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Salloum G, Bresnick AR, Backer JM. Macropinocytosis: mechanisms and regulation. Biochem J 2023; 480:335-362. [PMID: 36920093 DOI: 10.1042/bcj20210584] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/22/2023] [Accepted: 02/27/2023] [Indexed: 03/16/2023]
Abstract
Macropinocytosis is defined as an actin-dependent but coat- and dynamin-independent endocytic uptake process, which generates large intracellular vesicles (macropinosomes) containing a non-selective sampling of extracellular fluid. Macropinocytosis provides an important mechanism of immune surveillance by dendritic cells and macrophages, but also serves as an essential nutrient uptake pathway for unicellular organisms and tumor cells. This review examines the cell biological mechanisms that drive macropinocytosis, as well as the complex signaling pathways - GTPases, lipid and protein kinases and phosphatases, and actin regulatory proteins - that regulate macropinosome formation, internalization, and disposition.
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Affiliation(s)
- Gilbert Salloum
- Department of Molecular Pharamacology, Albert Einstein College of Medicine, Bronx, NY, U.S.A
| | - Anne R Bresnick
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, U.S.A
| | - Jonathan M Backer
- Department of Molecular Pharamacology, Albert Einstein College of Medicine, Bronx, NY, U.S.A
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, U.S.A
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2
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Bettegazzi B, Bellani S, Cattaneo S, Codazzi F, Grohovaz F, Zacchetti D. Gα13 Contributes to LPS-Induced Morphological Alterations and Affects Migration of Microglia. Mol Neurobiol 2021; 58:6397-6414. [PMID: 34529232 DOI: 10.1007/s12035-021-02553-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 08/26/2021] [Indexed: 11/24/2022]
Abstract
Microglia are the resident immune cells of the CNS that are activated in response to a variety of stimuli. This phenotypical change is aimed to maintain the local homeostasis, also by containing the insults and repair the damages. All these processes are tightly regulated and coordinated and a failure in restoring homeostasis by microglia can result in the development of neuroinflammation that can facilitate the progression of pathological conditions. Indeed, chronic microglia activation is commonly recognized as a hallmark of many neurological disorders, especially at an early stage. Many complex pathways, including cytoskeletal remodeling, are involved in the control of the microglial phenotypical and morphological changes that occur during activation. In this work, we focused on the small GTPase Gα13 and its role at the crossroad between RhoA and Rac1 signaling when microglia is exposed to pro-inflammatory stimulation. We propose the direct involvement of Gα13 in the cytoskeletal rearrangements mediated by FAK, LIMK/cofilin, and Rac1 during microglia activation. In fact, we show that Gα13 knockdown significantly inhibited LPS-induced microglial cell activation, in terms of both changes in morphology and migration, through the modulation of FAK and one of its downstream effectors, Rac1. In conclusion, we propose Gα13 as a critical factor in the regulation of morphological and functional properties of microglia during activation, which might become a target of intervention for the control of microglia inflammation.
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Affiliation(s)
- Barbara Bettegazzi
- IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy.
- Vita-Salute San Raffaele University, via Olgettina 58, 20132, Milan, Italy.
| | - Serena Bellani
- IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy
| | - Stefano Cattaneo
- IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy
- Vita-Salute San Raffaele University, via Olgettina 58, 20132, Milan, Italy
| | - Franca Codazzi
- IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy
- Vita-Salute San Raffaele University, via Olgettina 58, 20132, Milan, Italy
| | - Fabio Grohovaz
- IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy
- Vita-Salute San Raffaele University, via Olgettina 58, 20132, Milan, Italy
| | - Daniele Zacchetti
- IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy.
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3
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Abstract
Pain is an essential protective mechanism that the body uses to alert or prevent further damage. Pain sensation is a complex event involving perception, transmission, processing, and response. Neurons at different levels (peripheral, spinal cord, and brain) are responsible for these pro- or antinociceptive activities to ensure an appropriate response to external stimuli. The terminals of these neurons, both in the peripheral endings and in the synapses, are equipped with G protein-coupled receptors (GPCRs), voltage- and ligand-gated ion channels that sense structurally diverse stimuli and inhibitors of neuronal activity. This review will focus on the largest class of sensory proteins, the GPCRs, as they are distributed throughout ascending and descending neurons and regulate activity at each step during pain transmission. GPCR activation also directly or indirectly controls the function of co-localized ion channels. The levels and types of some GPCRs are significantly altered in different pain models, especially chronic pain states, emphasizing that these molecules could be new targets for therapeutic intervention in chronic pain.
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Affiliation(s)
- Tao Che
- Department of Anesthesiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri 63110, United States.,Center for Clinical Pharmacology, St. Louis College of Pharmacology and Washington University in St. Louis, St. Louis, Missouri 63110, United States
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4
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Nakano S, Inoue K, Xu C, Deng Z, Syrovatkina V, Vitone G, Zhao L, Huang XY, Zhao B. G-protein Gα 13 functions as a cytoskeletal and mitochondrial regulator to restrain osteoclast function. Sci Rep 2019; 9:4236. [PMID: 30862896 PMCID: PMC6414604 DOI: 10.1038/s41598-019-40974-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 02/19/2019] [Indexed: 12/13/2022] Open
Abstract
Excessive osteoclastic bone erosion disrupts normal bone remodeling and leads to bone loss in many skeletal diseases, including inflammatory arthritis, such as rheumatoid arthritis (RA) and psoriatic arthritis, periodontitis and peri-prosthetic loosening. Functional control of osteoclasts is critical for the maintenance of bone homeostasis. However, the mechanisms that restrain osteoclast resorptive function are not fully understood. In this study, we identify a previously unrecognized role for G-protein Gα13 in inhibition of osteoclast adhesion, fusion and bone resorptive function. Gα13 is highly expressed in mature multinucleated osteoclasts, but not during early differentiation. Deficiency of Gα13 in myeloid osteoclast lineage (Gα13ΔM/ΔM mice) leads to super spread morphology of multinucleated giant osteoclasts with elevated bone resorptive capacity, corroborated with an osteoporotic bone phenotype in the Gα13ΔM/ΔM mice. Mechanistically, Gα13 functions as a brake that restrains the c-Src, Pyk2, RhoA-Rock2 mediated signaling pathways and related gene expressions to control the ability of osteoclasts in fusion, adhesion, actin cytoskeletal remodeling and resorption. Genome wide analysis reveals cytoskeleton related genes that are suppressed by Gα13, identifying Gα13 as a critical cytoskeletal regulator in osteoclasts. We also identify a genome wide regulation of genes responsible for mitochondrial biogenesis and function by Gα13 in osteoclasts. Furthermore, the significant correlation between Gα13 expression levels, TNF activity and RA disease activity in RA patients suggests that the Gα13 mediated mechanisms represent attractive therapeutic targets for diseases associated with excessive bone resorption.
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Affiliation(s)
- Shinichi Nakano
- Arthritis and Tissue Degeneration Program and The David Z, Rosensweig Genomics Research Center, Hospital for Special Surgery, New York, New York, USA
| | - Kazuki Inoue
- Arthritis and Tissue Degeneration Program and The David Z, Rosensweig Genomics Research Center, Hospital for Special Surgery, New York, New York, USA
- Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Cheng Xu
- Arthritis and Tissue Degeneration Program and The David Z, Rosensweig Genomics Research Center, Hospital for Special Surgery, New York, New York, USA
| | - Zhonghao Deng
- Arthritis and Tissue Degeneration Program and The David Z, Rosensweig Genomics Research Center, Hospital for Special Surgery, New York, New York, USA
- Department of Orthopedic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Viktoriya Syrovatkina
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, USA
| | - Gregory Vitone
- Arthritis and Tissue Degeneration Program and The David Z, Rosensweig Genomics Research Center, Hospital for Special Surgery, New York, New York, USA
| | - Liang Zhao
- Department of Orthopedic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Xin-Yun Huang
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, USA
| | - Baohong Zhao
- Arthritis and Tissue Degeneration Program and The David Z, Rosensweig Genomics Research Center, Hospital for Special Surgery, New York, New York, USA.
- Department of Medicine, Weill Cornell Medical College, New York, New York, USA.
- Graduate Program in Cell & Developmental Biology, Weill Cornell Graduate School of Medical Sciences, New York, New York, USA.
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5
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Banu A, Liu KJ, Lax AJ, Grigoriadis AE. G-Alpha Subunit Abundance and Activity Differentially Regulate β-Catenin Signaling. Mol Cell Biol 2019; 39:MCB.00422-18. [PMID: 30559307 PMCID: PMC6379582 DOI: 10.1128/mcb.00422-18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 11/27/2018] [Indexed: 11/29/2022] Open
Abstract
Heterotrimeric G proteins are signal transduction proteins involved in regulating numerous signaling events. In particular, previous studies have demonstrated a role for G-proteins in regulating β-catenin signaling. However, the link between G-proteins and β-catenin signaling is controversial and appears to depend on G-protein specificity. We describe a detailed analysis of a link between specific G-alpha subunits and β-catenin using G-alpha subunit genetic knockout and knockdown approaches. The Pasteurella multocida toxin was utilized as a unique tool to activate G-proteins, with LiCl treatment serving as a β-catenin signaling agonist. The results show that Pasteurella multocida toxin (PMT) significantly enhanced LiCl-induced active β-catenin levels in HEK293T cells and mouse embryo fibroblasts. Evaluation of the effect of specific G-alpha proteins on the regulation of β-catenin showed that Gq/11 and G12/13 knockout cells had significantly higher levels of active and total β-catenin than wild-type cells. The stimulation of active β-catenin by PMT and LiCl was lost upon both constitutive and transient knockdown of G12 and G13 but not Gq Based on our results, we conclude that endogenous G-alpha proteins are negative regulators of active β-catenin; however, PMT-activated G-alpha subunits positively regulate LiCl-induced β-catenin expression in a G12/13-dependent manner. Hence, G-alpha subunit regulation of β-catenin is context dependent.
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Affiliation(s)
- Arshiya Banu
- Department of Microbiology, King's College London, Guy's Hospital, London, United Kingdom
| | - Karen J Liu
- Centre for Craniofacial and Regenerative Biology, King's College London, Guy's Hospital, London, United Kingdom
| | - Alistair J Lax
- Department of Microbiology, King's College London, Guy's Hospital, London, United Kingdom
| | - Agamemnon E Grigoriadis
- Centre for Craniofacial and Regenerative Biology, King's College London, Guy's Hospital, London, United Kingdom
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6
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Syrovatkina V, Huang XY. Signaling mechanisms and physiological functions of G-protein Gα 13 in blood vessel formation, bone homeostasis, and cancer. Protein Sci 2018; 28:305-312. [PMID: 30345641 DOI: 10.1002/pro.3531] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/08/2018] [Accepted: 10/15/2018] [Indexed: 12/12/2022]
Abstract
Heterotrimeric G-proteins are cellular signal transducers. They mainly relay signals from G-protein-coupled receptors (GPCRs). GPCRs function as guanine nucleotide-exchange factors to active these G-proteins. Based on the sequence and functional similarities, these G-proteins are grouped into four subfamilies: Gs , Gi , Gq , and G12/13 . The G12/13 subfamily consists of two members: G12 and G13 . G12/13 -mediated signaling pathways play pivotal roles in a variety of physiological processes, while aberrant regulation of this pathway has been identified in various human diseases. Here we summarize the signaling mechanisms and physiological functions of Gα13 in blood vessel formation and bone homeostasis. We further discuss the expanding roles of Gα13 in cancers, serving as oncogenes as well as tumor suppressors.
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Affiliation(s)
- Viktoriya Syrovatkina
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York, 10065
| | - Xin-Yun Huang
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York, 10065
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7
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Blurring Boundaries: Receptor Tyrosine Kinases as functional G Protein-Coupled Receptors. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 339:1-40. [DOI: 10.1016/bs.ircmb.2018.02.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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8
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G-Protein Gα 13 Functions with Abl Kinase to Regulate Actin Cytoskeletal Reorganization. J Mol Biol 2017; 429:3836-3849. [PMID: 29079481 DOI: 10.1016/j.jmb.2017.10.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/17/2017] [Accepted: 10/18/2017] [Indexed: 11/23/2022]
Abstract
Heterotrimeric G-proteins are essential cellular signal transducers. One of the G-proteins, Gα13, is critical for actin cytoskeletal reorganization, cell migration, cell proliferation, and apoptosis. Previously, we have shown that Gα13 is essential for both G-protein-coupled receptor and receptor tyrosine kinase-induced actin cytoskeletal reorganization such as dynamic dorsal ruffle turnover and cell migration. However, the mechanism by which Gα13 signals to actin cytoskeletal reorganization is not completely understood. Here we show that Gα13 directly interacts with Abl tyrosine kinase, which is a critical regulator of actin cytoskeleton. This interaction is critical for Gα13-induced dorsal ruffle turnover, endothelial cell remodeling, and cell migration. Our data uncover a new molecular signaling pathway by which Gα13 controls actin cytoskeletal reorganization.
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9
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Syrovatkina V, Alegre KO, Dey R, Huang XY. Regulation, Signaling, and Physiological Functions of G-Proteins. J Mol Biol 2016; 428:3850-68. [PMID: 27515397 DOI: 10.1016/j.jmb.2016.08.002] [Citation(s) in RCA: 265] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 07/31/2016] [Accepted: 08/03/2016] [Indexed: 12/31/2022]
Abstract
Heterotrimeric guanine-nucleotide-binding regulatory proteins (G-proteins) mainly relay the information from G-protein-coupled receptors (GPCRs) on the plasma membrane to the inside of cells to regulate various biochemical functions. Depending on the targeted cell types, tissues, and organs, these signals modulate diverse physiological functions. The basic schemes of heterotrimeric G-proteins have been outlined. In this review, we briefly summarize what is known about the regulation, signaling, and physiological functions of G-proteins. We then focus on a few less explored areas such as the regulation of G-proteins by non-GPCRs and the physiological functions of G-proteins that cannot be easily explained by the known G-protein signaling pathways. There are new signaling pathways and physiological functions for G-proteins to be discovered and further interrogated. With the advancements in structural and computational biological techniques, we are closer to having a better understanding of how G-proteins are regulated and of the specificity of G-protein interactions with their regulators.
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Affiliation(s)
- Viktoriya Syrovatkina
- Department of Physiology and Biophysics, Weill Cornell Medical College, of Cornell University, 1300 York Avenue, New York, NY 10065, USA
| | - Kamela O Alegre
- Department of Physiology and Biophysics, Weill Cornell Medical College, of Cornell University, 1300 York Avenue, New York, NY 10065, USA
| | - Raja Dey
- Department of Physiology and Biophysics, Weill Cornell Medical College, of Cornell University, 1300 York Avenue, New York, NY 10065, USA
| | - Xin-Yun Huang
- Department of Physiology and Biophysics, Weill Cornell Medical College, of Cornell University, 1300 York Avenue, New York, NY 10065, USA.
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10
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Liu J, Ji X, Li Z, Yang X, Wang W, Zhang X. G protein γ subunit 7 induces autophagy and inhibits cell division. Oncotarget 2016; 7:24832-47. [PMID: 27056891 PMCID: PMC5029746 DOI: 10.18632/oncotarget.8559] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 02/28/2016] [Indexed: 11/25/2022] Open
Abstract
GNG7 (G protein γ subunit 7), a subunit of heterotrimeric G protein, is ubiquitously expressed in multiple tissues but is down-regulated in various cancers. Its expression could reduce tumor volume in mice but the mechanism was not clear. Here we show that GNG7 overexpression inhibits cell proliferation and increases cell death. GNG7 level is cell cycle-dependent and it regulates actin cytoskeleton and cell division. In addition, GNG7 is an autophagy inducer, which is the first reported Gγ protein involved in autophagy. GNG7 knockdown reduces Rapamycin and starvation-induced autophagy. Further analysis reveals that GNG7 inhibits MTOR in cells, a central regulator for autophagy and cell proliferation. In conclusion, GNG7 inhibits MTOR pathway to induce autophagy and cell death, inhibits cell division by regulating actin cytoskeleton. These combined effects lead to the antitumor capacity of GNG7.
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Affiliation(s)
- Juanjuan Liu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China
- University of Science and Technology of China, Hefei, Anhui, 230036, P. R. China
| | - Xinmiao Ji
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China
| | - Zhiyuan Li
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China
| | - Xingxing Yang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China
| | - Wenchao Wang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China
| | - Xin Zhang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China
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11
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Pore D, Gupta N. The ezrin-radixin-moesin family of proteins in the regulation of B-cell immune response. Crit Rev Immunol 2016; 35:15-31. [PMID: 25746045 DOI: 10.1615/critrevimmunol.2015012327] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Dynamic reorganization of the cortical cytoskeleton is essential for numerous cellular processes, including B- and T-cell activation and migration. The ezrin-radixin-moesin (ERM) family of proteins plays structural and regulatory roles in the rearrangement of plasma membrane flexibility and protrusions through its members' reversible interaction with cortical actin filaments and the plasma membrane. Recent studies demonstrated that ERM proteins not only are involved in cytoskeletal organization but also offer a platform for the transmission of signals in response to a variety of extracellular stimuli through their ability to cross-link transmembrane receptors with downstream signaling components. In this review, we summarize present knowledge relating to ERMs and recent progress made toward elucidating a novel role for them in the regulation of B-cell function in health and disease.
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Affiliation(s)
- Debasis Pore
- Department of Immunology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Neetu Gupta
- Department of Immunology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
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12
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Vannini L, Augustine Dunn W, Reed TW, Willis JH. Changes in transcript abundance for cuticular proteins and other genes three hours after a blood meal in Anopheles gambiae. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 44:33-43. [PMID: 24269292 PMCID: PMC3970321 DOI: 10.1016/j.ibmb.2013.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 10/24/2013] [Accepted: 11/05/2013] [Indexed: 05/03/2023]
Abstract
Numerous studies have examined changes in transcript levels after Anopheles gambiae takes a blood meal. Marinotti et al. (2006) used microarrays and reported massive changes in transcript levels 3 h after feeding (BF3h) compared to non-blood fed (NBF). We were intrigued by the number of transcripts for structural cuticular proteins (CPs) that showed such major differences in levels and employed paired-end (50 bp) RNA-seq technology to compare whole body transcriptomes from 5-day-old females NBF and BF3h. We detected transcripts for the majority of CPs (164/243) but levels of only 12 were significantly altered by the blood meal. While relative transcript levels of NBF females were somewhat similar to the microarray data, there were major differences in BF3h animals, resulting in levels of many transcripts, both for CPs and other genes changing in the opposite direction. We compared our data also to other studies done with both microarrays and RNA-seq. Findings were consistent that a small number of CP genes have transcripts that persist even in 5-day-old adults. Some of these transcripts showed diurnal rhythms (Rund et al., 2013; Rinker et al., 2013). In situ hybridization revealed that transcripts for several of these CP genes were found exclusively or predominantly in the eye. Transcripts other than for CPs that changed in response to blood-feeding were predominantly expressed in midgut and Malpighian tubules. Even in these tissues, genes responsible for proteins with similar functions, such as immunity or digestion, responded differently, with transcript levels for some rising and others falling. These data demonstrate that genes coding for some CPs are dynamic in expression even in adults and that the response to a blood meal is rapid and precisely orchestrated.
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Affiliation(s)
- Laura Vannini
- University of Georgia, Cellular Biology, Athens, GA 30602, USA.
| | - W Augustine Dunn
- University of California Irvine, Molecular Biology and Biochemistry, Irvine, CA 92697, USA.
| | - Tyler W Reed
- University of Georgia, Cellular Biology, Athens, GA 30602, USA.
| | - Judith H Willis
- University of Georgia, Cellular Biology, Athens, GA 30602, USA.
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13
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Xing B, Wang L, Guo D, Huang J, Espenel C, Kreitzer G, Zhang JJ, Guo L, Huang XY. Atypical protein kinase Cλ is critical for growth factor receptor-induced dorsal ruffle turnover and cell migration. J Biol Chem 2013; 288:32827-36. [PMID: 24092753 DOI: 10.1074/jbc.m113.489427] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Gα13, a member of the heterotrimeric G proteins, is critical for actin cytoskeletal reorganization and cell migration. Previously we have shown that Gα13 is essential for both G protein-coupled receptor and receptor tyrosine kinase-induced actin cytoskeletal reorganization such as dynamic dorsal ruffle turnover and cell migration. Ric-8A, a non-receptor guanine nucleotide exchange factor for some heterotrimeric G proteins, is critical for coupling receptor tyrosine kinases to Gα13. Here, we show that PDGF can induce phosphorylation of Ric-8A. Atypical protein kinase Cλ (aPKCλ) is required for Ric-8A phosphorylation. Furthermore, aPKCλ is required for PDGF-induced dorsal ruffle turnover and cell migration as demonstrated by both down-regulation of aPKCλ protein levels in cells by RNA interference and by studies in aPKCλ knock-out cells. Moreover, phosphorylation of Ric-8A modulates its subcellular localization. Hence, aPKCλ is critical for PDGF-induced actin cytoskeletal reorganization and cell migration.
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Affiliation(s)
- Bowen Xing
- From the College of Life Sciences, Wuhan University, Wuhan 430072, China, and
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14
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Zhang X, Eggert US. Non-traditional roles of G protein-coupled receptors in basic cell biology. MOLECULAR BIOSYSTEMS 2013; 9:586-95. [PMID: 23247090 PMCID: PMC3628546 DOI: 10.1039/c2mb25429h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
G protein-coupled receptors (GPCRs) are key signaling proteins that regulate how cells interact with their environment. Traditional signaling cascades involving GPCRs have been well described and are well established and very important clinical targets. With the development of more recent technologies, hints about the involvement of GPCRs in fundamental cell biological processes are beginning to emerge. In this review, we give a basic introduction to GPCR signaling and highlight some less well described roles of GPCRs, including in cell division and membrane trafficking, which may occur through canonical and non-canonical signaling pathways.
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Affiliation(s)
- Xin Zhang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, P.R. China
- Dana-Farber Cancer Institute and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Ulrike S. Eggert
- Dana-Farber Cancer Institute and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
- Department of Chemistry and Randall Division of Cell and Molecular Biophysics, King’s College London, London, UK
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15
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Abstract
Cells construct a number of plasma membrane structures to meet a range of physiological demands. Driven by juxtamembrane actin machinery, these actin-based membrane protrusions are essential for the operation and maintenance of cellular life. They are required for diverse cellular functions, such as directed cell motility, cell spreading, adhesion, and substrate/matrix degradation. Circular dorsal ruffles (CDRs) are one class of such structures characterized as F-actin-rich membrane projections on the apical cell surface. CDRs commence their formation minutes after stimulation as flat, open, and immature ruffles and progressively develop into fully enclosed circular ruffles. These "rings" then mature and contract centrifugally before subsiding. Serving a critical function in receptor internalization and cell migration, CDRs are thus highly dynamic but transient formations. Here, we review the current state of knowledge concerning the regulation of circular dorsal ruffles. We focus specifically on the biochemical pathways leading to CDR formation in order to better define the roles and functions of these enigmatic structures.
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16
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Hasegawa J, Tsujita K, Takenawa T, Itoh T. ARAP1 regulates the ring size of circular dorsal ruffles through Arf1 and Arf5. Mol Biol Cell 2012; 23:2481-9. [PMID: 22573888 PMCID: PMC3386212 DOI: 10.1091/mbc.e12-01-0017] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Circular dorsal ruffles (CDRs) are highly dynamic F-actin–based membrane structures involved in bulk endocytosis of membrane receptors and macropinocytosis. A key role of ARAP1, an Arf GAP protein, is found to be in the control of the ring size of CDRs. Small guanosine triphosphatase (GTPase) ADP-ribosylation factors (Arfs) regulate membrane traffic and actin reorganization under the strict control of GTPase-activating proteins (GAPs). ARAP1 (Arf GAP with Rho GAP domain, ankyrin repeat, and PH domain 1) is an Arf GAP molecule with multiple PH domains that recognize phosphatidylinositol 3,4,5-trisphosphate. We found that growth factor stimulation induced localization of ARAP1 to an area of the plasma membrane inside the ring structure of circular dorsal ruffles (CDRs). Moreover, expression of ARAP1 increased the size of the CDR filamentous-actin ring in an Arf GAP activity–dependent manner, whereas smaller CDRs were formed by ARAP1 knockdown. In addition, expression of a dominant-negative mutant of Arf1 and Arf5, the substrates of ARAP1, expanded the size of CDRs, suggesting that the two Arf isoforms regulate ring structure downstream of ARAP1. Therefore our results reveal a novel molecular mechanism of CDR ring size control through the ARAP1–Arf1/5 pathway.
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Affiliation(s)
- Junya Hasegawa
- Division of Membrane Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
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17
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Wang L, Guo D, Xing B, Zhang JJ, Shu HB, Guo L, Huang XY. Resistance to inhibitors of cholinesterase-8A (Ric-8A) is critical for growth factor receptor-induced actin cytoskeletal reorganization. J Biol Chem 2011; 286:31055-31061. [PMID: 21771786 DOI: 10.1074/jbc.m111.253427] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Heterotrimeric G proteins are critical transducers of cellular signaling. In addition to their classic roles in relaying signals from G protein-coupled receptors (GPCRs), heterotrimeric G proteins also mediate physiological functions from non-GPCRs. Previously, we have shown that Gα(13), a member of the heterotrimeric G proteins, is essential for growth factor receptor-induced actin cytoskeletal reorganization such as dynamic dorsal ruffle turnover and cell migration. These Gα(13)-mediated dorsal ruffle turnover and cell migration by growth factors acting on their receptor tyrosine kinases (RTKs) are independent of GPCRs. However, the mechanism by which RTKs signal to Gα(13) is not known. Here, we show that cholinesterase-8A (Ric-8A), a nonreceptor guanine nucleotide exchange factor for some heterotrimeric G proteins, is critical for coupling RTKs to Gα(13). Down-regulation of Ric-8A protein levels in cells by RNA interference slowed down platelet-derived growth factor (PDGF)-induced dorsal ruffle turnover and inhibited PDGF-initiated cell migration. PDGF was able to increase the activity of Ric-8A in cells. Furthermore, purified Ric-8A proteins interact directly with purified Gα(13) protein in a nucleotide-dependent manner. Deficiency of Ric-8A prevented the translocation of Gα(13) to the cell cortex. Hence, Ric-8A is critical for growth factor receptor-induced actin cytoskeletal reorganization.
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Affiliation(s)
- Limin Wang
- College of Life Sciences, Wuhan University, Wuhan, China 430072
| | - Dagang Guo
- Department of Physiology, Cornell University Weill Medical College, New York, New York 10065
| | - Bowen Xing
- College of Life Sciences, Wuhan University, Wuhan, China 430072
| | - J Jillian Zhang
- Department of Physiology, Cornell University Weill Medical College, New York, New York 10065
| | - Hong-Bing Shu
- College of Life Sciences, Wuhan University, Wuhan, China 430072
| | - Lin Guo
- College of Life Sciences, Wuhan University, Wuhan, China 430072
| | - Xin-Yun Huang
- College of Life Sciences, Wuhan University, Wuhan, China 430072.
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Chen L, Zhang JJ, Rafii S, Huang XY. Suppression of tumor angiogenesis by Galpha(13) haploinsufficiency. J Biol Chem 2009; 284:27409-15. [PMID: 19654325 DOI: 10.1074/jbc.m109.025460] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Heterotrimeric G proteins are critical transducers of cellular signaling. Of the four families of G proteins, the physiological function of Galpha(13) is less well understood. Galpha(13) gene-deleted mice die at embryonic day approximately 9.5. Here, we show that heterozygous Galpha(13)(+/-) mice display defects in adult angiogenesis. Female Galpha(13)(+/-) mice showed a higher number of immature follicles and a lower density of blood vessels in the mature corpus luteum compared with Galpha(13)(+/+) mice. Furthermore, implanted tumors grew slower in Galpha(13)(+/-) host mice. These tumor tissues had many fewer blood vessels compared with those from Galpha(13)(+/+) host mice. Moreover, bone marrow-derived progenitor cells from Galpha(13)(+/+) mice rescued the failed growth of allografted tumors when reconstituted into irradiated Galpha(13)(+/-) mice. Hence, Galpha(13) is haploinsufficient for adult angiogenesis in both the female reproductive system and tumor angiogenesis.
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Affiliation(s)
- Lin Chen
- Department of Physiology, Weill Medical College of Cornell University, New York, New York 10065, USA
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19
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Yang S, Zhang JJ, Huang XY. Orai1 and STIM1 are critical for breast tumor cell migration and metastasis. Cancer Cell 2009; 15:124-34. [PMID: 19185847 DOI: 10.1016/j.ccr.2008.12.019] [Citation(s) in RCA: 532] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Revised: 08/28/2008] [Accepted: 12/29/2008] [Indexed: 11/26/2022]
Abstract
Tumor metastasis is the primary cause of death of cancer patients. Understanding the molecular mechanisms underlying tumor metastasis will provide potential drug targets. We report here that Orai1 and STIM1, both of which are involved in store-operated calcium entry, are essential for breast tumor cell migration in vitro and tumor metastasis in mice. Reduction of Orai1 or STIM1 by RNA interference in highly metastatic human breast cancer cells or treatment with a pharmacological inhibitor of store-operated calcium channels decreased tumor metastasis in animal models. Our data demonstrate a role for Orai1 and STIM1 in tumor metastasis and suggest store-operated calcium entry channels as potential cancer therapeutic targets.
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Affiliation(s)
- Shengyu Yang
- Department of Physiology, Weill Medical College of Cornell University, New York, NY 10065, USA
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Chen L, Zhang JJ, Huang XY. cAMP inhibits cell migration by interfering with Rac-induced lamellipodium formation. J Biol Chem 2008; 283:13799-805. [PMID: 18353776 DOI: 10.1074/jbc.m800555200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cell migration is critical for animal development and physiological as well as pathological responses. One important step during cell migration is the formation of lamellipodia at the leading edge of migrating cells. Here we report that the second messenger cAMP inhibits the migration of mouse embryonic fibroblast cells and mouse breast tumor cells. cAMP acts downstream of the small GTPase Rac and interferes with the formation of lamellipodia. Moreover, cAMP decreases the phosphorylation of the myosin light chain at the leading edge of cells and increases the phosphorylation of the vasodilator-stimulated phosphoprotein. Together with our previous report of a positive role of another second messenger, cGMP, in lamellipodium formation, our data indicate that cAMP and cGMP play opposite roles in modulating lamellipodium formation.
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Affiliation(s)
- Lin Chen
- Department of Physiology, Cornell University Weill Medical College, New York, New York 10021, USA
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21
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Wang Y, Zhou K, Zeng X, Lin J, Zhan X. Tyrosine phosphorylation of missing in metastasis protein is implicated in platelet-derived growth factor-mediated cell shape changes. J Biol Chem 2007; 282:7624-31. [PMID: 17224454 DOI: 10.1074/jbc.m608448200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Missing in metastasis gene, or MTSS1, encodes an intracellular protein that is implicated in actin cytoskeleton reorganization and often down-regulated in certain types of tumor cells. In response to platelet-derived growth factor (PDGF), green fluorescent protein (GFP)-tagged murine Mtss1 (Mtss1-GFP) underwent redistribution from the cytoplasm to dorsal membrane ruffles along with phosphorylation at tyrosine residues in a time-dependent manner. Tyrosine phosphorylation of Mtss1-GFP was also elevated in cells where an oncogenic Src was activated but severely impaired in Src knock-out cells or cells treated with Src kinase inhibitor PP2. Mutagenesis analysis has revealed that phosphorylation occurs at multiple sites, including tyrosine residues Tyr-397 and Tyr-398. Mutation at both Tyr-397 and Tyr-398 abolished the PDGF-mediated tyrosine phosphorylation. Furthermore, recombinant Mtss1 protein was phosphorylated by recombinant Src in a manner dependent on Tyr-397 and Tyr-398. Efficient tyrosine phosphorylation of Mtss1 in response to PDGF also involves a coiled-coil domain, which is essential for a proper distribution to the cell leading edge and dorsal ruffles. Interestingly, overexpression of wild type Mtss1-GFP promoted the PDGF-induced dorsal ruffling, whereas overexpression of a mutant deficient in phosphorylation at Tyr-397 and Tyr-398 or a mutant with deletion of the coiled-coil domain impaired the formation of dorsal ruffles. These data indicate that Mtss1 represents a novel signaling pathway from PDGF receptor to the actin cytoskeleton via Src-related kinases.
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Affiliation(s)
- Ying Wang
- Department of Pathology, University of Maryland Marlene and Stewart Greenebaum Cancer Center, Center for Vascular and Inflammatory Diseases, Baltimore, Maryland 21201, USA
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