1
|
Park JC, Luebbers A, Dao M, Semeano A, Nguyen AM, Papakonstantinou MP, Broselid S, Yano H, Martemyanov KA, Garcia-Marcos M. Fine-tuning GPCR-mediated neuromodulation by biasing signaling through different G protein subunits. Mol Cell 2023; 83:2540-2558.e12. [PMID: 37390816 PMCID: PMC10527995 DOI: 10.1016/j.molcel.2023.06.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/28/2023] [Accepted: 06/02/2023] [Indexed: 07/02/2023]
Abstract
G-protein-coupled receptors (GPCRs) mediate neuromodulation through the activation of heterotrimeric G proteins (Gαβγ). Classical models depict that G protein activation leads to a one-to-one formation of Gα-GTP and Gβγ species. Each of these species propagates signaling by independently acting on effectors, but the mechanisms by which response fidelity is ensured by coordinating Gα and Gβγ responses remain unknown. Here, we reveal a paradigm of G protein regulation whereby the neuronal protein GINIP (Gα inhibitory interacting protein) biases inhibitory GPCR responses to favor Gβγ over Gα signaling. Tight binding of GINIP to Gαi-GTP precludes its association with effectors (adenylyl cyclase) and, simultaneously, with regulator-of-G-protein-signaling (RGS) proteins that accelerate deactivation. As a consequence, Gαi-GTP signaling is dampened, whereas Gβγ signaling is enhanced. We show that this mechanism is essential to prevent the imbalances of neurotransmission that underlie increased seizure susceptibility in mice. Our findings reveal an additional layer of regulation within a quintessential mechanism of signal transduction that sets the tone of neurotransmission.
Collapse
Affiliation(s)
- Jong-Chan Park
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Alex Luebbers
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Maria Dao
- U.F. Scripps Biomedical Research, University of Florida, Jupiter, FL 33458, USA
| | - Ana Semeano
- Department of Pharmaceutical Sciences, Center for Drug Discovery, School of Pharmacy and Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, MA 02115, USA
| | - Anh Minh Nguyen
- Department of Pharmaceutical Sciences, Center for Drug Discovery, School of Pharmacy and Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, MA 02115, USA
| | - Maria P Papakonstantinou
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Stefan Broselid
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Hideaki Yano
- Department of Pharmaceutical Sciences, Center for Drug Discovery, School of Pharmacy and Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, MA 02115, USA
| | | | - Mikel Garcia-Marcos
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA; Department of Biology, College of Arts & Sciences, Boston University, Boston, MA 02115, USA.
| |
Collapse
|
2
|
Li Z, Bao X, Liu X, Wang W, Yang J. Gene network analyses of larvae under different egg-protecting behaviors provide novel insights into immune response mechanisms of Amphioctopus fangsiao. FISH & SHELLFISH IMMUNOLOGY 2023; 136:108733. [PMID: 37028690 DOI: 10.1016/j.fsi.2023.108733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/28/2023] [Accepted: 04/03/2023] [Indexed: 06/19/2023]
Abstract
Amphioctopus fangsiao was a representative economic species in cephalopods, which was vulnerable to marine bacteria. Vibrio anguillarum was a highly infectious pathogen that have recently been found to infect A. fangsiao and inhibit its growth and development. There were significant differences in the immune response mechanisms between egg-protected and egg-unprotected larvae. To explore larval immunity under different egg-protecting behaviors, we infected A. fangsiao larvae with V. anguillarum for 24 h and analyzed the transcriptome data about egg-protected and egg-unprotected larvae infected with 0, 4, 12, and 24 h using weighted gene co-expression networks (WGCNA) and protein-protein interaction (PPI) networks. Network analyses revealed a series of immune response processes after infection, and identified six key modules and multiple immune-related hub genes. Meanwhile, we found that ZNF family, such as ZNF32, ZNF160, ZNF271, ZNF479, and ZNF493 might play significant roles in A. fangsiao immune response processes. We first creatively combined WGCNA and PPI network analysis to deeply explore the immune response mechanisms of A. fangsiao larvae with different egg-protecting behaviors. Our results provided further insights into the immunity of V. anguillarum infected invertebrates, and laid the foundation for exploring the immune differences among cephalopods with different egg protecting behaviors.
Collapse
Affiliation(s)
- Zan Li
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Xiaokai Bao
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Xiumei Liu
- College of Life Sciences, Yantai University, Yantai, 264005, China
| | - Weijun Wang
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Jianmin Yang
- School of Agriculture, Ludong University, Yantai, 264025, China.
| |
Collapse
|
3
|
Sinha S, Callow BW, Farfel AP, Roy S, Chen S, Rajendran S, Buschhaus JM, Luker KE, Ghosh P, Luker GD. A Multiomic Analysis Reveals How Breast Cancers Disseminated to the Bone Marrow Acquire Aggressive Phenotypes through Tumor-Stroma Tunnels. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.18.533175. [PMID: 36993616 PMCID: PMC10055300 DOI: 10.1101/2023.03.18.533175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Estrogen receptor-positive (ER+) breast cancer commonly disseminates to bone marrow, where interactions with mesenchymal stromal cells (MSCs) shape disease trajectory. We modeled these interactions with tumor-MSC co-cultures and used an integrated transcriptome-proteome-network- analyses workflow to identify a comprehensive catalog of contact-induced changes. Induced genes and proteins in cancer cells, some borrowed and others tumor-intrinsic, were not recapitulated merely by conditioned media from MSCs. Protein-protein interaction networks revealed the rich connectome between 'borrowed' and 'intrinsic' components. Bioinformatic approaches prioritized one of the 'borrowed' components, CCDC88A /GIV, a multi-modular metastasis-related protein which has recently been implicated in driving one of the hallmarks of cancers, i.e., growth signaling autonomy. MSCs transferred GIV protein to ER+ breast cancer cells (that lack GIV) through tunnelling nanotubes via connexin (Cx)43-facilitated intercellular transport. Reinstating GIV alone in GIV-negative breast cancer cells reproduced ∼20% of both the 'borrowed' and the 'intrinsic' gene induction patterns from contact co-cultures; conferred resistance to anti-estrogen drugs; and enhanced tumor dissemination. Findings provide a multiomic insight into MSC→tumor cell intercellular transport and validate how transport of one such candidate, GIV, from the haves (MSCs) to have-nots (ER+ breast cancer) orchestrates aggressive disease states.
Collapse
|
4
|
Laidlaw KME, Paine KM, Bisinski DD, Calder G, Hogg K, Ahmed S, James S, O’Toole PJ, MacDonald C. Endosomal cargo recycling mediated by Gpa1 and phosphatidylinositol 3-kinase is inhibited by glucose starvation. Mol Biol Cell 2022; 33:ar31. [PMID: 35080991 PMCID: PMC9250360 DOI: 10.1091/mbc.e21-04-0163] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Cell surface protein trafficking is regulated in response to nutrient availability, with multiple pathways directing surface membrane proteins to the lysosome for degradation in response to suboptimal extracellular nutrients. Internalized protein and lipid cargoes recycle back to the surface efficiently in glucose-replete conditions, but this trafficking is attenuated following glucose starvation. We find that cells with either reduced or hyperactive phosphatidylinositol 3-kinase (PI3K) activity are defective for endosome to surface recycling. Furthermore, we find that the yeast Gα subunit Gpa1, an endosomal PI3K effector, is required for surface recycling of cargoes. Following glucose starvation, mRNA and protein levels of a distinct Gα subunit Gpa2 are elevated following nuclear translocation of Mig1, which inhibits recycling of various cargoes. As Gpa1 and Gpa2 interact at the surface where Gpa2 concentrates during glucose starvation, we propose that this disrupts PI3K activity required for recycling, potentially diverting Gpa1 to the surface and interfering with its endosomal role in recycling. In support of this model, glucose starvation and overexpression of Gpa2 alter PI3K endosomal phosphoinositide production. Glucose deprivation therefore triggers a survival mechanism to increase retention of surface cargoes in endosomes and promote their lysosomal degradation.
Collapse
Affiliation(s)
| | | | | | - Grant Calder
- Bioscience Technology Facility, Department of Biology, University of York, YO10 5DD York, UK
| | - Karen Hogg
- Bioscience Technology Facility, Department of Biology, University of York, YO10 5DD York, UK
| | - Sophia Ahmed
- Bioscience Technology Facility, Department of Biology, University of York, YO10 5DD York, UK
| | - Sally James
- Bioscience Technology Facility, Department of Biology, University of York, YO10 5DD York, UK
| | - Peter J. O’Toole
- Bioscience Technology Facility, Department of Biology, University of York, YO10 5DD York, UK
| | - Chris MacDonald
- York Biomedical Research Institute and Department of Biology and,*Address correspondence to: Chris MacDonald ()
| |
Collapse
|
5
|
Zhang Y, Hong Y, Wang D, Duan L, Liu Y, Li L, Liu D, Zhuang K, Wei C, Zheng G, Huo C, Liu G. Hsa_circ_0076305 induces migration-proliferation dichotomy in gastric cancer. Oncol Lett 2021; 21:220. [PMID: 33613709 PMCID: PMC7859472 DOI: 10.3892/ol.2021.12481] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 11/13/2020] [Indexed: 12/27/2022] Open
Abstract
Recent studies have demonstrated that circular RNAs (circRNAs) play an important role in the development of gastric cancer (GC). The present study aimed to investigate the role of hsa_circ_0076305 (circPGC) in GC. The levels of circRNAs and mRNAs in AGS cell lines were detected via reverse transcription-quantitative PCR, and western blotting was performed to detect protein expression levels. Functional studies were explored by CCK8 assay and cell migration assay. Functional studies have indicated that circPGC orchestrates two cellular processes; it inhibits proliferation, and promotes migration and invasion in the GC AGS cell line, a phenomenon called ‘migration-proliferation dichotomy’, as well as epithelial-to-mesenchymal transition in AGS cells. In addition, circPGC degrades the extracellular matrix and basement membrane through matrix metallopeptidase (MMP)9 and MMP14, providing a microenvironment that facilitates cell migration. The results also demonstrated that circPGC expression is lower in clinical patients with later stages of GC, which is associated with poor prognosis. Taken together, these results suggest that circPGC exhibits migration-proliferation dichotomy during GC development, invasion and migration.
Collapse
Affiliation(s)
- Yuhai Zhang
- Department of Gastrointestinal Surgery, Zhongshan Hospital of Xiamen University, Xiamen, Fujian 361004, P.R. China.,Department of Basic Medicine, Medical College of Xiamen University, Xiamen, Fujian 361000, P.R. China
| | - Yuling Hong
- Department of Basic Medicine, Medical College of Xiamen University, Xiamen, Fujian 361000, P.R. China.,Department of Cancer Prevention and Rehabilitation, Huayan Science and Technology Cancer Prevention and Rehabilitation Research Center, School of Pharmaceutical Sciences Xiamen University, Xiamen, Fujian 361102, P.R. China
| | - Dan Wang
- Department of Basic Medicine, Medical College of Xiamen University, Xiamen, Fujian 361000, P.R. China
| | - Linshan Duan
- Department of Cancer Prevention and Rehabilitation, Huayan Science and Technology Cancer Prevention and Rehabilitation Research Center, School of Pharmaceutical Sciences Xiamen University, Xiamen, Fujian 361102, P.R. China
| | - Yanling Liu
- Department of Cancer Prevention and Rehabilitation, Huayan Science and Technology Cancer Prevention and Rehabilitation Research Center, School of Pharmaceutical Sciences Xiamen University, Xiamen, Fujian 361102, P.R. China
| | - Long Li
- Department of Cancer Prevention and Rehabilitation, Huayan Science and Technology Cancer Prevention and Rehabilitation Research Center, School of Pharmaceutical Sciences Xiamen University, Xiamen, Fujian 361102, P.R. China
| | - Di Liu
- Department of Gastrointestinal Surgery, Zhongshan Hospital of Xiamen University, Xiamen, Fujian 361004, P.R. China.,Department of Basic Medicine, Medical College of Xiamen University, Xiamen, Fujian 361000, P.R. China
| | - Kunbin Zhuang
- Department of Gastrointestinal Surgery, Zhongshan Hospital of Xiamen University, Xiamen, Fujian 361004, P.R. China.,Department of Basic Medicine, Medical College of Xiamen University, Xiamen, Fujian 361000, P.R. China
| | - Chaoxin Wei
- School of Clinical Medicine, Fujian Medical University, Fuzhou, Fujian 350000, P.R. China
| | - Guogeng Zheng
- School of Clinical Medicine, Fujian Medical University, Fuzhou, Fujian 350000, P.R. China
| | - Chunyong Huo
- School of Clinical Medicine, Fujian Medical University, Fuzhou, Fujian 350000, P.R. China
| | - Guoyan Liu
- Department of Gastrointestinal Surgery, Zhongshan Hospital of Xiamen University, Xiamen, Fujian 361004, P.R. China.,Department of Basic Medicine, Medical College of Xiamen University, Xiamen, Fujian 361000, P.R. China.,Department of Cancer Prevention and Rehabilitation, Huayan Science and Technology Cancer Prevention and Rehabilitation Research Center, School of Pharmaceutical Sciences Xiamen University, Xiamen, Fujian 361102, P.R. China.,School of Clinical Medicine, Fujian Medical University, Fuzhou, Fujian 350000, P.R. China.,College of Food an Biological Engineering, Jimei University, Xiamen, Fujian 361021, P.R. China
| |
Collapse
|
6
|
Garcia-Marcos M, Parag-Sharma K, Marivin A, Maziarz M, Luebbers A, Nguyen LT. Optogenetic activation of heterotrimeric G-proteins by LOV2GIVe, a rationally engineered modular protein. eLife 2020; 9:60155. [PMID: 32936073 PMCID: PMC7515630 DOI: 10.7554/elife.60155] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 09/15/2020] [Indexed: 12/24/2022] Open
Abstract
Heterotrimeric G-proteins are signal transducers involved in mediating the action of many natural extracellular stimuli and many therapeutic agents. Non-invasive approaches to manipulate the activity of G-proteins with high precision are crucial to understand their regulation in space and time. Here, we developed LOV2GIVe, an engineered modular protein that allows the activation of heterotrimeric G-proteins with blue light. This optogenetic construct relies on a versatile design that differs from tools previously developed for similar purposes, that is metazoan opsins, which are light-activated G-protein-coupled receptors (GPCRs). Instead, LOV2GIVe consists of the fusion of a G-protein activating peptide derived from a non-GPCR regulator of G-proteins to a small plant protein domain, such that light uncages the G-protein activating module. Targeting LOV2GIVe to cell membranes allowed for light-dependent activation of Gi proteins in different experimental systems. In summary, LOV2GIVe expands the armamentarium and versatility of tools available to manipulate heterotrimeric G-protein activity.
Collapse
Affiliation(s)
- Mikel Garcia-Marcos
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Kshitij Parag-Sharma
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Arthur Marivin
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Marcin Maziarz
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Alex Luebbers
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Lien T Nguyen
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| |
Collapse
|
7
|
Functional cycle of EEA1-positive early endosome: Direct evidence for pre-existing compartment of degradative pathway. PLoS One 2020; 15:e0232532. [PMID: 32357161 PMCID: PMC7194439 DOI: 10.1371/journal.pone.0232532] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 04/16/2020] [Indexed: 01/11/2023] Open
Abstract
Early endosomes, regarded as the main sorting station on endocytic pathway, are characterized by high frequency of homotypic fusions mediated by tethering protein EEA1. Despite intensive investigations, biogenesis of endosomes, boundaries between early and late endosomes, and process of cargo transition though them remain obscure. Here, using EGF/EGFR endocytosis as a model and confocal microscopy of fixed and live cells, we provide evidence favoring EEA1-vesicles being pre-existed vesicular compartment, that maintains its resident proteins’ level and is sensitive to biosynthetic, but not endocytic pathway disturbance. EEA1-vesicles directly fuse with incoming EGF/EGFR-vesicles into hybrid endosomes with separated EEA1- and EGFR-domains, thus providing a platform for rapid achievement of an excess of surface-derived membrane that is used to form intraluminal vesicles (ILVs). Thus, multivesicular structures colocalized with EEA1 are still early endosomes. “EEA1-cycle” ends by exclusion of EGFR-containing domains with ILVs inside that turns into MVE and restoration of initial EEA1-vesicles population.
Collapse
|
8
|
Getz M, Rangamani P, Ghosh P. Regulating cellular cyclic adenosine monophosphate: "Sources," "sinks," and now, "tunable valves". WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2020; 12:e1490. [PMID: 32323924 DOI: 10.1002/wsbm.1490] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 01/31/2020] [Accepted: 03/31/2020] [Indexed: 12/16/2022]
Abstract
A number of hormones and growth factors stimulate target cells via the second messenger pathways, which in turn regulate cellular phenotypes. Cyclic adenosine monophosphate (cAMP) is a ubiquitous second messenger that facilitates numerous signal transduction pathways; its production in cells is tightly balanced by ligand-stimulated receptors that activate adenylate cyclases (ACs), that is, "source" and by phosphodiesterases (PDEs) that hydrolyze it, that is, "sinks." Because it regulates various cellular functions, including cell growth and differentiation, gene transcription and protein expression, the cAMP signaling pathway has been exploited for the treatment of numerous human diseases. Reduction in cAMP is achieved by blocking "sources"; however, elevation in cAMP is achieved by either stimulating "source" or blocking "sinks." Here we discuss an alternative paradigm for the regulation of cellular cAMP via GIV/Girdin, the prototypical member of a family of modulators of trimeric GTPases, Guanine nucleotide Exchange Modulators (GEMs). Cells upregulate or downregulate cellular levels of GIV-GEM, which modulates cellular cAMP via spatiotemporal mechanisms distinct from the two most often targeted classes of cAMP modulators, "sources" and "sinks." A network-based compartmental model for the paradigm of GEM-facilitated cAMP signaling has recently revealed that GEMs such as GIV serve much like a "tunable valve" that cells may employ to finetune cellular levels of cAMP. Because dysregulated signaling via GIV and other GEMs has been implicated in multiple disease states, GEMs constitute a hitherto untapped class of targets that could be exploited for modulating aberrant cAMP signaling in disease states. This article is categorized under: Models of Systems Properties and Processes > Mechanistic Models Biological Mechanisms > Cell Signaling.
Collapse
Affiliation(s)
- Michael Getz
- Chemical Engineering Graduate Program, University of California San Diego, La Jolla, California, USA
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA
| | - Pradipta Ghosh
- Department of Medicine, University of California San Diego, La Jolla, California, USA
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California, USA
- Moores Comprehensive Cancer Center, University of California San Diego, La Jolla, California, USA
| |
Collapse
|
9
|
Marivin A, Maziarz M, Zhao J, DiGiacomo V, Olmos Calvo I, Mann EA, Ear J, Blanco-Canosa JB, Ross EM, Ghosh P, Garcia-Marcos M. DAPLE protein inhibits nucleotide exchange on Gα s and Gα q via the same motif that activates Gαi. J Biol Chem 2020; 295:2270-2284. [PMID: 31949046 DOI: 10.1074/jbc.ra119.011648] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/08/2020] [Indexed: 01/03/2023] Open
Abstract
Besides being regulated by G-protein-coupled receptors, the activity of heterotrimeric G proteins is modulated by many cytoplasmic proteins. GIV/Girdin and DAPLE (Dvl-associating protein with a high frequency of leucine) are the best-characterized members of a group of cytoplasmic regulators that contain a Gα-binding and -activating (GBA) motif and whose dysregulation underlies human diseases, including cancer and birth defects. GBA motif-containing proteins were originally reported to modulate G proteins by binding Gα subunits of the Gi/o family (Gαi) over other families (such as Gs, Gq/11, or G12/13), and promoting nucleotide exchange in vitro However, some evidence suggests that this is not always the case, as phosphorylation of the GBA motif of GIV promotes its binding to Gαs and inhibits nucleotide exchange. The G-protein specificity of DAPLE and how it might affect nucleotide exchange on G proteins besides Gαi remain to be investigated. Here, we show that DAPLE's GBA motif, in addition to Gαi, binds efficiently to members of the Gs and Gq/11 families (Gαs and Gαq, respectively), but not of the G12/13 family (Gα12) in the absence of post-translational phosphorylation. We pinpointed Met-1669 as the residue in the GBA motif of DAPLE that diverges from that in GIV and enables better binding to Gαs and Gαq Unlike the nucleotide-exchange acceleration observed for Gαi, DAPLE inhibited nucleotide exchange on Gαs and Gαq These findings indicate that GBA motifs have versatility in their G-protein-modulating effect, i.e. they can bind to Gα subunits of different classes and either stimulate or inhibit nucleotide exchange depending on the G-protein subtype.
Collapse
Affiliation(s)
- Arthur Marivin
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Marcin Maziarz
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Jingyi Zhao
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Vincent DiGiacomo
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Isabel Olmos Calvo
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Emily A Mann
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Jason Ear
- Department of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093
| | - Juan B Blanco-Canosa
- Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain 08034
| | - Elliott M Ross
- Department of Pharmacology, Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Pradipta Ghosh
- Department of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093
| | - Mikel Garcia-Marcos
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118.
| |
Collapse
|
10
|
Ji S, Dong W, Qi Y, Gao H, Zhao D, Xu M, Li T, Yu H, Sun Y, Ma R, Shi J, Gao C. Phagocytosis by endothelial cells inhibits procoagulant activity of platelets of essential thrombocythemia in vitro. J Thromb Haemost 2020; 18:222-233. [PMID: 31442368 PMCID: PMC6973277 DOI: 10.1111/jth.14617] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 08/03/2019] [Accepted: 08/19/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND Essential thrombocythemia (ET) is characterized by thrombocytosis with increased platelet number and persistent activation. The mechanisms of thrombosis and the fate of these platelets are not clear. The aim of the present study is to explore the phagocytosis of platelets of ET patients by endothelial cells (ECs) in vitro and its relevance to the procoagulant activity (PCA). METHODS Phosphatidylserine (PS) exposure on platelets was detected by flow cytometry. Phagocytosis of the platelets by ECs was performed using flow cytometry, confocal microscopy, and electron microscopy. The PCA of platelets was evaluated by coagulation time and purified coagulation complex assays. RESULTS The PS exposure on platelets in ET patients is higher than that in healthy controls. The PS-exposed platelets are highly procoagulant and lactadherin reduced 80% of the PCA by blockade of PS. When cocultured, the platelets of ET patients were sequestered by ECs in a time-dependent fashion. Lactadherin enhanced phagocytosis by bridging the PS on activated platelets and the integrin αvβ3 on ECs, and P-selectin played at least a partial role in this process. Furthermore, factor Xa and prothrombinase activity of PS-exposed platelets were decreased after incubation with ECs. CONCLUSION Our results suggest that phagocytic clearance of platelets by ECs occurs in ET patients, thus representing a novel mechanism to remove activated platelets from the circulation; lactadherin and phagocytosis could cooperatively limit the thrombophilia in ET patients.
Collapse
Affiliation(s)
- Shuting Ji
- Department of Medical Laboratory Science and TechnologyHarbin Medical University‐DaqingDaqingChina
| | - Weijun Dong
- Department of General SurgeryThe Fifth HospitalHarbin Medical UniversityDaqingChina
| | - Yushan Qi
- Department of Medical Laboratory Science and TechnologyHarbin Medical University‐DaqingDaqingChina
| | - Hong Gao
- Department of Hygienic MicrobiologyPublic Health CollegeHarbin Medical UniversityHarbinChina
| | - Danwei Zhao
- Department of EndocrinologyBeijing United Family HospitalBeijingChina
| | - Minghui Xu
- Department of Medical Laboratory Science and TechnologyHarbin Medical University‐DaqingDaqingChina
| | - Tingting Li
- Department of Medical Laboratory Science and TechnologyHarbin Medical University‐DaqingDaqingChina
| | - Hongyin Yu
- Department of Medical Laboratory Science and TechnologyHarbin Medical University‐DaqingDaqingChina
| | - Yuting Sun
- Department of Medical Laboratory Science and TechnologyHarbin Medical University‐DaqingDaqingChina
| | - Ruishuang Ma
- The Key Laboratory of Myocardial IschemiaMinistry of EducationHarbin Medical UniversityHarbinChina
| | - Jialan Shi
- Department of HematologyThe First HospitalHarbin Medical UniversityHarbinChina
- Departments of MedicineBrigham and Women's HospitalHarvard Medical SchoolBostonMassachusetts
| | - Chunyan Gao
- Department of Medical Laboratory Science and TechnologyHarbin Medical University‐DaqingDaqingChina
| |
Collapse
|
11
|
Getz M, Swanson L, Sahoo D, Ghosh P, Rangamani P. A predictive computational model reveals that GIV/girdin serves as a tunable valve for EGFR-stimulated cyclic AMP signals. Mol Biol Cell 2019; 30:1621-1633. [PMID: 31017840 PMCID: PMC6727633 DOI: 10.1091/mbc.e18-10-0630] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cellular levels of the versatile second messenger cyclic (c)AMP are regulated by the antagonistic actions of the canonical G protein → adenylyl cyclase pathway that is initiated by G-protein–coupled receptors (GPCRs) and attenuated by phosphodiesterases (PDEs). Dysregulated cAMP signaling drives many diseases; for example, its low levels facilitate numerous sinister properties of cancer cells. Recently, an alternative paradigm for cAMP signaling has emerged in which growth factor–receptor tyrosine kinases (RTKs; e.g., EGFR) access and modulate G proteins via a cytosolic guanine-nucleotide exchange modulator (GEM), GIV/girdin; dysregulation of this pathway is frequently encountered in cancers. In this study, we present a network-based compartmental model for the paradigm of GEM-facilitated cross-talk between RTKs and G proteins and how that impacts cellular cAMP. Our model predicts that cross-talk between GIV, Gαs, and Gαi proteins dampens ligand-stimulated cAMP dynamics. This prediction was experimentally verified by measuring cAMP levels in cells under different conditions. We further predict that the direct proportionality of cAMP concentration as a function of receptor number and the inverse proportionality of cAMP concentration as a function of PDE concentration are both altered by GIV levels. Taking these results together, our model reveals that GIV acts as a tunable control valve that regulates cAMP flux after growth factor stimulation. For a given stimulus, when GIV levels are high, cAMP levels are low, and vice versa. In doing so, GIV modulates cAMP via mechanisms distinct from the two most often targeted classes of cAMP modulators, GPCRs and PDEs.
Collapse
Affiliation(s)
- Michael Getz
- Chemical Engineering Graduate Program, University of California, San Diego, La Jolla, CA 92093
| | - Lee Swanson
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093.,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Debashish Sahoo
- Department of Computer Science and Engineering, University of California, San Diego, La Jolla, CA 92093.,Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093.,Moores Comprehensive Cancer Center, University of California, San Diego, La Jolla, CA 92093
| | - Pradipta Ghosh
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093.,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.,Moores Comprehensive Cancer Center, University of California, San Diego, La Jolla, CA 92093
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093
| |
Collapse
|
12
|
Hanyaloglu AC. Advances in Membrane Trafficking and Endosomal Signaling of G Protein-Coupled Receptors. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 339:93-131. [PMID: 29776606 DOI: 10.1016/bs.ircmb.2018.03.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The integration of GPCR signaling with membrane trafficking, as a single orchestrated system, is a theme increasingly evident with the growing reports of GPCR endosomal signaling. Once viewed as a mechanism to regulate cell surface heterotrimeric G protein signaling, the endocytic trafficking system is complex, highly compartmentalized, yet deeply interconnected with cell signaling. The organization of receptors into distinct plasma membrane signalosomes, biochemically distinct endosomal populations, endosomal microdomains, and its communication with distinct subcellular organelles such as the Golgi provides multiple unique signaling platforms that are critical for specifying receptor function physiologically and pathophysiologically. In this chapter I discuss our emerging understanding in the endocytic trafficking systems employed by GPCRs and their novel roles in spatial control of signaling. Given the extensive roles that GPCRs play in vivo, these evolving models are starting to provide mechanistic understanding of distinct diseases and provide novel therapeutic avenues that are proving to be viable targets.
Collapse
Affiliation(s)
- Aylin C Hanyaloglu
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Imperial College London, London, United Kingdom.
| |
Collapse
|
13
|
Gosney JA, Wilkey DW, Merchant ML, Ceresa BP. Proteomics reveals novel protein associations with early endosomes in an epidermal growth factor-dependent manner. J Biol Chem 2018. [PMID: 29523688 DOI: 10.1074/jbc.ra117.000632] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is an integral component of proliferative signaling. EGFRs on the cell surface become activated upon EGF binding and have an increased rate of endocytosis. Once in the cytoplasm, the EGF·EGFR complex is trafficked to the lysosome for degradation, and signaling is terminated. During trafficking, the EGFR kinase domain remains active, and the internalized EGFR can continue signaling to downstream effectors. Although effector activity varies based on the EGFR's endocytic location, it is not clear how this occurs. In an effort to identify proteins that uniquely associate with the internalized, liganded EGFR in the early endosome, we developed an early endosome isolation strategy to analyze their protein composition. Post-nuclear supernatant from HeLa cells stimulated with and without EGF were separated on an isotonic 17% Percoll gradient. The gradient was fractionated, and early endosomal fractions were pooled and immunoisolated with an EEA1 mAb. The isolated endosomes were validated by immunoblot using antibodies against organelle-specific marker proteins and transmission EM. These early endosomes were also subjected to LC-MS/MS for proteomic analysis. Five proteins were detected in endosomes in a ligand-dependent manner: EGFR, RUFY1, STOML2, PTPN23, and CCDC51. Knockdown of RUFY1 or PTPN23 by RNAi indicated that both proteins play a role in EGFR trafficking. These experiments indicate that endocytic trafficking of activated EGFR changes the protein composition, membrane trafficking, and signaling potential of the early endosome.
Collapse
Affiliation(s)
| | - Daniel W Wilkey
- Medicine, University of Louisville, Louisville, Kentucky 40202
| | | | | |
Collapse
|
14
|
Hou J, Chen Q, Wu X, Zhao D, Reuveni H, Licht T, Xu M, Hu H, Hoeft A, Ben-Sasson SA, Shu Q, Fang X. S1PR3 Signaling Drives Bacterial Killing and Is Required for Survival in Bacterial Sepsis. Am J Respir Crit Care Med 2017; 196:1559-1570. [PMID: 28850247 DOI: 10.1164/rccm.201701-0241oc] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
RATIONALE Efficient elimination of pathogenic bacteria is a critical determinant in the outcome of sepsis. Sphingosine-1-phosphate receptor 3 (S1PR3) mediates multiple aspects of the inflammatory response during sepsis, but whether S1PR3 signaling is necessary for eliminating the invading pathogens remains unknown. OBJECTIVES To investigate the role of S1PR3 in antibacterial immunity during sepsis. METHODS Loss- and gain-of-function experiments were performed using cell and murine models. S1PR3 levels were determined in patients with sepsis and healthy volunteers. MEASUREMENTS AND MAIN RESULTS S1PR3 protein levels were up-regulated in macrophages upon bacterial stimulation. S1pr3-/- mice showed increased mortality and increased bacterial burden in multiple models of sepsis. The transfer of wild-type bone marrow-derived macrophages rescued S1pr3-/- mice from lethal sepsis. S1PR3-overexpressing macrophages further ameliorated the mortality rate of sepsis. Loss of S1PR3 led to markedly decreased bacterial killing in macrophages. Enhancing endogenous S1PR3 activity using a peptide agonist potentiated the macrophage bactericidal function and improved survival rates in multiple models of sepsis. Mechanically, the reactive oxygen species levels were decreased and phagosome maturation was delayed in S1pr3-/- macrophages due to impaired recruitment of vacuolar protein-sorting 34 to the phagosomes. In addition, S1RP3 expression levels were elevated in monocytes from patients with sepsis. Higher levels of monocytic S1PR3 were associated with efficient intracellular bactericidal activity, better immune status, and preferable outcomes. CONCLUSIONS S1PR3 signaling drives bacterial killing and is essential for survival in bacterial sepsis. Interventions targeting S1PR3 signaling could have translational implications for manipulating the innate immune response to combat pathogens.
Collapse
Affiliation(s)
- JinChao Hou
- 1 Department of Anesthesiology and Intensive Care, The First Affiliated Hospital
| | | | - XiaoLiang Wu
- 1 Department of Anesthesiology and Intensive Care, The First Affiliated Hospital
| | - DongYan Zhao
- 3 Department of Anesthesiology and Intensive Care Medicine, University of Bonn Medical Center, Bonn, Germany; and
| | - Hadas Reuveni
- 4 Department of Developmental Biology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Tamar Licht
- 4 Department of Developmental Biology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - MengLong Xu
- 1 Department of Anesthesiology and Intensive Care, The First Affiliated Hospital
| | - Hu Hu
- 5 Department of Pathology and Pathophysiology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Andreas Hoeft
- 3 Department of Anesthesiology and Intensive Care Medicine, University of Bonn Medical Center, Bonn, Germany; and
| | - Shmuel A Ben-Sasson
- 4 Department of Developmental Biology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | | | - XiangMing Fang
- 1 Department of Anesthesiology and Intensive Care, The First Affiliated Hospital
| |
Collapse
|
15
|
Ly S, Navaroli DM, Didiot MC, Cardia J, Pandarinathan L, Alterman JF, Fogarty K, Standley C, Lifshitz LM, Bellve KD, Prot M, Echeverria D, Corvera S, Khvorova A. Visualization of self-delivering hydrophobically modified siRNA cellular internalization. Nucleic Acids Res 2017; 45:15-25. [PMID: 27899655 PMCID: PMC5224471 DOI: 10.1093/nar/gkw1005] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 10/07/2016] [Accepted: 10/24/2016] [Indexed: 01/07/2023] Open
Abstract
siRNAs are a new class of therapeutic modalities with promising clinical efficacy that requires modification or formulation for delivery to the tissue and cell of interest. Conjugation of siRNAs to lipophilic groups supports efficient cellular uptake by a mechanism that is not well characterized. Here we study the mechanism of internalization of asymmetric, chemically stabilized, cholesterol-modified siRNAs (sd-rxRNAs®) that efficiently enter cells and tissues without the need for formulation. We demonstrate that uptake is rapid with significant membrane association within minutes of exposure followed by the formation of vesicular structures and internalization. Furthermore, sd-rxRNAs are internalized by a specific class of early endosomes and show preferential association with epidermal growth factor (EGF) but not transferrin (Tf) trafficking pathways as shown by live cell TIRF and structured illumination microscopy (SIM). In fixed cells, we observe ∼25% of sd-rxRNA co-localizing with EGF and <5% with Tf, which is indicative of selective endosomal sorting. Likewise, preferential sd-rxRNA co-localization was demonstrated with EEA1 but not RBSN-containing endosomes, consistent with preferential EGF-like trafficking through EEA1-containing endosomes. sd-rxRNA cellular uptake is a two-step process, with rapid membrane association followed by internalization through a selective, saturable subset of the endocytic process. However, the mechanistic role of EEA1 is not yet known. This method of visualization can be used to better understand the kinetics and mechanisms of hydrophobic siRNA cellular uptake and will assist in further optimization of these types of compounds for therapeutic intervention.
Collapse
Affiliation(s)
- Socheata Ly
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Deanna M Navaroli
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Marie-Cécile Didiot
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | | | | | - Julia F Alterman
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Kevin Fogarty
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Clive Standley
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Lawrence M Lifshitz
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Karl D Bellve
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Matthieu Prot
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Dimas Echeverria
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Silvia Corvera
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Anastasia Khvorova
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01655, USA
| |
Collapse
|
16
|
Ghosh P, Aznar N, Swanson L, Lo IC, Lopez-Sanchez I, Ear J, Rohena C, Kalogriopoulos N, Joosen L, Dunkel Y, Sun N, Nguyen P, Bhandari D. Biochemical, Biophysical and Cellular Techniques to Study the Guanine Nucleotide Exchange Factor, GIV/Girdin. CURRENT PROTOCOLS IN CHEMICAL BIOLOGY 2016; 8:265-298. [PMID: 27925669 PMCID: PMC5154557 DOI: 10.1002/cpch.13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Canonical signal transduction via heterotrimeric G proteins is spatiotemporally restricted, i.e., triggered exclusively at the plasma membrane, only by agonist activation of G protein-coupled receptors via a finite process that is terminated within a few hundred milliseconds. Recently, a rapidly emerging paradigm has revealed a noncanonical pathway for activation of heterotrimeric G proteins via the nonreceptor guanidine-nucleotide exchange factor, GIV/Girdin. Biochemical, biophysical, and functional studies evaluating this pathway have unraveled its unique properties and distinctive spatiotemporal features. As in the case of any new pathway/paradigm, these studies first required an in-depth optimization of tools/techniques and protocols, governed by rationale and fundamentals unique to the pathway, and more specifically to the large multimodular GIV protein. Here we provide the most up-to-date overview of protocols that have generated most of what we know today about noncanonical G protein activation by GIV and its relevance in health and disease. © 2016 by John Wiley & Sons, Inc.
Collapse
Affiliation(s)
- Pradipta Ghosh
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093-0651
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093-0651
| | - Nicolas Aznar
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093-0651
| | - Lee Swanson
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093-0651
| | - I-Chung Lo
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093-0651
| | | | - Jason Ear
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093-0651
| | - Cristina Rohena
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093-0651
| | | | - Linda Joosen
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093-0651
| | - Ying Dunkel
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093-0651
| | - Nina Sun
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093-0651
| | - Peter Nguyen
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, CA 90840-9507
| | - Deepali Bhandari
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, CA 90840-9507
| |
Collapse
|
17
|
Parag-Sharma K, Leyme A, DiGiacomo V, Marivin A, Broselid S, Garcia-Marcos M. Membrane Recruitment of the Non-receptor Protein GIV/Girdin (Gα-interacting, Vesicle-associated Protein/Girdin) Is Sufficient for Activating Heterotrimeric G Protein Signaling. J Biol Chem 2016; 291:27098-27111. [PMID: 27864364 DOI: 10.1074/jbc.m116.764431] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Revised: 11/17/2016] [Indexed: 11/06/2022] Open
Abstract
GIV (aka Girdin) is a guanine nucleotide exchange factor that activates heterotrimeric G protein signaling downstream of RTKs and integrins, thereby serving as a platform for signaling cascade cross-talk. GIV is recruited to the cytoplasmic tail of receptors upon stimulation, but the mechanism of activation of its G protein regulatory function is not well understood. Here we used assays in humanized yeast models and G protein activity biosensors in mammalian cells to investigate the role of GIV subcellular compartmentalization in regulating its ability to promote G protein signaling. We found that in unstimulated cells GIV does not co-fractionate with its substrate G protein Gαi3 on cell membranes and that constitutive membrane anchoring of GIV in yeast cells or rapid membrane translocation in mammalian cells via chemically induced dimerization leads to robust G protein activation. We show that membrane recruitment of the GIV "Gα binding and activating" motif alone is sufficient for G protein activation and that it does not require phosphomodification. Furthermore, we engineered a synthetic protein to show that recruitment of the GIV "Gα binding and activating" motif to membranes via association with active RTKs, instead of via chemically induced dimerization, is also sufficient for G protein activation. These results reveal that recruitment of GIV to membranes in close proximity to its substrate G protein is a major mechanism responsible for the activation of its G protein regulatory function.
Collapse
Affiliation(s)
- Kshitij Parag-Sharma
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Anthony Leyme
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Vincent DiGiacomo
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Arthur Marivin
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Stefan Broselid
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Mikel Garcia-Marcos
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| |
Collapse
|
18
|
GIV/Girdin activates Gαi and inhibits Gαs via the same motif. Proc Natl Acad Sci U S A 2016; 113:E5721-30. [PMID: 27621449 DOI: 10.1073/pnas.1609502113] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We previously showed that guanine nucleotide-binding (G) protein α subunit (Gα)-interacting vesicle-associated protein (GIV), a guanine-nucleotide exchange factor (GEF), transactivates Gα activity-inhibiting polypeptide 1 (Gαi) proteins in response to growth factors, such as EGF, using a short C-terminal motif. Subsequent work demonstrated that GIV also binds Gαs and that inactive Gαs promotes maturation of endosomes and shuts down mitogenic MAPK-ERK1/2 signals from endosomes. However, the mechanism and consequences of dual coupling of GIV to two G proteins, Gαi and Gαs, remained unknown. Here we report that GIV is a bifunctional modulator of G proteins; it serves as a guanine nucleotide dissociation inhibitor (GDI) for Gαs using the same motif that allows it to serve as a GEF for Gαi. Upon EGF stimulation, GIV modulates Gαi and Gαs sequentially: first, a key phosphomodification favors the assembly of GIV-Gαi complexes and activates GIV's GEF function; then a second phosphomodification terminates GIV's GEF function, triggers the assembly of GIV-Gαs complexes, and activates GIV's GDI function. By comparing WT and GIV mutants, we demonstrate that GIV inhibits Gαs activity in cells responding to EGF. Consequently, the cAMP→PKA→cAMP response element-binding protein signaling axis is inhibited, the transit time of EGF receptor through early endosomes are accelerated, mitogenic MAPK-ERK1/2 signals are rapidly terminated, and proliferation is suppressed. These insights define a paradigm in G-protein signaling in which a pleiotropically acting modulator uses the same motif both to activate and to inhibit G proteins. Our findings also illuminate how such modulation of two opposing Gα proteins integrates downstream signals and cellular responses.
Collapse
|
19
|
Bamidele AO, Kremer KN, Hirsova P, Clift IC, Gores GJ, Billadeau DD, Hedin KE. IQGAP1 promotes CXCR4 chemokine receptor function and trafficking via EEA-1+ endosomes. J Cell Biol 2016. [PMID: 26195666 PMCID: PMC4508899 DOI: 10.1083/jcb.201411045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
IQGAP1 mediates CXCR4 cell surface expression and signaling by regulating EEA-1+ endosome interactions with microtubules during CXCR4 trafficking and recycling. IQ motif–containing GTPase-activating protein 1 (IQGAP1) is a cytoskeleton-interacting scaffold protein. CXCR4 is a chemokine receptor that binds stromal cell–derived factor-1 (SDF-1; also known as CXCL12). Both IQGAP1 and CXCR4 are overexpressed in cancer cell types, yet it was unclear whether these molecules functionally interact. Here, we show that depleting IQGAP1 in Jurkat T leukemic cells reduced CXCR4 expression, disrupted trafficking of endocytosed CXCR4 via EEA-1+ endosomes, and decreased efficiency of CXCR4 recycling. SDF-1–induced cell migration and activation of extracellular signal-regulated kinases 1 and 2 (ERK) MAPK were strongly inhibited, even when forced overexpression restored CXCR4 levels. Similar results were seen in KMBC and HEK293 cells. Exploring the mechanism, we found that SDF-1 treatment induced IQGAP1 binding to α-tubulin and localization to CXCR4-containing endosomes and that CXCR4-containing EEA-1+ endosomes were abnormally located distal from the microtubule (MT)-organizing center (MTOC) in IQGAP1-deficient cells. Thus, IQGAP1 critically mediates CXCR4 cell surface expression and signaling, evidently by regulating EEA-1+ endosome interactions with MTs during CXCR4 trafficking and recycling. IQGAP1 may similarly promote CXCR4 functions in other cancer cell types.
Collapse
Affiliation(s)
- Adebowale O Bamidele
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905 Department of Immunology, Mayo Clinic, Rochester, MN 55905
| | | | - Petra Hirsova
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905
| | - Ian C Clift
- Department of Immunology, Mayo Clinic, Rochester, MN 55905 Neurobiology of Disease Research Program, Mayo Clinic, Rochester, MN 55905
| | - Gregory J Gores
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905
| | - Daniel D Billadeau
- Department of Immunology, Mayo Clinic, Rochester, MN 55905 Division of Oncology Research, Mayo Clinic, Rochester, MN 55905
| | - Karen E Hedin
- Department of Immunology, Mayo Clinic, Rochester, MN 55905
| |
Collapse
|
20
|
Nahorski MS, Asai M, Wakeling E, Parker A, Asai N, Canham N, Holder SE, Chen YC, Dyer J, Brady AF, Takahashi M, Woods CG. CCDC88A mutations cause PEHO-like syndrome in humans and mouse. Brain 2016; 139:1036-44. [PMID: 26917597 PMCID: PMC4806221 DOI: 10.1093/brain/aww014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 12/23/2015] [Indexed: 11/14/2022] Open
Abstract
Progressive encephalopathy with oedema, hypsarrhythmia and optic atrophy (PEHO) syndrome is a rare Mendelian phenotype comprising severe retardation, early onset epileptic seizures, optic nerve/cerebellar atrophy, pedal oedema, and early death. Atypical cases are often known as PEHO-like, and there is an overlap with 'early infantile epileptic encephalopathy'. PEHO is considered to be recessive, but surprisingly since initial description in 1991, no causative recessive gene(s) have been described. Hence, we report a multiplex consanguineous family with the PEHO phenotype where affected individuals had a homozygous frame-shift deletion in CCDC88A (c.2313delT, p.Leu772*ter). Analysis of cDNA extracted from patient lymphocytes unexpectedly failed to show non-sense mediated decay, and we demonstrate that the mutation produces a truncated protein lacking the crucial C-terminal half of CCDC88A (girdin). To further investigate the possible role of CCDC88A in human neurodevelopment we re-examined the behaviour and neuroanatomy of Ccdc88a knockout pups. These mice had mesial-temporal lobe epilepsy, microcephaly and corpus callosum deficiency, and by postnatal Day 21, microcephaly; the mice died at an early age. As the mouse knockout phenotype mimics the human PEHO phenotype this suggests that loss of CCDC88A is a cause of the PEHO phenotype, and that CCDC88A is essential for multiple aspects of normal human neurodevelopment.
Collapse
Affiliation(s)
- Michael S Nahorski
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Masato Asai
- Department of Pathology, Centre for Neurological Disease and Cancer, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466N, Japan
| | - Emma Wakeling
- North West Thames Regional Genetics Service, Level 8V, London North West Healthcare NHS Trust, Watford Road, Harrow, HA1 3UJ, UK
| | - Alasdair Parker
- Department of Paediatric Neuroscience, Addenbrooke's Hospital, Hills Rd, Cambridge, CB2 0QQ, UK
| | - Naoya Asai
- Department of Pathology, Centre for Neurological Disease and Cancer, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466N, Japan
| | - Natalie Canham
- North West Thames Regional Genetics Service, Level 8V, London North West Healthcare NHS Trust, Watford Road, Harrow, HA1 3UJ, UK
| | - Susan E Holder
- North West Thames Regional Genetics Service, Level 8V, London North West Healthcare NHS Trust, Watford Road, Harrow, HA1 3UJ, UK
| | - Ya-Chun Chen
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Joshua Dyer
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Angela F Brady
- North West Thames Regional Genetics Service, Level 8V, London North West Healthcare NHS Trust, Watford Road, Harrow, HA1 3UJ, UK
| | - Masahide Takahashi
- Department of Pathology, Centre for Neurological Disease and Cancer, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466N, Japan
| | - C Geoffrey Woods
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| |
Collapse
|
21
|
Aznar N, Kalogriopoulos N, Midde KK, Ghosh P. Heterotrimeric G protein signaling via GIV/Girdin: Breaking the rules of engagement, space, and time. Bioessays 2016; 38:379-93. [PMID: 26879989 DOI: 10.1002/bies.201500133] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Canonical signal transduction via heterotrimeric G proteins is spatially and temporally restricted, that is, triggered exclusively at the plasma membrane (PM), only by agonist activation of G protein-coupled receptors (GPCRs) via a process that completes within a few hundred milliseconds. Recently, a rapidly emerging paradigm has revealed a non-canonical pathway for activation of heterotrimeric G proteins by the non-receptor guanidine-nucleotide exchange factor (GEF), GIV/Girdin. This pathway has distinctive temporal and spatial features and an unusual profile of receptor engagement: diverse classes of receptors, not just GPCRs can engage with GIV to trigger such activation. Such activation is spatially and temporally unrestricted, that is, can occur both at the PM and on internal membranes discontinuous with the PM, and can continue for prolonged periods of time. Here, we provide the most complete up-to-date review of the molecular mechanisms that govern the unique spatiotemporal aspects of non-canonical G protein activation by GIV and the relevance of this new paradigm in health and disease.
Collapse
Affiliation(s)
- Nicolas Aznar
- Department of Medicine, University of California at San Diego, La Jolla, CA, USA
| | | | - Krishna K Midde
- Department of Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Pradipta Ghosh
- Department of Medicine, University of California at San Diego, La Jolla, CA, USA.,Department of Cell and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
| |
Collapse
|
22
|
Ma GS, Lopez-Sanchez I, Aznar N, Kalogriopoulos N, Pedram S, Midde K, Ciaraldi TP, Henry RR, Ghosh P. Activation of G proteins by GIV-GEF is a pivot point for insulin resistance and sensitivity. Mol Biol Cell 2015; 26:4209-23. [PMID: 26378251 PMCID: PMC4642855 DOI: 10.1091/mbc.e15-08-0553] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 09/11/2015] [Indexed: 11/11/2022] Open
Abstract
A long-held tenet in the field of diabetes is that the tipping point between insulin sensitivity and resistance resides at the level of insulin receptor/insulin receptor substrate–adaptor complexes. Here it is shown that activation of Gαi by GIV/Girdin is a decisive event within the metabolic insulin signaling cascade that reversibly orchestrates insulin sensitivity or resistance. Insulin resistance (IR) is a metabolic disorder characterized by impaired insulin signaling and cellular glucose uptake. The current paradigm for insulin signaling centers upon the insulin receptor (InsR) and its substrate IRS1; the latter is believed to be the sole conduit for postreceptor signaling. Here we challenge that paradigm and show that GIV/Girdin, a guanidine exchange factor (GEF) for the trimeric G protein Gαi, is another major hierarchical conduit for the metabolic insulin response. By virtue of its ability to directly bind InsR, IRS1, and phosphoinositide 3-kinase, GIV serves as a key hub in the immediate postreceptor level, which coordinately enhances the metabolic insulin response and glucose uptake in myotubes via its GEF function. Site-directed mutagenesis or phosphoinhibition of GIV-GEF by the fatty acid/protein kinase C-theta pathway triggers IR. Insulin sensitizers reverse phosphoinhibition of GIV and reinstate insulin sensitivity. We also provide evidence for such reversible regulation of GIV-GEF in skeletal muscles from patients with IR. Thus GIV is an essential upstream component that couples InsR to G-protein signaling to enhance the metabolic insulin response, and impairment of such coupling triggers IR. We also provide evidence that GIV-GEF serves as therapeutic target for exogenous manipulation of physiological insulin response and reversal of IR in skeletal muscles.
Collapse
Affiliation(s)
- Gary S Ma
- Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093
| | - Inmaculada Lopez-Sanchez
- Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093
| | - Nicolas Aznar
- Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093
| | - Nicholas Kalogriopoulos
- Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093
| | - Shabnam Pedram
- Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093
| | - Krishna Midde
- Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093
| | - Theodore P Ciaraldi
- Department of Veterans Affairs, VA San Diego Healthcare System, San Diego, CA 92161
| | - Robert R Henry
- Department of Veterans Affairs, VA San Diego Healthcare System, San Diego, CA 92161
| | - Pradipta Ghosh
- Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093 Department of Veterans Affairs, VA San Diego Healthcare System, San Diego, CA 92161 Department of Cell and Molecular Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093
| |
Collapse
|
23
|
Cyclin-dependent kinase 5 activates guanine nucleotide exchange factor GIV/Girdin to orchestrate migration-proliferation dichotomy. Proc Natl Acad Sci U S A 2015; 112:E4874-83. [PMID: 26286990 DOI: 10.1073/pnas.1514157112] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Signals propagated by receptor tyrosine kinases (RTKs) can drive cell migration and proliferation, two cellular processes that do not occur simultaneously--a phenomenon called "migration-proliferation dichotomy." We previously showed that epidermal growth factor (EGF) signaling is skewed to favor migration over proliferation via noncanonical transactivation of Gαi proteins by the guanine exchange factor (GEF) GIV. However, what turns on GIV-GEF downstream of growth factor RTKs remained unknown. Here we reveal the molecular mechanism by which phosphorylation of GIV by cyclin-dependent kinase 5 (CDK5) triggers GIV's ability to bind and activate Gαi in response to growth factors and modulate downstream signals to establish a dichotomy between migration and proliferation. We show that CDK5 binds and phosphorylates GIV at Ser1674 near its GEF motif. When Ser1674 is phosphorylated, GIV activates Gαi and enhances promigratory Akt signals. Phosphorylated GIV also binds Gαs and enhances endosomal maturation, which shortens the transit time of EGFR through early endosomes, thereby limiting mitogenic MAPK signals. Consequently, this phosphoevent triggers cells to preferentially migrate during wound healing and transmigration of cancer cells. When Ser1674 cannot be phosphorylated, GIV cannot bind either Gαi or Gαs, Akt signaling is suppressed, mitogenic signals are enhanced due to delayed transit time of EGFR through early endosomes, and cells preferentially proliferate. These results illuminate how GIV-GEF is turned on upon receptor activation, adds GIV to the repertoire of CDK5 substrates, and defines a mechanism by which this unusual CDK orchestrates migration-proliferation dichotomy during cancer invasion, wound healing, and development.
Collapse
|
24
|
Abstract
Environmental cues are transmitted to the interior of the cell via a complex network of signaling hubs. Receptor tyrosine kinases (RTKs) and trimeric G proteins are 2 such major signaling hubs in eukaryotes. Canonical signal transduction via trimeric G proteins is spatially and temporally restricted, i.e., triggered exclusively at the plasma membrane (PM) by agonist activation of G-protein-coupled receptors (GPCRs) via a process that completes within a few hundred milliseconds. Recently, a rapidly emerging paradigm has revealed a non-canonical pathway for activation of trimeric G proteins by the non-receptor GEF, GIV/Girdin, that has distinctive temporal and spatial features. Such activation can be triggered by multiple growth factor RTKs, can occur at the PM and on internal membranes discontinuous with the PM, and can continue for prolonged periods of time. The molecular mechanisms that govern such non-canonical G protein activation and the relevance of this new paradigm in health and disease is discussed.
Collapse
Affiliation(s)
- Pradipta Ghosh
- a Department of Medicine ; University of California at San Diego ; La Jolla , CA USA
| |
Collapse
|
25
|
Midde KK, Aznar N, Laederich MB, Ma GS, Kunkel MT, Newton AC, Ghosh P. Multimodular biosensors reveal a novel platform for activation of G proteins by growth factor receptors. Proc Natl Acad Sci U S A 2015; 112:E937-46. [PMID: 25713130 PMCID: PMC4352799 DOI: 10.1073/pnas.1420140112] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Environmental cues are transmitted to the interior of the cell via a complex network of signaling hubs. Receptor tyrosine kinases (RTKs) and trimeric G proteins are two such major signaling hubs in eukaryotes. Conventionally, canonical signal transduction via trimeric G proteins is thought to be triggered exclusively by G protein-coupled receptors. Here we used molecular engineering to develop modular fluorescent biosensors that exploit the remarkable specificity of bimolecular recognition, i.e., of both G proteins and RTKs, and reveal the workings of a novel platform for activation of G proteins by RTKs in single living cells. Comprised of the unique modular makeup of guanidine exchange factor Gα-interacting vesicle-associated protein (GIV)/girdin, a guanidine exchange factor that links G proteins to a variety of RTKs, these biosensors provide direct evidence that RTK-GIV-Gαi ternary complexes are formed in living cells and that Gαi is transactivated within minutes after growth factor stimulation at the plasma membrane. Thus, GIV-derived biosensors provide a versatile strategy for visualizing, monitoring, and manipulating the dynamic association of Gαi with RTKs for noncanonical transactivation of G proteins in cells and illuminate a fundamental signaling event regulated by GIV during diverse cellular processes and pathophysiologic states.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Pradipta Ghosh
- Departments of Medicine and Pharmacology and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093
| |
Collapse
|
26
|
Garcia-Marcos M, Ghosh P, Farquhar MG. GIV/Girdin transmits signals from multiple receptors by triggering trimeric G protein activation. J Biol Chem 2015; 290:6697-704. [PMID: 25605737 DOI: 10.1074/jbc.r114.613414] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Activation of trimeric G proteins has been traditionally viewed as the exclusive job of G protein-coupled receptors (GPCRs). This view has been challenged by the discovery of non-receptor activators of trimeric G proteins. Among them, GIV (a.k.a. Girdin) is the first for which a guanine nucleotide exchange factor (GEF) activity has been unequivocally associated with a well defined motif. Here we discuss how GIV assembles alternative signaling pathways by sensing cues from various classes of surface receptors and relaying them via G protein activation. We also describe the dysregulation of this mechanism in disease and how its targeting holds promise for novel therapeutics.
Collapse
Affiliation(s)
- Mikel Garcia-Marcos
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118 and
| | | | - Marilyn G Farquhar
- Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093-0651
| |
Collapse
|
27
|
Sanin DE, Mountford AP. Sm16, a major component of Schistosoma mansoni cercarial excretory/secretory products, prevents macrophage classical activation and delays antigen processing. Parasit Vectors 2015; 8:1. [PMID: 25561160 PMCID: PMC4297449 DOI: 10.1186/s13071-014-0608-1] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 12/16/2014] [Indexed: 11/10/2022] Open
Abstract
Background Schistosoma mansoni cercariae penetrate the skin by releasing excretory/secretory (E/S) products known as 0-3hRP, which are associated with immune modulation through Toll like receptor (TLR) signalling. Furthermore, these secretions contain Sm16, which when given to cells as a recombinant protein inhibits human monocyte derived cytokine responses to TLR4 and TLR3 ligands. Nonetheless, the extent and mechanism(s) of these inhibitory effects remain largely uncharacterized. Methods Murine bone marrow derived macrophages were exposed to different fractions of 0-3hRP, obtained via ultracentrifugation, or recombinant Sm16. These cells were exposed to the parasite molecules in combination with different TLR ligands, or Interferon gamma, and tested for the production of the cytokines IL-10 and IL-12p40, and their ability to process antigen. Results The immunomodulatory function of 0-3hRP is enriched predominantly in the pellet fraction, which contains a greater proportion of Sm16, also corroborating the ability of recombinant Sm16 to inhibit macrophage activation in response to TLR ligands. We further demonstrate that Sm16 blocks classical activation of macrophages to LPS or IFN-γ stimulation in vitro, and that inhibition of macrophage classical activation is independent of TLR2 recognition. Finally we show that Sm16 shares the altered intracellular processing observed for 0-3hRP, and is able to delay antigen processing by macrophages. Conclusions Collectively, our findings show that Sm16 is a major component of S. mansoni cercarial E/S products, and is partly responsible for its immune-regulatory properties. Moreover, we propose that the mechanism employed by Sm16 to exert its inhibitory function is likely to be linked with alteration of endosomal trafficking and is not dependent on particular TLR receptors. Finally, we suggest that accumulation of Sm16 in the skin after percutaneous infection with S. mansoni cercariae could contribute to limiting dermal inflammation. Electronic supplementary material The online version of this article (doi:10.1186/s13071-014-0608-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- David E Sanin
- Centre for Immunology and Infection, Department of Biology, University of York, York, UK.
| | - Adrian P Mountford
- Centre for Immunology and Infection, Department of Biology, University of York, York, UK.
| |
Collapse
|
28
|
Cao K, Lu C, Han S, Zou Q, Li J, Xie D, He S, Yu L, Zhou J, Peng X, Cao P. Expression of Girdin in primary hepatocellular carcinoma and its effect on cell proliferation and invasion. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2015; 8:551-559. [PMID: 25755745 PMCID: PMC4348923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Accepted: 12/25/2014] [Indexed: 06/04/2023]
Abstract
Girdin has been proven to play a vital role in the process of proliferation, apoptosis, and invasion in various cancer cells, yet the underlying molecular mechanism in primary hepatocellular carcinoma (HCC) has not yet been clarified. Thereafter, we performed immunohistochemistry to detect the expression of Girdin in 40 primary HCC tissues and 30 matched adjacent tissues using hepatic carcinoma tissue microarray. Our data showed that the positive expression rate of Girdin in hepatocellular carcinoma tissues was 67.5%, higher than that found in adjacent tissues of 16.7% (P < 0.05). It closely correlates to tumor size, T stage, TNM stage and Edmondson-Steiner stage (P < 0.05) of HCC patients. After specific small interfering RNA of Girdin was transfected into HepG2 and Huh7.5.1 cells, the proliferation and invasion ability of tumor cells were significantly inhibited. In summary, we suggest that the oncogenic role of Girdin could provide new molecular target for the treatment of HCC.
Collapse
Affiliation(s)
- Ke Cao
- Department of Oncology, The Third Xiangya Hospital, Central South UniversityChangsha, China
| | - Can Lu
- Department of Oncology, The Third Xiangya Hospital, Central South UniversityChangsha, China
| | - Shuang Han
- Department of Oncology, The Third Xiangya Hospital, Central South UniversityChangsha, China
| | - Qiong Zou
- Department of Pathology, The Third Xiangya Hospital, Central South UniversityChangsha, China
| | - Jingjing Li
- Department of Pathology, Xiangya Hospital, Central South UniversityChangsha, China
| | - Dingfang Xie
- Department of Oncology, The Third Xiangya Hospital, Central South UniversityChangsha, China
| | - Siqi He
- Department of Oncology, The Third Xiangya Hospital, Central South UniversityChangsha, China
| | - Li Yu
- Department of Oncology, The Third Xiangya Hospital, Central South UniversityChangsha, China
| | - Jianda Zhou
- Department of Burn And Plastic Surgery, The Third Xiangya Hospital, Central South UniversityChangsha, China
| | - Xiaowei Peng
- Department of Head And Neck Surgery, Hunan Provincial Tumor HospitalChangsha, China
| | - Peiguo Cao
- Department of Oncology, The Third Xiangya Hospital, Central South UniversityChangsha, China
| |
Collapse
|
29
|
Lin C, Ear J, Midde K, Lopez-Sanchez I, Aznar N, Garcia-Marcos M, Kufareva I, Abagyan R, Ghosh P. Structural basis for activation of trimeric Gi proteins by multiple growth factor receptors via GIV/Girdin. Mol Biol Cell 2014; 25:3654-71. [PMID: 25187647 PMCID: PMC4230624 DOI: 10.1091/mbc.e14-05-0978] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
GIV, a guanidine exchange factor for trimeric Gi, contains a unique domain that functions like a SH2 domain. GIV's SH2-like domain binds autophosphorylated RTKs. Binding of GIV's SH2 to RTKs enables the receptors to activate trimeric Gi. Inhibition of GIV:RTK interaction abolishes GIV-dependent Akt enhancement downstream of RTKs. A long-standing issue in the field of signal transduction is to understand the cross-talk between receptor tyrosine kinases (RTKs) and heterotrimeric G proteins, two major and distinct signaling hubs that control eukaryotic cell behavior. Although stimulation of many RTKs leads to activation of trimeric G proteins, the molecular mechanisms behind this phenomenon remain elusive. We discovered a unifying mechanism that allows GIV/Girdin, a bona fide metastasis-related protein and a guanine-nucleotide exchange factor (GEF) for Gαi, to serve as a direct platform for multiple RTKs to activate Gαi proteins. Using a combination of homology modeling, protein–protein interaction, and kinase assays, we demonstrate that a stretch of ∼110 amino acids within GIV C-terminus displays structural plasticity that allows folding into a SH2-like domain in the presence of phosphotyrosine ligands. Using protein–protein interaction assays, we demonstrated that both SH2 and GEF domains of GIV are required for the formation of a ligand-activated ternary complex between GIV, Gαi, and growth factor receptors and for activation of Gαi after growth factor stimulation. Expression of a SH2-deficient GIV mutant (Arg 1745→Leu) that cannot bind RTKs impaired all previously demonstrated functions of GIV—Akt enhancement, actin remodeling, and cell migration. The mechanistic and structural insights gained here shed light on the long-standing questions surrounding RTK/G protein cross-talk, set a novel paradigm, and characterize a unique pharmacological target for uncoupling GIV-dependent signaling downstream of multiple oncogenic RTKs.
Collapse
Affiliation(s)
- Changsheng Lin
- Department of Medicine, University of California, San Diego, School of Medicine, CA 92093
| | - Jason Ear
- Department of Medicine, University of California, San Diego, School of Medicine, CA 92093
| | - Krishna Midde
- Department of Medicine, University of California, San Diego, School of Medicine, CA 92093
| | | | - Nicolas Aznar
- Department of Medicine, University of California, San Diego, School of Medicine, CA 92093
| | - Mikel Garcia-Marcos
- Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, CA 92093
| | - Irina Kufareva
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Ruben Abagyan
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Pradipta Ghosh
- Department of Medicine, University of California, San Diego, School of Medicine, CA 92093
| |
Collapse
|
30
|
Wang Y, Chen X, Chen X, Chen Q, Huo K. Transcriptional profiling and dynamical regulation analysis identify potential kernel target genes of SCYL1-BP1 in HEK293T cells. Mol Cells 2014; 37:691-8. [PMID: 25234469 PMCID: PMC4179138 DOI: 10.14348/molcells.2014.0184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 08/11/2014] [Accepted: 08/13/2014] [Indexed: 01/24/2023] Open
Abstract
SCYL1-BP1 is thought to function in the p53 pathway through Mdm2 and hPirh2, and mutations in SCYL1-BP1 are associated with premature aging syndromes such as Geroderma Osteodysplasticum; however, these mechanisms are unclear. Here, we report significant alterations in miRNA expression levels when SCYL1-BP1 expression was inhibited by RNA interference in HEK293T cells. We functionally characterized the effects of potential kernel miRNA-target genes by miRNA-target network and protein-protein interaction network analysis. Importantly, we showed the diminished SCYL1-BP1 dramatically reduced the expression levels of EEA1, BMPR2 and BRCA2 in HEK293T cells. Thus, we infer that SCYL1-BP1 plays a critical function in HEK293T cell development and directly regulates miRNA-target genes, including, but not limited to, EEA1, BMPR2, and BRCA2, suggesting a new strategy for investigating the molecular mechanism of SCYL1-BP1.
Collapse
Affiliation(s)
- Yang Wang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Xiaomei Chen
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Xiaojing Chen
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Qilong Chen
- Research Center for TCM Complexity System, Shanghai University of TCM, Shanghai 201203, China
| | - Keke Huo
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China
| |
Collapse
|
31
|
Rosciglione S, Thériault C, Boily MO, Paquette M, Lavoie C. Gαs regulates the post-endocytic sorting of G protein-coupled receptors. Nat Commun 2014; 5:4556. [PMID: 25089012 PMCID: PMC4846350 DOI: 10.1038/ncomms5556] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 06/30/2014] [Indexed: 12/31/2022] Open
Abstract
The role of Gαs in G protein-coupled receptor (GPCR) signalling at the cell surface is well established. Recent evidence has revealed the presence of Gαs on endosomes and its capacity to elicit GPCR-promoted signalling from this intracellular compartment. Here, we report an unconventional role for Gαs in the endocytic sorting of GPCRs to lysosomes. Cellular depletion of Gαs specifically delays the lysosomal degradation of GPCRs by disrupting the transfer of GPCRs into the intraluminal vesicles (ILVs) of multivesicular bodies. We show that Gαs interacts with GPCR-associated binding protein-1 (GASP1) and dysbindin, two key proteins that serve as linkers between GPCRs and the endosomal-sorting complex required for transport (ESCRT) machinery involved in receptor sorting into ILVs. Our findings reveal that Gαs plays a role in both GPCR signalling and trafficking pathways, providing another piece in the intertwining molecular network between these processes.
Collapse
Affiliation(s)
- Stéphanie Rosciglione
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Caroline Thériault
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Marc-Olivier Boily
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Marilène Paquette
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Christine Lavoie
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| |
Collapse
|
32
|
Abstract
The endocytic network comprises a vast and intricate system of membrane-delimited cell entry and cargo sorting routes running between biochemically and functionally distinct intracellular compartments. The endocytic network caters to the organization and redistribution of diverse subcellular components, and mediates appropriate shuttling and processing of materials acquired from neighboring cells or the extracellular milieu. Such trafficking logistics, despite their importance, represent only one facet of endocytic function. The endocytic network also plays a key role in organizing, mediating, and regulating cellular signal transduction events. Conversely, cellular signaling processes tightly control the endocytic pathway at different steps. The present article provides a perspective on the intimate relationships that exist between particular endocytic and cellular signaling processes in mammalian cells, within the context of understanding the impact of this nexus on integrated physiology.
Collapse
Affiliation(s)
- Pier Paolo Di Fiore
- Department of Experimental Oncology, Istituto Europeo di Oncologia, 20141 Milan, Italy Dipartimento di Scienze della Salute, Università degli Studi di Milano, 20122 Milan, Italy
| | - Mark von Zastrow
- Department of Psychiatry, University of California San Francisco School of Medicine, San Francisco, California 94158 Department of Cellular & Molecular Pharmacology, University of California San Francisco School of Medicine, San Francisco, California 94158
| |
Collapse
|
33
|
Alakus H, Babicky ML, Ghosh P, Yost S, Jepsen K, Dai Y, Arias A, Samuels ML, Mose ES, Schwab RB, Peterson MR, Lowy AM, Frazer KA, Harismendy O. Genome-wide mutational landscape of mucinous carcinomatosis peritonei of appendiceal origin. Genome Med 2014; 6:43. [PMID: 24944587 PMCID: PMC4062050 DOI: 10.1186/gm559] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Accepted: 05/23/2014] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Mucinous neoplasms of the appendix (MNA) are rare tumors which may progress from benign to malignant disease with an aggressive biological behavior. MNA is often diagnosed after metastasis to the peritoneal surfaces resulting in mucinous carcinomatosis peritonei (MCP). Genetic alterations in MNA are poorly characterized due to its low incidence, the hypo-cellularity of MCPs, and a lack of relevant pre-clinical models. As such, application of targeted therapies to this disease is limited to those developed for colorectal cancer and not based on molecular rationale. METHODS We sequenced the whole exomes of 10 MCPs of appendiceal origin to identify genome-wide somatic mutations and copy number aberrations and validated significant findings in 19 additional cases. RESULTS Our study demonstrates that MNA has a different molecular makeup than colorectal cancer. Most tumors have co-existing oncogenic mutations in KRAS (26/29) and GNAS (20/29) and are characterized by downstream PKA activation. High-grade tumors are GNAS wild-type (5/6), suggesting they do not progress from low-grade tumors. MNAs do share some genetic alterations with colorectal cancer including gain of 1q (5/10), Wnt, and TGFβ pathway alterations. In contrast, mutations in TP53 (1/10) and APC (0/10), common in colorectal cancer, are rare in MNA. Concurrent activation of the KRAS and GNAS mediated signaling pathways appears to be shared with pancreatic intraductal papillary mucinous neoplasm. CONCLUSIONS MNA genome-wide mutational analysis reveals genetic alterations distinct from colorectal cancer, in support of its unique pathophysiology and suggests new targeted therapeutic opportunities.
Collapse
Affiliation(s)
- Hakan Alakus
- Division of Genome Information Sciences, Department of Pediatrics and Rady Children's Hospital, University of California San Diego, La Jolla, CA, USA ; Department of General, Visceral and Cancer Surgery, University of Cologne, Köln, Germany
| | - Michele L Babicky
- Division of Surgical Oncology, Department of Surgery, University of California San Diego, La Jolla, CA, USA
| | - Pradipta Ghosh
- Department of Medicine, University of California San Diego, La Jolla, CA, USA ; Moores UCSD Cancer Center, University of California San Diego, La Jolla, CA, USA
| | - Shawn Yost
- Bioinformatics Graduate Program, University of California San Diego, La Jolla, CA, USA
| | - Kristen Jepsen
- Division of Genome Information Sciences, Department of Pediatrics and Rady Children's Hospital, University of California San Diego, La Jolla, CA, USA
| | - Yang Dai
- Division of Genome Information Sciences, Department of Pediatrics and Rady Children's Hospital, University of California San Diego, La Jolla, CA, USA
| | - Angelo Arias
- Division of Genome Information Sciences, Department of Pediatrics and Rady Children's Hospital, University of California San Diego, La Jolla, CA, USA
| | | | - Evangeline S Mose
- Division of Surgical Oncology, Department of Surgery, University of California San Diego, La Jolla, CA, USA
| | - Richard B Schwab
- Department of Medicine, University of California San Diego, La Jolla, CA, USA ; Moores UCSD Cancer Center, University of California San Diego, La Jolla, CA, USA
| | - Michael R Peterson
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Andrew M Lowy
- Division of Surgical Oncology, Department of Surgery, University of California San Diego, La Jolla, CA, USA ; Moores UCSD Cancer Center, University of California San Diego, La Jolla, CA, USA
| | - Kelly A Frazer
- Division of Genome Information Sciences, Department of Pediatrics and Rady Children's Hospital, University of California San Diego, La Jolla, CA, USA ; Moores UCSD Cancer Center, University of California San Diego, La Jolla, CA, USA ; Clinical and Translational Science Institute, University of California San Diego, La Jolla, CA, USA ; Institute for Genomic Medicine, University of California San Diego, La Jolla, CA, USA
| | - Olivier Harismendy
- Division of Genome Information Sciences, Department of Pediatrics and Rady Children's Hospital, University of California San Diego, La Jolla, CA, USA ; Moores UCSD Cancer Center, University of California San Diego, La Jolla, CA, USA ; Clinical and Translational Science Institute, University of California San Diego, La Jolla, CA, USA
| |
Collapse
|
34
|
Gαs protein expression is an independent predictor of recurrence in prostate cancer. J Immunol Res 2014; 2014:301376. [PMID: 24741584 PMCID: PMC3988704 DOI: 10.1155/2014/301376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 02/27/2014] [Indexed: 11/18/2022] Open
Abstract
Background. T393C polymorphism in the gene GNAS1, which encodes the G-protein alpha s subunit (Gαs) of heterotrimeric G protein, is significantly associated with the clinical outcome of patients suffering from several cancers. However, studies on the role and protein expression of Gαs subunit in prostate cancer were still unavailable. Methods. The immunohistochemical staining was used to assess Gαs expression through tissue microarray procedure of 56 metastatic PCas, 291 localized PCas, and 67 benign hyperplasia (BPH). Gαs expression was semiquantitatively scored and evaluated the correlation with pathologic parameters and biochemical recurrence of prostate-specific antigen (PSA). Results. Gαs expression was localized in nuclear and cytoplasm in prostate cancer cells and downregulated in metastatic PCa compared to localized PCa and BPH (P < 0.001). Gαs was inversely associated with PSA level and Gleason scores; patients with low expression of Gαs had adverse clincopathological features. In multivariable Cox regression analysis, high Gαs expression and Gleason scores were independent predictors of both PSA progression-free and overall survival. Conclusions. Gαs down-expression is associated with adverse pathologic features and clinical PSA biochemical recurrence of prostate cancer. Gαs is an independent predictor to help determine the risk of PSA progression and death.
Collapse
|
35
|
Blumer JB, Lanier SM. Activators of G protein signaling exhibit broad functionality and define a distinct core signaling triad. Mol Pharmacol 2013; 85:388-96. [PMID: 24302560 DOI: 10.1124/mol.113.090068] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Activators of G protein signaling (AGS), initially discovered in the search for receptor-independent activators of G protein signaling, define a broad panel of biologic regulators that influence signal transfer from receptor to G-protein, guanine nucleotide binding and hydrolysis, G protein subunit interactions, and/or serve as alternative binding partners for Gα and Gβγ independently of the classic heterotrimeric Gαβγ. AGS proteins generally fall into three groups based upon their interaction with and regulation of G protein subunits: group I, guanine nucleotide exchange factors (GEF); group II, guanine nucleotide dissociation inhibitors; and group III, entities that bind to Gβγ. Group I AGS proteins can engage all subclasses of G proteins, whereas group II AGS proteins primarily engage the Gi/Go/transducin family of G proteins. A fourth group of AGS proteins with selectivity for Gα16 may be defined by the Mitf-Tfe family of transcription factors. Groups I-III may act in concert, generating a core signaling triad analogous to the core triad for heterotrimeric G proteins (GEF + G proteins + effector). These two core triads may function independently of each other or actually cross-integrate for additional signal processing. AGS proteins have broad functional roles, and their discovery has advanced new concepts in signal processing, cell and tissue biology, receptor pharmacology, and system adaptation, providing unexpected platforms for therapeutic and diagnostic development.
Collapse
Affiliation(s)
- Joe B Blumer
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina
| | | |
Collapse
|
36
|
Farquhar M. Marilyn Farquhar: from the beginning. Interview by Sedwick Caitlin. J Cell Biol 2013; 203:554-5. [PMID: 24385482 PMCID: PMC3840935 DOI: 10.1083/jcb.2034pi] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Farquhar studies cellular secretion, endocytosis, and podocytes in the kidney.
Collapse
|
37
|
Shah M, Baterina OY, Taupin V, Farquhar MG. ARH directs megalin to the endocytic recycling compartment to regulate its proteolysis and gene expression. ACTA ACUST UNITED AC 2013; 202:113-27. [PMID: 23836931 PMCID: PMC3704979 DOI: 10.1083/jcb.201211110] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
ARH is required for the trafficking of megalin from early endosomes to the endocytic recycling compartment, where megalin undergoes intramembrane proteolysis, releasing a tail fragment that represses megalin transcription. Receptors internalized by endocytosis can return to the plasma membrane (PM) directly from early endosomes (EE; fast recycling) or they can traffic from EE to the endocytic recycling compartment (ERC) and recycle from there (slow recycling). How receptors are sorted for trafficking along these two pathways remains unclear. Here we show that autosomal recessive hypercholesterolemia (ARH) is required for trafficking of megalin, a member of the LDL receptor family, from EE to the ERC by coupling it to dynein; in the absence of ARH, megalin returns directly to the PM from EE via the connecdenn2/Rab35 fast recycling pathway. Binding of ARH to the endocytic adaptor AP-2 prevents fast recycling of megalin. ARH-mediated trafficking of megalin to the ERC is necessary for γ-secretase mediated cleavage of megalin and release of a tail fragment that mediates transcriptional repression. These results identify a novel mechanism for sorting receptors for trafficking to the ERC and link ERC trafficking to regulated intramembrane proteolysis (RIP) and expression of megalin.
Collapse
Affiliation(s)
- Mehul Shah
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | | | | | | |
Collapse
|