1
|
Ansari SS, Dillard ME, Zhang Y, Austria MA, Boatwright N, Shelton EL, Stewart DP, Johnson A, Wang CE, Young BM, Rankovic Z, Hansen BS, Pruett-Miller SM, Carisey AF, Schuetz JD, Robinson CG, Ogden SK. Sonic Hedgehog activates prostaglandin signaling to stabilize primary cilium length. J Cell Biol 2024; 223:e202306002. [PMID: 38856684 PMCID: PMC11166601 DOI: 10.1083/jcb.202306002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 04/03/2024] [Accepted: 05/24/2024] [Indexed: 06/11/2024] Open
Abstract
Sonic Hedgehog (SHH) is a driver of embryonic patterning that, when corrupted, triggers developmental disorders and cancers. SHH effector responses are organized through primary cilia (PC) that grow and retract with the cell cycle and in response to extracellular cues. Disruption of PC homeostasis corrupts SHH regulation, placing significant pressure on the pathway to maintain ciliary fitness. Mechanisms by which ciliary robustness is ensured in SHH-stimulated cells are not yet known. Herein, we reveal a crosstalk circuit induced by SHH activation of Phospholipase A2α that drives ciliary E-type prostanoid receptor 4 (EP4) signaling to ensure PC function and stabilize ciliary length. We demonstrate that blockade of SHH-EP4 crosstalk destabilizes PC cyclic AMP (cAMP) equilibrium, slows ciliary transport, reduces ciliary length, and attenuates SHH pathway induction. Accordingly, Ep4-/- mice display shortened neuroepithelial PC and altered SHH-dependent neuronal cell fate specification. Thus, SHH initiates coordination between distinct ciliary receptors to maintain PC function and length homeostasis for robust downstream signaling.
Collapse
Affiliation(s)
- Shariq S. Ansari
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Miriam E. Dillard
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Yan Zhang
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Mary Ashley Austria
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
- Rhodes College Summer Plus Program, Memphis, TN, USA
| | - Naoko Boatwright
- Department of Pediatrics, Monroe Carell Jr. Children’s Hospital at Vanderbilt and Vanderbilt University Medical Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Elaine L. Shelton
- Department of Pediatrics, Monroe Carell Jr. Children’s Hospital at Vanderbilt and Vanderbilt University Medical Center, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Daniel P. Stewart
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Amanda Johnson
- Cell and Tissue Imaging Center, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Christina E. Wang
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
- Graduate School of Biomedical Sciences, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Brandon M. Young
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Zoran Rankovic
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Baranda S. Hansen
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
- Center for Advanced Genome Engineering, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Shondra M. Pruett-Miller
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
- Center for Advanced Genome Engineering, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Alexandre F. Carisey
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - John D. Schuetz
- Department of Pharmaceutical Sciences, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Camenzind G. Robinson
- Cell and Tissue Imaging Center, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Stacey K. Ogden
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| |
Collapse
|
2
|
Walker MF, Zhang J, Steiner W, Ku PI, Zhu JF, Michaelson Z, Yen YC, Lee A, Long AB, Casey MJ, Poddar A, Nelson IB, Arveseth CD, Nagel F, Clough R, LaPotin S, Kwan KM, Schulz S, Stewart RA, Tesmer JJG, Caspary T, Subramanian R, Ge X, Myers BR. GRK2 kinases in the primary cilium initiate SMOOTHENED-PKA signaling in the Hedgehog cascade. PLoS Biol 2024; 22:e3002685. [PMID: 39138140 PMCID: PMC11322411 DOI: 10.1371/journal.pbio.3002685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 05/21/2024] [Indexed: 08/15/2024] Open
Abstract
During Hedgehog (Hh) signal transduction in development and disease, the atypical G protein-coupled receptor (GPCR) SMOOTHENED (SMO) communicates with GLI transcription factors by binding the protein kinase A catalytic subunit (PKA-C) and physically blocking its enzymatic activity. Here, we show that GPCR kinase 2 (GRK2) orchestrates this process during endogenous mouse and zebrafish Hh pathway activation in the primary cilium. Upon SMO activation, GRK2 rapidly relocalizes from the ciliary base to the shaft, triggering SMO phosphorylation and PKA-C interaction. Reconstitution studies reveal that GRK2 phosphorylation enables active SMO to bind PKA-C directly. Lastly, the SMO-GRK2-PKA pathway underlies Hh signal transduction in a range of cellular and in vivo models. Thus, GRK2 phosphorylation of ciliary SMO and the ensuing PKA-C binding and inactivation are critical initiating events for the intracellular steps in Hh signaling. More broadly, our study suggests an expanded role for GRKs in enabling direct GPCR interactions with diverse intracellular effectors.
Collapse
Affiliation(s)
- Madison F. Walker
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Jingyi Zhang
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California, United States of America
| | - William Steiner
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Pei-I Ku
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA; Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ju-Fen Zhu
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Zachary Michaelson
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Yu-Chen Yen
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Annabel Lee
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Alyssa B. Long
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Mattie J. Casey
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Abhishek Poddar
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA; Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Isaac B. Nelson
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Corvin D. Arveseth
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | | | - Ryan Clough
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Sarah LaPotin
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Kristen M. Kwan
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Stefan Schulz
- 7TM Antibodies GmbH, Jena, Germany
- Institute of Pharmacology and Toxicology, University Hospital Jena, Jena, Germany
| | - Rodney A. Stewart
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - John J. G. Tesmer
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Radhika Subramanian
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA; Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Xuecai Ge
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, California, United States of America
| | - Benjamin R. Myers
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| |
Collapse
|
3
|
Walker MF, Zhang J, Steiner W, Ku PI, Zhu JF, Michaelson Z, Yen YC, Lee A, Long AB, Casey MJ, Poddar A, Nelson IB, Arveseth CD, Nagel F, Clough R, LaPotin S, Kwan KM, Schulz S, Stewart RA, Tesmer JJG, Caspary T, Subramanian R, Ge X, Myers BR. GRK2 Kinases in the Primary Cilium Initiate SMOOTHENED-PKA Signaling in the Hedgehog Cascade. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.10.540226. [PMID: 37214942 PMCID: PMC10197709 DOI: 10.1101/2023.05.10.540226] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
During Hedgehog (Hh) signal transduction in development and disease, the atypical G protein-coupled receptor (GPCR) SMOOTHENED (SMO) communicates with GLI transcription factors by binding the protein kinase A catalytic subunit (PKA-C) and physically blocking its enzymatic activity. Here we show that GPCR kinase 2 (GRK2) orchestrates this process during endogenous Hh pathway activation in the vertebrate primary cilium. Upon SMO activation, GRK2 rapidly relocalizes from the ciliary base to the shaft, triggering SMO phosphorylation and PKA-C interaction. Reconstitution studies reveal that GRK2 phosphorylation enables active SMO to bind PKA-C directly. Lastly, the SMO-GRK2-PKA pathway underlies Hh signal transduction in a range of cellular and in vivo models. Thus, GRK2 phosphorylation of ciliary SMO, and the ensuing PKA-C binding and inactivation, are critical initiating events for the intracellular steps in Hh signaling. More broadly, our study suggests an expanded role for GRKs in enabling direct GPCR interactions with diverse intracellular effectors.
Collapse
|
4
|
Wang W, Shiraishi R, Kawauchi D. Sonic Hedgehog Signaling in Cerebellar Development and Cancer. Front Cell Dev Biol 2022; 10:864035. [PMID: 35573667 PMCID: PMC9100414 DOI: 10.3389/fcell.2022.864035] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/28/2022] [Indexed: 12/30/2022] Open
Abstract
The sonic hedgehog (SHH) pathway regulates the development of the central nervous system in vertebrates. Aberrant regulation of SHH signaling pathways often causes neurodevelopmental diseases and brain tumors. In the cerebellum, SHH secreted by Purkinje cells is a potent mitogen for granule cell progenitors, which are the most abundant cell type in the mature brain. While a reduction in SHH signaling induces cerebellar structural abnormalities, such as hypoplasia in various genetic disorders, the constitutive activation of SHH signaling often induces medulloblastoma (MB), one of the most common pediatric malignant brain tumors. Based on the existing literature on canonical and non-canonical SHH signaling pathways, emerging basic and clinical studies are exploring novel therapeutic approaches for MB by targeting SHH signaling at distinct molecular levels. In this review, we discuss the present consensus on SHH signaling mechanisms, their roles in cerebellar development and tumorigenesis, and the recent advances in clinical trials for MB.
Collapse
Affiliation(s)
- Wanchen Wang
- Department of Biochemistry and Cellular Biology, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan
| | - Ryo Shiraishi
- Department of Biochemistry and Cellular Biology, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan
- Department of NCNP Brain Physiology and Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Daisuke Kawauchi
- Department of Biochemistry and Cellular Biology, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan
- *Correspondence: Daisuke Kawauchi,
| |
Collapse
|
5
|
Jin D, Zhong TP. Prostaglandin signaling in ciliogenesis and development. J Cell Physiol 2021; 237:2632-2643. [PMID: 34927727 DOI: 10.1002/jcp.30659] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/02/2021] [Accepted: 12/06/2021] [Indexed: 11/09/2022]
Abstract
Prostaglandin (PG) signaling regulates a wide variety of physiological and pathological processes, including body temperature, cardiovascular homeostasis, reproduction, and inflammation. Recent studies have revealed that PGs play pivotal roles in embryo development, ciliogenesis, and organ formation. Prostaglandin E2 (PGE2) and its receptor EP4 modulate ciliogenesis by increasing the anterograde intraflagellar transport. Many G-protein-coupled receptors (GPCRs) including EP4 are localized in cilia for modulating cAMP signaling under various conditions. During development, PGE2 signaling regulates embryogenesis, hepatocyte differentiation, hematopoiesis, and kidney formation. Prostaglandins are also essential for skeletal muscle repair. This review outlines recent advances in understanding the functions and mechanisms of prostaglandin signaling in ciliogenesis, embryo development, and organ formation.
Collapse
Affiliation(s)
- Daqing Jin
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, China
| | - Tao P Zhong
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, School of Life Sciences, East China Normal University, Shanghai, China
| |
Collapse
|
6
|
Kopinke D, Norris AM, Mukhopadhyay S. Developmental and regenerative paradigms of cilia regulated hedgehog signaling. Semin Cell Dev Biol 2021; 110:89-103. [PMID: 32540122 PMCID: PMC7736055 DOI: 10.1016/j.semcdb.2020.05.029] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 05/25/2020] [Accepted: 05/29/2020] [Indexed: 01/08/2023]
Abstract
Primary cilia are immotile appendages that have evolved to receive and interpret a variety of different extracellular cues. Cilia play crucial roles in intercellular communication during development and defects in cilia affect multiple tissues accounting for a heterogeneous group of human diseases called ciliopathies. The Hedgehog (Hh) signaling pathway is one of these cues and displays a unique and symbiotic relationship with cilia. Not only does Hh signaling require cilia for its function but the majority of the Hh signaling machinery is physically located within the cilium-centrosome complex. More specifically, cilia are required for both repressing and activating Hh signaling by modifying bifunctional Gli transcription factors into repressors or activators. Defects in balancing, interpreting or establishing these repressor/activator gradients in Hh signaling either require cilia or phenocopy disruption of cilia. Here, we will summarize the current knowledge on how spatiotemporal control of the molecular machinery of the cilium allows for a tight control of basal repression and activation states of the Hh pathway. We will then discuss several paradigms on how cilia influence Hh pathway activity in tissue morphogenesis during development. Last, we will touch on how cilia and Hh signaling are being reactivated and repurposed during adult tissue regeneration. More specifically, we will focus on mesenchymal stem cells within the connective tissue and discuss the similarities and differences of how cilia and ciliary Hh signaling control the formation of fibrotic scar and adipose tissue during fatty fibrosis of several tissues.
Collapse
Affiliation(s)
- Daniel Kopinke
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA.
| | - Alessandra M Norris
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Saikat Mukhopadhyay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|
7
|
Somatilaka BN, Hwang SH, Palicharla VR, White KA, Badgandi H, Shelton JM, Mukhopadhyay S. Ankmy2 Prevents Smoothened-Independent Hyperactivation of the Hedgehog Pathway via Cilia-Regulated Adenylyl Cyclase Signaling. Dev Cell 2020; 54:710-726.e8. [PMID: 32702291 PMCID: PMC9042708 DOI: 10.1016/j.devcel.2020.06.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 04/12/2020] [Accepted: 06/26/2020] [Indexed: 12/21/2022]
Abstract
The mechanisms underlying subcellular targeting of cAMP-generating adenylyl cyclases and processes regulated by their compartmentalization are poorly understood. Here, we identify Ankmy2 as a repressor of the Hedgehog pathway via adenylyl cyclase targeting. Ankmy2 binds to multiple adenylyl cyclases, determining their maturation and trafficking to primary cilia. Mice lacking Ankmy2 are mid-embryonic lethal. Knockout embryos have increased Hedgehog signaling and completely open neural tubes showing co-expansion of all ventral neuroprogenitor markers, comparable to the loss of the Hedgehog receptor Patched1. Ventralization in Ankmy2 knockout is completely independent of the Hedgehog pathway transducer Smoothened. Instead, ventralization results from the reduced formation of Gli2 and Gli3 repressors and early depletion of adenylyl cyclase III in neuroepithelial cilia, implicating deficient pathway repression. Ventralization in Ankmy2 knockout requires both cilia and Gli2 activation. These findings indicate that cilia-dependent adenylyl cyclase signaling represses the Hedgehog pathway and promotes morphogenetic patterning.
Collapse
Affiliation(s)
| | - Sun-Hee Hwang
- Department of Cell Biology, Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Vivek Reddy Palicharla
- Department of Cell Biology, Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kevin Andrew White
- Department of Cell Biology, Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Hemant Badgandi
- Department of Cell Biology, Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - John Michael Shelton
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Saikat Mukhopadhyay
- Department of Cell Biology, Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|
8
|
Jiang Y, Zhuo X, Mao C. G Protein-coupled Receptors in Cancer Stem Cells. Curr Pharm Des 2020; 26:1952-1963. [DOI: 10.2174/1381612826666200305130009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/10/2020] [Indexed: 12/19/2022]
Abstract
G protein-coupled receptors (GPCRs) are highly expressed on a variety of tumour tissues while several
GPCR exogenous ligands become marketed pharmaceuticals. In recent decades, cancer stem cells (CSCs) become
widely investigated drug targets for cancer therapy but the underlying mechanism is still not fully elucidated.
There are vigorous participations of GPCRs in CSCs-related signalling and functions, such as biomarkers for
CSCs, activation of Wnt, Hedgehog (HH) and other signalling to facilitate CSCs progressions. This relationship
can not only uncover a novel molecular mechanism for GPCR-mediated cancer cell functions but also assist our
understanding of maintaining and modulating CSCs. Moreover, GPCR antagonists and monoclonal antibodies
could be applied to impair CSCs functions and consequently attenuate tumour growth, some of which have been
undergoing clinical studies and are anticipated to turn into marketed anticancer drugs. Therefore, this review
summarizes and provides sufficient evidences on the regulation of GPCR signalling in the maintenance, differentiation
and pluripotency of CSCs, suggesting that targeting GPCRs on the surface of CSCs could be potential
therapeutic strategies for cancer therapy.
Collapse
Affiliation(s)
- Yuhong Jiang
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Xin Zhuo
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Canquan Mao
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, China
| |
Collapse
|
9
|
Gigante ED, Caspary T. Signaling in the primary cilium through the lens of the Hedgehog pathway. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 9:e377. [PMID: 32084300 DOI: 10.1002/wdev.377] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/22/2020] [Accepted: 01/25/2020] [Indexed: 12/14/2022]
Abstract
Cilia are microtubule-based, cell-surface projections whose machinery is evolutionarily conserved. In vertebrates, cilia are observed on almost every cell type and are either motile or immotile. Immotile sensory, or primary cilia, are responsive to extracellular ligands and signals. Cilia can be thought of as compartments, functionally distinct from the cell that provides an environment for signaling cascades. Hedgehog is a critical developmental signaling pathway which is functionally linked to primary cilia in vertebrates. The major components of the vertebrate Hedgehog signaling pathway dynamically localize to the ciliary compartment and ciliary membrane. Critically, G-protein coupled receptor (GPCR) Smoothened, the obligate transducer of the pathway, is enriched and activated in the cilium. While Smoothened is the most intensely studied ciliary receptor, many GPCRs localize within cilia. Understanding the link between Smoothened and cilia defines common features, and distinctions, of GPCR signaling within the primary cilium. This article is categorized under: Signaling Pathways > Global Signaling Mechanisms Signaling Pathways > Cell Fate Signaling.
Collapse
Affiliation(s)
- Eduardo D Gigante
- Graduate Program in Neuroscience, Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| |
Collapse
|
10
|
Loskutov YV, Griffin CL, Marinak KM, Bobko A, Margaryan NV, Geldenhuys WJ, Sarkaria JN, Pugacheva EN. LPA signaling is regulated through the primary cilium: a novel target in glioblastoma. Oncogene 2018; 37:1457-1471. [PMID: 29321663 PMCID: PMC5854509 DOI: 10.1038/s41388-017-0049-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 09/06/2017] [Accepted: 09/24/2017] [Indexed: 01/23/2023]
Abstract
The primary cilium is a ubiquitous organelle presented on most human cells. It is a crucial signaling hub for multiple pathways including growth factor and G-protein coupled receptors. Loss of primary cilia, observed in various cancers, has been shown to affect cell proliferation. Primary cilia formation is drastically decreased in glioblastoma (GBM), however, the role of cilia in normal astrocyte or glioblastoma proliferation has not been explored. Here, we report that loss of primary cilia in human astrocytes stimulates growth rate in a lysophosphatidic acid (LPA)-dependent manner. We show that lysophosphatidic acid receptor 1 (LPAR1) is accumulated in primary cilia. LPAR1 signaling through Gα12/Gαq was previously reported to be responsible for cancer cell proliferation. We found that in ciliated cells, Gα12 and Gαq are excluded from the cilium, creating a barrier against unlimited proliferation, one of the hallmarks of cancer. Upon loss of primary cilia, LPAR1 redistributes to the plasma membrane with a concomitant increase in LPAR1 association with Gα12 and Gαq. Inhibition of LPA signaling with the small molecule compound Ki16425 in deciliated highly proliferative astrocytes or glioblastoma patient-derived cells/xenografts drastically suppresses their growth both in vitro and in vivo. Moreover, Ki16425 brain delivery via PEG-PLGA nanoparticles inhibited tumor progression in an intracranial glioblastoma PDX model. Overall, our findings establish a novel mechanism by which primary cilium restricts proliferation and indicate that loss of primary cilia is sufficient to increase mitogenic signaling, and is important for the maintenance of a highly proliferative phenotype. Clinical application of LPA inhibitors may prove beneficial to restrict glioblastoma growth and ensure local control of disease.
Collapse
Affiliation(s)
- Yuriy V Loskutov
- WVU Cancer Institute, West Virginia University School of Medicine, Morgantown, WV, USA
| | - Caryn L Griffin
- WVU Cancer Institute, West Virginia University School of Medicine, Morgantown, WV, USA
| | - Kristina M Marinak
- WVU Cancer Institute, West Virginia University School of Medicine, Morgantown, WV, USA
| | - Andrey Bobko
- Department of Biochemistry, West Virginia University School of Medicine, Morgantown, WV, USA
| | - Naira V Margaryan
- Department of Biochemistry, West Virginia University School of Medicine, Morgantown, WV, USA
| | - Werner J Geldenhuys
- Department of Pharmaceutical Sciences, West Virginia University School of Medicine, Morgantown, WV, USA
| | | | - Elena N Pugacheva
- WVU Cancer Institute, West Virginia University School of Medicine, Morgantown, WV, USA.
- Department of Biochemistry, West Virginia University School of Medicine, Morgantown, WV, USA.
- Department of Radiation Oncology, West Virginia University School of Medicine, Morgantown, WV, USA.
| |
Collapse
|
11
|
Pusapati GV, Kong JH, Patel BB, Gouti M, Sagner A, Sircar R, Luchetti G, Ingham PW, Briscoe J, Rohatgi R. G protein-coupled receptors control the sensitivity of cells to the morphogen Sonic Hedgehog. Sci Signal 2018; 11:eaao5749. [PMID: 29438014 PMCID: PMC5828112 DOI: 10.1126/scisignal.aao5749] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The morphogen Sonic Hedgehog (SHH) patterns tissues during development by directing cell fates in a concentration-dependent manner. The SHH signal is transmitted across the membrane of target cells by the heptahelical transmembrane protein Smoothened (SMO), which activates the GLI family of transcription factors through a mechanism that is undefined in vertebrates. Using CRISPR-edited null alleles and small-molecule inhibitors, we systematically analyzed the epistatic interactions between SMO and three proteins implicated in SMO signaling: the heterotrimeric G protein subunit GαS, the G protein-coupled receptor kinase 2 (GRK2), and the GαS-coupled receptor GPR161. Our experiments uncovered a signaling mechanism that modifies the sensitivity of target cells to SHH and consequently changes the shape of the SHH dose-response curve. In both fibroblasts and spinal neural progenitors, the loss of GPR161, previously implicated as an inhibitor of basal SHH signaling, increased the sensitivity of target cells across the entire spectrum of SHH concentrations. Even in cells lacking GPR161, GRK2 was required for SHH signaling, and Gαs, which promotes the activation of protein Kinase A (PKA), antagonized SHH signaling. We propose that the sensitivity of target cells to Hedgehog morphogens, and the consequent effects on gene expression and differentiation outcomes, can be controlled by signals from G protein-coupled receptors that converge on Gαs and PKA.
Collapse
Affiliation(s)
- Ganesh V Pusapati
- Departments of Medicine and Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jennifer H Kong
- Departments of Medicine and Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Bhaven B Patel
- Departments of Medicine and Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Mina Gouti
- The Francis Crick Institute, Midland Road, London NW1 1AT, UK
| | - Andreas Sagner
- The Francis Crick Institute, Midland Road, London NW1 1AT, UK
| | - Ria Sircar
- Departments of Medicine and Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Giovanni Luchetti
- Departments of Medicine and Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Philip W Ingham
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 639798, Singapore
- Living Systems Institute, University of Exeter, Exeter EX4 4RJ, UK
| | - James Briscoe
- The Francis Crick Institute, Midland Road, London NW1 1AT, UK
| | - Rajat Rohatgi
- Departments of Medicine and Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA.
| |
Collapse
|
12
|
Rao R, Salloum R, Xin M, Lu QR. The G protein Gαs acts as a tumor suppressor in sonic hedgehog signaling-driven tumorigenesis. Cell Cycle 2018; 15:1325-30. [PMID: 27052725 DOI: 10.1080/15384101.2016.1164371] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are critical players in tumor growth and progression. The redundant roles of GPCRs in tumor development confound effective treatment; therefore, targeting a single common signaling component downstream of these receptors may be efficacious. GPCRs transmit signals through heterotrimeric G proteins composed of Gα and Gβγ subunits. Hyperactive Gαs signaling can mediate tumor progression in some tissues; however, recent work in medulloblastoma and basal cell carcinoma revealed that Gαs can also function as a tumor suppressor in neoplasms derived from ectoderm cells including neural and epidermal stem/progenitor cells. In these stem-cell compartments, signaling through Gαs suppresses self-renewal by inhibiting the Sonic Hedgehog (SHH) and Hippo pathways. The loss of GNAS, which encodes Gαs, leads to activation of these pathways, over-proliferation of progenitor cells, and tumor formation. Gαs activates the cAMP-dependent protein kinase A (PKA) signaling pathway and inhibits activation of SHH effectors Smoothened-Gli. In addition, Gαs-cAMP-PKA activation negatively regulates the Hippo pathway by blocking the NF2-LATS1/2-Yap signaling. In this review, we will address the novel function of the signaling network regulated by Gαs in suppression of SHH-driven tumorigenesis and the therapeutic approaches that can be envisioned to harness this pathway to inhibit tumor growth and progression.
Collapse
Affiliation(s)
- Rohit Rao
- a University of Cincinnati Medical Scientist Training Program , Cincinnati , OH , USA
| | - Ralph Salloum
- b Brain Tumor Center, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center , Cincinnati , OH , USA
| | - Mei Xin
- b Brain Tumor Center, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center , Cincinnati , OH , USA
| | - Q Richard Lu
- b Brain Tumor Center, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center , Cincinnati , OH , USA
| |
Collapse
|
13
|
Abstract
The Sonic Hedgehog (Shh) signaling pathway is active during embryonic development in metazoans, and provides instructional cues necessary for proper tissue patterning. The pathway signal transducing component, Smoothened (Smo), is a G protein-coupled receptor (GPCR) that has been demonstrated to signal through at least two effector routes. The first is a G protein–independent canonical route that signals to Gli transcriptional effectors to establish transcriptional programs specifying cell fate during early embryonic development. The second, commonly referred to as the noncanonical Smo signal, induces rapid, transcription-independent responses that are essential for establishing and maintaining distinct cell behaviors during development. Herein, we discuss contributions of this noncanonical route during embryonic development. We also highlight important open questions regarding noncanonical Smo signal route selection during development, and consider implications of noncanonical signal corruption in disease.
Collapse
|
14
|
Feng S, Ma S, Jia C, Su Y, Yang S, Zhou K, Liu Y, Cheng J, Lu D, Fan L, Wang Y. Sonic hedgehog is a regulator of extracellular glutamate levels and epilepsy. EMBO Rep 2016; 17:682-94. [PMID: 27113760 DOI: 10.15252/embr.201541569] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 03/07/2016] [Indexed: 12/23/2022] Open
Abstract
Sonic hedgehog (Shh), both as a mitogen and as a morphogen, plays an important role in cell proliferation and differentiation during early development. Here, we show that Shh inhibits glutamate transporter activities in neurons, rapidly enhances extracellular glutamate levels, and affects the development of epilepsy. Shh is quickly released in response to epileptic, but not physiological, stimuli. Inhibition of neuronal glutamate transporters by Shh depends on heterotrimeric G protein subunit Gαi and enhances extracellular glutamate levels. Inhibiting Shh signaling greatly reduces epileptiform activities in both cell cultures and hippocampal slices. Moreover, pharmacological or genetic inhibition of Shh signaling markedly suppresses epileptic phenotypes in kindling or pilocarpine models. Our results suggest that Shh contributes to the development of epilepsy and suppression of its signaling prevents the development of the disease. Thus, Shh can act as a modulator of neuronal activity, rapidly regulating glutamate levels and promoting epilepsy.
Collapse
Affiliation(s)
- Shengjie Feng
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China University of Chinese Academy of Sciences, Shanghai, China
| | - Shaorong Ma
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China University of Chinese Academy of Sciences, Shanghai, China
| | - Caixia Jia
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yujuan Su
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China University of Chinese Academy of Sciences, Shanghai, China
| | - Shenglian Yang
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Kechun Zhou
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yani Liu
- Center of Cognition and Brain Science, AMMS, Beijing, China
| | - Ju Cheng
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China University of Chinese Academy of Sciences, Shanghai, China
| | - Dunguo Lu
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Liu Fan
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yizheng Wang
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| |
Collapse
|
15
|
Hilgendorf KI, Johnson CT, Jackson PK. The primary cilium as a cellular receiver: organizing ciliary GPCR signaling. Curr Opin Cell Biol 2016; 39:84-92. [PMID: 26926036 DOI: 10.1016/j.ceb.2016.02.008] [Citation(s) in RCA: 160] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 02/03/2016] [Accepted: 02/04/2016] [Indexed: 12/12/2022]
Abstract
The primary cilium is an antenna-like cellular protrusion mediating sensory and neuroendocrine signaling. Its localization within tissue architecture and a growing list of cilia-localized receptors, in particular G-protein-coupled receptors, determine a host of crucial physiologies, which are disrupted in human ciliopathies. Here, we discuss recent advances in the identification and characterization of ciliary signaling components and pathways. Recent studies have highlighted the unique signaling environment of the primary cilium and we are just beginning to understand how this design allows for highly amplified and regulated signaling.
Collapse
Affiliation(s)
- Keren I Hilgendorf
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Carl T Johnson
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Medicine, Stem Cell and Regenerative Medicine PhD Program, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Peter K Jackson
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| |
Collapse
|
16
|
Mick DU, Rodrigues RB, Leib RD, Adams CM, Chien AS, Gygi SP, Nachury MV. Proteomics of Primary Cilia by Proximity Labeling. Dev Cell 2015; 35:497-512. [PMID: 26585297 DOI: 10.1016/j.devcel.2015.10.015] [Citation(s) in RCA: 291] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 09/26/2015] [Accepted: 10/19/2015] [Indexed: 11/17/2022]
Abstract
While cilia are recognized as important signaling organelles, the extent of ciliary functions remains unknown because of difficulties in cataloguing proteins from mammalian primary cilia. We present a method that readily captures rapid snapshots of the ciliary proteome by selectively biotinylating ciliary proteins using a cilia-targeted proximity labeling enzyme (cilia-APEX). Besides identifying known ciliary proteins, cilia-APEX uncovered several ciliary signaling molecules. The kinases PKA, AMPK, and LKB1 were validated as bona fide ciliary proteins and PKA was found to regulate Hedgehog signaling in primary cilia. Furthermore, proteomics profiling of Ift27/Bbs19 mutant cilia correctly detected BBSome accumulation inside Ift27(-/-) cilia and revealed that β-arrestin 2 and the viral receptor CAR are candidate cargoes of the BBSome. This work demonstrates that proximity labeling can be applied to proteomics of non-membrane-enclosed organelles and suggests that proteomics profiling of cilia will enable a rapid and powerful characterization of ciliopathies.
Collapse
Affiliation(s)
- David U Mick
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305-5345, USA
| | - Rachel B Rodrigues
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Ryan D Leib
- Stanford University Mass Spectrometry, Stanford University, Stanford, CA 94305, USA
| | - Christopher M Adams
- Stanford University Mass Spectrometry, Stanford University, Stanford, CA 94305, USA
| | - Allis S Chien
- Stanford University Mass Spectrometry, Stanford University, Stanford, CA 94305, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Maxence V Nachury
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305-5345, USA.
| |
Collapse
|
17
|
Singh J, Wen X, Scales SJ. The Orphan G Protein-coupled Receptor Gpr175 (Tpra40) Enhances Hedgehog Signaling by Modulating cAMP Levels. J Biol Chem 2015; 290:29663-75. [PMID: 26451044 DOI: 10.1074/jbc.m115.665810] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Indexed: 11/06/2022] Open
Abstract
The Hedgehog (Hh) signaling pathway plays an essential role in vertebrate embryonic tissue patterning of many developing organs. Signaling occurs predominantly in primary cilia and is initiated by the entry of the G protein-coupled receptor (GPCR)-like protein Smoothened into cilia and culminates in gene transcription via the Gli family of transcription factors upon their nuclear entry. Here we identify an orphan GPCR, Gpr175 (also known as Tpra1 or Tpra40: transmembrane protein, adipocyte associated 1 or of 40 kDa), which also localizes to primary cilia upon Hh stimulation and positively regulates Hh signaling. Interaction experiments place Gpr175 at the level of PKA and upstream of the Gαi component of heterotrimeric G proteins, which itself localizes to cilia and can modulate Hh signaling. Gpr175 or Gαi1 depletion leads to increases in cellular cAMP levels and in Gli3 processing into its repressor form. Thus we propose that Gpr175 coupled to Gαi1 normally functions to inhibit the production of cAMP by adenylyl cyclase upon Hh stimulation, thus maximizing signaling by turning off PKA activity and hence Gli3 repressor formation. Taken together our data suggest that Gpr175 is a novel positive regulator of the Hh signaling pathway.
Collapse
Affiliation(s)
- Jaskirat Singh
- From the Department of Molecular Biology, Genentech, South San Francisco, California 94080
| | - Xiaohui Wen
- From the Department of Molecular Biology, Genentech, South San Francisco, California 94080
| | - Suzie J Scales
- From the Department of Molecular Biology, Genentech, South San Francisco, California 94080
| |
Collapse
|
18
|
Arensdorf AM, Marada S, Ogden SK. Smoothened Regulation: A Tale of Two Signals. Trends Pharmacol Sci 2015; 37:62-72. [PMID: 26432668 DOI: 10.1016/j.tips.2015.09.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/31/2015] [Accepted: 09/01/2015] [Indexed: 02/09/2023]
Abstract
The G protein-coupled receptor (GPCR) Smoothened (Smo) is the signal transducer of the developmentally and therapeutically relevant Hedgehog (Hh) pathway. Although recent structural analyses have advanced our understanding of Smo biology, several questions remain. Chief among them are the identity of its natural ligand, the regulatory processes controlling its activation, and the mechanisms by which it signals to downstream effectors. In this review, we discuss recent discoveries from multiple model systems that have set the stage for solving these mysteries. We focus on the roles of distinct Smo functional domains, post-translational modifications, and trafficking, and conclude by discussing their contributions to signal output.
Collapse
Affiliation(s)
- Angela M Arensdorf
- Department of Cell and Molecular Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place MS#340, Memphis, TN 38105, USA
| | - Suresh Marada
- Department of Cell and Molecular Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place MS#340, Memphis, TN 38105, USA
| | - Stacey K Ogden
- Department of Cell and Molecular Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place MS#340, Memphis, TN 38105, USA.
| |
Collapse
|
19
|
Villanueva H, Visbal AP, Obeid NF, Ta AQ, Faruki AA, Wu MF, Hilsenbeck SG, Shaw CA, Yu P, Plummer NW, Birnbaumer L, Lewis MT. An essential role for Gα(i2) in Smoothened-stimulated epithelial cell proliferation in the mammary gland. Sci Signal 2015; 8:ra92. [PMID: 26373672 DOI: 10.1126/scisignal.aaa7355] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Hedgehog (Hh) signaling is critical for organogenesis, tissue homeostasis, and stem cell maintenance. The gene encoding Smoothened (SMO), the primary effector of Hh signaling, is expressed aberrantly in human breast cancer, as well as in other cancers. In mice that express a constitutively active form of SMO that does not require Hh stimulation in mammary glands, the cells near the transgenic cells proliferate and participate in hyperplasia formation. Although SMO is a seven-transmembrane receptor like G protein-coupled receptors (GPCRs), SMO-mediated activation of the Gli family of transcription factors is not known to involve G proteins. However, data from Drosophila and mammalian cell lines indicate that SMO functions as a GPCR that couples to heterotrimeric G proteins of the pertussis toxin (PTX)-sensitive Gαi class. Using genetically modified mice, we demonstrated that SMO signaling through G proteins occurred in the mammary gland in vivo. SMO-induced stimulation of proliferation was PTX-sensitive and required Gαi2, but not Gαi1, Gαi3, or activation of Gli1 or Gli2. Our findings show that activated SMO functions as a GPCR to stimulate proliferation in vivo, a finding that may have clinical importance because most SMO-targeted agents have been selected based largely on their ability to block Gli-mediated transcription.
Collapse
Affiliation(s)
- Hugo Villanueva
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA. Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Adriana P Visbal
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA. Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Nadine F Obeid
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Andrew Q Ta
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Adeel A Faruki
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meng-Fen Wu
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Susan G Hilsenbeck
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA. Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Chad A Shaw
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Peng Yu
- Department of Electrical and Computer Engineering, TEES-AgriLife Center for Bioinformatics and Genomic Systems Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Nicholas W Plummer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Lutz Birnbaumer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Michael T Lewis
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA. Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA. Department of Radiology, Baylor College of Medicine, Houston, TX 77030, USA.
| |
Collapse
|
20
|
Abstract
In this issue of Science Signaling, Villanueva et al. report on the identification of heterotrimeric guanine nucleotide-binding protein (G protein) Gαi2 as an essential effector of Smoothened-mediated mammary epithelial cell proliferation. Through a series of in vivo experiments, the authors delineate a Smoothened-regulated Gli-independent Gαi signal that provides direct genetic evidence connecting Smoothened with Gαi in mice.
Collapse
Affiliation(s)
- Stacey K Ogden
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
| |
Collapse
|
21
|
Vuolo L, Herrera A, Torroba B, Menendez A, Pons S. Ciliary adenylyl cyclases control the Hedgehog pathway. J Cell Sci 2015; 128:2928-37. [PMID: 26092933 DOI: 10.1242/jcs.172635] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 06/15/2015] [Indexed: 12/20/2022] Open
Abstract
Protein kinase A (PKA) accumulates at the base of the cilium where it negatively regulates the Hedgehog (Hh) pathway. Although PKA activity is essentially controlled by the cAMP produced by adenylyl cyclases, the influence of these enzymes on the Hh pathway remains unclear. Here, we show that adenylyl cyclase 5 and adenylyl cyclase 6 (AC5 and AC6, also known as ADCY5 and ADCY6, respectively) are the two isoforms most strongly expressed in cerebellar granular neuron precursors (CGNPs). We found that overexpression of AC5 and AC6 represses, whereas their knockdown activates, the Hh pathway in CGNPs and in the embryonic neural tube. Indeed, AC5 and AC6 concentrate in the primary cilium, and mutation of a previously undescribed cilium-targeting motif in AC5 suppresses its ciliary location, as well as its capacity to inhibit Hh signalling. Stimulatory and inhibitory Gα proteins, which are engaged by the G-protein-coupled receptors (GPCRs), control AC5 and AC6 activity and regulate the Hh pathway in CGNPs and in the neural tube. Therefore, we propose that the activity of different ciliary GPCRs converges on AC5 and AC6 to control PKA activity and, hence, the Hh pathway.
Collapse
Affiliation(s)
- Laura Vuolo
- Instituto de Biología Molecular de Barcelona (CSIC), Parc Científic de Barcelona, Baldiri Reixac 10-12, Barcelona 08028, Spain
| | - Antonio Herrera
- Instituto de Biología Molecular de Barcelona (CSIC), Parc Científic de Barcelona, Baldiri Reixac 10-12, Barcelona 08028, Spain
| | - Blanca Torroba
- Instituto de Biología Molecular de Barcelona (CSIC), Parc Científic de Barcelona, Baldiri Reixac 10-12, Barcelona 08028, Spain
| | - Anghara Menendez
- Instituto de Biología Molecular de Barcelona (CSIC), Parc Científic de Barcelona, Baldiri Reixac 10-12, Barcelona 08028, Spain
| | - Sebastian Pons
- Instituto de Biología Molecular de Barcelona (CSIC), Parc Científic de Barcelona, Baldiri Reixac 10-12, Barcelona 08028, Spain
| |
Collapse
|
22
|
Teperino R, Aberger F, Esterbauer H, Riobo N, Pospisilik JA. Canonical and non-canonical Hedgehog signalling and the control of metabolism. Semin Cell Dev Biol 2014; 33:81-92. [PMID: 24862854 DOI: 10.1016/j.semcdb.2014.05.007] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 05/07/2014] [Accepted: 05/08/2014] [Indexed: 02/07/2023]
Abstract
Obesity and diabetes represent key healthcare challenges of our day, affecting upwards of one billion people worldwide. These individuals are at higher risk for cancer, stroke, blindness, heart and cardiovascular disease, and to date, have no effective long-term treatment options available. Recent and accumulating evidence has implicated the developmental morphogen Hedgehog and its downstream signalling in metabolic control. Generally thought to be quiescent in adults, Hedgehog is associated with several human cancers, and as such, has already emerged as a therapeutic target in oncology. Here, we attempt to give a comprehensive overview of the key signalling events associated with both canonical and non-canonical Hedgehog signalling, and highlight the increasingly complex regulatory modalities that appear to link Hedgehog and control metabolism. We highlight these key findings and discuss their impact for therapeutic development, cancer and metabolic disease.
Collapse
Affiliation(s)
- Raffaele Teperino
- Department of Epigenetics, Max-Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Fritz Aberger
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Harald Esterbauer
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Natalia Riobo
- Department of Biochemistry and Molecular Biology and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - John Andrew Pospisilik
- Department of Epigenetics, Max-Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.
| |
Collapse
|
23
|
Ruat M, Hoch L, Faure H, Rognan D. Targeting of Smoothened for therapeutic gain. Trends Pharmacol Sci 2014; 35:237-46. [DOI: 10.1016/j.tips.2014.03.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 02/26/2014] [Accepted: 03/04/2014] [Indexed: 02/06/2023]
|
24
|
Niewiadomski P, Zhujiang A, Youssef M, Waschek JA. Interaction of PACAP with Sonic hedgehog reveals complex regulation of the hedgehog pathway by PKA. Cell Signal 2013; 25:2222-30. [PMID: 23872071 PMCID: PMC3768265 DOI: 10.1016/j.cellsig.2013.07.012] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 06/17/2013] [Accepted: 07/12/2013] [Indexed: 01/06/2023]
Abstract
Sonic hedgehog (Shh) signaling is essential for proliferation of cerebellar granule cell progenitors (cGCPs) and its aberrant activation causes a cerebellar cancer medulloblastoma. Pituitary adenylate cyclase activating polypeptide (PACAP) inhibits Shh-driven proliferation of cGCPs and acts as tumor suppressor in murine medulloblastoma. We show that PACAP blocks canonical Shh signaling by a mechanism that involves activation of protein kinase A (PKA) and inhibition of the translocation of the Shh-dependent transcription factor Gli2 into the primary cilium. PKA is shown to play an essential role in inhibiting gene transcription in the absence of Shh, but global PKA activity levels are found to be a poor predictor of the degree of Shh pathway activation. We propose that the core Shh pathway regulates a small compartmentalized pool of PKA in the vicinity of primary cilia. GPCRs that affect global PKA activity levels, such as the PACAP receptor, cooperate with the canonical Shh signal to regulate Gli protein phosphorylation by PKA. This interaction serves to fine-tune the transcriptional and physiological function of the Shh pathway.
Collapse
Affiliation(s)
- Pawel Niewiadomski
- Intellectual Development and Disabilities Research Center, The David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Annie Zhujiang
- Intellectual Development and Disabilities Research Center, The David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Mary Youssef
- Intellectual Development and Disabilities Research Center, The David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - James A. Waschek
- Intellectual Development and Disabilities Research Center, The David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095
| |
Collapse
|
25
|
Dasgupta S, Bandyopadhyay M. Neuroprotective mode of action of resveratrol in central nervous system. PHARMANUTRITION 2013. [DOI: 10.1016/j.phanu.2013.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
26
|
Masyuk AI, Huang BQ, Radtke BN, Gajdos GB, Splinter PL, Masyuk TV, Gradilone SA, LaRusso NF. Ciliary subcellular localization of TGR5 determines the cholangiocyte functional response to bile acid signaling. Am J Physiol Gastrointest Liver Physiol 2013; 304:G1013-24. [PMID: 23578785 PMCID: PMC3680685 DOI: 10.1152/ajpgi.00383.2012] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
TGR5, the G protein-coupled bile acid receptor that transmits bile acid signaling into a cell functional response via the intracellular cAMP signaling pathway, is expressed in human and rodent cholangiocytes. However, detailed information on the localization and function of cholangiocyte TGR5 is limited. We demonstrated that in human (H69 cells) and rat cholangiocytes, TGR5 is localized to multiple, diverse subcellular compartments, with its strongest expression on the apical plasma, ciliary, and nuclear membranes. To evaluate the relationship between ciliary TGR5 and the cholangiocyte functional response to bile acid signaling, we used a model of ciliated and nonciliated H69 cells and demonstrated that TGR5 agonists induce opposite changes in cAMP and ERK levels in cells with and without primary cilia. The cAMP level was increased in nonciliated cholangiocytes but decreased in ciliated cells. In contrast, ERK signaling was induced in ciliated cholangiocytes but suppressed in cells without cilia. TGR5 agonists inhibited proliferation of ciliated cholangiocytes but activated proliferation of nonciliated cells. The observed differential effects of TGR5 agonists were associated with the coupling of TGR5 to Gαi protein in ciliated cells and Gαs protein in nonciliated cholangiocytes. The functional responses of nonciliated and ciliated cholangiocytes to TGR5-mediated bile acid signaling may have important pathophysiological significance in cilia-related liver disorders (i.e., cholangiociliopathies), such as polycystic liver disease. In summary, TGR5 is expressed on diverse cholangiocyte compartments, including a primary cilium, and its ciliary localization determines the cholangiocyte functional response to bile acid signaling.
Collapse
Affiliation(s)
- Anatoliy I. Masyuk
- Mayo Clinic College of Medicine, Department of Internal Medicine, Rochester, Minnesota
| | - Bing Q. Huang
- Mayo Clinic College of Medicine, Department of Internal Medicine, Rochester, Minnesota
| | - Brynn N. Radtke
- Mayo Clinic College of Medicine, Department of Internal Medicine, Rochester, Minnesota
| | - Gabriella B. Gajdos
- Mayo Clinic College of Medicine, Department of Internal Medicine, Rochester, Minnesota
| | - Patrick L. Splinter
- Mayo Clinic College of Medicine, Department of Internal Medicine, Rochester, Minnesota
| | - Tatyana V. Masyuk
- Mayo Clinic College of Medicine, Department of Internal Medicine, Rochester, Minnesota
| | - Sergio A. Gradilone
- Mayo Clinic College of Medicine, Department of Internal Medicine, Rochester, Minnesota
| | - Nicholas F. LaRusso
- Mayo Clinic College of Medicine, Department of Internal Medicine, Rochester, Minnesota
| |
Collapse
|
27
|
Mahoney WM, Gunaje J, Daum G, Dong XR, Majesky MW. Regulator of G-protein signaling - 5 (RGS5) is a novel repressor of hedgehog signaling. PLoS One 2013; 8:e61421. [PMID: 23637832 PMCID: PMC3630190 DOI: 10.1371/journal.pone.0061421] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 03/10/2013] [Indexed: 01/11/2023] Open
Abstract
Hedgehog (Hh) signaling plays fundamental roles in morphogenesis, tissue repair, and human disease. Initiation of Hh signaling is controlled by the interaction of two multipass membrane proteins, patched (Ptc) and smoothened (Smo). Recent studies identify Smo as a G-protein coupled receptor (GPCR)-like protein that signals through large G-protein complexes which contain the Gαi subunit. We hypothesize Regulator of G-Protein Signaling (RGS) proteins, and specifically RGS5, are endogenous repressors of Hh signaling via their ability to act as GTPase activating proteins (GAPs) for GTP-bound Gαi, downstream of Smo. In support of this hypothesis, we demonstrate that RGS5 over-expression inhibits sonic hedgehog (Shh)-mediated signaling and osteogenesis in C3H10T1/2 cells. Conversely, signaling is potentiated by siRNA-mediated knock-down of RGS5 expression, but not RGS4 expression. Furthermore, using immuohistochemical analysis and co-immunoprecipitation (Co-IP), we demonstrate that RGS5 is present with Smo in primary cilia. This organelle is required for canonical Hh signaling in mammalian cells, and RGS5 is found in a physical complex with Smo in these cells. We therefore conclude that RGS5 is an endogenous regulator of Hh-mediated signaling and that RGS proteins are potential targets for novel therapeutics in Hh-mediated diseases.
Collapse
Affiliation(s)
- William M. Mahoney
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington, United States of America
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail: (WMM); (MWM)
| | - Jagadambika Gunaje
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington, United States of America
| | - Guenter Daum
- Department of Surgery, University of Washington, Seattle, Washington, United States of America
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington, United States of America
| | - Xiu Rong Dong
- Seattle Children’s Research Institute, University of Washington, Seattle, Washington, United States of America
| | - Mark W. Majesky
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
- Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington, United States of America
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, United States of America
- Seattle Children’s Research Institute, University of Washington, Seattle, Washington, United States of America
- * E-mail: (WMM); (MWM)
| |
Collapse
|
28
|
Abstract
Neurogenesis during embryonic and adult life is tightly regulated by a network of transcriptional, growth and hormonal factors. Emerging evidence indicates that activation of the stress response, via the associated glucocorticoid increase, reduces neurogenesis and contributes to the development of adult diseases.As corticotrophin-releasing hormone (CRH) or factor is the major mediator of adaptive response to stressors, we sought to investigate its involvement in this process. Accordingly, we found that CRH could reverse the damaging effects of glucocorticoid on neural stem/progenitor cells (NS/PCs), while its genetic deficiency results in compromised proliferation and enhanced apoptosis during neurogenesis. Analyses in fetal and adult mouse brain revealed significant expression of CRH receptors in proliferating neuronal progenitors. Furthermore, by using primary cultures of NS/PCs, we characterized the molecular mechanisms and identified CRH receptor-1 as the receptor mediating the neuroprotective effects of CRH. Finally, we demonstrate the expression of CRH receptors in human fetal brain from early gestational age, in areas of active neuronal proliferation. These observations raise the intriguing possibility for CRH-mediated pharmacological applications in diseases characterized by altered neuronal homeostasis, including depression, dementia, neurodegenerative diseases, brain traumas and obesity.
Collapse
|
29
|
Ric-8a, a guanine nucleotide exchange factor for heterotrimeric G proteins, regulates bergmann glia-basement membrane adhesion during cerebellar foliation. J Neurosci 2013; 32:14979-93. [PMID: 23100420 DOI: 10.1523/jneurosci.1282-12.2012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The cerebellum consists of an intricate array of lobules that arises during the process of foliation. Foliation not only increases surface area, but may also facilitate organization of cerebellar neural circuitry. Defects in cerebellar foliation are associated with a number of diseases. Yet, little is known about how foliation, a process involving large-scale and simultaneous movement of several different cell types, is coordinated by cell-cell signaling at the molecular level. Here we show that Ric-8a, a guanine nucleotide exchange factor in the G-protein-coupled receptor pathway, is specifically required in Bergmann glia during cerebellar foliation. We find that ric-8a mutation in mice results in disorganized Bergmann glial scaffolding, defective granule cell migration, and disrupted Purkinje cell positioning. These abnormalities result from primary defects in Bergmann glia since mutations in granule cells do not show similar effects. They first arise during late embryogenesis, at the onset of foliation, when ric-8a mutant Bergmann glia fail to maintain adhesion to the basement membrane specifically at emerging fissures. This suggests that Ric-8a is essential for the enhanced Bergmann glia-basement membrane adhesion required for fissure formation. Indeed, we find that ric-8a-deficient cerebellar glia show decreased affinity for basement membrane components. We also find that weakening Bergmann glia-basement membrane interaction by β1 integrin deletion results in a similar phenotype. These results thus reveal a novel role of Ric-8a in modulating Bergmann glia-basement membrane adhesion during foliation, and provide new insights into the signaling pathways that coordinate cellular movement during cerebellar morphogenesis.
Collapse
|
30
|
Shen F, Cheng L, Douglas AE, Riobo NA, Manning DR. Smoothened is a fully competent activator of the heterotrimeric G protein G(i). Mol Pharmacol 2013; 83:691-7. [PMID: 23292797 DOI: 10.1124/mol.112.082511] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Smoothened (Smo) is a 7-transmembrane protein essential to the activation of Gli transcription factors (Gli) by hedgehog morphogens. The structure of Smo implies interactions with heterotrimeric G proteins, but the degree to which G proteins participate in the actions of hedgehogs remains controversial. We posit that the G(i) family of G proteins provides to hedgehogs the ability to expand well beyond the bounds of Gli. In this regard, we evaluate here the efficacy of Smo as it relates to the activation of G(i), by comparing Smo with the 5-hydroxytryptamine(1A) (5-HT(1A)) receptor, a quintessential G(i)-coupled receptor. We find that with use of [(35)S]guanosine 5'-(3-O-thio)triphosphate, first, with forms of G(i) endogenous to human embryonic kidney (HEK)-293 cells made to express epitope-tagged receptors and, second, with individual forms of Gα(i) fused to the C terminus of each receptor, Smo is equivalent to the 5-HT(1A) receptor in the assay as it relates to capacity to activate G(i). This finding is true regardless of subtype of G(i) (e.g., G(i2), G(o), and G(z)) tested. We also find that Smo endogenous to HEK-293 cells, ostensibly through inhibition of adenylyl cyclase, decreases intracellular levels of cAMP. The results indicate that Smo is a receptor that can engage not only Gli but also other more immediate effectors.
Collapse
Affiliation(s)
- Feng Shen
- Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, Pennsylvania 19104-6084, USA
| | | | | | | | | |
Collapse
|
31
|
Development of the mammalian axial skeleton requires signaling through the Gα(i) subfamily of heterotrimeric G proteins. Proc Natl Acad Sci U S A 2012; 109:21366-71. [PMID: 23236180 DOI: 10.1073/pnas.1219810110] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
129/SvEv mice with a loss-of-function mutation in the heterotrimeric G protein α-subunit gene Gnai3 have fusions of ribs and lumbar vertebrae, indicating a requirement for Gα(i) (the "inhibitory" class of α-subunits) in somite derivatives. Mice with mutations of Gnai1 or Gnai2 have neither defect, but loss of both Gnai3 and one of the other two genes increases the number and severity of rib fusions without affecting the lumbar fusions. No myotome defects are observed in Gnai3/Gnai1 double-mutant embryos, and crosses with a conditional allele of Gnai2 indicate that Gα(i) is specifically required in cartilage precursors. Penetrance and expressivity of the rib fusion phenotype is altered in mice with a mixed C57BL/6 × 129/SvEv genetic background. These phenotypes reveal a previously unknown role for G protein-coupled signaling pathways in development of the axial skeleton.
Collapse
|
32
|
Abstract
Hedgehog (Hh) proteins regulate the development of a wide range of metazoan embryonic and adult structures, and disruption of Hh signaling pathways results in various human diseases. Here, we provide a comprehensive review of the signaling pathways regulated by Hh, consolidating data from a diverse array of organisms in a variety of scientific disciplines. Similar to the elucidation of many other signaling pathways, our knowledge of Hh signaling developed in a sequential manner centered on its earliest discoveries. Thus, our knowledge of Hh signaling has for the most part focused on elucidating the mechanism by which Hh regulates the Gli family of transcription factors, the so-called "canonical" Hh signaling pathway. However, in the past few years, numerous studies have shown that Hh proteins can also signal through Gli-independent mechanisms collectively referred to as "noncanonical" signaling pathways. Noncanonical Hh signaling is itself subdivided into two distinct signaling modules: (i) those not requiring Smoothened (Smo) and (ii) those downstream of Smo that do not require Gli transcription factors. Thus, Hh signaling is now proposed to occur through a variety of distinct context-dependent signaling modules that have the ability to crosstalk with one another to form an interacting, dynamic Hh signaling network.
Collapse
Affiliation(s)
- David J Robbins
- Molecular Oncology Program, Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.
| | | | | |
Collapse
|
33
|
Bee WT, Xie W, Truong M, Will M, Turunen B, Zuercher WJ, McMillan L, Li H, Hornberger KR, Davenport EA, Ames RS, Kallal LA. The Development of a High-Content Screening Binding Assay for the Smoothened Receptor. ACTA ACUST UNITED AC 2012; 17:900-11. [DOI: 10.1177/1087057112447872] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In this study, the development of an image-based high-content screening (HCS) binding assay for the seven-transmembrane (7TM) receptor Smoothened (Smo) is described. Using BacMam-based gene delivery of Smo, BODIPY-cyclopamine as a fluorescent probe, and a confocal imaging system, a robust 384-well assay that could be used for high-throughput compound profiling activities was developed. The statistically robust HCS binding assay was developed through optimization of multiple parameters, including cell transduction conditions, Smo expression levels, the image analysis algorithm, and staining procedures. Evaluation of structurally diverse compounds, including functional Smo activators, inhibitors, and related analogs, demonstrated good compound potency correlations between high-content imaging binding, membrane fluorescence polarization binding, and gene reporter assays. Statistical analysis of data from a screening test set of compounds at a single 10-µM concentration suggested that the high-content imaging Smo binding assay is amenable for use in hit identification. The 384-well HCS assay was rapidly developed and met statistical assay performance targets, thus demonstrating its utility as a fluorescent whole-cell binding assay suitable for compound screening and profiling.
Collapse
Affiliation(s)
- Weilin Tiger Bee
- Department of Biological Reagents and Assay Development, Molecular Discovery Research, GlaxoSmithKline, Collegeville, PA, USA
| | - Wensheng Xie
- Department of Biological Reagents and Assay Development, Molecular Discovery Research, GlaxoSmithKline, Collegeville, PA, USA
| | - Maggie Truong
- Department of Biological Reagents and Assay Development, Molecular Discovery Research, GlaxoSmithKline, Collegeville, PA, USA
| | - Matthew Will
- Department of Biological Reagents and Assay Development, Molecular Discovery Research, GlaxoSmithKline, King of Prussia, PA, USA
| | - Brandon Turunen
- Discovery Medicinal Chemistry, GlaxoSmithKline, Research Triangle Park, NC, USA
| | - William J. Zuercher
- Discovery Medicinal Chemistry, GlaxoSmithKline, Research Triangle Park, NC, USA
| | - Lynette McMillan
- Department of Biological Reagents and Assay Development, Molecular Discovery Research, GlaxoSmithKline, King of Prussia, PA, USA
| | - Hu Li
- Department of Biological Reagents and Assay Development, Molecular Discovery Research, GlaxoSmithKline, Collegeville, PA, USA
| | | | - Elizabeth A. Davenport
- Department of Biological Reagents and Assay Development, Molecular Discovery Research, GlaxoSmithKline, Collegeville, PA, USA
| | - Robert S. Ames
- Department of Biological Reagents and Assay Development, Molecular Discovery Research, GlaxoSmithKline, Collegeville, PA, USA
| | - Lorena A. Kallal
- Department of Biological Reagents and Assay Development, Molecular Discovery Research, GlaxoSmithKline, Collegeville, PA, USA
| |
Collapse
|
34
|
Ruat M, Roudaut H, Ferent J, Traiffort E. Hedgehog trafficking, cilia and brain functions. Differentiation 2012; 83:S97-104. [DOI: 10.1016/j.diff.2011.11.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 11/21/2011] [Accepted: 11/22/2011] [Indexed: 10/14/2022]
|
35
|
Abstract
Protein kinase A (PKA) is a well-known kinase that plays fundamental roles in a variety of biological processes. In Hedgehog-responsive cells, PKA plays key roles in proliferation and fate specification by modulating the transduction of Hedgehog signaling. In the absence of Hedgehog, a basal level of PKA activity represses the transcription of Hedgehog target genes. The main substrates of PKA in this process are the Ci/Gli family of bipotential transcription factors, which activate and repress Hedgehog target gene expression. PKA phosphorylates Ci/Gli, promoting the production of the repressor forms of Ci/Gli and thus repressing Hedgehog target gene expression. In contrast, the activation of Hedgehog signaling in response to Hedgehog increases the active forms of Ci/Gli, resulting in Hedgehog target gene expression. Because both decreased and increased levels of PKA activity cause abnormal cell proliferation and alter cell fate specification, the basal level of PKA activity in Hedgehog-responsive cells should be precisely regulated. However, the mechanism by which PKA activity is regulated remains obscure and appears to vary between cell types, tissues, and organisms. To date, two mechanisms have been proposed. One is a classical mechanism in which PKA activity is regulated by a small second messenger, cAMP; the other is a novel mechanism in which PKA activity is regulated by a protein, Misty somites.
Collapse
|
36
|
Abstract
Hedgehog (Hh) signaling plays a central role in many developmental processes. Hh protein is a developmental morphogen that elicits a graded cellular response depending on the distance between the recipient cell and the ligand-secreting cell. Gli transcription factors are effectors that induce the expression of downstream target genes. The outline of this cascade from Hh to Gli has been elucidated, and many components have been identified. However, the interpretation of graded ligand stimulation remains to be resolved. Among the components, adenosine 3'5'-cyclic monophosphate-dependent protein kinase (PKA) functions as a negative regulator that phosphorylates a specific region of Gli, thereby inducing proteolytic cleavage to generate the repressor form. In addition, recent studies have identified different mechanisms that are followed by PKA phosphorylation of Gli. In this review, we examine Hh signaling and PKA phosphorylation and propose a possible interaction between the multiple mechanisms regulated by PKA and the gradient-dependent response.
Collapse
Affiliation(s)
- Yoshinari Asaoka
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
37
|
Abstract
PURPOSE OF REVIEW Cells lining the biliary tree are targets of injury, but also orchestrate liver repair. The latter involves autocrine/paracrine signaling that enhances the viability and growth of residual ductular cells and promotes accumulation of inflammatory and myofibroblastic cells. The mechanisms mediating this so-called 'ductular reaction' need to be better understood to improve injury outcomes. Studies are revealing that ductular cells produce and respond to hedgehog (Hh) ligands, developmental morphogens that control progenitor cell fate and tissue construction during embryogenesis. Because this has potential implications for liver repair, this review will summarize current knowledge about Hh signaling and cholangiocytes. RECENT FINDINGS Diverse types of liver injury stimulate cholangiocytes to generate Hh ligands, and cholangiocyte-derived Hh ligands interact with receptors on cholangiocytes and neighboring cells to modulate virtually every aspect of the ductular reaction to injury. Excessive Hh signaling promotes dysfunctional repair and results in chronic hepatic inflammation, fibrogenesis, and carcinogenesis. SUMMARY The Hh pathway is part of the complex signaling network that orchestrates liver repair. How other pathways and posttranscriptional mechanisms modulate Hh signaling in ductular cells remains unclear. Further research in this area may identify novel therapeutic targets for the treatment of cholangiopathies and cholangiocarcinoma.
Collapse
Affiliation(s)
- Alessia Omenetti
- Division of Gastroenterology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | | |
Collapse
|
38
|
Matise MP, Wang H. Sonic hedgehog signaling in the developing CNS where it has been and where it is going. Curr Top Dev Biol 2011; 97:75-117. [PMID: 22074603 DOI: 10.1016/b978-0-12-385975-4.00010-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Sonic Hedgehog (Shh) is one of three mammalian orthologs of the Hedgehog (Hh) family of secreted proteins first identified for their role in patterning the Drosophila embryo. In this review, we will highlight some of the outstanding questions regarding how Shh signaling controls embryonic development. We will mainly consider its role in the developing mammalian central nervous system (CNS) where the pathway plays a critical role in orchestrating the specification of distinct cell fates within ventral regions, a process of exquisite complexity that is necessary for the proper wiring and hence function of the mature system. Embryonic development is a process that plays out in both the spatial and the temporal dimensions, and it is becoming increasingly clear that our understanding of Shh signaling in the CNS is grounded in an appreciation for the dynamic nature of this process. In addition, any consideration of Hh signaling must by necessity include a consideration of data from many different model organisms and systems. In many cases, the extent to which insights gained from these studies are applicable to the CNS remains to be determined, yet they provide a strong framework in which to explore its role in CNS development. We will also discuss how Shh controls cell fate diversification through the regulation of patterned target gene expression in the spinal cord, a region where our understanding of the morphogenetic action of graded Shh signaling is perhaps the furthest advanced.
Collapse
Affiliation(s)
- Michael P Matise
- UMDNJ/Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | | |
Collapse
|