1
|
Zheng X, Xue Q, Wang Y, Lu L, Pan Y, Xu J, Zhang J. A. officinarum Hance - P. cablin (Blanco) Benth drug pair improves oxidative stress, intracellular Ca 2+ concentrations and apoptosis by inhibiting the AGE/RAGE axis to ameliorate diabetic gastroparesis: In vitro and in vivo studies. JOURNAL OF ETHNOPHARMACOLOGY 2024; 324:117832. [PMID: 38280660 DOI: 10.1016/j.jep.2024.117832] [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: 12/17/2023] [Accepted: 01/24/2024] [Indexed: 01/29/2024]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Alpinia officinarum Hance is a perennial natural medicine herbivorous plant, has been used in the management of treat stomach pain and diabetes, it is abundantly cultivated in Qiongzhong, Baisha and other places. P. cablin (Blanco) Benth, one of the most important traditional Chinese plants, which plays functions in antioxidant and gastrointestinal regulation, has been extensively planted in Hainan, Guangdong and other regions. AIM OF THE STUDY In this study, we investigated the role and underlying molecular mechanism of AP on diabetic gastroparesis (DGP) in vitro and in vivo. MATERIALS AND METHODS In this study, using ultra-high performance liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS/MS) to identify active compounds in A. officinarum Hance-P. cablin (Blanco) Benth drug pair (AP). Molecular docking were utilized to explore the potential mechanism of AP treatment of DGP. In in vitro assays, gastric smooth muscle cells (GSMCs) were treated with 35 mM glucose to promote apoptosis and construct the DGP model, which was treated with different concentrations of AP. Furthermore, transfection technology was used to overexpress RAGE in GSMCs and elucidate the underlying mechanisms of alleviation of DGP by AP. RESULTS Using UPLC-MS/MS analysis, nine components of AP were identified. We found that AP effectively blocked the increase in apoptosis, oxidative stress, and intracellular Ca2+ concentrations. For in vivo experiments, mice were fed with a high-fat irregular diet to construct DGP model, and AP was co-administered via oral gavage daily to prevent the development of DGP. Compared with DGP mice, AP significantly decreased fasting blood glucose levels and increased gastric emptying levels. Consistent with in vitro experiments, AP also considerably decreased the increase in oxidative stress in DGP mice. Mechanistically, AP alleviates apoptosis and DGP by decreasing oxidative stress and intracellular Ca2+ concentrations via the inhibition of the AGE/RAGE axis. CONCLUSIONS Collectively, this study has established that AP can improve DGP, and the mechanism may be related to the inhibition the AGE/RAGE axis to mitigate apoptosis and DGP. To summarize, this study provides a novel supplementary strategy for DGP treatment.
Collapse
Affiliation(s)
- Xiuwen Zheng
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Provincial Key Laboratory of R & D on Tropical Herbs, Haikou Key Laboratory of Li Nationality Medicine, School of Pharmacy, Hepatobiliary and Liver Transplantation Department of Hainan Digestive Disease Center of The Second Affiliated Hospital of Hainan Medical University, Engineering Research Center of Tropical Medicine of Ministry of Education, The First Affiliated Hospital, Hainan Medical University, Haikou, China.
| | - Qianrong Xue
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Provincial Key Laboratory of R & D on Tropical Herbs, Haikou Key Laboratory of Li Nationality Medicine, School of Pharmacy, Hepatobiliary and Liver Transplantation Department of Hainan Digestive Disease Center of The Second Affiliated Hospital of Hainan Medical University, Engineering Research Center of Tropical Medicine of Ministry of Education, The First Affiliated Hospital, Hainan Medical University, Haikou, China.
| | - Yinghuan Wang
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Provincial Key Laboratory of R & D on Tropical Herbs, Haikou Key Laboratory of Li Nationality Medicine, School of Pharmacy, Hepatobiliary and Liver Transplantation Department of Hainan Digestive Disease Center of The Second Affiliated Hospital of Hainan Medical University, Engineering Research Center of Tropical Medicine of Ministry of Education, The First Affiliated Hospital, Hainan Medical University, Haikou, China.
| | - Lu Lu
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Provincial Key Laboratory of R & D on Tropical Herbs, Haikou Key Laboratory of Li Nationality Medicine, School of Pharmacy, Hepatobiliary and Liver Transplantation Department of Hainan Digestive Disease Center of The Second Affiliated Hospital of Hainan Medical University, Engineering Research Center of Tropical Medicine of Ministry of Education, The First Affiliated Hospital, Hainan Medical University, Haikou, China.
| | - Yipeng Pan
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Provincial Key Laboratory of R & D on Tropical Herbs, Haikou Key Laboratory of Li Nationality Medicine, School of Pharmacy, Hepatobiliary and Liver Transplantation Department of Hainan Digestive Disease Center of The Second Affiliated Hospital of Hainan Medical University, Engineering Research Center of Tropical Medicine of Ministry of Education, The First Affiliated Hospital, Hainan Medical University, Haikou, China.
| | - Jian Xu
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Provincial Key Laboratory of R & D on Tropical Herbs, Haikou Key Laboratory of Li Nationality Medicine, School of Pharmacy, Hepatobiliary and Liver Transplantation Department of Hainan Digestive Disease Center of The Second Affiliated Hospital of Hainan Medical University, Engineering Research Center of Tropical Medicine of Ministry of Education, The First Affiliated Hospital, Hainan Medical University, Haikou, China.
| | - Junqing Zhang
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Provincial Key Laboratory of R & D on Tropical Herbs, Haikou Key Laboratory of Li Nationality Medicine, School of Pharmacy, Hepatobiliary and Liver Transplantation Department of Hainan Digestive Disease Center of The Second Affiliated Hospital of Hainan Medical University, Engineering Research Center of Tropical Medicine of Ministry of Education, The First Affiliated Hospital, Hainan Medical University, Haikou, China.
| |
Collapse
|
2
|
Grebert C, Becq F, Vandebrouck C. Phospholipase C controls chloride-dependent short-circuit current in human bronchial epithelial cells. Am J Physiol Lung Cell Mol Physiol 2020; 320:L205-L219. [PMID: 33236921 DOI: 10.1152/ajplung.00437.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chloride secretion by airway epithelial cells is primordial for water and ion homeostasis and airways surface prevention of infections. This secretion is impaired in several human diseases, including cystic fibrosis, a genetic pathology due to CFTR gene mutations leading to chloride channel defects. A potential therapeutic approach is aiming at increasing chloride secretion either by correcting the mutated CFTR itself or by stimulating non-CFTR chloride channels at the plasma membrane. Here, we studied the role of phospholipase C in regulating the transepithelial chloride secretion in human airway epithelial 16HBE14o- and CFBE cells over-expressing wild type (WT)- or F508del-CFTR. Western blot analysis shows expression of the three endogenous phospholipase C (PLC) isoforms, namely, PLCδ1, PLCγ1, and PLCβ3 in 16HBE14o- cells. In 16HBE14o- cells, we performed Ussing chamber experiments after silencing each of these PLC isoforms or using the PLC inhibitor U73122 or its inactive analogue U73343. Our results show the involvement of PLCβ3 and PLCγ1 in CFTR-dependent short-circuit current activated by forskolin, but not of PLCδ1. In CFBE-WT CFTR and corrected CFBE-F508del CFTR cells, PLCβ3 silencing also inhibits CFTR-dependent current activated by forskolin and UTP-activated calcium-dependent chloride channels (CaCC). Our study supports the importance of PLC in maintaining CFTR-dependent chloride secretion over time, getting maximal CFTR-dependent current and increasing CaCC activation in bronchial epithelial cells.
Collapse
Affiliation(s)
- Chloé Grebert
- Laboratoire Signalisation et Transports Ioniques Membranaires, Université de Poitiers, Poitiers, France
| | - Frédéric Becq
- Laboratoire Signalisation et Transports Ioniques Membranaires, Université de Poitiers, Poitiers, France
| | - Clarisse Vandebrouck
- Laboratoire Signalisation et Transports Ioniques Membranaires, Université de Poitiers, Poitiers, France
| |
Collapse
|
3
|
Katan M, Cockcroft S. Phospholipase C families: Common themes and versatility in physiology and pathology. Prog Lipid Res 2020; 80:101065. [PMID: 32966869 DOI: 10.1016/j.plipres.2020.101065] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/14/2020] [Accepted: 09/17/2020] [Indexed: 12/20/2022]
Abstract
Phosphoinositide-specific phospholipase Cs (PLCs) are expressed in all mammalian cells and play critical roles in signal transduction. To obtain a comprehensive understanding of these enzymes in physiology and pathology, a detailed structural, biochemical, cell biological and genetic information is required. In this review, we cover all these aspects to summarize current knowledge of the entire superfamily. The families of PLCs have expanded from 13 enzymes to 16 with the identification of the atypical PLCs in the human genome. Recent structural insights highlight the common themes that cover not only the substrate catalysis but also the mechanisms of activation. This involves the release of autoinhibitory interactions that, in the absence of stimulation, maintain classical PLC enzymes in their inactive forms. Studies of individual PLCs provide a rich repertoire of PLC function in different physiologies. Furthermore, the genetic studies discovered numerous mutated and rare variants of PLC enzymes and their link to human disease development, greatly expanding our understanding of their roles in diverse pathologies. Notably, substantial evidence now supports involvement of different PLC isoforms in the development of specific cancer types, immune disorders and neurodegeneration. These advances will stimulate the generation of new drugs that target PLC enzymes, and will therefore open new possibilities for treatment of a number of diseases where current therapies remain ineffective.
Collapse
Affiliation(s)
- Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
| | - Shamshad Cockcroft
- Department of Neuroscience, Physiology and Pharmacology, Division of Biosciences, University College London, 21 University Street, London WC1E 6JJ, UK.
| |
Collapse
|
4
|
Abstract
Phospholipase C (PLC) family members constitute a family of diverse enzymes. Thirteen different family members have been cloned. These family members have unique structures that mediate various functions. Although PLC family members all appear to signal through the bi-products of cleaving phospholipids, it is clear that each family member, and at times each isoform, contributes to unique cellular functions. This chapter provides a review of the current literature on PLC. In addition, references have been provided for more in-depth information regarding areas that are not discussed including tyrosine kinase activation of PLC. Understanding the roles of the individual PLC enzymes, and their distinct cellular functions, will lead to a better understanding of the physiological roles of these enzymes in the development of diseases and the maintenance of homeostasis.
Collapse
|
5
|
Hwang HJ, Jang HJ, Cocco L, Suh PG. The regulation of insulin secretion via phosphoinositide-specific phospholipase Cβ signaling. Adv Biol Regul 2019; 71:10-18. [PMID: 30293894 DOI: 10.1016/j.jbior.2018.09.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 09/17/2018] [Accepted: 09/17/2018] [Indexed: 06/08/2023]
Abstract
Phospholipase Cβ (PLCβ) is a membrane-associated enzyme activated by membrane receptors, especially G-protein coupled receptors (GPCRs). It propagates intracellular signaling by mediating phospholipid metabolism and generating key second messengers, such as inositol triphosphate and diacylglycerol, leading to intracellular Ca2+ mobilization and activation of kinases, such as protein kinases C. In pancreatic β-cells, PLCβ-mediated signaling activated by various factors, such as free fatty acids and neuronal and hormonal ligands, has been confirmed as being involved in the regulation of insulin secretion, and PLCβs have been regarded as essential mediators for augmenting insulin secretion. In this review, we describe the physiological function of PLCβs in the regulation of glucose-stimulated insulin secretion and discuss emerging data on GPCR/PLCβ signaling that is being developed as a target for the treatment of diabetes mellitus.
Collapse
Affiliation(s)
- Hyeon-Jeong Hwang
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Hyun-Jun Jang
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Lucio Cocco
- Cellular Signaling Laboratory, Department of Biomedical Sciences, University of Bologna, Via Irnerio, 48, I-40126, Bologna, Italy
| | - Pann-Ghill Suh
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea.
| |
Collapse
|
6
|
Wang Q, Song R, Zhao C, Liu H, Yang Y, Gu S, Feng D, He J. HPV16 E6 promotes cervical cancer cell migration and invasion by downregulation of NHERF1. Int J Cancer 2018; 144:1619-1632. [PMID: 30230542 DOI: 10.1002/ijc.31876] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 07/29/2018] [Accepted: 09/03/2018] [Indexed: 12/21/2022]
Abstract
HPV16 is the predominant type of HPV causing invasive cervical cancer. However, the underlying molecular mechanism of the unparalleled carcinogenic power of HPV16 compared to other types of high-risk (HR)-HPV including HPV18 remains elusive. The PDZ binding motif (PBM) of high-risk HPV E6 plays an important role in neoplasia and progression of cervical cancer. HPV16 E6 rather than HPV18 E6, interacted with NHERF1 by its PBM region, and induced degradation of NHERF1. NHERF1 retarded the assembly of cytoskeleton by downregulation of ACTN4, thereby inhibited the migration and invasion of cervical cancer cells in both cell and mouse model. HPV16 E6 was confirmed to enhance actin polymerization with increased ACTN4 level by downregulation of NHERF1, and result in enhanced migration and invasion of cervical cancer cells. GSEA analysis of cervical cancer specimens also showed that HPV16 E6 rather than HPV18 E6, was significantly associated with actin cytoskeleton assembly. That downregulation of NHERF1 by HPV16 E6 promoted cytoskeleton assembly and cell invasion, was an important cause in cervical cancer carcinogenesis. These findings provided the differential mechanism between HPV16 E6 and HPV18 E6 in the development and progression of cervical cancer, which may partially explain the differences of carcinogenic power between these two types of HR-HPVs.
Collapse
Affiliation(s)
- Qiqi Wang
- Department of Biochemistry and Molecular Biology, Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University, Beijing, People's Republic of China
| | - Ran Song
- Department of Biochemistry and Molecular Biology, Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University, Beijing, People's Republic of China
| | - Chunjuan Zhao
- Department of Biochemistry and Molecular Biology, Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University, Beijing, People's Republic of China
| | - Hua Liu
- Department of Biochemistry and Molecular Biology, Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University, Beijing, People's Republic of China
| | - Ying Yang
- Core Facilities Center, Capital Medical University, Beijing, People's Republic of China
| | - Siyu Gu
- Department of Biochemistry and Molecular Biology, Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University, Beijing, People's Republic of China
| | - Duiping Feng
- Department of Interventional Radiology, First Hospital of Shanxi Medical University, Taiyuan, People's Republic of China
| | - Junqi He
- Department of Biochemistry and Molecular Biology, Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University, Beijing, People's Republic of China
| |
Collapse
|
7
|
Avula LR, Chen T, Kovbasnjuk O, Donowitz M. Both NHERF3 and NHERF2 are necessary for multiple aspects of acute regulation of NHE3 by elevated Ca 2+, cGMP, and lysophosphatidic acid. Am J Physiol Gastrointest Liver Physiol 2018; 314:G81-G90. [PMID: 28882822 PMCID: PMC5866371 DOI: 10.1152/ajpgi.00140.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The intestinal epithelial brush border Na+/H+ exchanger NHE3 accounts for a large component of intestinal Na absorption. NHE3 is regulated during digestion by signaling complexes on its COOH terminus that include the four multi-PDZ domain-containing NHERF family proteins. All bind to NHE3 and take part in different aspects of NHE3 regulation. Because the roles of each NHERF appear to vary on the basis of the cell model or intestinal segment studied and because of our recent finding that a NHERF3-NHERF2 heterodimer appears important for NHE3 regulation in Caco-2 cells, we examined the role of NHERF3 and NHERF2 in C57BL/6 mouse jejunum using homozygous NHERF2 and NHERF3 knockout mice. NHE3 activity was determined with two-photon microscopy and the dual-emission pH-sensitive dye SNARF-4F. The jejunal apical membrane of NHERF3-null mice appeared similar to wild-type (WT) mice in surface area, microvillus number, and height, which is similar to results previously reported for jejunum of NHERF2-null mice. NHE3 basal activity was not different from WT in either NHERF2- or NHERF3-null jejunum, while d-glucose-stimulated NHE3 activity was reduced in NHERF2, but similar to WT in NHERF3 KO. LPA stimulation and UTP (elevated Ca2+) and cGMP inhibition of NHE3 were markedly reduced in both NHERF2- and NHERF3-null jejunum. Forskolin inhibited NHE3 in NHERF3-null jejunum, but the extent of inhibition was reduced compared with WT. The forskolin inhibition of NHE3 in NHERF2-null mice was too inconsistent to determine whether there was an effect and whether it was altered compared with the WT response. These results demonstrate similar requirement for NHERF2 and NHERF3 in mouse jejunal NHE3 regulation by LPA, Ca2+, and cGMP. The explanation for the similarity is not known but is consistent with involvement of a brush-border NHERF3-NHERF2 heterodimer or sequential NHERF-dependent effects in these aspects of NHE3 regulation. NEW & NOTEWORTHY NHERF2 and NHERF3 are apical membrane multi-PDZ domain-containing proteins that are involved in regulation of intestinal NHE3. This study demonstrates that NHERF2 and NHERF3 have overlapping roles in NHE3 stimulation by LPA and inhibition by elevated Ca2+ and cGMP. These results are consistent with their role being as a NHERF3-NHERF2 heterodimer or via sequential NHERF-dependent signaling steps, and they begin to clarify a role for multiple NHERF proteins in NHE3 regulation.
Collapse
Affiliation(s)
- Leela Rani Avula
- 1Department of Medicine, the Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Tiane Chen
- 1Department of Medicine, the Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Olga Kovbasnjuk
- 1Department of Medicine, the Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Mark Donowitz
- 1Department of Medicine, the Johns Hopkins School of Medicine, Baltimore, Maryland,2Department of Physiology, the Johns Hopkins University School of Medicine, Baltimore, Maryland
| |
Collapse
|
8
|
Huang W, Wang X, Endo-Streeter S, Barrett M, Waybright J, Wohlfeld C, Hajicek N, Harden TK, Sondek J, Zhang Q. A membrane-associated, fluorogenic reporter for mammalian phospholipase C isozymes. J Biol Chem 2017; 293:1728-1735. [PMID: 29263090 DOI: 10.1074/jbc.ra117.000926] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 12/05/2017] [Indexed: 11/06/2022] Open
Abstract
A diverse group of cell-surface receptors, including many G protein-coupled receptors and receptor tyrosine kinases, activate phospholipase C (PLC) isozymes to hydrolyze phosphatidylinositol 4,5-bisphosphate into the second messengers diacylglycerol and 1,4,5-inositol trisphosphate. Consequently, PLCs control various cellular processes, and their aberrant regulation contributes to many diseases, including cancer, atherosclerosis, and rheumatoid arthritis. Despite the widespread importance of PLCs in human biology and disease, it has been impossible to directly monitor the real-time activation of these enzymes at membranes. To overcome this limitation, here we describe XY-69, a fluorogenic reporter that preferentially partitions into membranes and provides a selective tool for measuring the real-time activity of PLCs as either purified enzymes or in cellular lysates. Indeed, XY-69 faithfully reported the membrane-dependent activation of PLC-β3 by Gαq Therefore, XY-69 can replace radioactive phosphatidylinositol 4,5-bisphosphate used in conventional PLC assays and will enable high-throughput screens to identify both orthosteric and allosteric PLC inhibitors. In the future, cell-permeable variants of XY-69 represent promising candidates for reporting the activation of PLCs in live cells with high spatiotemporal resolution.
Collapse
Affiliation(s)
- Weigang Huang
- From the Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy
| | - Xiaoyang Wang
- From the Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy
| | | | | | - Jarod Waybright
- From the Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy
| | - Christian Wohlfeld
- From the Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy
| | | | | | - John Sondek
- Departments of Pharmacology and.,Biochemistry and Biophysics, School of Medicine, and.,the Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Qisheng Zhang
- From the Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, .,Departments of Pharmacology and.,the Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| |
Collapse
|
9
|
Topological organisation of the phosphatidylinositol 4,5-bisphosphate-phospholipase C resynthesis cycle: PITPs bridge the ER-PM gap. Biochem J 2017; 473:4289-4310. [PMID: 27888240 DOI: 10.1042/bcj20160514c] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/08/2016] [Accepted: 09/12/2016] [Indexed: 12/13/2022]
Abstract
Phospholipase C (PLC) is a receptor-regulated enzyme that hydrolyses phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) at the plasma membrane (PM) triggering three biochemical consequences, the generation of soluble inositol 1,4,5-trisphosphate (IP3), membrane-associated diacylglycerol (DG) and the consumption of PM PI(4,5)P2 Each of these three signals triggers multiple molecular processes impacting key cellular properties. The activation of PLC also triggers a sequence of biochemical reactions, collectively referred to as the PI(4,5)P2 cycle that culminates in the resynthesis of this lipid. The biochemical intermediates of this cycle and the enzymes that mediate these reactions are topologically distributed across two membrane compartments, the PM and the endoplasmic reticulum (ER). At the PM, the DG formed during PLC activation is rapidly converted into phosphatidic acid (PA) that needs to be transported to the ER where the machinery for its conversion into PI is localised. Conversely, PI from the ER needs to be rapidly transferred to the PM where it can be phosphorylated by lipid kinases to regenerate PI(4,5)P2 Thus, two lipid transport steps between membrane compartments through the cytosol are required for the replenishment of PI(4,5)P2 at the PM. Here, we review the topological constraints in the PI(4,5)P2 cycle and current understanding how these constraints are overcome during PLC signalling. In particular, we discuss the role of lipid transfer proteins in this process. Recent findings on the biochemical properties of a membrane-associated lipid transfer protein of the PITP family, PITPNM proteins (alternative name RdgBα/Nir proteins) that localise to membrane contact sites are discussed. Studies in both Drosophila and mammalian cells converge to provide a resolution to the conundrum of reciprocal transfer of PA and PI during PLC signalling.
Collapse
|
10
|
Llavero F, Artaso A, Lacerda HM, Parada LA, Zugaza JL. Lck/PLCγ control migration and proliferation of interleukin (IL)-2-stimulated T cells via the Rac1 GTPase/glycogen phosphorylase pathway. Cell Signal 2016; 28:1713-24. [DOI: 10.1016/j.cellsig.2016.07.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 07/29/2016] [Accepted: 07/29/2016] [Indexed: 02/02/2023]
|
11
|
Jansen F, Kalbe B, Scholz P, Fränzel B, Osterloh M, Wolters D, Hatt H, Neuhaus EM, Osterloh S. Biochemical Large-Scale Interaction Analysis of Murine Olfactory Receptors and Associated Signaling Proteins with Post-Synaptic Density 95, Drosophila Discs Large, Zona-Occludens 1 (PDZ) Domains. Mol Cell Proteomics 2015; 14:2072-84. [PMID: 25979994 DOI: 10.1074/mcp.m114.045997] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Indexed: 11/06/2022] Open
Abstract
G protein-coupled receptors (GPCRs) constitute the largest family among mammalian membrane proteins and are capable of initiating numerous essential signaling cascades. Various GPCR-mediated pathways are organized into protein microdomains that can be orchestrated and regulated through scaffolding proteins, such as PSD-95/discs-large/ZO1 (PDZ) domain proteins. However, detailed binding characteristics of PDZ-GPCR interactions remain elusive because these interactions seem to be more complex than previously thought. To address this issue, we analyzed binding modalities using our established model system. This system includes the 13 individual PDZ domains of the multiple PDZ domain protein 1 (MUPP1; the largest PDZ protein), a broad range of murine olfactory receptors (a multifaceted gene cluster within the family of GPCRs), and associated olfactory signaling proteins. These proteins were analyzed in a large-scale peptide microarray approach and continuative interaction studies. As a result, we demonstrate that canonical binding motifs were not overrepresented among the interaction partners of MUPP1. Furthermore, C-terminal phosphorylation and distinct amino acid replacements abolished PDZ binding promiscuity. In addition to the described in vitro experiments, we identified new interaction partners within the murine olfactory epithelium using pull-down-based interactomics and could verify the partners through co-immunoprecipitation. In summary, the present study provides important insight into the complexity of the binding characteristics of PDZ-GPCR interactions based on olfactory signaling proteins, which could identify novel clinical targets for GPCR-associated diseases in the future.
Collapse
Affiliation(s)
- Fabian Jansen
- From the ‡Department of Cell Physiology, Faculty for Biology and Biotechnology
| | - Benjamin Kalbe
- From the ‡Department of Cell Physiology, Faculty for Biology and Biotechnology
| | - Paul Scholz
- From the ‡Department of Cell Physiology, Faculty for Biology and Biotechnology
| | - Benjamin Fränzel
- §Department of Analytical Chemistry, Faculty for Chemistry and Biochemistry, Ruhr-University Bochum, Germany
| | - Markus Osterloh
- From the ‡Department of Cell Physiology, Faculty for Biology and Biotechnology
| | - Dirk Wolters
- §Department of Analytical Chemistry, Faculty for Chemistry and Biochemistry, Ruhr-University Bochum, Germany
| | - Hanns Hatt
- From the ‡Department of Cell Physiology, Faculty for Biology and Biotechnology
| | | | - Sabrina Osterloh
- From the ‡Department of Cell Physiology, Faculty for Biology and Biotechnology,
| |
Collapse
|
12
|
Tan J, Yu CY, Wang ZH, Chen HY, Guan J, Chen YX, Fang JY. Genetic variants in the inositol phosphate metabolism pathway and risk of different types of cancer. Sci Rep 2015; 5:8473. [PMID: 25683757 PMCID: PMC4329558 DOI: 10.1038/srep08473] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 01/21/2015] [Indexed: 12/23/2022] Open
Abstract
Members of the inositol phosphate metabolism pathway regulate cell proliferation, migration and phosphatidylinositol-3-kinase (PI3K)/Akt signaling, and are frequently dysregulated in cancer. Whether germline genetic variants in inositol phosphate metabolism pathway are associated with cancer risk remains to be clarified. We examined the association between inositol phosphate metabolism pathway genes and risk of eight types of cancer using data from genome-wide association studies. Logistic regression models were applied to evaluate SNP-level associations. Gene- and pathway-based associations were tested using the permutation-based adaptive rank-truncated product method. The overall inositol phosphate metabolism pathway was significantly associated with risk of lung cancer (P = 2.00 × 10−4), esophageal squamous cell carcinoma (P = 5.70 × 10−3), gastric cancer (P = 3.03 × 10−2) and renal cell carcinoma (P = 1.26 × 10−2), but not with pancreatic cancer (P = 1.40 × 10−1), breast cancer (P = 3.03 × 10−1), prostate cancer (P = 4.51 × 10−1), and bladder cancer (P = 6.30 × 10−1). Our results provide a link between inherited variation in the overall inositol phosphate metabolism pathway and several individual genes and cancer. Further studies will be needed to validate these positive findings, and to explore its mechanisms.
Collapse
Affiliation(s)
- Juan Tan
- State Key Laboratory of Oncogene and Related Genes, Key Laboratory of Gastroenterology &Hepatology, Ministry of Health, Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Cancer Institute, Shanghai Institution of Digestive Disease, 145 Middle Shandong Rd, Shanghai 200001, China
| | - Chen-Yang Yu
- State Key Laboratory of Oncogene and Related Genes, Key Laboratory of Gastroenterology &Hepatology, Ministry of Health, Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Cancer Institute, Shanghai Institution of Digestive Disease, 145 Middle Shandong Rd, Shanghai 200001, China
| | - Zhen-Hua Wang
- State Key Laboratory of Oncogene and Related Genes, Key Laboratory of Gastroenterology &Hepatology, Ministry of Health, Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Cancer Institute, Shanghai Institution of Digestive Disease, 145 Middle Shandong Rd, Shanghai 200001, China
| | - Hao-Yan Chen
- State Key Laboratory of Oncogene and Related Genes, Key Laboratory of Gastroenterology &Hepatology, Ministry of Health, Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Cancer Institute, Shanghai Institution of Digestive Disease, 145 Middle Shandong Rd, Shanghai 200001, China
| | - Jian Guan
- Department of Otolaryngology, The Affiliated Sixth People's Hospital, Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai 200233, China
| | - Ying-Xuan Chen
- State Key Laboratory of Oncogene and Related Genes, Key Laboratory of Gastroenterology &Hepatology, Ministry of Health, Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Cancer Institute, Shanghai Institution of Digestive Disease, 145 Middle Shandong Rd, Shanghai 200001, China
| | - Jing-Yuan Fang
- State Key Laboratory of Oncogene and Related Genes, Key Laboratory of Gastroenterology &Hepatology, Ministry of Health, Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Cancer Institute, Shanghai Institution of Digestive Disease, 145 Middle Shandong Rd, Shanghai 200001, China
| |
Collapse
|
13
|
Crystallographic analysis of NHERF1–PLCβ3 interaction provides structural basis for CXCR2 signaling in pancreatic cancer. Biochem Biophys Res Commun 2014; 446:638-43. [PMID: 24642259 DOI: 10.1016/j.bbrc.2014.03.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 03/09/2014] [Indexed: 01/25/2023]
|
14
|
Kan W, Adjobo-Hermans M, Burroughs M, Faibis G, Malik S, Tall GG, Smrcka AV. M3 muscarinic receptor interaction with phospholipase C β3 determines its signaling efficiency. J Biol Chem 2014; 289:11206-11218. [PMID: 24596086 DOI: 10.1074/jbc.m113.538546] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Phospholipase Cβ (PLCβ) enzymes are activated by G protein-coupled receptors through receptor-catalyzed guanine nucleotide exchange on Gαβγ heterotrimers containing Gq family G proteins. Here we report evidence for a direct interaction between M3 muscarinic receptor (M3R) and PLCβ3. Both expressed and endogenous M3R interacted with PLCβ in coimmunoprecipitation experiments. Stimulation of M3R with carbachol significantly increased this association. Expression of M3R in CHO cells promoted plasma membrane localization of YFP-PLCβ3. Deletion of the PLCβ3 C terminus or deletion of the PLCβ3 PDZ ligand inhibited coimmunoprecipitation with M3R and M3R-dependent PLCβ3 plasma membrane localization. Purified PLCβ3 bound directly to glutathione S-transferase (GST)-fused M3R intracellular loops 2 and 3 (M3Ri2 and M3Ri3) as well as M3R C terminus (M3R/H8-CT). PLCβ3 binding to M3Ri3 was inhibited when the PDZ ligand was removed. In assays using reconstituted purified components in vitro, M3Ri2, M3Ri3, and M3R/H8-CT potentiated Gαq-dependent but not Gβγ-dependent PLCβ3 activation. Disruption of key residues in M3Ri3N and of the PDZ ligand in PLCβ3 inhibited M3Ri3-mediated potentiation. We propose that the M3 muscarinic receptor maximizes the efficiency of PLCβ3 signaling beyond its canonical role as a guanine nucleotide exchange factor for Gα.
Collapse
Affiliation(s)
- Wei Kan
- Departments of Pharmacology and Physiology and University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Merel Adjobo-Hermans
- Department of Biochemistry, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands
| | - Michael Burroughs
- Departments of Pharmacology and Physiology and University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Guy Faibis
- Departments of Pharmacology and Physiology and University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Sundeep Malik
- Departments of Pharmacology and Physiology and University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Gregory G Tall
- Departments of Pharmacology and Physiology and University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Alan V Smrcka
- Departments of Pharmacology and Physiology and University of Rochester School of Medicine and Dentistry, Rochester, New York 14642; Biochemistry and Biophysics and University of Rochester School of Medicine and Dentistry, Rochester, New York 14642; Aab Institute of Cardiovascular Research, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642 and.
| |
Collapse
|
15
|
García del Caño G, Montaña M, Aretxabala X, González-Burguera I, López de Jesús M, Barrondo S, Sallés J. Nuclear phospholipase C-β1 and diacylglycerol LIPASE-α in brain cortical neurons. Adv Biol Regul 2014; 54:12-23. [PMID: 24076015 DOI: 10.1016/j.jbior.2013.09.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 09/03/2013] [Accepted: 09/03/2013] [Indexed: 06/02/2023]
Abstract
Phosphoinositide (PtdIns) signaling involves the generation of lipid second messengers in response to stimuli in a receptor-mediated manner at the plasma membrane. In neuronal cells of adult brain, the standard model proposes that activation of metabotropic receptors coupled to Phospholipase C-β1 (PLC-β1) is linked to endocannabinoid signaling through the production of diacylglycerol (DAG), which could be systematically metabolized by 1,2-diacylglycerol Lipases (DAGL) to produce an increase of 2-arachidonoyl-glycerol (2-AG), the most abundant endocannabinoid in the brain. However, the existence of a nuclear PtdIns metabolism independent from that occurring elsewhere in the cell is now widely accepted, suggesting that the nucleus constitutes both a functional and a distinct compartment for PtdIns metabolism. In this review, we shall highlight the main achievements in the field of neuronal nuclear inositol lipid metabolism with particular attention to progress made linked to the 2-AG biosynthesis. Our aim has been to identify potential sites of 2-AG synthesis other than the neuronal cytoplasmic compartment by determining the subcellular localization of PLC-β1 and DAGL-α, which is much more abundant than DAGL-β in brain. Our data show that PLC-β1 and DAGL-α are detected in discrete brain regions, with a marked predominance of pyramidal morphologies of positive cortical cells, consistent with their role in the biosynthesis and release of 2-AG by pyramidal neurons to control their synaptic inputs. However, as novelty, we showed here an integrated description of the localization of PLC-β1 and DAGL-α in the neuronal nuclear compartment. We discuss our comparative analysis of the expression patterns of PLC-β1 and DAGL-α, providing some insight into the potential autocrine role of 2-AG production in the neuronal nuclear compartment that probably subserve additional roles to the recognized activation of the CB1 cannabinoid receptor.
Collapse
Affiliation(s)
- Gontzal García del Caño
- Departamento de Neurociencias, Facultad de Farmacia (Vitoria-Gasteiz), Universidad del País Vasco (UPV/EHU), Spain
| | - Mario Montaña
- Departamento de Farmacología, Facultad de Farmacia (Vitoria-Gasteiz), Universidad del País Vasco (UPV/EHU), Spain; CIBERSAM, Spain
| | - Xabier Aretxabala
- Departamento de Neurociencias, Facultad de Farmacia (Vitoria-Gasteiz), Universidad del País Vasco (UPV/EHU), Spain
| | - Imanol González-Burguera
- Departamento de Farmacología, Facultad de Farmacia (Vitoria-Gasteiz), Universidad del País Vasco (UPV/EHU), Spain
| | - Maider López de Jesús
- Departamento de Farmacología, Facultad de Farmacia (Vitoria-Gasteiz), Universidad del País Vasco (UPV/EHU), Spain; CIBERSAM, Spain
| | - Sergio Barrondo
- Departamento de Farmacología, Facultad de Farmacia (Vitoria-Gasteiz), Universidad del País Vasco (UPV/EHU), Spain; CIBERSAM, Spain
| | - Joan Sallés
- Departamento de Farmacología, Facultad de Farmacia (Vitoria-Gasteiz), Universidad del País Vasco (UPV/EHU), Spain; CIBERSAM, Spain.
| |
Collapse
|
16
|
Abstract
Rapid progress has recently been made regarding how phospholipase C (PLC)-β functions downstream of G protein-coupled receptors and how PLC-β functions in the nucleus. PLC-β has also been shown to interplay with tyrosine kinase-based signaling pathways, specifically to inhibit Stat5 activation by recruiting the protein-tyrosine phosphatase SHP-1. In this regard, a new multimolecular signaling platform, named SPS complex, has been identified. The SPS complex has important regulatory roles in tumorigenesis and immune cell activation. Furthermore, a growing body of work suggests that PLC-β also participates in the differentiation and activation of immune cells that control both the innate and adaptive immune systems.
Collapse
Affiliation(s)
- Wenbin Xiao
- Department of Pathology, University Hospital Case Medical Center, Case Western Reserve University, Cleveland, OH 44106, USA.
| | | | | |
Collapse
|
17
|
Lau WW, Chan AS, Poon LS, Zhu J, Wong YH. Gβγ-mediated activation of protein kinase D exhibits subunit specificity and requires Gβγ-responsive phospholipase Cβ isoforms. Cell Commun Signal 2013; 11:22. [PMID: 23561540 PMCID: PMC3637504 DOI: 10.1186/1478-811x-11-22] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 03/22/2013] [Indexed: 11/29/2022] Open
Abstract
Background Protein kinase D (PKD) constitutes a novel family of serine/threonine protein kinases implicated in fundamental biological activities including cell proliferation, survival, migration, and immune responses. Activation of PKD in these cellular activities has been linked to many extracellular signals acting through antigen receptor engagement, receptor tyrosine kinases, as well as G protein-coupled receptors. In the latter case, it is generally believed that the Gα subunits of the Gq family are highly effective in mediating PKD activation, whereas little is known with regard to the ability of Gβγ dimers and other Gα subunits to stimulate PKD. It has been suggested that the interaction between Gβγ and the PH domain of PKD, or the Gβγ-induced PLCβ/PKC activity is critical for the induction of PKD activation. However, the relative contribution of these two apparently independent events to Gβγ-mediated PKD activation has yet to be addressed. Results In this report, we demonstrate that among various members in the four G protein families, only the Gα subunits of the Gq family effectively activate all the three PKD isoforms (PKD1/2/3), while Gα subunits of other G protein families (Gs, Gi, and G12) are ineffective. Though the Gα subunits of Gi family are unable to stimulate PKD, receptors linked to Gi proteins are capable of triggering PKD activation in cell lines endogenously expressing (HeLa cells and Jurkat T-cells) or exogenously transfected with (HEK293 cells) Gβγ-sensitive PLCβ2/3 isoforms. This indicates that the Gi-mediated PKD activation is dependent on the released Gβγ dimers upon stimulation. Further investigation on individual Gβγ combinations (i.e. Gβ1 with Gγ1–13) revealed that, even if they can stimulate the PLCβ activity in a comparable manner, only those Gβ1γ dimers with γ2, γ3, γ4, γ5, γ7, and γ10 can serve as effective activators of PKD. We also demonstrated that Gi-mediated PKD activation is essential for the SDF-1α-induced chemotaxis on Jurkat T-cells. Conclusions Our current report illustrates that Gβγ dimers from the Gi proteins may activate PKD in a PLCβ2/3-dependent manner, and the specific identities of Gγ components within Gβγ dimers may determine this stimulatory action.
Collapse
Affiliation(s)
- Winnie Wi Lau
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
| | | | | | | | | |
Collapse
|
18
|
CXCR2 macromolecular complex in pancreatic cancer: a potential therapeutic target in tumor growth. Transl Oncol 2013; 6:216-25. [PMID: 23544174 DOI: 10.1593/tlo.13133] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 01/28/2013] [Accepted: 01/29/2013] [Indexed: 12/22/2022] Open
Abstract
The signaling mediated by the chemokine receptor CXC chemokine receptor 2 (CXCR2) plays an important role in promoting the progression of many cancers, including pancreatic cancer, one of the most lethal human malignancies. CXCR2 possesses a consensus PSD-95/DlgA/ZO-1 (PDZ) motif at its carboxyl termini, which might interact with potential PDZ scaffold/adaptor proteins. We have previously reported that CXCR2 PDZ motif-mediated protein interaction is an important regulator for neutrophil functions. Here, using a series of biochemical assays, we demonstrate that CXCR2 is physically coupled to its downstream effector phospholipase C-β3 (PLC-β3) that is mediated by PDZ scaffold protein Na(+)/H(+) exchange regulatory factor 1 (NHERF1) into a macromolecular signaling complex both in vitro and in pancreatic cancer cells. We also observe that disrupting the CXCR2 complex, by gene delivery or peptide delivery of exogenous CXCR2 C-tail, significantly inhibits the biologic functions of pancreatic cancer cells (i.e., proliferation and invasion) in a PDZ motif-dependent manner. In addition, using a human pancreatic tumor xenograft model, we show that gene delivery of CXCR2 C-tail sequence (containing the PDZ motif) by adeno-associated virus type 2 viral vector potently suppresses human pancreatic tumor growth in immunodeficient mice. In summary, our results suggest the existence of a physical and functional coupling of CXCR2 and PLC-β3 mediated through NHERF1, forming a macromolecular complex that is critical for efficient and specific CXCR2 signaling in pancreatic cancer progression. Disrupting this CXCR2 complex could represent a novel and effective treatment strategy against pancreatic cancer.
Collapse
|
19
|
Phospholipases of mineralization competent cells and matrix vesicles: roles in physiological and pathological mineralizations. Int J Mol Sci 2013; 14:5036-129. [PMID: 23455471 PMCID: PMC3634480 DOI: 10.3390/ijms14035036] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 01/24/2013] [Accepted: 01/25/2013] [Indexed: 02/08/2023] Open
Abstract
The present review aims to systematically and critically analyze the current knowledge on phospholipases and their role in physiological and pathological mineralization undertaken by mineralization competent cells. Cellular lipid metabolism plays an important role in biological mineralization. The physiological mechanisms of mineralization are likely to take place in tissues other than in bones and teeth under specific pathological conditions. For instance, vascular calcification in arteries of patients with renal failure, diabetes mellitus or atherosclerosis recapitulates the mechanisms of bone formation. Osteoporosis—a bone resorbing disease—and rheumatoid arthritis originating from the inflammation in the synovium are also affected by cellular lipid metabolism. The focus is on the lipid metabolism due to the effects of dietary lipids on bone health. These and other phenomena indicate that phospholipases may participate in bone remodelling as evidenced by their expression in smooth muscle cells, in bone forming osteoblasts, chondrocytes and in bone resorbing osteoclasts. Among various enzymes involved, phospholipases A1 or A2, phospholipase C, phospholipase D, autotaxin and sphingomyelinase are engaged in membrane lipid remodelling during early stages of mineralization and cell maturation in mineralization-competent cells. Numerous experimental evidences suggested that phospholipases exert their action at various stages of mineralization by affecting intracellular signaling and cell differentiation. The lipid metabolites—such as arachidonic acid, lysophospholipids, and sphingosine-1-phosphate are involved in cell signaling and inflammation reactions. Phospholipases are also important members of the cellular machinery engaged in matrix vesicle (MV) biogenesis and exocytosis. They may favour mineral formation inside MVs, may catalyse MV membrane breakdown necessary for the release of mineral deposits into extracellular matrix (ECM), or participate in hydrolysis of ECM. The biological functions of phospholipases are discussed from the perspective of animal and cellular knockout models, as well as disease implications, development of potent inhibitors and therapeutic interventions.
Collapse
|
20
|
Dystrophin/α1-syntrophin scaffold regulated PLC/PKC-dependent store-operated calcium entry in myotubes. Cell Calcium 2012; 52:445-56. [DOI: 10.1016/j.ceca.2012.08.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 07/16/2012] [Accepted: 08/06/2012] [Indexed: 11/17/2022]
|
21
|
Abstract
Phospholipase C (PLC) converts phosphatidylinositol 4,5-bisphosphate (PIP(2)) to inositol 1,4,5-trisphosphate (IP(3)) and diacylglycerol (DAG). DAG and IP(3) each control diverse cellular processes and are also substrates for synthesis of other important signaling molecules. PLC is thus central to many important interlocking regulatory networks. Mammals express six families of PLCs, each with both unique and overlapping controls over expression and subcellular distribution. Each PLC also responds acutely to its own spectrum of activators that includes heterotrimeric G protein subunits, protein tyrosine kinases, small G proteins, Ca(2+), and phospholipids. Mammalian PLCs are autoinhibited by a region in the catalytic TIM barrel domain that is the target of much of their acute regulation. In combination, the PLCs act as a signaling nexus that integrates numerous signaling inputs, critically governs PIP(2) levels, and regulates production of important second messengers to determine cell behavior over the millisecond to hour timescale.
Collapse
Affiliation(s)
- Ganesh Kadamur
- Department of Pharmacology, Molecular Biophysics Graduate Program and Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | | |
Collapse
|
22
|
Kim JK, Kwon O, Kim J, Kim EK, Park HK, Lee JE, Kim KL, Choi JW, Lim S, Seok H, Lee-Kwon W, Choi JH, Kang BH, Kim S, Ryu SH, Suh PG. PDZ domain-containing 1 (PDZK1) protein regulates phospholipase C-β3 (PLC-β3)-specific activation of somatostatin by forming a ternary complex with PLC-β3 and somatostatin receptors. J Biol Chem 2012; 287:21012-24. [PMID: 22528496 DOI: 10.1074/jbc.m111.337865] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phospholipase C-β (PLC-β) is a key molecule in G protein-coupled receptor (GPCR)-mediated signaling. Many studies have shown that the four PLC-β subtypes have different physiological functions despite their similar structures. Because the PLC-β subtypes possess different PDZ-binding motifs, they have the potential to interact with different PDZ proteins. In this study, we identified PDZ domain-containing 1 (PDZK1) as a PDZ protein that specifically interacts with PLC-β3. To elucidate the functional roles of PDZK1, we next screened for potential interacting proteins of PDZK1 and identified the somatostatin receptors (SSTRs) as another protein that interacts with PDZK1. Through these interactions, PDZK1 assembles as a ternary complex with PLC-β3 and SSTRs. Interestingly, the expression of PDZK1 and PLC-β3, but not PLC-β1, markedly potentiated SST-induced PLC activation. However, disruption of the ternary complex inhibited SST-induced PLC activation, which suggests that PDZK1-mediated complex formation is required for the specific activation of PLC-β3 by SST. Consistent with this observation, the knockdown of PDZK1 or PLC-β3, but not that of PLC-β1, significantly inhibited SST-induced intracellular Ca(2+) mobilization, which further attenuated subsequent ERK1/2 phosphorylation. Taken together, our results strongly suggest that the formation of a complex between SSTRs, PDZK1, and PLC-β3 is essential for the specific activation of PLC-β3 and the subsequent physiologic responses by SST.
Collapse
Affiliation(s)
- Jung Kuk Kim
- Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
Phospholipase C (PLC) family members constitute a family of diverse enzymes. Thirteen different family members have been cloned. These family members have unique structures that mediate diverse functions. Although PLC family members all appear to signal through the bi-products of cleaving phospholipids, it is clear that each family member, and at times each isoform, contributes to unique cellular functions. This chapter provides a review of the current literature. In addition, references have been provided for more in depth information regarding areas that are discussed. Ultimately, understanding the roles of the individual PLC enzymes, and their distinct cellular functions, will lead to a better understanding of the development of diseases and the maintenance of homeostasis.
Collapse
|
24
|
Pfreimer M, Vatter P, Langer T, Wieland T, Gierschik P, Moepps B. LARG links histamine-H1-receptor-activated Gq to Rho-GTPase-dependent signaling pathways. Cell Signal 2011; 24:652-63. [PMID: 22100544 DOI: 10.1016/j.cellsig.2011.10.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/25/2011] [Accepted: 10/27/2011] [Indexed: 12/11/2022]
Abstract
Activation of heterotrimeric G proteins, such as G(12/13) and G(q), by cell surface receptors is coupled to the regulation of numerous cellular functions controlled by activated Rho GTPases. Previous studies have implicated the Rho guanine nucleotide exchange factor (RhoGEF) leukemia-associated RhoGEF (LARG) as a regulatory protein receiving stimulatory inputs from activated Gα(12/13) and Gα(q). However, the molecular mechanisms of the Gα(q)-mediated LARG activation are not fully understood and the structural elements of LARG involved in this process have remained unclear. In the present work, the specific coupling of the histamine H1 receptor (HRH1) exogenously expressed in COS-7 cells to G(q), but not to G(12/13), was used to conduct a detailed analysis of receptor- and Gα(q)-mediated LARG activation and to define its structural requirements. The results show that HRH1-mediated activation of the strictly Rho-dependent transcriptional activity of serum response factor requires the PDZ domain of LARG and can be mimicked by activated Gα(q)(Q209L). The functional interaction between activated Gα(q) and LARG requires no more than the catalytic DH-PH tandem of LARG, and is independent of PLCβ activation and distinct from the mechanisms of Gα(q)-mediated p63RhoGEF and PLCβ(3) activation. Activated Gα(q) physically interacts with the relevant portions of LARG in COS-7 cells and histamine causes activation of LARG in native HeLa cells endogenously expressing HRH1, G(q), and LARG. This work is the first positive demonstration of a stimulatory effect of LARG on the ability of a strictly G(q)-coupled receptor to cause activation of a Rho-GTPase-dependent signaling pathway.
Collapse
Affiliation(s)
- Mariana Pfreimer
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | | | | | | | | | | |
Collapse
|
25
|
Mahon MJ. Apical membrane segregation of phosphatidylinositol-4,5-bisphosphate influences parathyroid hormone 1 receptor compartmental signaling and localization via direct regulation of ezrin in LLC-PK1 cells. Cell Signal 2011; 23:1659-68. [PMID: 21672629 PMCID: PMC3148343 DOI: 10.1016/j.cellsig.2011.05.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 05/23/2011] [Indexed: 01/30/2023]
Abstract
The parathyroid hormone 1 receptor (PTH1R), a primary regulator of mineral ion homeostasis, is expressed on both the apical and basolateral membranes of kidney proximal tubules and in the LLC-PK1 kidney cell line. In LLC-PK1 cells, apical PTH1R subpopulations are far more effective at signaling via phospholipase (PLC) than basolateral counterparts, revealing the presence of compartmental signaling. Apical PTH1R localization is dependent upon direct interactions with ezrin, an actin-membrane cross-linking scaffold protein. Ezrin undergoes an activation process that is dependent upon phosphorylation and binding to phosphatidylinositol-4,5-bisphosphate (PIP2), a lipid that is selectively concentrated to apical surfaces of polarized epithelia. Consistently, the intracellular probe for PIP2, GFP-PLCδ1-PH, localizes to the apical membranes of LLC-PK1 cells, directly overlapping ezrin and PTH1R expression. Activation of the apical PTH1R shifts the GFP-PLCδ1-PH probe from the apical membrane to the cytosol and basolateral membranes, reflecting domain-specific activation of PLC and hydrolysis of PIP2. This compartmental signaling is likely due to the polarized localization of PIP2, the substrate for PLC. PIP2 degradation using a membrane-directed phosphatase shifts ezrin localization to the cytosol and induces ezrin de-phosphorylation, processes consistent with inactivation. PIP2 degradation also shifts PTH1R expression from brush border microvilli to basolateral membranes and markedly blunts PTH-elicited activation of the MAPK pathway. Transient expression of ezrin in HEK293 cells shifts PTH1R expression from the plasma membrane to microvilli-like surface projections that also contain PIP2. As a result, ezrin enhances PTH mediated activation of the PLC pathway in this cell model with increasing total receptor surface expression. Collectively, these findings demonstrate that the apical segregation of PIP2 to the apical domains not only promotes the activation of ezrin and the subsequent formation of the PTH1R containing scaffold, but also ensures the presence of ample substrate for propagating the PLC pathway.
Collapse
Affiliation(s)
- Matthew J Mahon
- Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114, United States.
| |
Collapse
|