorders such as Alzheimer's and Parkinson's disease, cardiovascular disease and Type 2 diabetes mellitus. The intense complexity of the aging process creates an incentive to develop more specific drugs that attenuate or even reverse some of the features of premature aging. As our current pharmacopeia is dominated by therapeutics that target members of the G protein-coupled receptor (GPCR) superfamily it may be prudent to search for effective anti-aging therapeutics in this fertile domain. Since the first demonstration of GPCR-based β-arrestin signaling, it has become clear that an enhanced appreciation of GPCR signaling diversity may facilitate the creation of therapeutics with selective signaling activities. Such 'biased' ligand signaling profiles can be effectively investigated using both standard molecular biological techniques as well as high-dimensionality data analyses. Through a more nuanced appreciation of the quantitative nature across the multiple dimensions of signaling bias that drugs possess, researchers may be able to further refine the efficacy of GPCR modulators to impact the complex aberrations that constitute the aging process. Identifying novel effector profiles could expand the effective pharmacopeia and assist in the design of precision medicines. This review discusses potential non-G protein effectors, and specifically their potential therapeutic suitability in aging and age-related disorders.
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Affiliation(s)
- Jaana van Gastel
- Receptor Biology Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Faculty of Pharmacy, Biomedical and Veterinary Science, University of Antwerp, Antwerp, Belgium
| | - Hanne Leysen
- Receptor Biology Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Faculty of Pharmacy, Biomedical and Veterinary Science, University of Antwerp, Antwerp, Belgium
| | - Jan Boddaert
- Molecular Pathology Group, Faculty of Medicine and Health Sciences, Laboratory of Cell Biology and Histology, Antwerp, Belgium
| | - Laura Vangenechten
- Receptor Biology Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Louis M Luttrell
- Division of Endocrinology, Diabetes & Medical Genetics, Medical University of South Carolina, USA
| | - Bronwen Martin
- Faculty of Pharmacy, Biomedical and Veterinary Science, University of Antwerp, Antwerp, Belgium
| | - Stuart Maudsley
- Receptor Biology Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Faculty of Pharmacy, Biomedical and Veterinary Science, University of Antwerp, Antwerp, Belgium.
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13
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Zhu J, Zhou Q, Xia Y, Lin L, Li J, Peng M, Zhang R, Zhang M. GIT/PIX Condensates Are Modular and Ideal for Distinct Compartmentalized Cell Signaling. Mol Cell 2020; 79:782-796.e6. [DOI: 10.1016/j.molcel.2020.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/02/2020] [Accepted: 07/03/2020] [Indexed: 11/17/2022]
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14
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Abedrabbo M, Ravid S. Scribble, Lgl1, and myosin II form a complex in vivo to promote directed cell migration. Mol Biol Cell 2020; 31:2234-2248. [PMID: 32697665 PMCID: PMC7550706 DOI: 10.1091/mbc.e19-11-0657] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Scribble (Scrib) and Lethal giant larvae 1 (Lgl1) are conserved polarity proteins that play important roles in different forms of cell polarity. The roles of Scrib and Lgl1 in apical-basal cell polarity have been studied extensively, but little is known about their roles in the cell polarity of migrating cells. Furthermore, the effect of Scrib and Lgl1 interaction on cell polarity is largely unknown. In this study, we show that Scrib, through its leucine-rich repeat domain, forms a complex in vivo with Lgl1. Scrib also forms a complex with myosin II, and Scrib, Lgl1, and myosin II colocalize at the leading edge of migrating cells. The cellular localization and the cytoskeletal association of Scrib and Lgl1 are interdependent, as depletion of either protein affects its counterpart. In addition, depletion of either Scrib or Lgl1 disrupts the cellular localization of myosin II. We show that depletion of either Scrib or Lgl1 affects cell adhesion through the inhibition of focal adhesion disassembly. Finally, we show that Scrib and Lgl1 are required for proper cell polarity of migrating cells. These results provide new insights into the mechanism regulating the cell polarity of migrating cells by Scrib, Lgl1, and myosin II.
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Affiliation(s)
- Maha Abedrabbo
- Department of Biochemistry and Molecular Biology, The Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Shoshana Ravid
- Department of Biochemistry and Molecular Biology, The Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
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15
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Guan X, Guan X, Dong C, Jiao Z. Rho GTPases and related signaling complexes in cell migration and invasion. Exp Cell Res 2020; 388:111824. [PMID: 31926148 DOI: 10.1016/j.yexcr.2020.111824] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 12/16/2022]
Abstract
Cell migration and invasion play an important role in the development of cancer. Cell migration is associated with several specific actin filament-based structures, including lamellipodia, filopodia, invadopodia and blebs, and with cell-cell adhesion, cell-extracellular matrix adhesion. Migration occurs via different modes, human epithelial cancer cells mainly migrate collectively, while in vivo imaging studies in laboratory animals have found that most cells migrate as single cells. Rho GTPases play an important role in the process of cell migration, and several Rho GTPase-related signaling complexes are also involved. However, the exact mechanism by which these signaling complexes act remains unclear. This paper reviews how Rho GTPases and related signaling complexes interact with other proteins, how their expression is regulated, how tumor microenvironment-related factors play a role in invasion and metastasis, and the mechanism of these complex signaling networks in cell migration and invasion.
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Affiliation(s)
- Xiaoying Guan
- Pathology Department, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Xiaoli Guan
- General Medicine Department, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Chi Dong
- Pathology Department, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Zuoyi Jiao
- The First Department of General Surgery, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China.
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16
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Suman SK, Daday C, Ferraro T, Vuong-Brender T, Tak S, Quintin S, Robin F, Gräter F, Labouesse M. The plakin domain of C. elegans VAB-10/plectin acts as a hub in a mechanotransduction pathway to promote morphogenesis. Development 2019; 146:dev183780. [PMID: 31784459 PMCID: PMC7375825 DOI: 10.1242/dev.183780] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 11/18/2019] [Indexed: 12/29/2022]
Abstract
Mechanical forces can elicit a mechanotransduction response through junction-associated proteins. In contrast to the wealth of knowledge available for focal adhesions and adherens junctions, much less is known about mechanotransduction at hemidesmosomes. Here, we focus on the C. elegans plectin homolog VAB-10A, the only evolutionary conserved hemidesmosome component. In C. elegans, muscle contractions induce a mechanotransduction pathway in the epidermis through hemidesmosomes. We used CRISPR to precisely remove spectrin repeats (SRs) or a partially hidden Src homology 3 (SH3) domain within the VAB-10 plakin domain. Deleting the SH3 or SR8 domains in combination with mutations affecting mechanotransduction, or just the part of SR5 shielding the SH3 domain, induced embryonic elongation arrest because hemidesmosomes collapse. Notably, recruitment of GIT-1, the first mechanotransduction player, requires the SR5 domain and the hemidesmosome transmembrane receptor LET-805. Furthermore, molecular dynamics simulations confirmed that forces acting on VAB-10 could make the central SH3 domain, otherwise in contact with SR4, available for interaction. Collectively, our data strongly indicate that the plakin domain plays a central role in mechanotransduction and raise the possibility that VAB-10/plectin might act as a mechanosensor.
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Affiliation(s)
- Shashi Kumar Suman
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Laboratoire de Biologie du Développement/UMR7622,7 Quai St-Bernard, 75005 Paris, France
- Development and Stem Cells Program, IGBMC, CNRS (UMR7104), INSERM (U964), Université de Strasbourg, 1 rue Laurent Fries, BP10142, 67400 Illkirch, France
| | - Csaba Daday
- Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Mathematikon, INF 205, 69120 Heidelberg, Germany
- Heidelberg Institute for Theoretical Studies, Schloß-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany
| | - Teresa Ferraro
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Laboratoire de Biologie du Développement/UMR7622,7 Quai St-Bernard, 75005 Paris, France
| | - Thanh Vuong-Brender
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Laboratoire de Biologie du Développement/UMR7622,7 Quai St-Bernard, 75005 Paris, France
- Development and Stem Cells Program, IGBMC, CNRS (UMR7104), INSERM (U964), Université de Strasbourg, 1 rue Laurent Fries, BP10142, 67400 Illkirch, France
| | - Saurabh Tak
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Laboratoire de Biologie du Développement/UMR7622,7 Quai St-Bernard, 75005 Paris, France
- Development and Stem Cells Program, IGBMC, CNRS (UMR7104), INSERM (U964), Université de Strasbourg, 1 rue Laurent Fries, BP10142, 67400 Illkirch, France
| | - Sophie Quintin
- Development and Stem Cells Program, IGBMC, CNRS (UMR7104), INSERM (U964), Université de Strasbourg, 1 rue Laurent Fries, BP10142, 67400 Illkirch, France
| | - François Robin
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Laboratoire de Biologie du Développement/UMR7622,7 Quai St-Bernard, 75005 Paris, France
| | - Frauke Gräter
- Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Mathematikon, INF 205, 69120 Heidelberg, Germany
- Heidelberg Institute for Theoretical Studies, Schloß-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany
| | - Michel Labouesse
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Laboratoire de Biologie du Développement/UMR7622,7 Quai St-Bernard, 75005 Paris, France
- Development and Stem Cells Program, IGBMC, CNRS (UMR7104), INSERM (U964), Université de Strasbourg, 1 rue Laurent Fries, BP10142, 67400 Illkirch, France
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17
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Juin A, Spence HJ, Martin KJ, McGhee E, Neilson M, Cutiongco MFA, Gadegaard N, Mackay G, Fort L, Lilla S, Kalna G, Thomason P, Koh YWH, Norman JC, Insall RH, Machesky LM. N-WASP Control of LPAR1 Trafficking Establishes Response to Self-Generated LPA Gradients to Promote Pancreatic Cancer Cell Metastasis. Dev Cell 2019; 51:431-445.e7. [PMID: 31668663 PMCID: PMC6863394 DOI: 10.1016/j.devcel.2019.09.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 07/23/2019] [Accepted: 09/24/2019] [Indexed: 02/07/2023]
Abstract
Pancreatic ductal adenocarcinoma is one of the most invasive and metastatic cancers and has a dismal 5-year survival rate. We show that N-WASP drives pancreatic cancer metastasis, with roles in both chemotaxis and matrix remodeling. lysophosphatidic acid, a signaling lipid abundant in blood and ascites fluid, is both a mitogen and chemoattractant for cancer cells. Pancreatic cancer cells break lysophosphatidic acid down as they respond to it, setting up a self-generated gradient driving tumor egress. N-WASP-depleted cells do not recognize lysophosphatidic acid gradients, leading to altered RhoA activation, decreased contractility and traction forces, and reduced metastasis. We describe a signaling loop whereby N-WASP and the endocytic adapter SNX18 promote lysophosphatidic acid-induced RhoA-mediated contractility and force generation by controlling lysophosphatidic acid receptor recycling and preventing degradation. This chemotactic loop drives collagen remodeling, tumor invasion, and metastasis and could be an important target against pancreatic cancer spread.
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Affiliation(s)
| | | | | | | | | | - Marie F A Cutiongco
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, UK
| | - Nikolaj Gadegaard
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, UK
| | | | - Loic Fort
- CRUK Beatson Institute, Glasgow G61 1BD, UK
| | | | | | | | | | - Jim C Norman
- CRUK Beatson Institute, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Glasgow G61 1BD, UK
| | - Robert H Insall
- CRUK Beatson Institute, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Glasgow G61 1BD, UK
| | - Laura M Machesky
- CRUK Beatson Institute, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Glasgow G61 1BD, UK.
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18
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Ho PY, Li H, Cheng L, Bhalla V, Fenton RA, Hallows KR. AMPK phosphorylation of the β 1Pix exchange factor regulates the assembly and function of an ENaC inhibitory complex in kidney epithelial cells. Am J Physiol Renal Physiol 2019; 317:F1513-F1525. [PMID: 31566435 DOI: 10.1152/ajprenal.00592.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The metabolic sensor AMP-activated protein kinase (AMPK) inhibits the epithelial Na+ channel (ENaC), a key regulator of salt reabsorption by the kidney and thus total body volume and blood pressure. Recent studies have suggested that AMPK promotes the association of p21-activated kinase-interacting exchange factor-β1 β1Pix, 14-3-3 proteins, and the ubiquitin ligase neural precursor cell expressed developmentally downregulated protein (Nedd)4-2 into a complex that inhibits ENaC by enhancing Nedd4-2 binding to ENaC and ENaC degradation. Functional β1Pix is required for ENaC inhibition by AMPK and promotes Nedd4-2 phosphorylation and stability in mouse kidney cortical collecting duct cells. Here, we report that AMPK directly phosphorylates β1Pix in vitro. Among several AMPK phosphorylation sites on β1Pix detected by mass spectrometry, Ser71 was validated as functionally significant. Compared with wild-type β1Pix, overexpression of a phosphorylation-deficient β1Pix-S71A mutant attenuated ENaC inhibition and the AMPK-activated interaction of both β1Pix and Nedd4-2 to 14-3-3 proteins in cortical collecting duct cells. Similarly, overexpression of a β1Pix-Δ602-611 deletion tract mutant unable to bind 14-3-3 proteins decreased the interaction between Nedd4-2 and 14-3-3 proteins, suggesting that 14-3-3 binding to β1Pix is critical for the formation of a β1Pix/Nedd4-2/14-3-3 complex. With expression of a general peptide inhibitor of 14-3-3-target protein interactions (R18), binding of both β1Pix and Nedd4-2 to 14-3-3 proteins was reduced, and AMPK-dependent ENaC inhibition was also attenuated. Altogether, our results demonstrate the importance of AMPK-mediated phosphorylation of β1Pix at Ser71, which promotes 14-3-3 interactions with β1Pix and Nedd4-2 to form a tripartite ENaC inhibitory complex, in the mechanism of ENaC regulation by AMPK.
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Affiliation(s)
- Pei-Yin Ho
- Division of Nephrology and Hypertension, Department of Medicine and USC/UKRO Kidney Research Center, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Hui Li
- Division of Nephrology and Hypertension, Department of Medicine and USC/UKRO Kidney Research Center, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Lei Cheng
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Vivek Bhalla
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, California
| | - Robert A Fenton
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Kenneth R Hallows
- Division of Nephrology and Hypertension, Department of Medicine and USC/UKRO Kidney Research Center, Keck School of Medicine, University of Southern California, Los Angeles, California
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19
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The Small GTPase Arf6: An Overview of Its Mechanisms of Action and of Its Role in Host⁻Pathogen Interactions and Innate Immunity. Int J Mol Sci 2019; 20:ijms20092209. [PMID: 31060328 PMCID: PMC6539230 DOI: 10.3390/ijms20092209] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/26/2019] [Accepted: 04/27/2019] [Indexed: 12/15/2022] Open
Abstract
The small GTase Arf6 has several important functions in intracellular vesicular trafficking and regulates the recycling of different types of cargo internalized via clathrin-dependent or -independent endocytosis. It activates the lipid modifying enzymes PIP 5-kinase and phospholipase D, promotes actin polymerization, and affects several functionally distinct processes in the cell. Arf6 is used for the phagocytosis of pathogens and can be directly or indirectly targeted by various pathogens to block phagocytosis or induce the uptake of intracellular pathogens. Arf6 is also used in the signaling of Toll-like receptors and in the activation of NADPH oxidases. In this review, we first give an overview of the different roles and mechanisms of action of Arf6 and then focus on its role in innate immunity and host–pathogen interactions.
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20
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Young LC, Rodriguez-Viciana P. MRAS: A Close but Understudied Member of the RAS Family. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a033621. [PMID: 29311130 DOI: 10.1101/cshperspect.a033621] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
MRAS is the closest relative to the classical RAS oncoproteins and shares most regulatory and effector interactions. However, it also has unique functions, including its ability to function as a phosphatase regulatory subunit when in complex with SHOC2 and protein phosphatase 1 (PP1). This phosphatase complex regulates a crucial step in the activation cycle of RAF kinases and provides a key coordinate input required for efficient ERK pathway activation and transformation by RAS. MRAS mutations rarely occur in cancer but deregulated expression may play a role in tumorigenesis in some settings. Activating mutations in MRAS (as well as SHOC2 and PP1) do occur in the RASopathy Noonan syndrome, underscoring a key role for MRAS within the RAS-ERK pathway. MRAS also has unique roles in cell migration and differentiation and has properties consistent with a key role in the regulation of cell polarity. Further investigations should shed light on what remains a relatively understudied RAS family member.
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Affiliation(s)
- Lucy C Young
- UCSF Helen Diller Family Comprehensive Cancer Center, San Francisco, California 94158
| | - Pablo Rodriguez-Viciana
- UCL Cancer Institute, Paul O'Gorman Building, University College London, London WC1E 6BT, United Kingdom
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21
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Pathogenic predictions of non-synonymous variants and their impacts: A computational assessment of ARHGEF6 gene. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2018. [DOI: 10.1016/j.ejmhg.2018.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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22
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Pires HR, Boxem M. Mapping the Polarity Interactome. J Mol Biol 2018; 430:3521-3544. [DOI: 10.1016/j.jmb.2017.12.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/14/2017] [Accepted: 12/18/2017] [Indexed: 12/11/2022]
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23
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Zhang W, Bhetwal BP, Gunst SJ. Rho kinase collaborates with p21-activated kinase to regulate actin polymerization and contraction in airway smooth muscle. J Physiol 2018; 596:3617-3635. [PMID: 29746010 DOI: 10.1113/jp275751] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 05/04/2018] [Indexed: 12/16/2022] Open
Abstract
KEY POINTS The mechanisms by which Rho kinase (ROCK) regulates airway smooth muscle contraction were determined in tracheal smooth muscle tissues. ROCK may mediate smooth muscle contraction by inhibiting myosin regulatory light chain (RLC) phosphatase. ROCK can also regulate F-actin dynamics during cell migration, and actin polymerization is critical for airway smooth muscle contraction. Our results show that ROCK does not regulate airway smooth muscle contraction by inhibiting myosin RLC phosphatase or by stimulating myosin RLC phosphorylation. We find that ROCK regulates airway smooth muscle contraction by activating the serine-threonine kinase Pak, which mediates the activation of Cdc42 and neuronal Wiskott-Aldrich syndrome protein (N-WASp). N-WASP transmits signals from Cdc42 to the Arp2/3 complex for the nucleation of actin filaments. These results demonstrate a novel molecular function for ROCK in the regulation of Pak and Cdc42 activation that is critical for the processes of actin polymerization and contractility in airway smooth muscle. ABSTRACT Rho kinase (ROCK), a RhoA GTPase effector, can regulate the contraction of airway and other smooth muscle tissues. In some tissues, ROCK can inhibit myosin regulatory light chain (RLC) phosphatase, which increases the phosphorylation of myosin RLC and promotes smooth muscle contraction. ROCK can also regulate cell motility and migration by affecting F-actin dynamics. Actin polymerization is stimulated by contractile agonists in airway smooth muscle tissues and is required for contractile tension development in addition to myosin RLC phosphorylation. We investigated the mechanisms by which ROCK regulates the contractility of tracheal smooth muscle tissues by expressing a kinase-inactive mutant of ROCK, ROCK-K121G, in the tissues or by treating them with the ROCK inhibitor H-1152P. Our results show no role for ROCK in the regulation of non-muscle or smooth muscle myosin RLC phosphorylation during contractile stimulation in this tissue. We found that ROCK regulates airway smooth muscle contraction by mediating activation of p21-activated kinase (Pak), a serine-threonine kinase, to promote actin polymerization. Pak catalyses paxillin phosphorylation on Ser273 and coupling of the GIT1-βPIX-Pak signalling module to paxillin, which activates the guanine nucleotide exchange factor (GEF) activity of βPIX towards Cdc42. Cdc42 is required for the activation of neuronal Wiskott-Aldrich syndrome protein (N-WASp), which transmits signals from Cdc42 to the Arp2/3 complex for the nucleation of actin filaments. Our results demonstrate a novel molecular function for ROCK in the regulation of Pak and Cdc42 activation that is critical for the processes of actin polymerization and contractility in airway smooth muscle.
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Affiliation(s)
- Wenwu Zhang
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Bhupal P Bhetwal
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Susan J Gunst
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
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24
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Rathor N, Chung HK, Wang SR, Qian M, Turner DJ, Wang JY, Rao JN. β-PIX plays an important role in regulation of intestinal epithelial restitution by interacting with GIT1 and Rac1 after wounding. Am J Physiol Gastrointest Liver Physiol 2018; 314:G399-G407. [PMID: 29191942 PMCID: PMC5899242 DOI: 10.1152/ajpgi.00296.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Early gut mucosal restitution is a process by which intestinal epithelial cells (IECs) migrate over the wounded area, and its defective regulation occurs commonly in various critical pathological conditions. This rapid reepithelialization is mediated by different activating small GTP-binding proteins, but the exact mechanism underlying this process remains largely unknown. Recently, it has been reported that interaction between p21-activated kinase-interacting exchange factor (β-PIX) and G protein-coupled receptor kinase-interacting protein 1 (GIT1) activates small GTPases and plays an important role in the regulation of cell motility. Here, we show that induced association of β-PIX with GIT1 is essential for the stimulation of IEC migration after wounding by activating Rac1. Levels of β-PIX and GIT1 proteins and their association in differentiated IECs (line of IEC-Cdx2L1) were much higher than those observed in undifferentiated IECs (line of IEC-6), which was associated with an increase in IEC migration after wounding. Decreased levels of endogenous β-PIX by its gene-silencing destabilized β-PIX/GIT1 complexes, repressed Rac1 activity and inhibited cell migration over the wounded area. In contrast, ectopic overexpression of β-PIX increased the levels of β-PIX/GIT1 complexes, stimulated Rac1 activity, and enhanced intestinal epithelial restitution. Increased levels of cellular polyamines also stimulated β-PIX/GIT1 association, increased Rac1 activity, and promoted the epithelial restitution. Moreover, polyamine depletion decreased cellular abundances of β-PIX/GIT1 complex and repressed IEC migration after wounding, which was rescued by ectopic overexpression of β-PIX or GIT1. These results indicate that β-PIX/GIT1/Rac1 association is necessary for stimulation of IEC migration after wounding and that this signaling pathway is tightly regulated by cellular polyamines. NEW & NOTEWORTHY Our current study demonstrates that induced association of β-PIX with GIT1 is essential for the stimulation of intestinal epithelial restitution by activating Rac1, and this signaling pathway is tightly regulated by cellular polyamines.
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Affiliation(s)
- Navneeta Rathor
- 1Department of Surgery, Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland,2Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Hee Kyoung Chung
- 1Department of Surgery, Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland,2Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Shelley R. Wang
- 1Department of Surgery, Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland,2Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Michael Qian
- 1Department of Surgery, Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland
| | - Douglas J. Turner
- 1Department of Surgery, Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland,2Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jian-Ying Wang
- 1Department of Surgery, Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland,2Baltimore Veterans Affairs Medical Center, Baltimore, Maryland,3Department of Pathology, Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland
| | - Jaladanki N. Rao
- 1Department of Surgery, Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland,2Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
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25
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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: 329] [Impact Index Per Article: 54.8] [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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26
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Karayel Ö, Şanal E, Giese SH, Üretmen Kagıalı ZC, Polat AN, Hu CK, Renard BY, Tuncbag N, Özlü N. Comparative phosphoproteomic analysis reveals signaling networks regulating monopolar and bipolar cytokinesis. Sci Rep 2018; 8:2269. [PMID: 29396449 PMCID: PMC5797227 DOI: 10.1038/s41598-018-20231-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/05/2018] [Indexed: 01/21/2023] Open
Abstract
The successful completion of cytokinesis requires the coordinated activities of diverse cellular components including membranes, cytoskeletal elements and chromosomes that together form partly redundant pathways, depending on the cell type. The biochemical analysis of this process is challenging due to its dynamic and rapid nature. Here, we systematically compared monopolar and bipolar cytokinesis and demonstrated that monopolar cytokinesis is a good surrogate for cytokinesis and it is a well-suited system for global biochemical analysis in mammalian cells. Based on this, we established a phosphoproteomic signature of cytokinesis. More than 10,000 phosphorylation sites were systematically monitored; around 800 of those were up-regulated during cytokinesis. Reconstructing the kinase-substrate interaction network revealed 31 potentially active kinases during cytokinesis. The kinase-substrate network connects proteins between cytoskeleton, membrane and cell cycle machinery. We also found consensus motifs of phosphorylation sites that can serve as biochemical markers specific to cytokinesis. Beyond the kinase-substrate network, our reconstructed signaling network suggests that combination of sumoylation and phosphorylation may regulate monopolar cytokinesis specific signaling pathways. Our analysis provides a systematic approach to the comparison of different cytokinesis types to reveal alternative ways and a global overview, in which conserved genes work together and organize chromatin and cytoplasm during cytokinesis.
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Affiliation(s)
- Özge Karayel
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Erdem Şanal
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Sven H Giese
- Bioinformatics Division (MF1), Robert Koch Institute, Berlin, Germany
- Chair of Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | | | - Ayşe Nur Polat
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Chi-Kuo Hu
- Department of Genetics, Stanford University, School of Medicine, CA, USA
| | - Bernhard Y Renard
- Bioinformatics Division (MF1), Robert Koch Institute, Berlin, Germany
| | - Nurcan Tuncbag
- Graduate School of Informatics, Department of Health Informatics, METU, Ankara, Turkey
- Cancer Systems Biology Laboratory (CanSyL), METU, Ankara, Turkey
| | - Nurhan Özlü
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey.
- Koç University Research Center for Translational Medicine (KUTTAM), Istanbul, Turkey.
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Yoo SM, Cerione RA, Antonyak MA. The Arf-GAP and protein scaffold Cat1/Git1 as a multifaceted regulator of cancer progression. Small GTPases 2017; 11:77-85. [PMID: 28981399 DOI: 10.1080/21541248.2017.1362496] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Cool-associated tyrosine phosphorylated protein 1 (Cat1), also referred to as GPCR-kinase interacting protein 1 (Git1), is a ubiquitously expressed, multi-domain protein that is best known for regulating cell shape and migration. Cat1/Git1 functions as a GTPase activating protein (GAP) that inactivates certain members of the ADP-ribosylation factor (Arf) family of small GTPases. It is also a scaffold that brings together several signaling proteins at specific locations within the cell, ensuring their efficient activation. Here we will discuss what is known regarding the classical role of Cat1/Git1 in the regulation of cell morphology and migration, as well as highlight some more recent findings that suggest this interesting signaling/scaffolding protein may also contribute in unexpected ways to oncogenic transformation.
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Affiliation(s)
- Sungsoo M Yoo
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Richard A Cerione
- Department of Molecular Medicine, Cornell University, Ithaca, NY, USA.,Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Marc A Antonyak
- Department of Molecular Medicine, Cornell University, Ithaca, NY, USA
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28
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Zhou W, Li X, Premont RT. Expanding functions of GIT Arf GTPase-activating proteins, PIX Rho guanine nucleotide exchange factors and GIT-PIX complexes. J Cell Sci 2017; 129:1963-74. [PMID: 27182061 DOI: 10.1242/jcs.179465] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The GIT proteins, GIT1 and GIT2, are GTPase-activating proteins (inactivators) for the ADP-ribosylation factor (Arf) small GTP-binding proteins, and function to limit the activity of Arf proteins. The PIX proteins, α-PIX and β-PIX (also known as ARHGEF6 and ARHGEF7, respectively), are guanine nucleotide exchange factors (activators) for the Rho family small GTP-binding protein family members Rac1 and Cdc42. Through their multi-domain structures, GIT and PIX proteins can also function as signaling scaffolds by binding to numerous protein partners. Importantly, the constitutive association of GIT and PIX proteins into oligomeric GIT-PIX complexes allows these two proteins to function together as subunits of a larger structure that coordinates two distinct small GTP-binding protein pathways and serves as multivalent scaffold for the partners of both constituent subunits. Studies have revealed the involvement of GIT and PIX proteins, and of the GIT-PIX complex, in numerous fundamental cellular processes through a wide variety of mechanisms, pathways and signaling partners. In this Commentary, we discuss recent findings in key physiological systems that exemplify current understanding of the function of this important regulatory complex. Further, we draw attention to gaps in crucial information that remain to be filled to allow a better understanding of the many roles of the GIT-PIX complex in health and disease.
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Affiliation(s)
- Wu Zhou
- Department of Medicine, College of Medicine and Health, Lishui University, Lishui 323000, China
| | - Xiaobo Li
- Department of Computer Science and Technology, College of Engineering and Design, Lishui University, Lishui 323000, China
| | - Richard T Premont
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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29
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Rui M, Qian J, Liu L, Cai Y, Lv H, Han J, Jia Z, Xie W. The neuronal protein Neurexin directly interacts with the Scribble-Pix complex to stimulate F-actin assembly for synaptic vesicle clustering. J Biol Chem 2017; 292:14334-14348. [PMID: 28710284 PMCID: PMC5582829 DOI: 10.1074/jbc.m117.794040] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 06/29/2017] [Indexed: 01/17/2023] Open
Abstract
Synaptic vesicles (SVs) form distinct pools at synaptic terminals, and this well-regulated separation is necessary for normal neurotransmission. However, how the SV cluster, in particular synaptic compartments, maintains normal neurotransmitter release remains a mystery. The presynaptic protein Neurexin (NRX) plays a significant role in synaptic architecture and function, and some evidence suggests that NRX is associated with neurological disorders, including autism spectrum disorders. However, the role of NRX in SV clustering is unclear. Here, using the neuromuscular junction at the 2-3 instar stages of Drosophila larvae as a model and biochemical imaging and electrophysiology techniques, we demonstrate that Drosophila NRX (DNRX) plays critical roles in regulating synaptic terminal clustering and release of SVs. We found that DNRX controls the terminal clustering and release of SVs by stimulating presynaptic F-actin. Furthermore, our results indicate that DNRX functions through the scaffold protein Scribble and the GEF protein DPix to activate the small GTPase Ras-related C3 Botulinum toxin substrate 1 (Rac1). We observed a direct interaction between the C-terminal PDZ-binding motif of DNRX and the PDZ domains of Scribble and that Scribble bridges DNRX to DPix, forming a DNRX-Scribble-DPix complex that activates Rac1 and subsequently stimulates presynaptic F-actin assembly and SV clustering. Taken together, our work provides important insights into the function of DNRX in regulating SV clustering, which could help inform further research into pathological neurexin-mediated mechanisms in neurological disorders such as autism.
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Affiliation(s)
- Menglong Rui
- From Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Jinjun Qian
- From Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Lijuan Liu
- From Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Yihan Cai
- From Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Huihui Lv
- From Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Junhai Han
- From Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China.,the Institute of Life Sciences, the Collaborative Innovation Center for Brain Science, Southeast University, Nanjing 210096, China
| | - Zhengping Jia
- the Department of Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada, and.,the Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Wei Xie
- From Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China, .,the Institute of Life Sciences, the Collaborative Innovation Center for Brain Science, Southeast University, Nanjing 210096, China
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30
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Yoo SM, Latifkar A, Cerione RA, Antonyak MA. Cool-associated Tyrosine-phosphorylated Protein 1 Is Required for the Anchorage-independent Growth of Cervical Carcinoma Cells by Binding Paxillin and Promoting AKT Activation. J Biol Chem 2017; 292:3947-3957. [PMID: 28100775 DOI: 10.1074/jbc.m116.769190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/18/2017] [Indexed: 12/12/2022] Open
Abstract
Cool-associated tyrosine-phosphorylated protein 1 (Cat-1) is a signaling scaffold as well as an ADP-ribosylation factor-GTPase-activating protein. Although best known for its role in cell migration, we recently showed that the ability of Cat-1 to bind paxillin, a major constituent of focal complexes, is also essential for the anchorage-independent growth of HeLa cervical carcinoma cells. Here we set out to learn more about the underlying mechanism by which Cat-paxillin interactions mediate this effect. We show that knocking down paxillin expression in HeLa cells promotes their ability to form colonies in soft agar, whereas ectopically expressing paxillin in these cells inhibits this transformed growth phenotype. Although knocking down Cat-1 prevents HeLa cells from forming colonies in soft agar, when paxillin is knocked down together with Cat-1, the cells are again able to undergo anchorage-independent growth. These results suggest that the requirement of Cat-1 for this hallmark of cellular transformation is coupled to its ability to bind paxillin and abrogate its actions as a negative regulator of anchorage-independent growth. We further show that knocking down Cat-1 expression in HeLa cells leads to a reduction in Akt activation, which can be reversed by knocking down paxillin. Moreover, expression of constitutively active forms of Akt1 and Akt2 restores the anchorage-independent growth capability of HeLa cells depleted of Cat-1 expression. Together, these findings highlight a novel mechanism whereby interactions between Cat-1 and its binding partner paxillin are necessary to ensure sufficient Akt activation so that cancer cells are able to grow under anchorage-independent conditions.
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Affiliation(s)
- Sungsoo M Yoo
- From the Departments of Molecular Medicine, College of Veterinary Medicine and.,the Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Arash Latifkar
- From the Departments of Molecular Medicine, College of Veterinary Medicine and.,Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853 and
| | - Richard A Cerione
- From the Departments of Molecular Medicine, College of Veterinary Medicine and .,Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853 and
| | - Marc A Antonyak
- From the Departments of Molecular Medicine, College of Veterinary Medicine and
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The focal adhesion-associated proteins DOCK5 and GIT2 comprise a rheostat in control of epithelial invasion. Oncogene 2016; 36:1816-1828. [PMID: 27669437 PMCID: PMC5366285 DOI: 10.1038/onc.2016.345] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 08/07/2016] [Accepted: 08/15/2016] [Indexed: 11/23/2022]
Abstract
DOCK proteins are guanine nucleotide exchange factors for Rac and Cdc42 GTPases. DOCK1 is the founding member of the family and acts downstream of integrins via the canonical Crk-p130Cas complex to activate Rac GTPases in numerous contexts. In contrast, DOCK5, which possesses the greatest similarity to DOCK1, remains sparingly studied. Here we establish that DOCK5 has a non-redundant role in regulating motile and invasive capacities of epithelial cells. DOCK1 is constitutively associated with sites of integrin attachment termed focal adhesions (FAs). In contrast, we demonstrate that DOCK5 recruitment to FAs in Hela cells is restricted by GIT2, an established regulator of FA signaling. We determine that GIT2 is targeted to FAs in response to Rho-ROCK signaling and actomyosin contractility. Accordingly, inhibition of ROCK activity or MLC function promotes enrichment of DOCK5 in membrane protrusions and nascent cell–substratum adhesions. We further demonstrate that GIT2 inhibits the interaction of DOCK5 with Crk. Moreover, we show that depletion of GIT2 promotes DOCK5-dependent activation of the Crk-p130Cas signaling cascade to promote Rac1-mediated lamellipodial protrusion and FA turnover. The antagonism between GIT2 and DOCK5 extends to non-transformed MCF10A mammary epithelial cells, with DOCK5 ‘dialing-up' and GIT2 ‘dialing-down' invasiveness. Finally, we determine that DOCK5 inhibition attenuates invasion and metastasis of MDA-MB-231 cells and prolongs life span of mice injected with these cells. Collectively, our work identifies DOCK5 as a key regulator of epithelial invasion and metastasis, and demonstrates that suppression of DOCK5 by GIT2 represents a previously unappreciated mechanism for coordination of Rho and Rac GTPases.
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Zhang W, Huang Y, Gunst SJ. p21-Activated kinase (Pak) regulates airway smooth muscle contraction by regulating paxillin complexes that mediate actin polymerization. J Physiol 2016; 594:4879-900. [PMID: 27038336 DOI: 10.1113/jp272132] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 03/28/2016] [Indexed: 01/01/2023] Open
Abstract
KEY POINTS In airway smooth muscle, tension development caused by a contractile stimulus requires phosphorylation of the 20 kDa myosin light chain (MLC), which activates crossbridge cycling and the polymerization of a pool of submembraneous actin. The p21-activated kinases (Paks) can regulate the contractility of smooth muscle and non-muscle cells, and there is evidence that this occurs through the regulation of MLC phosphorylation. We show that Pak has no effect on MLC phosphorylation during the contraction of airway smooth muscle, and that it regulates contraction by mediating actin polymerization. We find that Pak phosphorylates the adhesion junction protein, paxillin, on Ser273, which promotes the formation of a signalling complex that activates the small GTPase, cdc42, and the actin polymerization catalyst, neuronal Wiskott-Aldrich syndrome protein (N-WASP). These studies demonstrate a novel role for Pak in regulating the contractility of smooth muscle by regulating actin polymerization. ABSTRACT The p21-activated kinases (Pak) can regulate contractility in smooth muscle and other cell and tissue types, but the mechanisms by which Paks regulate cell contractility are unclear. In airway smooth muscle, stimulus-induced contraction requires phosphorylation of the 20 kDa light chain of myosin, which activates crossbridge cycling, as well as the polymerization of a small pool of actin. The role of Pak in airway smooth muscle contraction was evaluated by inhibiting acetylcholine (ACh)-induced Pak activation through the expression of a kinase inactive mutant, Pak1 K299R, or by treating tissues with the Pak inhibitor, IPA3. Pak inhibition suppressed actin polymerization and contraction in response to ACh, but it did not affect myosin light chain phosphorylation. Pak activation induced paxillin phosphorylation on Ser273; the paxillin mutant, paxillin S273A, inhibited paxillin Ser273 phosphorylation and inhibited actin polymerization and contraction. Immunoprecipitation analysis of tissue extracts and proximity ligation assays in dissociated cells showed that Pak activation and paxillin Ser273 phosphorylation triggered the formation of an adhesion junction signalling complex with paxillin that included G-protein-coupled receptor kinase-interacting protein (GIT1) and the cdc42 guanine exchange factor, βPIX (Pak interactive exchange factor). Assembly of the Pak-GIT1-βPIX-paxillin complex was necessary for cdc42 and neuronal Wiskott-Aldrich syndrome protein (N-WASP) activation, actin polymerization and contraction in response to ACh. RhoA activation was also required for the recruitment of Pak to adhesion junctions, Pak activation, paxillin Ser273 phosphorylation and paxillin complex assembly. These studies demonstrate a novel role for Pak in the regulation of N-WASP activation, actin dynamics and cell contractility.
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Affiliation(s)
- Wenwu Zhang
- Department of Cellular and Integrative Physiology, Indiana University School Medicine, Indianapolis, IN, 46202-5120, USA
| | - Youliang Huang
- Department of Cellular and Integrative Physiology, Indiana University School Medicine, Indianapolis, IN, 46202-5120, USA
| | - Susan J Gunst
- Department of Cellular and Integrative Physiology, Indiana University School Medicine, Indianapolis, IN, 46202-5120, USA
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GIT1/βPIX signaling proteins and PAK1 kinase regulate microtubule nucleation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1282-97. [PMID: 27012601 DOI: 10.1016/j.bbamcr.2016.03.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 03/14/2016] [Accepted: 03/18/2016] [Indexed: 12/13/2022]
Abstract
Microtubule nucleation from γ-tubulin complexes, located at the centrosome, is an essential step in the formation of the microtubule cytoskeleton. However, the signaling mechanisms that regulate microtubule nucleation in interphase cells are largely unknown. In this study, we report that γ-tubulin is in complexes containing G protein-coupled receptor kinase-interacting protein 1 (GIT1), p21-activated kinase interacting exchange factor (βPIX), and p21 protein (Cdc42/Rac)-activated kinase 1 (PAK1) in various cell lines. Immunofluorescence microscopy revealed association of GIT1, βPIX and activated PAK1 with centrosomes. Microtubule regrowth experiments showed that depletion of βPIX stimulated microtubule nucleation, while depletion of GIT1 or PAK1 resulted in decreased nucleation in the interphase cells. These data were confirmed for GIT1 and βPIX by phenotypic rescue experiments, and counting of new microtubules emanating from centrosomes during the microtubule regrowth. The importance of PAK1 for microtubule nucleation was corroborated by the inhibition of its kinase activity with IPA-3 inhibitor. GIT1 with PAK1 thus represent positive regulators, and βPIX is a negative regulator of microtubule nucleation from the interphase centrosomes. The regulatory roles of GIT1, βPIX and PAK1 in microtubule nucleation correlated with recruitment of γ-tubulin to the centrosome. Furthermore, in vitro kinase assays showed that GIT1 and βPIX, but not γ-tubulin, serve as substrates for PAK1. Finally, direct interaction of γ-tubulin with the C-terminal domain of βPIX and the N-terminal domain of GIT1, which targets this protein to the centrosome, was determined by pull-down experiments. We propose that GIT1/βPIX signaling proteins with PAK1 kinase represent a novel regulatory mechanism of microtubule nucleation in interphase cells.
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Gramolelli S, Weidner-Glunde M, Abere B, Viejo-Borbolla A, Bala K, Rückert J, Kremmer E, Schulz TF. Inhibiting the Recruitment of PLCγ1 to Kaposi's Sarcoma Herpesvirus K15 Protein Reduces the Invasiveness and Angiogenesis of Infected Endothelial Cells. PLoS Pathog 2015; 11:e1005105. [PMID: 26295810 PMCID: PMC4546648 DOI: 10.1371/journal.ppat.1005105] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 07/22/2015] [Indexed: 11/28/2022] Open
Abstract
Kaposi’s sarcoma (KS), caused by Kaposi’s sarcoma herpesvirus (KSHV), is a highly vascularised tumour of endothelial origin. KSHV infected endothelial cells show increased invasiveness and angiogenesis. Here, we report that the KSHV K15 protein, which we showed previously to contribute to KSHV-induced angiogenesis, is also involved in KSHV-mediated invasiveness in a PLCγ1-dependent manner. We identified βPIX, GIT1 and cdc42, downstream effectors of PLCγ1 in cell migration, as K15 interacting partners and as contributors to KSHV-triggered invasiveness. We mapped the interaction between PLCγ1, PLCγ2 and their individual domains with two K15 alleles, P and M. We found that the PLCγ2 cSH2 domain, by binding to K15P, can be used as dominant negative inhibitor of the K15P-PLCγ1 interaction, K15P-dependent PLCγ1 phosphorylation, NFAT-dependent promoter activation and the increased invasiveness and angiogenic properties of KSHV infected endothelial cells. We increased the binding of the PLCγ2 cSH2 domain for K15P by substituting two amino acids, thereby creating an improved dominant negative inhibitor of the K15P-dependent PLCγ1 activation. Taken together, these results demonstrate a necessary role of K15 in the increased invasiveness and angiogenesis of KSHV infected endothelial cells and suggest the K15-PLCγ1 interaction as a possible new target for inhibiting the angiogenic and invasive properties of KSHV. Kaposi’s Sarcoma (KS), etiologically linked to Kaposi’s sarcoma herpesvirus (KSHV), is a tumour of endothelial origin characterised by angiogenesis and invasiveness. In vitro, KSHV infected endothelial cells display an increased invasiveness and high angiogenicity. Here we report that the KSHV protein K15, which increases the angiogenicity of endothelial cells, contributes to KSHV-mediated invasiveness by the recruitment and activation of the cellular protein PLCγ1 and its downstream effectors βPIX, GIT1 and cdc42. We explored the functional consequences of disrupting the K15-PLCγ1 interaction by using an isolated PLCγ2 cSH2 domain as a dominant negative inhibitor. This protein fragment, by interacting with K15, reduces K15-driven recruitment and activation of PLCγ1 in a dose-dependent manner. Moreover, the PCLγ2 cSH2 domain, when overexpressed in KSHV infected endothelial cells, reduces the angiogenesis and invasiveness induced by the virus. These findings highlight the role of the K15-PLCγ1 interaction in KSHV-mediated invasiveness and identify it as a possible therapeutic target.
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Affiliation(s)
- Silvia Gramolelli
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Magdalena Weidner-Glunde
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Bizunesh Abere
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Braunschweig, Germany
| | | | - Kiran Bala
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | - Jessica Rückert
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Elisabeth Kremmer
- Institute of Molecular Immunology, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Munich, Germany
| | - Thomas F. Schulz
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Braunschweig, Germany
- * E-mail:
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Kortüm F, Harms FL, Hennighausen N, Rosenberger G. αPIX Is a Trafficking Regulator that Balances Recycling and Degradation of the Epidermal Growth Factor Receptor. PLoS One 2015; 10:e0132737. [PMID: 26177020 PMCID: PMC4503440 DOI: 10.1371/journal.pone.0132737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 06/17/2015] [Indexed: 12/14/2022] Open
Abstract
Endosomal sorting is an essential control mechanism for signaling through the epidermal growth factor receptor (EGFR). We report here that the guanine nucleotide exchange factor αPIX, which modulates the activity of Rho-GTPases, is a potent bimodal regulator of EGFR trafficking. αPIX interacts with the E3 ubiquitin ligase c-Cbl, an enzyme that attaches ubiquitin to EGFR, thereby labelling this tyrosine kinase receptor for lysosomal degradation. We show that EGF stimulation induces αPIX::c-Cbl complex formation. Simultaneously, αPIX and c-Cbl protein levels decrease, which depends on both αPIX binding to c-Cbl and c-Cbl ubiquitin ligase activity. Through interaction αPIX sequesters c-Cbl from EGFR and this results in reduced EGFR ubiquitination and decreased EGFR degradation upon EGF treatment. However, quantitatively more decisive for cellular EGFR distribution than impaired EGFR degradation is a strong stimulating effect of αPIX on EGFR recycling to the cell surface. This function depends on the GIT binding domain of αPIX but not on interaction with c-Cbl or αPIX exchange activity. In summary, our data demonstrate a previously unappreciated function of αPIX as a strong promoter of EGFR recycling. We suggest that the novel recycling regulator αPIX and the degradation factor c-Cbl closely cooperate in the regulation of EGFR trafficking: uncomplexed αPIX and c-Cbl mediate a positive and a negative feedback on EGFR signaling, respectively; αPIX::c-Cbl complex formation, however, results in mutual inhibition, which may reflect a stable condition in the homeostasis of EGF-induced signal flow.
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Affiliation(s)
- Fanny Kortüm
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Frederike Leonie Harms
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Natascha Hennighausen
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Georg Rosenberger
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- * E-mail:
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van Buul JD, Geerts D, Huveneers S. Rho GAPs and GEFs: controling switches in endothelial cell adhesion. Cell Adh Migr 2015; 8:108-24. [PMID: 24622613 PMCID: PMC4049857 DOI: 10.4161/cam.27599] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Within blood vessels, endothelial cell–cell and cell–matrix adhesions are crucial to preserve barrier function, and these adhesions are tightly controlled during vascular development, angiogenesis, and transendothelial migration of inflammatory cells. Endothelial cellular signaling that occurs via the family of Rho GTPases coordinates these cell adhesion structures through cytoskeletal remodelling. In turn, Rho GTPases are regulated by GTPase-activating proteins (GAPs) and guanine nucleotide exchange factors (GEFs). To understand how endothelial cells initiate changes in the activity of Rho GTPases, and thereby regulate cell adhesion, we will discuss the role of Rho GAPs and GEFs in vascular biology. Many potentially important Rho regulators have not been studied in detail in endothelial cells. We therefore will first overview which GAPs and GEFs are highly expressed in endothelium, based on comparative gene expression analysis of human endothelial cells compared with other tissue cell types. Subsequently, we discuss the relevance of Rho GAPs and GEFs for endothelial cell adhesion in vascular homeostasis and disease.
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Affiliation(s)
- Jaap D van Buul
- Department of Molecular Cell Biology; Sanquin Research and Swammerdam Institute for Life Sciences; University of Amsterdam; The Netherlands
| | - Dirk Geerts
- Department of Pediatric Oncology/Hematology; Erasmus University Medical Center; Rotterdam, The Netherlands
| | - Stephan Huveneers
- Department of Molecular Cell Biology; Sanquin Research and Swammerdam Institute for Life Sciences; University of Amsterdam; The Netherlands
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37
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Sulimenko V, Hájková Z, Černohorská M, Sulimenko T, Sládková V, Dráberová L, Vinopal S, Dráberová E, Dráber P. Microtubule Nucleation in Mouse Bone Marrow–Derived Mast Cells Is Regulated by the Concerted Action of GIT1/βPIX Proteins and Calcium. THE JOURNAL OF IMMUNOLOGY 2015; 194:4099-111. [DOI: 10.4049/jimmunol.1402459] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 02/27/2015] [Indexed: 11/19/2022]
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38
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Lin L, Hu K. LRP-1: functions, signaling and implications in kidney and other diseases. Int J Mol Sci 2014; 15:22887-901. [PMID: 25514242 PMCID: PMC4284744 DOI: 10.3390/ijms151222887] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 11/06/2014] [Accepted: 12/04/2014] [Indexed: 12/17/2022] Open
Abstract
Low-density lipoprotein (LDL)-related protein-1 (LRP-1) is a member of LDL receptor family that is implicated in lipoprotein metabolism and in the homeostasis of proteases and protease inhibitors. Expression of LRP-1 is ubiquitous. Up-regulation of LRP-1 has been reported in numerous human diseases. In addition to its function as a scavenger receptor for various ligands, LRP-1 has been shown to transduce multiple intracellular signal pathways including mitogen-activated protein kinase (MAPK), Akt, Rho, and the integrin signaling. LRP-1 signaling plays an important role in the regulation of diverse cellular process, such as cell proliferation, survival, motility, differentiation, and transdifferentiation, and thus participates in the pathogenesis of organ dysfunction and injury. In this review, we focus on the current understanding of LRP-1 signaling and its roles in the development and progression of kidney disease. The role and signaling of LRP-1 in the nervous and cardiovascular systems, as well as in carcinogenesis, are also briefly discussed.
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Affiliation(s)
- Ling Lin
- Division of Nephrology, Department of Medicine, College of Medicine, Penn State University, 500 University Drive, Hershey, PA 17033, USA.
| | - Kebin Hu
- Division of Nephrology, Department of Medicine, College of Medicine, Penn State University, 500 University Drive, Hershey, PA 17033, USA.
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Dent LG, Poon CLC, Zhang X, Degoutin JL, Tipping M, Veraksa A, Harvey KF. The GTPase regulatory proteins Pix and Git control tissue growth via the Hippo pathway. Curr Biol 2014; 25:124-30. [PMID: 25484297 DOI: 10.1016/j.cub.2014.11.041] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 11/17/2014] [Accepted: 11/18/2014] [Indexed: 01/01/2023]
Abstract
The Salvador-Warts-Hippo (Hippo) pathway is a conserved regulator of organ size and is deregulated in human cancers. In epithelial tissues, the Hippo pathway is regulated by fundamental cell biological properties, such as polarity and adhesion, and coordinates these with tissue growth. Despite its importance in disease, development, and regeneration, the complete set of proteins that regulate Hippo signaling remain undefined. To address this, we used proteomics to identify proteins that bind to the Hippo (Hpo) kinase. Prominent among these were PAK-interacting exchange factor (known as Pix or RtGEF) and G-protein-coupled receptor kinase-interacting protein (Git). Pix is a conserved Rho-type guanine nucleotide exchange factor (Rho-GEF) homologous to Beta-PIX and Alpha-PIX in mammals. Git is the single Drosophila melanogaster homolog of the mammalian GIT1 and GIT2 proteins, which were originally identified in the search for molecules that interact with G-protein-coupled receptor kinases. Pix and Git form an oligomeric scaffold to facilitate sterile 20-like kinase activation and have also been linked to GTPase regulation. We show that Pix and Git regulate Hippo-pathway-dependent tissue growth in D. melanogaster and that they do this in parallel to the known upstream regulator Fat cadherin. Pix and Git influence activity of the Hpo kinase by acting as a scaffold complex, rather than enzymes, and promote Hpo dimerization and autophosphorylation of Hpo's activation loop. Therefore, we provide important new insights into an ancient signaling network that controls the growth of metazoan tissues.
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Affiliation(s)
- Lucas G Dent
- Cell Growth and Proliferation Laboratory, Peter MacCallum Cancer Centre, 7 St Andrews Place, East Melbourne, VIC 3002, Australia; Department of Pathology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Carole L C Poon
- Cell Growth and Proliferation Laboratory, Peter MacCallum Cancer Centre, 7 St Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Xiaomeng Zhang
- Cell Growth and Proliferation Laboratory, Peter MacCallum Cancer Centre, 7 St Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia; Department of Pathology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Joffrey L Degoutin
- Cell Growth and Proliferation Laboratory, Peter MacCallum Cancer Centre, 7 St Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Marla Tipping
- Department of Biology, Providence College, Providence, RI 02918, USA
| | - Alexey Veraksa
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Kieran F Harvey
- Cell Growth and Proliferation Laboratory, Peter MacCallum Cancer Centre, 7 St Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia; Department of Pathology, University of Melbourne, Parkville, VIC 3010, Australia.
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Itzstein C, Coxon FP, Rogers MJ. The regulation of osteoclast function and bone resorption by small GTPases. Small GTPases 2014; 2:117-130. [PMID: 21776413 DOI: 10.4161/sgtp.2.3.16453] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 04/22/2011] [Accepted: 05/10/2011] [Indexed: 01/11/2023] Open
Abstract
Osteoclasts are multinucleated cells that are responsible for resorption of bone, and increased activity of these cells is associated with several common bone diseases, including postmenopausal osteoporosis. Upon adhesion to bone, osteoclasts become polarized and reorganise their cytoskeleton and membrane to form unique domains including the sealing zone (SZ), which is a dense ring of F-actin-rich podosomes delimiting the ruffled border (RB), where protons and proteases are secreted to demineralise and degrade the bone matrix, respectively. These processes are dependent on the activity of small GTPases. Rho GTPases are well known to control the organization of F-actin and adhesion structures of different cell types, affecting subsequently their migration. In osteoclasts, RhoA, Rac, Cdc42, RhoU and also Arf6 regulate podosome assembly and their organization into the SZ. By contrast, the formation of the RB involves vesicular trafficking pathways that are regulated by the Rab family of GTPases, in particular lysosomal Rab7. Finally, osteoclast survival is dependent on the activity of Ras GTPases. The correct function of almost all these GTPases is absolutely dependent on post-translational prenylation, which enables them to localize to specific target membranes. Bisphosphonate drugs, which are widely used in the treatment of bone diseases such as osteoporosis, act by preventing the prenylation of small GTPases, resulting in the loss of the SZ and RB and therefore inhibition of osteoclast activity, as well as inducing osteoclast apoptosis. In this review we summarize current understanding of the role of specific prenylated small GTPases in osteoclast polarization, function and survival.
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Affiliation(s)
- Cecile Itzstein
- Musculoskeletal Research Programme; Institute of Medical Sciences; University of Aberdeen; Aberdeen, Scotland UK
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Goicoechea SM, Awadia S, Garcia-Mata R. I'm coming to GEF you: Regulation of RhoGEFs during cell migration. Cell Adh Migr 2014; 8:535-49. [PMID: 25482524 PMCID: PMC4594598 DOI: 10.4161/cam.28721] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cell migration is a highly regulated multistep process that requires the coordinated regulation of cell adhesion, protrusion, and contraction. These processes require numerous protein–protein interactions and the activation of specific signaling pathways. The Rho family of GTPases plays a key role in virtually every aspect of the cell migration cycle. The activation of Rho GTPases is mediated by a large and diverse family of proteins; the guanine nucleotide exchange factors (RhoGEFs). GEFs work immediately upstream of Rho proteins to provide a direct link between Rho activation and cell–surface receptors for various cytokines, growth factors, adhesion molecules, and G protein-coupled receptors. The regulated targeting and activation of RhoGEFs is essential to coordinate the migratory process. In this review, we summarize the recent advances in our understanding of the role of RhoGEFs in the regulation of cell migration.
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Key Words
- DH, Dbl-homology
- DHR, DOCK homology region
- DOCK, dedicator of cytokinesis
- ECM, extracellular matrix
- EGF, epidermal growth factor
- FA, focal adhesion
- FN, fibronectin
- GAP, GTPase activating protein
- GDI, guanine nucleotide dissociation inhibitor
- GEF, guanine nucleotide exchange factor
- GPCR, G protein-coupled receptor
- HGF, hepatocyte growth factor
- LPA, lysophosphatidic acid
- MII, myosin II
- PA, phosphatidic acid
- PDGF, platelet-derived growth factor
- PH, pleckstrin-homology
- PIP2, phosphatidylinositol 4, 5-bisphosphate
- PIP3, phosphatidylinositol (3, 4, 5)-trisphosphate.
- Rho GEFs
- Rho GTPases
- bFGF, basic fibroblast growth factor
- cell migration
- cell polarization
- focal adhesions
- guanine nucleotide exchange factors
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Affiliation(s)
- Silvia M Goicoechea
- a Department of Biological Sciences ; University of Toledo ; Toledo , OH USA
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Lin L, Jin Y, Mars WM, Reeves WB, Hu K. Myeloid-derived tissue-type plasminogen activator promotes macrophage motility through FAK, Rac1, and NF-κB pathways. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:2757-67. [PMID: 25131752 DOI: 10.1016/j.ajpath.2014.06.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 06/04/2014] [Accepted: 06/13/2014] [Indexed: 12/23/2022]
Abstract
Macrophage accumulation is one of the hallmarks of progressive kidney disease. Tissue-type plasminogen activator (tPA) is known to promote macrophage infiltration and renal inflammation during chronic kidney injury. However, the underlying mechanism remains largely unknown. We examined the role of tPA in macrophage motility in vivo by tracking fluorescence-labeled bone marrow-derived macrophages, and found that tPA-deficient mice had markedly fewer infiltrating fluorescence-labeled macrophages than the wild-type (WT) mice. Experiments in bone marrow chimeric mice further demonstrated that myeloid cells are the main source of endogenous tPA that promotes macrophage migration. In vitro studies showed that tPA promoted macrophage motility through its CD11b-mediated protease-independent function; and focal adhesion kinase (FAK), Rac-1, and NF-κB were indispensable to tPA-induced macrophage migration as either infection of FAK dominant-negative adenovirus or treatment with a Rac-1-specific inhibitor or NF-κB inhibitor abolished the effect of tPA. Moreover, ectopic FAK mimicked tPA and induced macrophage motility. tPA also activated migratory signaling in vivo. The accumulation of phospho-FAK-positive CD11b macrophages in the obstructed kidneys from WT mice was clearly attenuated in tPA knockout mice, which also displayed lower Rac-1 activity than their WT counterparts. Therefore, our results indicate that myeloid-derived tPA promotes macrophage migration through a novel signaling cascade involving FAK, Rac-1, and NF-κB.
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Affiliation(s)
- Ling Lin
- Division of Nephrology, Department of Medicine, Penn State University College of Medicine, Hershey, Pennsylvania
| | - Yang Jin
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Wendy M Mars
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - W Brian Reeves
- Division of Nephrology, Department of Medicine, Penn State University College of Medicine, Hershey, Pennsylvania
| | - Kebin Hu
- Division of Nephrology, Department of Medicine, Penn State University College of Medicine, Hershey, Pennsylvania.
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Wilson E, Leszczynska K, Poulter NS, Edelmann F, Salisbury VA, Noy PJ, Bacon A, Rappoport JZ, Heath JK, Bicknell R, Heath VL. RhoJ interacts with the GIT-PIX complex and regulates focal adhesion disassembly. J Cell Sci 2014; 127:3039-51. [PMID: 24928894 PMCID: PMC4106786 DOI: 10.1242/jcs.140434] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
RhoJ is a Rho GTPase expressed in endothelial cells and tumour cells, which regulates cell motility, invasion, endothelial tube formation and focal adhesion numbers. This study aimed to further delineate the molecular function of RhoJ. Using timelapse microscopy RhoJ was found to regulate focal adhesion disassembly; small interfering RNA (siRNA)-mediated knockdown of RhoJ increased focal adhesion disassembly time, whereas expression of an active mutant (daRhoJ) decreased it. Furthermore, daRhoJ co-precipitated with the GIT–PIX complex, a regulator of focal adhesion disassembly. An interaction between daRhoJ and GIT1 was confirmed using yeast two-hybrid experiments, and this depended on the Spa homology domain of GIT1. GIT1, GIT2, β-PIX (also known as ARHGEF7) and RhoJ all colocalised in focal adhesions and depended on each other for their recruitment to focal adhesions. Functionally, the GIT–PIX complex regulated endothelial tube formation, with knockdown of both GIT1 and GIT2, or β-PIX phenocopying RhoJ knockdown. RhoJ-knockout mice showed reduced tumour growth and diminished tumour vessel density, identifying a role for RhoJ in mediating tumour angiogenesis. These studies give new insight into the molecular function of RhoJ in regulating cell motility and tumour vessel formation.
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Affiliation(s)
- Eleanor Wilson
- School of Immunity and Infection, Institute for Biomedical Research, The Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Katarzyna Leszczynska
- School of Immunity and Infection, Institute for Biomedical Research, The Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Natalie S Poulter
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Francesca Edelmann
- School of Immunity and Infection, Institute for Biomedical Research, The Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Victoria A Salisbury
- School of Immunity and Infection, Institute for Biomedical Research, The Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Peter J Noy
- School of Immunity and Infection, Institute for Biomedical Research, The Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Andrea Bacon
- School of Immunity and Infection, Institute for Biomedical Research, The Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | | | - John K Heath
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Roy Bicknell
- School of Immunity and Infection, Institute for Biomedical Research, The Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Victoria L Heath
- School of Immunity and Infection, Institute for Biomedical Research, The Medical School, University of Birmingham, Birmingham B15 2TT, UK
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A Trio-Rac1-Pak1 signalling axis drives invadopodia disassembly. Nat Cell Biol 2014; 16:574-86. [PMID: 24859002 PMCID: PMC4083618 DOI: 10.1038/ncb2972] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 04/17/2014] [Indexed: 12/11/2022]
Abstract
Rho family GTPases control cell migration and participate in the regulation of cancer metastasis. Invadopodia, associated with invasive tumor cells, are crucial for cellular invasion and metastasis. To study Rac1 GTPase in invadopodia dynamics, we developed a genetically-encoded, single-chain Rac1 Fluorescence Resonance Energy Transfer (FRET) biosensor. The biosensor shows Rac1 activity exclusion from the core of invadopodia, and higher activity when invadopodia disappear, suggesting that reduced Rac1 activity is necessary for their stability, and Rac1 activation is involved in disassembly. Photoactivating Rac1 at invadopodia confirmed this previously-unknown Rac1 function. We built an invadopodia disassembly model, where a signaling axis involving TrioGEF, Rac1, PAK1, and phosphorylation of cortactin, causing invadopodia dissolution. This mechanism is critical for the proper turnover of invasive structures during tumor cell invasion, where a balance of proteolytic activity and locomotory protrusions must be carefully coordinated to achieve a maximally invasive phenotype.
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45
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Liu S, Premont RT, Rockey DC. Endothelial nitric-oxide synthase (eNOS) is activated through G-protein-coupled receptor kinase-interacting protein 1 (GIT1) tyrosine phosphorylation and Src protein. J Biol Chem 2014; 289:18163-74. [PMID: 24764294 DOI: 10.1074/jbc.m113.521203] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Nitric oxide (NO) is a critical regulator of vascular tone and plays an especially prominent role in liver by controlling portal blood flow and pressure within liver sinusoids. Synthesis of NO in sinusoidal endothelial cells by endothelial nitric-oxide synthase (eNOS) is regulated in response to activation of endothelial cells by vasoactive signals such as endothelins. The endothelin B (ETB) receptor is a G-protein-coupled receptor, but the mechanisms by which it regulates eNOS activity in sinusoidal endothelial cells are not well understood. In this study, we built on two previous strands of work, the first showing that G-protein βγ subunits mediated activation of phosphatidylinositol 3-kinase and Akt to regulate eNOS and the second showing that eNOS directly bound to the G-protein-coupled receptor kinase-interacting protein 1 (GIT1) scaffold protein, and this association stimulated NO production. Here we investigated the mechanisms by which the GIT1-eNOS complex is formed and regulated. GIT1 was phosphorylated on tyrosine by Src, and Y293F and Y554F mutations reduced GIT1 phosphorylation as well as the ability of GIT1 to bind to and activate eNOS. Akt phosphorylation activated eNOS (at Ser(1177)), and Akt also regulated the ability of Src to phosphorylate GIT1 as well as GIT1-eNOS association. These pathways were activated by endothelin-1 through the ETB receptor; inhibiting receptor-activated G-protein βγ subunits blocked activation of Akt, GIT1 tyrosine phosphorylation, and ET-1-stimulated GIT1-eNOS association but did not affect Src activation. These data suggest a model in which Src and Akt cooperate to regulate association of eNOS with the GIT1 scaffold to facilitate NO production.
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Affiliation(s)
- Songling Liu
- From the Department of Medicine, Medical University of South Carolina, Charleston, South Carolina 29425 and
| | - Richard T Premont
- Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710
| | - Don C Rockey
- From the Department of Medicine, Medical University of South Carolina, Charleston, South Carolina 29425 and
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46
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Totaro A, Astro V, Tonoli D, de Curtis I. Identification of two tyrosine residues required for the intramolecular mechanism implicated in GIT1 activation. PLoS One 2014; 9:e93199. [PMID: 24699139 PMCID: PMC3974724 DOI: 10.1371/journal.pone.0093199] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Accepted: 03/03/2014] [Indexed: 11/21/2022] Open
Abstract
GIT1 is an ArfGAP and scaffolding protein regulating cell adhesion and migration. The multidomain structure of GIT1 allows the interaction with several partners. Binding of GIT1 to some of its partners requires activation of the GIT1 polypeptide. Our previous studies indicated that binding of paxillin to GIT1 is enhanced by release of an intramolecular interaction between the amino-terminal and carboxy-terminal portions that keeps the protein in a binding-incompetent state. Here we have addressed the mechanism mediating this intramolecular inhibitory mechanism by testing the effects of the mutation of several formerly identified GIT1 phosphorylation sites on the binding to paxillin. We have identified two tyrosines at positions 246 and 293 of the human GIT1 polypeptide that are needed to keep the protein in the inactive conformation. Interestingly, mutation of these residues to phenylalanine did not affect binding to paxillin, while mutation to either alanine or glutamic acid enhanced binding to paxillin, without affecting the constitutive binding to the Rac/Cdc42 exchange factor βPIX. The involvement of the two tyrosine residues in the intramolecular interaction was supported by reconstitution experiments showing that these residues are important for the binding between the amino-terminal fragment and carboxy-terminal portions of GIT1. Either GIT1 or GIT1-N tyrosine phosphorylation by Src and pervanadate treatment to inhibit protein tyrosine phosphatases did not affect the intramolecular binding between the amino- and carboxy-terminal fragments, nor the binding of GIT1 to paxillin. Mutations increasing the binding of GIT1 to paxillin positively affected cell motility, measured both by transwell migration and wound healing assays. Altogether these results show that tyrosines 246 and 293 of GIT1 are required for the intramolecular inhibitory mechanism that prevents the binding of GIT1 to paxillin. The data also suggest that tyrosine phosphorylation may not be sufficient to release the intramolecular interaction that keeps GIT1 in the inactive conformation.
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Affiliation(s)
- Antonio Totaro
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milano, Italy
| | - Veronica Astro
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milano, Italy
| | - Diletta Tonoli
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milano, Italy
| | - Ivan de Curtis
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milano, Italy; Università Vita-Salute San Raffaele, Milano, Italy
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Korthals M, Schilling K, Reichardt P, Mamula D, Schlüter T, Steiner M, Langnäse K, Thomas U, Gundelfinger E, Premont RT, Tedford K, Fischer KD. αPIX RhoGEF Supports Positive Selection by Restraining Migration and Promoting Arrest of Thymocytes. THE JOURNAL OF IMMUNOLOGY 2014; 192:3228-38. [DOI: 10.4049/jimmunol.1302585] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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48
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Fortin Ensign SP, Mathews IT, Symons MH, Berens ME, Tran NL. Implications of Rho GTPase Signaling in Glioma Cell Invasion and Tumor Progression. Front Oncol 2013; 3:241. [PMID: 24109588 PMCID: PMC3790103 DOI: 10.3389/fonc.2013.00241] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 09/02/2013] [Indexed: 01/21/2023] Open
Abstract
Glioblastoma (GB) is the most malignant of primary adult brain tumors, characterized by a highly locally invasive cell population, as well as abundant proliferative cells, neoangiogenesis, and necrosis. Clinical intervention with chemotherapy or radiation may either promote or establish an environment for manifestation of invasive behavior. Understanding the molecular drivers of invasion in the context of glioma progression may be insightful in directing new treatments for patients with GB. Here, we review current knowledge on Rho family GTPases, their aberrant regulation in GB, and their effect on GB cell invasion and tumor progression. Rho GTPases are modulators of cell migration through effects on actin cytoskeleton rearrangement; in non-neoplastic tissue, expression and activation of Rho GTPases are normally under tight regulation. In GB, Rho GTPases are deregulated, often via hyperactivity or overexpression of their activators, Rho GEFs. Downstream effectors of Rho GTPases have been shown to promote invasiveness and, importantly, glioma cell survival. The study of aberrant Rho GTPase signaling in GB is thus an important investigation of cell invasion as well as treatment resistance and disease progression.
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Affiliation(s)
- Shannon Patricia Fortin Ensign
- Cancer and Cell Biology Division, Translational Genomics Research Institute , Phoenix, AZ , USA ; Cancer Biology Graduate Interdisciplinary Program, University of Arizona , Tucson, AZ , USA
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49
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Bastos RN, Penate X, Bates M, Hammond D, Barr FA. CYK4 inhibits Rac1-dependent PAK1 and ARHGEF7 effector pathways during cytokinesis. ACTA ACUST UNITED AC 2013; 198:865-80. [PMID: 22945935 PMCID: PMC3432774 DOI: 10.1083/jcb.201204107] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
In mitosis, animal cells lose their adhesion to the surrounding surfaces and become rounded. During mitotic exit, they reestablish these adhesions and at the same time physically contract and divide. How these competing processes are spatially segregated at the cell cortex remains mysterious. To address this question, we define the specific effector pathways used by RhoA and Rac1 in mitotic cells. We demonstrate that the MKlp1-CYK4 centralspindlin complex is a guanosine triphosphatase-activating protein (GAP) for Rac1 and not RhoA and that CYK4 negatively regulated Rac1 activity at the cell equator in anaphase. Cells expressing a CYK4 GAP mutant had defects in cytokinesis and showed elevated staining for the cell adhesion marker vinculin. These defects could be rescued by depletion of ARHGEF7 and p21-activated kinase, Rac1-specific effector proteins required for cell adhesion. Based on these findings, we propose that CYK4 GAP activity is required during anaphase to inhibit Rac1-dependent effector pathways associated with control of cell spreading and adhesion.
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50
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Abstract
The Rho family of GTP binding proteins, also commonly referred to as the Rho GTPases, are master regulators of the platelet cytoskeleton and platelet function. These low-molecular-weight or 'small' GTPases act as signaling switches in the spatial and temporal transduction, and amplification of signals from platelet cell surface receptors to the intracellular signaling pathways that drive platelet function. The Rho GTPase family members RhoA, Cdc42 and Rac1 have emerged as key regulators in the dynamics of the actin cytoskeleton in platelets and play key roles in platelet aggregation, secretion, spreading and thrombus formation. Rho GTPase regulators, including GEFs and GAPs and downstream effectors, such as the WASPs, formins and PAKs, may also regulate platelet activation and function. In this review, we provide an overview of Rho GTPase signaling in platelet physiology. Previous studies of Rho GTPases and platelets have had a shared history, as platelets have served as an ideal, non-transformed cellular model to characterize Rho function. Likewise, recent studies of the cell biology of Rho GTPase family members have helped to build an understanding of the molecular regulation of platelet function and will continue to do so through the further characterization of Rho GTPases as well as Rho GAPs, GEFs, RhoGDIs and Rho effectors in actin reorganization and other Rho-driven cellular processes.
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Affiliation(s)
- J E Aslan
- Department of Biomedical Engineering and Cell & Developmental Biology, School of Medicine, Oregon Health & Science University, Portland, OR 97239, USA.
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