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Sulimenko V, Sládková V, Sulimenko T, Dráberová E, Vosecká V, Dráberová L, Skalli O, Dráber P. Regulation of microtubule nucleation in mouse bone marrow-derived mast cells by ARF GTPase-activating protein GIT2. Front Immunol 2024; 15:1321321. [PMID: 38370406 PMCID: PMC10870779 DOI: 10.3389/fimmu.2024.1321321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 01/16/2024] [Indexed: 02/20/2024] Open
Abstract
Aggregation of high-affinity IgE receptors (FcϵRIs) on granulated mast cells triggers signaling pathways leading to a calcium response and release of inflammatory mediators from secretory granules. While microtubules play a role in the degranulation process, the complex molecular mechanisms regulating microtubule remodeling in activated mast cells are only partially understood. Here, we demonstrate that the activation of bone marrow mast cells induced by FcϵRI aggregation increases centrosomal microtubule nucleation, with G protein-coupled receptor kinase-interacting protein 2 (GIT2) playing a vital role in this process. Both endogenous and exogenous GIT2 were associated with centrosomes and γ-tubulin complex proteins. Depletion of GIT2 enhanced centrosomal microtubule nucleation, and phenotypic rescue experiments revealed that GIT2, unlike GIT1, acts as a negative regulator of microtubule nucleation in mast cells. GIT2 also participated in the regulation of antigen-induced degranulation and chemotaxis. Further experiments showed that phosphorylation affected the centrosomal localization of GIT2 and that during antigen-induced activation, GIT2 was phosphorylated by conventional protein kinase C, which promoted microtubule nucleation. We propose that GIT2 is a novel regulator of microtubule organization in activated mast cells by modulating centrosomal microtubule nucleation.
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Affiliation(s)
- Vadym Sulimenko
- Laboratory of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Vladimíra Sládková
- Laboratory of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Tetyana Sulimenko
- Laboratory of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Eduarda Dráberová
- Laboratory of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Věra Vosecká
- Laboratory of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Lubica Dráberová
- Laboratory of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Omar Skalli
- Department of Biological Sciences, The University of Memphis, Memphis, TN, United States
| | - Pavel Dráber
- Laboratory of Biology of Cytoskeleton, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
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2
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Zhou W, Li X, Premont RT. Expanding functions of GIT Arf GTPase-activating proteins, PIX Rho guanine nucleotide exchange factors and GIT-PIX complexes. J Cell Sci 2017; 129:1963-74. [PMID: 27182061 DOI: 10.1242/jcs.179465] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The GIT proteins, GIT1 and GIT2, are GTPase-activating proteins (inactivators) for the ADP-ribosylation factor (Arf) small GTP-binding proteins, and function to limit the activity of Arf proteins. The PIX proteins, α-PIX and β-PIX (also known as ARHGEF6 and ARHGEF7, respectively), are guanine nucleotide exchange factors (activators) for the Rho family small GTP-binding protein family members Rac1 and Cdc42. Through their multi-domain structures, GIT and PIX proteins can also function as signaling scaffolds by binding to numerous protein partners. Importantly, the constitutive association of GIT and PIX proteins into oligomeric GIT-PIX complexes allows these two proteins to function together as subunits of a larger structure that coordinates two distinct small GTP-binding protein pathways and serves as multivalent scaffold for the partners of both constituent subunits. Studies have revealed the involvement of GIT and PIX proteins, and of the GIT-PIX complex, in numerous fundamental cellular processes through a wide variety of mechanisms, pathways and signaling partners. In this Commentary, we discuss recent findings in key physiological systems that exemplify current understanding of the function of this important regulatory complex. Further, we draw attention to gaps in crucial information that remain to be filled to allow a better understanding of the many roles of the GIT-PIX complex in health and disease.
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Affiliation(s)
- Wu Zhou
- Department of Medicine, College of Medicine and Health, Lishui University, Lishui 323000, China
| | - Xiaobo Li
- Department of Computer Science and Technology, College of Engineering and Design, Lishui University, Lishui 323000, China
| | - Richard T Premont
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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Franchi SA, Astro V, Macco R, Tonoli D, Barnier JV, Botta M, de Curtis I. Identification of a Protein Network Driving Neuritogenesis of MGE-Derived GABAergic Interneurons. Front Cell Neurosci 2016; 10:289. [PMID: 28066185 PMCID: PMC5174131 DOI: 10.3389/fncel.2016.00289] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/02/2016] [Indexed: 12/27/2022] Open
Abstract
Interneurons are essential modulators of brain activity and their abnormal maturation may lead to neural and intellectual disabilities. Here we show that cultures derived from murine medial ganglionic eminences (MGEs) produce virtually pure, polarized γ-aminobutyric acid (GABA)-ergic interneurons that can form morphologically identifiable inhibitory synapses. We show that Rac GTPases and a protein complex including the GIT family scaffold proteins are expressed during maturation in vitro, and are required for the normal development of neurites. GIT1 promotes neurite extension in a conformation-dependent manner, while affecting its interaction with specific partners reduces neurite branching. Proteins of the GIT network are concentrated at growth cones, and interaction mutants may affect growth cone behavior. Our findings identify the PIX/GIT1/liprin-α1/ERC1 network as critical for the regulation of interneuron neurite differentiation in vitro, and show that these cultures represent a valuable system to identify the molecular mechanisms driving the maturation of cortical/hippocampal interneurons.
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Affiliation(s)
- Sira A Franchi
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University Milano, Italy
| | - Veronica Astro
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University Milano, Italy
| | - Romina Macco
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University Milano, Italy
| | - Diletta Tonoli
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University Milano, Italy
| | - Jean-Vianney Barnier
- Neuroscience Paris-Saclay Institute, UMR 9197, Centre National de la Recherche Scientifique-Université Paris-Sud Orsay, France
| | - Martina Botta
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University Milano, Italy
| | - Ivan de Curtis
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University Milano, Italy
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4
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Duan B, Cui J, Sun S, Zheng J, Zhang Y, Ye B, Chen Y, Deng W, Du J, Zhu Y, Chen Y, Gu L. EGF-stimulated activation of Rab35 regulates RUSC2-GIT2 complex formation to stabilize GIT2 during directional lung cancer cell migration. Cancer Lett 2016; 379:70-83. [PMID: 27238570 DOI: 10.1016/j.canlet.2016.05.027] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 04/20/2016] [Accepted: 05/25/2016] [Indexed: 10/21/2022]
Abstract
Non-small cell lung cancer (NSCLC) remains one of the most metastasizing tumors, and directional cell migration is critical for targeting tumor metastasis. GIT2 has been known to bind to Paxillin to control cell polarization and directional migration. However, the molecular mechanisms underlying roles of GIT2 in controlling cell polarization and directional migration remain elusive. Here we demonstrated GIT2 control cell polarization and direction dependent on the regulation of Golgi through RUSC2. RUSC2 interacts with SHD of GIT2 in various lung cancer cells, and stabilizes GIT2 (Mazaki et al., 2006; Yu et al., 2009) by decreasing degradation and increasing its phosphorylation. Silencing of RUSC2 showed reduced stability of GIT2, defective Golgi reorientation toward the wound edge and decreased directional migration. Moreover, short-term EGF stimulation can increase the interaction between RUSC2 and GIT2, prolonged stimulation leads to a decrease of their interaction through activating Rab35. Silencing of Rab35 also reduced stability and phosphorylation of GIT2 and decreased cell migration. Taken together, our study indicated that RUSC2 participates in EGFR signaling and regulates lung cancer progression, and may be a new therapeutic target against lung cancer metastasis.
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Affiliation(s)
- Biao Duan
- Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Jie Cui
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu 210029, China; Department of Physiology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Shixiu Sun
- Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Jianchao Zheng
- Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Yujie Zhang
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu 210029, China; Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Bixing Ye
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Yan Chen
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Wenjie Deng
- Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Jun Du
- Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China; Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Yichao Zhu
- Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Yongchang Chen
- Department of Physiology, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Luo Gu
- Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China; Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu 210029, China; Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University, Nanjing, Jiangsu 211166, China.
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5
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Hao YE, He DF, Yin RH, Chen H, Wang J, Wang SX, Zhan YQ, Ge CH, Li CY, Yu M, Yang XM. GIT2 deficiency attenuates concanavalin A-induced hepatitis in mice. FEBS Open Bio 2015; 5:688-704. [PMID: 26380813 PMCID: PMC4556731 DOI: 10.1016/j.fob.2015.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 08/06/2015] [Accepted: 08/07/2015] [Indexed: 12/29/2022] Open
Abstract
GIT2 depletion attenuates Con A-induced immunological hepatic injuries. GIT2 depletion suppressed the activation and function of mouse CD4+ T cells. GIT2 depletion suppressed liver infiltration by lymphoid cells after Con A treatment. There were lower levels of proinflammatory cytokines in Git2−/− mice after Con A injection.
G protein-coupled receptor kinase interactor 2 (GIT2) is a signaling scaffold protein involved in regulation of cytoskeletal dynamics and the internalization of G protein-coupled receptors (GPCRs). The short-splice form of GIT2 is expressed in peripheral T cells and thymocytes. However, the functions of GIT2 in T cells have not yet been determined. We show that treatment with Con A in a model of polyclonal T-lymphocyte activation resulted in marked inhibitions in the intrahepatic infiltration of inflammatory cells, cytokine response and acute liver failure in Git2−/− mice. CD4+ T cells from Git2−/− mice showed significant impairment in proliferation, cytokine production and signal transduction upon TCR-stimulated activation. Our results suggested that GIT2 plays an important role in T-cell function in vivo and in vitro.
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Affiliation(s)
- Yu-E Hao
- Southern Medical University, Guangzhou, Guangdong Province, China ; State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Dong-Fang He
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China ; Anhui Medical University, Hefei 230032, Anhui Province, China
| | - Rong-Hua Yin
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Hui Chen
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Jian Wang
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Shao-Xia Wang
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Yi-Qun Zhan
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Chang-Hui Ge
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Chang-Yan Li
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Miao Yu
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Xiao-Ming Yang
- Southern Medical University, Guangzhou, Guangdong Province, China ; State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China ; Anhui Medical University, Hefei 230032, Anhui Province, China
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Sulimenko V, Hájková Z, Černohorská M, Sulimenko T, Sládková V, Dráberová L, Vinopal S, Dráberová E, Dráber P. Microtubule Nucleation in Mouse Bone Marrow–Derived Mast Cells Is Regulated by the Concerted Action of GIT1/βPIX Proteins and Calcium. THE JOURNAL OF IMMUNOLOGY 2015; 194:4099-111. [DOI: 10.4049/jimmunol.1402459] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 02/27/2015] [Indexed: 11/19/2022]
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7
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Zhang LQ, Zhao GZ, Xu XY, Fang J, Chen JM, Li JW, Gao XJ, Hao LJ, Chen YZ. Integrin-β1 regulates chondrocyte proliferation and apoptosis through the upregulation of GIT1 expression. Int J Mol Med 2015; 35:1074-80. [PMID: 25715677 DOI: 10.3892/ijmm.2015.2114] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 02/05/2015] [Indexed: 01/25/2023] Open
Abstract
Chondrocytes play a critical role in the repair process of osteoarthritis, which is also known as degenerative arthritis. Integrins, as the key family of cell surface receptors, are responsible for the regulation of chondrocyte proliferation, differentiation, survival and apoptosis through the recruitment and activation of downstream adaptor proteins. Moreover, G-protein-coupled receptor kinase interacting protein-1 (GIT1) exerts its effects on cell proliferation and migration through interaction with various cytokines. It has been previously suggested that GIT1 acts as a vital protein downstream of the integrin-mediated pathway. In the present study, we investigated the effects of integrin-β1 on cell proliferation and apoptosis, as well as the underlying mechanisms in chondrocytes in vitro. Following transfection with a vector expressing integrin-β1, our results revealed that the overexpression of integrin-β1 enhanced GIT1 expression, whereas the knockdown of integrin-β1 by siRNA suppressed GIT1 expression. However, no significant effect was observed on integrin-β1 expression following the enforced overexpression of GIT1, which suggests that GIT1 is localized downstream of integrin-β1. In other words, integrin-β1 regulates the expression of GIT1. Furthermore, this study demonstrated that integrin-β1 and GIT1 increased the expression levels of aggrecan and type II collagen, thus promoting chondrocyte proliferation; however, they inhibited chondrocyte apoptosis. Taken together, our data demonstrate that integrin-β1 plays a vital role in chondrocyte proliferation, differentiation and apoptosis. GIT1 exerts effects similar to those of integrin-β1 and is a downstream target of integrin-β1.
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Affiliation(s)
- Long-Qiang Zhang
- Department of Orthopedics, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Guang-Zong Zhao
- Department of Orthopedics, Yidu Central Hospital of Weifang, Weifang, Shandong 262500, P.R. China
| | - Xiao-Yan Xu
- Department of Oncology, Qingzhou Hospital of Traditional Chinese Medicine, Qingzhou, Shandong 262500, P.R. China
| | - Jun Fang
- Department of Orthopedics, Yidu Central Hospital of Weifang, Weifang, Shandong 262500, P.R. China
| | - Jing-Ming Chen
- Department of Orthopedics, Yidu Central Hospital of Weifang, Weifang, Shandong 262500, P.R. China
| | - Ji-Wen Li
- Department of Orthopedics, Yidu Central Hospital of Weifang, Weifang, Shandong 262500, P.R. China
| | - Xue-Jian Gao
- Department of Orthopedics, The 89th Hospital of PLA, Weifang, Shandong 261021, P.R. China
| | - Li-Juan Hao
- Department of Urologic Surgery, Yidu Central Hospital of Weifang, Weifang, Shandong 262500, P.R. China
| | - Yun-Zhen Chen
- Department of Orthopedics, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
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Wu Y, Zhang Y, Yin Q, Xia H, Wang J. Platelet‑derived growth factor promotes osteoblast proliferation by activating G‑protein‑coupled receptor kinase interactor‑1. Mol Med Rep 2014; 10:1349-54. [PMID: 25017023 DOI: 10.3892/mmr.2014.2374] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 03/19/2014] [Indexed: 11/05/2022] Open
Abstract
Platelet‑derived growth factor (PDGF) has been reported to stimulate bone fracture‑healing. Multiple studies have demonstrated that PDGF has a critical role in osteoblast or osteoprogenitor cell activation, although the underlying mechanism remains unclear. Studies have found that G‑protein‑coupled receptor kinase interactor‑1 (GIT1) is activated by PDGF and described as an important factor in bone metabolism. In the present study, the effects of PDGF and GIT1 on the proliferation and apoptosis of osteoblasts were investigated in cultured osteoblasts isolated from rat calvaria with PDGF stimulation and GIT1 small interfering RNA transfection. The results demonstrated that PDGF rapidly stimulated GTI1 expression in osteoblasts, increased osteoblast proliferation and inhibited cell apoptosis. Furthermore, cyclin D1 expression was significantly upregulated, the number of cells in the G0/G1 phase was decreased, while the number in the S phase was increased. In cells with knockdown of GIT1, the change stimulated by PDGF was not evident. The results indicate that, PDGF stimulated GIT1 activation of cyclin D1 expression, thereby promoting osteoblasts to enter the S phase from the stationary G0/G1 phase, leading to the proliferation of osteoblasts.
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Affiliation(s)
- You Wu
- Department of Traumatic Orthopedics, General Hospital of Guangzhou Military Area Command of Chinese PLA, Guangzhou, Guangdong 510010, P.R. China
| | - Ying Zhang
- Department of Traumatic Orthopedics, General Hospital of Guangzhou Military Area Command of Chinese PLA, Guangzhou, Guangdong 510010, P.R. China
| | - Qingshui Yin
- Department of Traumatic Orthopedics, General Hospital of Guangzhou Military Area Command of Chinese PLA, Guangzhou, Guangdong 510010, P.R. China
| | - Hong Xia
- Department of Traumatic Orthopedics, General Hospital of Guangzhou Military Area Command of Chinese PLA, Guangzhou, Guangdong 510010, P.R. China
| | - Jiajia Wang
- Department of Traumatic Orthopedics, General Hospital of Guangzhou Military Area Command of Chinese PLA, Guangzhou, Guangdong 510010, P.R. China
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9
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Ivanova H, Vervliet T, Missiaen L, Parys JB, De Smedt H, Bultynck G. Inositol 1,4,5-trisphosphate receptor-isoform diversity in cell death and survival. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:2164-83. [PMID: 24642269 DOI: 10.1016/j.bbamcr.2014.03.007] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 03/06/2014] [Accepted: 03/09/2014] [Indexed: 01/22/2023]
Abstract
Cell-death and -survival decisions are critically controlled by intracellular Ca(2+) homeostasis and dynamics at the level of the endoplasmic reticulum (ER). Inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) play a pivotal role in these processes by mediating Ca(2+) flux from the ER into the cytosol and mitochondria. Hence, it is clear that many pro-survival and pro-death signaling pathways and proteins affect Ca(2+) signaling by directly targeting IP3R channels, which can happen in an IP3R-isoform-dependent manner. In this review, we will focus on how the different IP3R isoforms (IP3R1, IP3R2 and IP3R3) control cell death and survival. First, we will present an overview of the isoform-specific regulation of IP3Rs by cellular factors like IP3, Ca(2+), Ca(2+)-binding proteins, adenosine triphosphate (ATP), thiol modification, phosphorylation and interacting proteins, and of IP3R-isoform specific expression patterns. Second, we will discuss the role of the ER as a Ca(2+) store in cell death and survival and how IP3Rs and pro-survival/pro-death proteins can modulate the basal ER Ca(2+) leak. Third, we will review the regulation of the Ca(2+)-flux properties of the IP3R isoforms by the ER-resident and by the cytoplasmic proteins involved in cell death and survival as well as by redox regulation. Hence, we aim to highlight the specific roles of the various IP3R isoforms in cell-death and -survival signaling. This article is part of a Special Issue entitled: Calcium signaling in health and disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau.
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Affiliation(s)
- Hristina Ivanova
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Tim Vervliet
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Ludwig Missiaen
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Jan B Parys
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Humbert De Smedt
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium.
| | - Geert Bultynck
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium.
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10
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Totaro A, Tavano S, Filosa G, Gärtner A, Pennucci R, Santambrogio P, Bachi A, Dotti CG, de Curtis I. Biochemical and functional characterisation of αPIX, a specific regulator of axonal and dendritic branching in hippocampal neurons. Biol Cell 2012; 104:533-52. [DOI: 10.1111/boc.201100060] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 04/24/2012] [Indexed: 01/13/2023]
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11
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Asperti C, Astro V, Pettinato E, Paris S, Bachi A, de Curtis I. Biochemical and functional characterization of the interaction between liprin-α1 and GIT1: implications for the regulation of cell motility. PLoS One 2011; 6:e20757. [PMID: 21695141 PMCID: PMC3113849 DOI: 10.1371/journal.pone.0020757] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 05/09/2011] [Indexed: 12/21/2022] Open
Abstract
We have previously identified the scaffold protein liprin-α1 as an important regulator of integrin-mediated cell motility and tumor cell invasion. Liprin-α1 may interact with different proteins, and the functional significance of these interactions in the regulation of cell motility is poorly known. Here we have addressed the involvement of the liprin-α1 partner GIT1 in liprin-α1-mediated effects on cell spreading and migration. GIT1 depletion inhibited spreading by affecting the lamellipodia, and prevented liprin-α1-enhanced spreading. Conversely inhibition of the formation of the liprin-α1-GIT complex by expression of liprin-ΔCC3 could still enhance spreading, although to a lesser extent compared to full length liprin-α1. No cumulative effects were observed after depletion of both liprin-α1 and GIT1, suggesting that the two proteins belong to the same signaling network in the regulation of cell spreading. Our data suggest that liprin-α1 may compete with paxillin for binding to GIT1, while binding of βPIX to GIT1 was unaffected by the presence of liprin-α1. Interestingly, GIT and liprin-α1 reciprocally regulated their subcellular localization, since liprin-α1 overexpression, but not the GIT binding-defective liprin-ΔCC3 mutant, affected the localization of endogenous GIT at peripheral and mature central focal adhesions, while the expression of a truncated, active form of GIT1 enhanced the localization of endogenous liprin-α1 at the edge of spreading cells. Moreover, GIT1 was required for liprin-α1-enhanced haptotatic migration, although the direct interaction between liprin-α1 and GIT1 was not needed. Our findings show that the functional interaction between liprin-α1 and GIT1 cooperate in the regulation of integrin-dependent cell spreading and motility on extracellular matrix. These findings and the possible competition of liprin-α1 with paxillin for binding to GIT1 suggest that alternative binding of GIT1 to either liprin-α1 or paxillin plays distinct roles in different phases of the protrusive activity in the cell.
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Affiliation(s)
- Claudia Asperti
- Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University, Milano, Italy
| | - Veronica Astro
- Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University, Milano, Italy
| | - Emanuela Pettinato
- Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University, Milano, Italy
| | - Simona Paris
- Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University, Milano, Italy
| | - Angela Bachi
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milano, Italy
| | - Ivan de Curtis
- Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University, Milano, Italy
- * E-mail:
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