1
|
Scarlata S. Unraveling Hidden Cell Signaling Pathways Using Biophysical Methods: Application to the Gαq/Phospholipase Cβ Signaling System. J Phys Chem B 2024; 128:2057-2064. [PMID: 38388346 DOI: 10.1021/acs.jpcb.4c00343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
The success of pharmaceutical therapies relies on how well cells respond to a particular drug, but accurately predicting responses can be difficult due to the complex and numerous potential molecular interactions that are possible in cells, and the responses of individuals can be variable due to cryptic and unexpected interactions. With the advancement of proteomics and fluorescence imaging methods, it is now possible to elucidate novel secondary signaling pathways and predict unexpected responses that might otherwise be missed, allowing for the development of better therapeutics. The Gαq/PLCβ signaling pathway is activated by agents that mediate allergic responses, neurotransmission, and heart rate, as well as other functions that are critical for survival. This Review describes the factors that must be considered in delineating signaling pathways and describes the novel translational role that we have uncovered for this signaling pathway.
Collapse
Affiliation(s)
- Suzanne Scarlata
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, Massachusetts 01609, United States
| |
Collapse
|
2
|
Rennie M, Lin G, Scarlata S. Multiple functions of phospholipase Cβ1 at a glance. J Cell Sci 2022; 135:276667. [PMID: 36125065 DOI: 10.1242/jcs.260282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phospholipase Cβ (PLCβ) is the main effector of the Gq family of heterotrimeric G proteins that transduces signals from hormones and neurotransmitters into Ca2+ signals. While PLCβ is critical for Ca2+ responses, recent studies have suggested that PLCβ has additional roles independent of its lipase activity. These novel functions are carried out by a cytosolic population of PLCβ that binds and inhibits the component 3 promoter of RNA-induced silencing complex (C3PO) to impact cytosolic RNA populations. Additionally, cytosolic PLCβ binds to stress granule proteins, keeping them dispersed and thus inhibiting stress granule formation. Upon activation of the Gα subunit of Gq (Gαq), cytosolic PLCβ relocalizes to the membrane, releasing C3PO and stress granule proteins, which in turn promotes activation of C3PO and RNA processing, as well as sequestration of specific transcripts into newly formed stress granules. As highlighted in this Cell Science at a Glance and the accompanying poster, the link between Gαq signaling, increased intracellular Ca2+ and changes in RNA processing impacts neuronal cell differentiation and may also affect neuronal development and dysfunction.
Collapse
Affiliation(s)
- Madison Rennie
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA
| | - Guanyu Lin
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA
| | - Suzanne Scarlata
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA
| |
Collapse
|
3
|
Activation of Gαq sequesters specific transcripts into Ago2 particles. Sci Rep 2022; 12:8758. [PMID: 35610292 PMCID: PMC9130320 DOI: 10.1038/s41598-022-12737-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 05/10/2022] [Indexed: 12/13/2022] Open
Abstract
The Gαq/phospholipase Cβ1 (PLCβ1) signaling system mediates calcium responses from hormones and neurotransmitters. While PLCβ1 functions on the plasma membrane, there is an atypical cytosolic population that binds Argonaute 2 (Ago2) and other proteins associated with stress granules preventing their aggregation. Activation of Gαq relocalizes cytosolic PLCβ1 to the membrane, releasing bound proteins, promoting the formation of stress granules. Here, we have characterized Ago2 stress granules associated with Gαq activation in differentiated PC12 cells, which have a robust Gαq/PLCβ1 signaling system. Characterization of Ago2-associated stress granules shows shifts in protein composition when cells are stimulated with a Gαq agonist, or subjected to heat shock or osmotic stress, consistent with the idea that different stresses result in unique stress granules. Purified Ago2 stress granules from control cells do not contain RNA, while those from heat shock contain many different mRNAs and miRs. Surprisingly, Ago2 particles from cells where Gαq was stimulated show only two transcripts, chromogranin B, which is involved in secretory function, and ATP synthase 5f1b, which is required for ATP synthesis. RT-PCR, western blotting and other studies support the idea that Gαq-activation protects these transcripts. Taken together, these studies show a novel pathway where Gαq/PLCβ regulates the translation of specific proteins.
Collapse
|
4
|
Qifti A, Balaji S, Scarlata S. Deformation of caveolae impacts global transcription and translation processes through relocalization of cavin-1. J Biol Chem 2022; 298:102005. [PMID: 35513070 PMCID: PMC9168624 DOI: 10.1016/j.jbc.2022.102005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 04/16/2022] [Accepted: 04/19/2022] [Indexed: 11/17/2022] Open
Abstract
Caveolae are invaginated membrane domains that provide mechanical strength to cells in addition to being focal points for the localization of signaling molecules. Caveolae are formed through the aggregation of caveolin-1 or -3 (Cav1/3), membrane proteins that assemble into multifunctional complexes with the help of caveola-associated protein cavin-1. In addition to its role in the formation of caveolae, cavin-1, also called polymerase I and transcript release factor, is further known to promote ribosomal RNA transcription in the nucleus. However, the mechanistic link between these functions is not clear. Here, we found that deforming caveolae by subjecting cells to mild osmotic stress (150–300 mOsm) changes levels of GAPDH, Hsp90, and Ras only when Cav1/cavin-1 levels are reduced, suggesting a link between caveola deformation and global protein expression. We show that this link may be due to relocalization of cavin-1 to the nucleus upon caveola deformation. Cavin-1 relocalization is also seen when Cav1-Gαq contacts change upon stimulation. Furthermore, Cav1 and cavin-1 levels have been shown to have profound effects on cytosolic RNA levels, which in turn impact the ability of cells to form stress granules and RNA-processing bodies (p-bodies) which sequester and degrade mRNAs, respectively. Our studies here using a cavin-1-knockout cell line indicate adaptive changes in cytosolic RNA levels but a reduced ability to form stress granules. Taken together, our findings suggest that caveolae, through release of cavin-1, communicate extracellular cues to the cell interior to impact transcriptional and translational.
Collapse
|
5
|
Lei L, Cheng A, Wang M, Jia R. The Influence of Host miRNA Binding to RNA Within RNA Viruses on Virus Multiplication. Front Cell Infect Microbiol 2022; 12:802149. [PMID: 35531344 PMCID: PMC9069554 DOI: 10.3389/fcimb.2022.802149] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 03/14/2022] [Indexed: 11/13/2022] Open
Abstract
microRNAs (miRNAs), non-coding RNAs about 22 nt long, regulate the post-transcription expression of genes to influence many cellular processes. The expression of host miRNAs is affected by virus invasion, which also affects virus replication. Increasing evidence has demonstrated that miRNA influences RNA virus multiplication by binding directly to the RNA virus genome. Here, the knowledge relating to miRNAs’ relationships between host miRNAs and RNA viruses are discussed.
Collapse
Affiliation(s)
- Lin Lei
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Anchun Cheng
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Mingshu Wang
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Renyong Jia
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- *Correspondence: Renyong Jia,
| |
Collapse
|
6
|
Qifti A, Jackson L, Singla A, Garwain O, Scarlata S. Stimulation of phospholipase Cβ1 by Gα q promotes the assembly of stress granule proteins. Sci Signal 2021; 14:eaav1012. [PMID: 34665639 DOI: 10.1126/scisignal.aav1012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
[Figure: see text].
Collapse
Affiliation(s)
- Androniqi Qifti
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Lela Jackson
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Ashima Singla
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Osama Garwain
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Suzanne Scarlata
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| |
Collapse
|
7
|
Jackson L, Qifti A, Pearce KM, Scarlata S. Regulation of bifunctional proteins in cells: Lessons from the phospholipase Cβ/G protein pathway. Protein Sci 2019; 29:1258-1268. [PMID: 31867822 DOI: 10.1002/pro.3809] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 12/17/2019] [Accepted: 12/18/2019] [Indexed: 12/14/2022]
Abstract
Some proteins can serve multiple functions depending on different cellular conditions. An example of a bifunctional protein is inositide-specific mammalian phospholipase Cβ (PLCβ). PLCβ is activated by G proteins in response to hormones and neurotransmitters to increase intracellular calcium. Recently, alternate cellular function(s) of PLCβ have become uncovered. However, the conditions that allow these different functions to be operative are unclear. Like many mammalian proteins, PLCβ has a conserved catalytic core along with several regulatory domains. These domains modulate the intensity and duration of calcium signals in response to external sensory information, and allow this enzyme to inhibit protein translation in a noncatalytic manner. In this review, we first describe PLCβ's cellular functions and regulation of the switching between these functions, and then discuss the thermodynamic considerations that offer insight into how cells manage multiple and competitive associations allowing them to rapidly shift between functional states.
Collapse
Affiliation(s)
- Lela Jackson
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts
| | - Androniqi Qifti
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts
| | - Katherine M Pearce
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts
| | - Suzanne Scarlata
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts
| |
Collapse
|
8
|
Tabujew I, Heidari M, Freidel C, Helm M, Tebbe L, Wolfrum U, Nagel-Wolfrum K, Koynov K, Biehl P, Schacher FH, Potestio R, Peneva K. Tackling the Limitations of Copolymeric Small Interfering RNA Delivery Agents by a Combined Experimental–Computational Approach. Biomacromolecules 2019; 20:4389-4406. [DOI: 10.1021/acs.biomac.9b01061] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ilja Tabujew
- Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University Jena, Lessingstraße 8, 07743 Jena, Germany
| | - Maziar Heidari
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Christoph Freidel
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Mark Helm
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz, Staudingerweg 5, 55128 Mainz, Germany
| | - Lars Tebbe
- Institute of Zoology, Johannes Gutenberg University Mainz, Muellerweg 6, 55099 Mainz, Germany
| | - Uwe Wolfrum
- Institute of Zoology, Johannes Gutenberg University Mainz, Muellerweg 6, 55099 Mainz, Germany
| | - Kerstin Nagel-Wolfrum
- Institute of Zoology, Johannes Gutenberg University Mainz, Muellerweg 6, 55099 Mainz, Germany
| | - Kaloian Koynov
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Philip Biehl
- Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University Jena, Lessingstraße 8, 07743 Jena, Germany
| | - Felix H. Schacher
- Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University Jena, Lessingstraße 8, 07743 Jena, Germany
| | - Raffaello Potestio
- Physics Department, University of Trento, Via Sommarive 14, I-38123 Trento, Italy
- INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, Via Sommarive 14, I-38123 Trento, Italy
| | - Kalina Peneva
- Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University Jena, Lessingstraße 8, 07743 Jena, Germany
| |
Collapse
|
9
|
Scarlata S. The role of phospholipase Cβ on the plasma membrane and in the cytosol: How modular domains enable novel functions. Adv Biol Regul 2019; 73:100636. [PMID: 31409535 DOI: 10.1016/j.jbior.2019.100636] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 07/14/2019] [Accepted: 07/25/2019] [Indexed: 01/14/2023]
Abstract
Phospholipase Cβ (PLCβ) is a signaling enzyme activated by G proteins to generate calcium signals. The catalytic core of PLCβ is surrounded by modular domains that mediate the interaction of the enzyme with known protein partners on the plasma membrane. The C-terminal region PLCβ contains a novel coiled-coil domain that is required for Gαq binding and activation. Recent work has shown that this domain also binds a number of cytosolic proteins that regulate protein translation, and that these proteins compete with Gαq for PLCβ binding. The ability of PLCβ to shuttle between the cytosol to impact protein translation and the plasma membrane to mediate calcium signals puts PLCβ in a central role in cell function.
Collapse
Affiliation(s)
- Suzanne Scarlata
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Rd., Worcester, MA, 01609, United States.
| |
Collapse
|
10
|
Hudson BN, Hyun SH, Thompson DH, Lyon AM. Phospholipase Cβ3 Membrane Adsorption and Activation Are Regulated by Its C-Terminal Domains and Phosphatidylinositol 4,5-Bisphosphate. Biochemistry 2017; 56:5604-5614. [PMID: 28945350 DOI: 10.1021/acs.biochem.7b00547] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Phospholipase Cβ (PLCβ) enzymes hydrolyze phosphatidylinositol 4,5-bisphosphate to produce second messengers that regulate intracellular Ca2+, cell proliferation, and survival. Their activity is dependent upon interfacial activation that occurs upon localization to cell membranes. However, the molecular basis for how these enzymes productively interact with the membrane is poorly understood. Herein, atomic force microscopy demonstrates that the ∼300-residue C-terminal domain promotes adsorption to monolayers and is required for spatial organization of the protein on the monolayer surface. PLCβ variants lacking this C-terminal domain display differences in their distribution on the surface. In addition, a previously identified autoinhibitory helix that binds to the PLCβ catalytic core negatively impacts membrane binding, providing an additional level of regulation for membrane adsorption. Lastly, defects in phosphatidylinositol 4,5-bisphosphate hydrolysis also alter monolayer adsorption, reflecting a role for the active site in this process. Together, these findings support a model in which multiple elements of PLCβ modulate adsorption, distribution, and catalysis at the cell membrane.
Collapse
Affiliation(s)
- Brianna N Hudson
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| | - Seok-Hee Hyun
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| | - David H Thompson
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| | - Angeline M Lyon
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| |
Collapse
|
11
|
Baraban JM, Shah A, Fu X. Multiple Pathways Mediate MicroRNA Degradation: Focus on the Translin/Trax RNase Complex. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 82:1-20. [PMID: 29413516 DOI: 10.1016/bs.apha.2017.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The discovery of the microRNA system has revolutionized our understanding of translational control. Furthermore, growing appreciation of the pivotal role that de novo translation plays in activity-dependent synaptic plasticity has fueled interest among neuroscientists in deciphering how the microRNA system impacts neuronal signaling and the pathophysiology of neuropsychiatric disorders. Although we have a general understanding of how the microRNA system operates, many key questions remain. In particular, the biosynthesis of microRNAs and their role in translational silencing are fairly well understood. However, much less is known about how microRNAs are degraded and silencing is reversed, crucial aspects of microRNA signaling. In contrast to microRNA synthesis which is mediated almost exclusively by a single pathway that culminates in Dicer, recent studies indicate that there are multiple pathways of microRNA degradation that target different subpopulations of microRNAs. While the Lin-28 pathway of microRNA degradation has been investigated extensively, the translin/trax RNase complex has emerged recently as another pathway mediating microRNA degradation. Accordingly, we summarize herein key features of the translin/trax RNase complex as well as important gaps in our understanding of its regulation and function that are the focus of ongoing studies.
Collapse
Affiliation(s)
- Jay M Baraban
- Johns Hopkins School of Medicine, Baltimore, MD, United States.
| | - Aparna Shah
- Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Xiuping Fu
- Johns Hopkins School of Medicine, Baltimore, MD, United States
| |
Collapse
|
12
|
Sahu S, Williams L, Perez A, Philip F, Caso G, Zurawsky W, Scarlata S. Regulation of the activity of the promoter of RNA-induced silencing, C3PO. Protein Sci 2017; 26:1807-1818. [PMID: 28714243 DOI: 10.1002/pro.3219] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 06/20/2017] [Accepted: 06/21/2017] [Indexed: 12/29/2022]
Abstract
RNA-induced silencing is a process which allows cells to regulate the synthesis of specific proteins. RNA silencing is promoted by the protein C3PO (component 3 of RISC). We have previously found that phospholipase Cβ, which increases intracellular calcium levels in response to specific G protein signals, inhibits C3PO activity towards certain genes. Understanding the parameters that control C3PO activity and which genes are impacted by G protein activation would help predict which genes are more vulnerable to downregulation. Here, using a library of 1018 oligonucleotides, we show that C3PO binds oligonucleotides with structural specificity but little sequence specificity. Alternately, C3PO hydrolyzes oligonucleotides with a rate that is sensitive to substrate stability. Importantly, we find that oligonucleotides with higher Tm values are inhibited by bound PLCβ. This finding is supported by microarray analysis in cells over-expressing PLCβ1. Taken together, this study allows predictions of the genes whose post-transcriptional regulation is responsive to the G protein/phospholipase Cβ/calcium signaling pathway.
Collapse
Affiliation(s)
- Shriya Sahu
- Department of Physiology & Biophysics, Stony Brook University, Stony Brook, New York
| | - Leo Williams
- Department of Physiology & Biophysics, Stony Brook University, Stony Brook, New York
| | - Alberto Perez
- Laufer Center for Computational Biology, Stony Brook University, Stony Brook, New York
| | - Finly Philip
- Department of Physiology & Biophysics, Stony Brook University, Stony Brook, New York
| | - Giuseppe Caso
- Department of Physiology & Biophysics, Stony Brook University, Stony Brook, New York
| | - Walter Zurawsky
- Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts, 01609
| | - Suzanne Scarlata
- Department of Physiology & Biophysics, Stony Brook University, Stony Brook, New York.,Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, 01609
| |
Collapse
|
13
|
Garwain O, Scarlata S. Phospholipase Cβ-TRAX Association Is Required for PC12 Cell Differentiation. J Biol Chem 2016; 291:22970-22976. [PMID: 27624933 DOI: 10.1074/jbc.m116.744953] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Indexed: 11/06/2022] Open
Abstract
When treated with nerve growth factor, PC12 cells will differentiate over the course of several days. Here, we have followed changes during differentiation in the cellular levels of phosphoinositide-specific phospholipase Cβ (PLCβ) and its activator, Gαq, which together mediate Ca2+ release. We also followed changes in the level of the novel PLCβ binding partner TRAX (translin-associated factor X), which promotes RNA-induced gene silencing. We find that the level of PLCβ increases 4-fold within 24 h, whereas Gαq increases only 1.4-fold, and this increase occurs ∼24 h later than PLCβ. Alternately, the level of TRAX remains constant over the 72 h tested. When PLCβ1 or TRAX is down-regulated, differentiation does not occur. The impact of PLCβ on differentiation appears independent of Gαq as down-regulating Gαq at constant PLCβ does not affect differentiation. Förster resonance energy transfer studies after PLCβ association with its partners indicate that PLCβ induced soon after nerve growth factor treatment associates with TRAX rather than Gαq Functional measurements of Ca2+ signals to assess the activity of PLCβ-Gαq complexes and measurements of the reversal of siRNA(GAPDH) to assess the activity of PLCβ-TRAX complexes additionally suggest that the newly synthesized PLCβ associates with TRAX to impact RNA-induced silencing. Taken together, our studies show that PLCβ, through its ability to bind TRAX and reverse RNA silencing of specific genes, plays a key role in switching PC12 cells to their differentiated state.
Collapse
Affiliation(s)
- Osama Garwain
- From the Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609
| | - Suzanne Scarlata
- From the Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609
| |
Collapse
|
14
|
Zheng Y, Tian S, Peng X, Yang J, Fu Y, Jiao Y, Zhao J, He J, Hong T. Kinesin-1 inhibits the aggregation of amyloid-β peptide as detected by fluorescence cross-correlation spectroscopy. FEBS Lett 2016; 590:1028-37. [DOI: 10.1002/1873-3468.12137] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 02/04/2016] [Accepted: 03/11/2016] [Indexed: 12/21/2022]
Affiliation(s)
- Yanpeng Zheng
- College of Life Sciences and Bioengineering; Beijing Jiaotong University; China
| | - Shijun Tian
- College of Life Sciences and Bioengineering; Beijing Jiaotong University; China
| | - Xianglei Peng
- College of Life Sciences and Bioengineering; Beijing Jiaotong University; China
| | - Jingfa Yang
- Beijing National Laboratory for Molecular Science; Institute of Chemistry; Chinese Academy of Sciences; Beijing China
| | - Yuanhui Fu
- College of Life Sciences and Bioengineering; Beijing Jiaotong University; China
| | - Yueying Jiao
- College of Life Sciences and Bioengineering; Beijing Jiaotong University; China
| | - Jiang Zhao
- Beijing National Laboratory for Molecular Science; Institute of Chemistry; Chinese Academy of Sciences; Beijing China
| | - Jinsheng He
- College of Life Sciences and Bioengineering; Beijing Jiaotong University; China
| | - Tao Hong
- College of Life Sciences and Bioengineering; Beijing Jiaotong University; China
- Institute for Viral Disease Control and Prevention; Chinese Centre for Disease Control and Prevention; Beijing China
| |
Collapse
|
15
|
Philip F, Sahu S, Golebiewska U, Scarlata S. RNA-induced silencing attenuates G protein-mediated calcium signals. FASEB J 2016; 30:1958-67. [PMID: 26862135 DOI: 10.1096/fj.201500140] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 01/25/2016] [Indexed: 11/11/2022]
Abstract
Phospholipase Cβ (PLCβ) is activated by G protein subunits in response to environmental stimuli to increase intracellular calcium. In cells, a significant portion of PLCβ is cytosolic, where it binds a protein complex required for efficient RNA-induced silencing called C3PO (component 3 promoter of RISC). Binding between C3PO and PLCβ raises the possibility that RNA silencing activity can affect the ability of PLCβ to mediate calcium signals. By use of human and rat neuronal cell lines (SK-N-SH and PC12), we show that overexpression of one of the main components of C3PO diminishes Ca(2+) release in response to Gαq/PLCβ stimulation by 30 to 40%. In untransfected SK-N-SH or PC12 cells, the introduction of siRNA(GAPDH) [small interfering RNA(glyceraldehyde 3-phosphate dehydrogenase)] reduces PLCβ-mediated calcium signals by ∼30%, but addition of siRNA(Hsp90) (heat shock protein 90) had little effect. Fluorescence imaging studies suggest an increase in PLCβ-C3PO association in cells treated with siRNA(GAPDH) but not siRNA(Hsp90). Taken together, our studies raise the possibility that Ca(2+) responses to extracellular stimuli can be modulated by components of the RNA silencing machinery.-Philip, F., Sahu, S., Golebiewska, U., Scarlata, S. RNA-induced silencing attenuates G protein-mediated calcium signals.
Collapse
Affiliation(s)
- Finly Philip
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York, USA
| | - Shriya Sahu
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York, USA
| | - Urszula Golebiewska
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York, USA; Department of Biological Sciences, Queensborough Community College, Bayside, New York, USA; and
| | - Suzanne Scarlata
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York, USA; Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| |
Collapse
|
16
|
Phospholipase Cβ connects G protein signaling with RNA interference. Adv Biol Regul 2015; 61:51-7. [PMID: 26746047 DOI: 10.1016/j.jbior.2015.11.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 11/19/2015] [Accepted: 11/20/2015] [Indexed: 11/24/2022]
Abstract
Phosphoinositide-specific-phospholipase Cβ (PLCβ) is the main effector of Gαq stimulation which is coupled to receptors that bind acetylcholine, bradykinin, dopamine, angiotensin II as well as other hormones and neurotransmitters. Using a yeast two-hybrid and other approaches, we have recently found that the same region of PLCβ that binds Gαq also interacts with Component 3 Promoter of RNA induced silencing complex (C3PO), which is required for efficient activity of the RNA-induced silencing complex. In purified form, C3PO competes with Gαq for PLCβ binding and at high concentrations can quench PLCβ activation. Additionally, we have found that the binding of PLCβ to C3PO inhibits its nuclease activity leading to reversal of RNA-induced silencing of specific genes. In cells, we found that PLCβ distributes between the plasma membrane where it localizes with Gαq, and in the cytosol where it localizes with C3PO. When cells are actively processing small interfering RNAs the interaction between PLCβ and C3PO gets stronger and leads to changes in the cellular distribution of PLCβ. The magnitude of attenuation is specific for different silencing RNAs. Our studies imply a direct link between calcium responses mediated through Gαq and post-transcriptional gene regulation through PLCβ.
Collapse
|