51
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Lau CI, Barbarulo A, Solanki A, Saldaña JI, Crompton T. The kinesin motor protein Kif7 is required for T-cell development and normal MHC expression on thymic epithelial cells (TEC) in the thymus. Oncotarget 2018; 8:24163-24176. [PMID: 28445929 PMCID: PMC5421836 DOI: 10.18632/oncotarget.15241] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 01/21/2017] [Indexed: 11/30/2022] Open
Abstract
Kif7 is a ciliary kinesin motor protein that regulates mammalian Hedgehog pathway activation through influencing structure of the primary cilium. Here we show that Kif7 is required for normal T-cell development, despite the fact that T-cells lack primary cilia. Analysis of Kif7-deficient thymus showed that Kif7-deficiency increases the early CD44+CD25+CD4-CD8- thymocyte progenitor population but reduces differentiation to CD4+CD8+ double positive (DP) cell. At the transition from DP to mature T-cell, Kif7-deficiency selectively delayed maturation to the CD8 lineage. Expression of CD5, which correlates with TCR signal strength, was reduced on DP and mature CD4 and CD8 cells, as a result of thymocyte-intrinsic Kif7-deficiency, and Kif7-deficient T-cells from radiation chimeras activated less efficiently when stimulated with anti-CD3 and anti-CD28 in vitro. Kif7-deficient thymocytes showed higher expression of the Hedgehog target gene Ptch1 than WT, but were less sensitive to treatment with recombinant Shh, and Kif7-deficient T-cell development was refractory to neutralisation of endogenous Hh proteins, indicating that Kif7-deficient thymocytes were unable to interpret changes in the Hedgehog signal. In addition, Kif7-deficiency reduced cell-surface MHCII expression on thymic epithelial cells.
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Affiliation(s)
- Ching-In Lau
- Immunobiology Section, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Alessandro Barbarulo
- Immunobiology Section, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Anisha Solanki
- Immunobiology Section, UCL Great Ormond Street Institute of Child Health, London, UK
| | - José Ignacio Saldaña
- Immunobiology Section, UCL Great Ormond Street Institute of Child Health, London, UK.,School of Health, Sport and Bioscience, University of East London, London, UK
| | - Tessa Crompton
- Immunobiology Section, UCL Great Ormond Street Institute of Child Health, London, UK
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52
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Huang D, Wang Y, Tang J, Luo S. Molecular mechanisms of suppressor of fused in regulating the hedgehog signalling pathway. Oncol Lett 2018; 15:6077-6086. [PMID: 29725392 DOI: 10.3892/ol.2018.8142] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Accepted: 10/17/2017] [Indexed: 02/07/2023] Open
Abstract
Highly conserved throughout evolution, the hedgehog (Hh) signalling pathway has been demonstrated to be involved in embryonic development, stem cell maintenance and tissue homeostasis in animals ranging from invertebrates to vertebrates. In the human body, a variety of cancer types are associated with the aberrantly activated Hh signalling pathway. Multiple studies have revealed suppressor of fused (Sufu) as a key negative regulator of this signalling pathway. In vertebrates, Sufu primarily functions as a tumor suppressor factor by interacting with and inhibiting glioma-associated oncogene homologues (GLIs), which are the terminal transcription factors of the Hh signalling pathway and belong to the Kruppel family of zinc finger proteins; by contrast, the regulation of Sufu itself remains relatively unclear. In the present review article, we focus on the effects of Sufu on the Hh signalling pathway in tumourigenesis and the molecular mechanisms underlying the regulation of GLI by Sufu. In addition, the factors modulating the activity of Sufu at post-transcriptional levels are also discussed.
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Affiliation(s)
- Dengliang Huang
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.,Jiangxi Key Laboratory of Molecular Diagnostics and Precision Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Yiting Wang
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.,Jiangxi Key Laboratory of Molecular Diagnostics and Precision Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Jiabin Tang
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Shiwen Luo
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.,Jiangxi Key Laboratory of Molecular Diagnostics and Precision Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
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53
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Bryant L, Lozynska O, Maguire AM, Aleman TS, Bennett J. Prescreening whole exome sequencing results from patients with retinal degeneration for variants in genes associated with retinal degeneration. Clin Ophthalmol 2017; 12:49-63. [PMID: 29343940 PMCID: PMC5749571 DOI: 10.2147/opth.s147684] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Background Accurate clinical diagnosis and prognosis of retinal degeneration can be aided by the identification of the disease-causing genetic variant. It can confirm the clinical diagnosis as well as inform the clinician of the risk for potential involvement of other organs such as kidneys. It also aids in genetic counseling for affected individuals who want to have a child. Finally, knowledge of disease-causing variants informs laboratory investigators involved in translational research. With the advent of next-generation sequencing, identifying pathogenic mutations is becoming easier, especially the identification of novel pathogenic variants. Methods We used whole exome sequencing on a cohort of 69 patients with various forms of retinal degeneration and in whom screens for previously identified disease-causing variants had been inconclusive. All potential pathogenic variants were verified by Sanger sequencing and, when possible, segregation analysis of immediate relatives. Potential variants were identified by using a semi-masked approach in which rare variants in candidate genes were identified without knowledge of the clinical diagnosis (beyond "retinal degeneration") or inheritance pattern. After the initial list of genes was prioritized, genetic diagnosis and inheritance pattern were taken into account. Results We identified the likely pathogenic variants in 64% of the subjects. Seven percent had a single heterozygous mutation identified that would cause recessive disease and 13% had no obviously pathogenic variants and no family members available to perform segregation analysis. Eleven subjects are good candidates for novel gene discovery. Two de novo mutations were identified that resulted in dominant retinal degeneration. Conclusion Whole exome sequencing allows for thorough genetic analysis of candidate genes as well as novel gene discovery. It allows for an unbiased analysis of genetic variants to reduce the chance that the pathogenic mutation will be missed due to incomplete or inaccurate family history or analysis at the early stage of a syndromic form of retinal degeneration.
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Affiliation(s)
- Laura Bryant
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Olga Lozynska
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Albert M Maguire
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Department of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Tomas S Aleman
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Department of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jean Bennett
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Department of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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54
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Wiegering A, Rüther U, Gerhardt C. The Role of Hedgehog Signalling in the Formation of the Ventricular Septum. J Dev Biol 2017; 5:E17. [PMID: 29615572 PMCID: PMC5831794 DOI: 10.3390/jdb5040017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/08/2017] [Accepted: 12/09/2017] [Indexed: 12/11/2022] Open
Abstract
An incomplete septation of the ventricles in the vertebrate heart that disturbes the strict separation between the contents of the two ventricles is termed a ventricular septal defect (VSD). Together with bicuspid aortic valves, it is the most frequent congenital heart disease in humans. Until now, life-threatening VSDs are usually treated surgically. To avoid surgery and to develop an alternative therapy (e.g., a small molecule therapy), it is necessary to understand the molecular mechanisms underlying ventricular septum (VS) development. Consequently, various studies focus on the investigation of signalling pathways, which play essential roles in the formation of the VS. In the past decade, several reports found evidence for an involvement of Hedgehog (HH) signalling in VS development. In this review article, we will summarise the current knowledge about the association between HH signalling and VS formation and discuss the use of such knowledge to design treatment strategies against the development of VSDs.
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Affiliation(s)
- Antonia Wiegering
- Institute for Animal Developmental and Molecular Biology, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany.
| | - Ulrich Rüther
- Institute for Animal Developmental and Molecular Biology, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany.
| | - Christoph Gerhardt
- Institute for Animal Developmental and Molecular Biology, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany.
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55
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Lenihan JA, Saha O, Young PW. Proteomic analysis reveals novel ligands and substrates for LNX1 E3 ubiquitin ligase. PLoS One 2017; 12:e0187352. [PMID: 29121065 PMCID: PMC5679597 DOI: 10.1371/journal.pone.0187352] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 10/18/2017] [Indexed: 11/25/2022] Open
Abstract
Ligand of Numb protein X1 (LNX1) is an E3 ubiquitin ligase that contains a catalytic RING (Really Interesting New Gene) domain and four PDZ (PSD-95, DlgA, ZO-1) domains. LNX1 can ubiquitinate Numb, as well as a number of other ligands. However, the physiological relevance of these interactions in vivo remain unclear. To gain functional insights into the LNX family, we have characterised the LNX1 interactome using affinity purification and mass spectrometry. This approach identified a large number of novel LNX1-interacting proteins, as well as confirming known interactions with NUMB and ERC2. Many of the novel interactions mapped to the LNX PDZ domains, particularly PDZ2, and many showed specificity for LNX1 over the closely related LNX2. We show that PPFIA1 (liprin-α1), KLHL11, KIF7 and ERC2 are substrates for ubiquitination by LNX1. LNX1 ubiquitination of liprin-α1 is dependent on a PDZ binding motif containing a carboxyl terminal cysteine that binds LNX1 PDZ2. Surprisingly, the neuronally-expressed LNX1p70 isoform, that lacks the RING domain, was found to promote ubiquitination of PPFIA1 and KLHL11, albeit to a lesser extent than the longer RING-containing LNX1p80 isoform. Of several E3-ligases identified in the LNX1 interactome we confirm interactions of LNX1 with MID2/TRIM1 and TRIM27. On this basis we propose a model whereby LNX1p70, despite lacking a catalytic RING domain, may function as a scaffold to promote ubiquitination of its ligands through recruitment of other E3-ligases. These findings provide functional insights into the LNX protein family, particularly the neuronal LNX1p70 isoform.
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Affiliation(s)
- Joan A. Lenihan
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Orthis Saha
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Paul W. Young
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
- * E-mail:
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56
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Wu C, Li J, Peterson A, Tao K, Wang B. Loss of dynein-2 intermediate chain Wdr34 results in defects in retrograde ciliary protein trafficking and Hedgehog signaling in the mouse. Hum Mol Genet 2017; 26:2386-2397. [PMID: 28379358 DOI: 10.1093/hmg/ddx127] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 03/28/2017] [Indexed: 11/14/2022] Open
Abstract
The Wdr34 gene encodes an intermediate chain of cytoplasmic dynein 2, the motor for retrograde intraflagellar transport (IFT) in primary cilia. Although mutations in human WDR34 have recently been reported, the association of WDR34 function with Hedgehog (Hh) signaling has not been established, and actual cilia defects in the WDR34 mutant cells have also not been completely characterized. In the present study, we show that Wdr34 mutant mice die in midgestation and exhibit open brain and polydactyly phenotypes. Several Hh-dependent ventral neural cell types are not specified in the mutant neural tube. The expression of the direct Hh targets, Gli1 and Patched 1, is inhibited, while the expression of limb patterning genes that are normally inhibited by the Gli3 repressor is anteriorly expanded in mutant limbs. Comparison of cilia phenotype and function among wild type, Dnchc2 (dynein 2 heavy chain), and Wdr34 mutant cells demonstrates that cilia in both Dnchc2 and Wdr34 mutant cells are stumpy. Several ciliary proteins examined abnormally accumulate in the cilia of both mutant cells. Consistent with its function, overexpressed Wdr34 is occasionally localized to cilia, and Wdr34 is required for the ciliary localization of dynein 2 light intermediate chain Lic3. More interestingly, we show that both Dnchc2 and Wdr34 act between Smo and Gli2/Gli3 in the Hh pathway. Therefore, like Dnchc2, Wdr34 is required for ciliogenesis, retrograde ciliary protein trafficking, and the regulation of Gli2/Gli3 activators and repressors. Furthermore, both Wdr34 and Dnchc2 promote microtubule growth, a novel dynein 2 function in a non-cilia structure.
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Affiliation(s)
- Chuanqing Wu
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China.,Department of Genetic Medicine, Weill Medical College of Cornell University, W404, New York, NY 10065,USA
| | - Jia Li
- Department of Genetic Medicine, Weill Medical College of Cornell University, W404, New York, NY 10065,USA.,Institute of Biological Sciences and Biotechnology, Donghua University, Shanghai 201620, China
| | - Andrew Peterson
- Department of Molecular Biology, Genentech, South San Francisco, CA 94080, USA
| | - Kaixiong Tao
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China
| | - Baolin Wang
- Department of Genetic Medicine, Weill Medical College of Cornell University, W404, New York, NY 10065,USA.,Department of Cell and Developmental Biology, Weill Medical College of Cornell University, W404, New York, NY 10065, USA
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57
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Zhao L, Wang L, Chi C, Lan W, Su Y. The emerging roles of phosphatases in Hedgehog pathway. Cell Commun Signal 2017; 15:35. [PMID: 28931407 PMCID: PMC5607574 DOI: 10.1186/s12964-017-0191-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 09/14/2017] [Indexed: 01/12/2023] Open
Abstract
Hedgehog signaling is evolutionarily conserved and plays a pivotal role in cell fate determination, embryonic development, and tissue renewal. As aberrant Hedgehog signaling is tightly associated with a broad range of human diseases, its activities must be precisely controlled. It has been known that several core components of Hedgehog pathway undergo reversible phosphorylations mediated by protein kinases and phosphatases, which acts as an effective regulatory mechanism to modulate Hedgehog signal activities. In contrast to kinases that have been extensively studied in these phosphorylation events, phosphatases were thought to function in an unspecific manner, thus obtained much less emphasis in the past. However, in recent years, increasing evidence has implicated that phosphatases play crucial and specific roles in the context of developmental signaling, including Hedgehog signaling. In this review, we present a summary of current progress on phosphatase studies in Hedgehog pathway, emphasizing the multiple employments of protein serine/threonine phosphatases during the transduction of morphogenic Hedgehog signal in both Drosophila and vertebrate systems, all of which provide insights into the importance of phosphatases in the specific regulation of Hedgehog signaling.
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Affiliation(s)
- Long Zhao
- Cardiovascular Research Center, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Liguo Wang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Chunli Chi
- Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Wenwen Lan
- Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Ying Su
- Institute of Evolution & Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
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58
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Han Y, Xiong Y, Shi X, Wu J, Zhao Y, Jiang J. Regulation of Gli ciliary localization and Hedgehog signaling by the PY-NLS/karyopherin-β2 nuclear import system. PLoS Biol 2017; 15:e2002063. [PMID: 28777795 PMCID: PMC5544186 DOI: 10.1371/journal.pbio.2002063] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 07/07/2017] [Indexed: 12/21/2022] Open
Abstract
Hedgehog (Hh) signaling in vertebrates depends on primary cilia. Upon stimulation, Hh pathway components, including Gli transcription factors, accumulate at primary cilia to transduce the Hh signal, but the mechanisms underlying their ciliary targeting remains largely unknown. Here, we show that the PY-type nuclear localization signal (PY-NLS)/karyopherinβ2 (Kapβ2) nuclear import system regulates Gli ciliary localization and Hh pathway activation. Mutating the PY-NLS in Gli or knockdown of Kapβ2 diminished Gli ciliary localization. Kapβ2 is required for the formation of Gli activator (GliA) in wild-type but not in Sufu mutant cells. Knockdown of Kapβ2 affected Hh signaling in zebrafish embryos, as well as in vitro cultured cerebellum granule neuron progenitors (CGNPs) and SmoM2-driven medulloblastoma cells. Furthermore, Kapβ2 depletion impaired the growth of cultured medulloblastoma cells, which was rescued by Gli overexpression. Interestingly, Kapβ2 is a transcriptional target of the Hh pathway, thus forming a positive feedback loop for Gli activation. Our study unravels the molecular mechanism and cellular machinery regulating Gli ciliary localization and identifies Kapβ2 as a critical regulator of the Hh pathway and a potential drug target for Hh-driven cancers. The secreted Hedgehog (Hh) protein plays an evolutionarily conserved role in both embryonic development and adult tissue homeostasis. Malfunction of Hh signaling activity contributes to a wide range of human diseases, including birth defects and cancer. Hh signaling in vertebrates critically depends on the primary cilium, a microtubule-based plasma membrane protrusion present on the surface of most mammalian cells. Upon ligand stimulation, Hh pathway components, including the seven-transmembrane protein Smoothened (Smo) and Gli transcription factors, accumulate at primary cilia to transduce the Hh signal, but the mechanisms underlying their ciliary targeting are still poorly understood. Here, we discover that the PY-type nuclear localization signal (PY-NLS) and the nuclear import factor karyopherinβ2 (Kapβ2) regulate Gli ciliary localization and Hh pathway activity. Mutating the PY-NLS in Gli or knockdown of Kapβ2 diminished Gli ciliary localization without affecting Smo ciliary accumulation in response to Hh. Kapβ2 regulates the formation of the active form of Gli, which is required for proper Hh signaling in zebrafish embryos and cultured cerebellum granule neuron progenitors (CGNPs). Kapβ2 depletion impaired the growth of medulloblastoma cells driven by an oncogenic form of Smo. Finally, Kapβ2 is a transcriptional target of the Hh pathway, forming a positive feedback loop to promote Gli activation. Our study reveals the molecular mechanism underlying the regulation of Gli ciliary targeting and identifies Kapβ2 as a potential cancer drug target.
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Affiliation(s)
- Yuhong Han
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Yue Xiong
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, Shanghai Institute of Life Sciences, CAS, School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Xuanming Shi
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Jiang Wu
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Yun Zhao
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, Shanghai Institute of Life Sciences, CAS, School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- * E-mail: (JJ); (YZ)
| | - Jin Jiang
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
- * E-mail: (JJ); (YZ)
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59
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Schwarz N, Lane A, Jovanovic K, Parfitt DA, Aguila M, Thompson CL, da Cruz L, Coffey PJ, Chapple JP, Hardcastle AJ, Cheetham ME. Arl3 and RP2 regulate the trafficking of ciliary tip kinesins. Hum Mol Genet 2017; 26:2480-2492. [PMID: 28444310 PMCID: PMC5808637 DOI: 10.1093/hmg/ddx143] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 04/07/2017] [Accepted: 04/11/2017] [Indexed: 11/14/2022] Open
Abstract
Ciliary trafficking defects are the underlying cause of many ciliopathies, including Retinitis Pigmentosa (RP). Anterograde intraflagellar transport (IFT) is mediated by kinesin motor proteins; however, the function of the homodimeric Kif17 motor in cilia is poorly understood, whereas Kif7 is known to play an important role in stabilizing cilia tips. Here we identified the ciliary tip kinesins Kif7 and Kif17 as novel interaction partners of the small GTPase Arl3 and its regulatory GTPase activating protein (GAP) Retinitis Pigmentosa 2 (RP2). We show that Arl3 and RP2 mediate the localization of GFP-Kif17 to the cilia tip and competitive binding of RP2 and Arl3 with Kif17 complexes. RP2 and Arl3 also interact with another ciliary tip kinesin, Kif7, which is a conserved regulator of Hedgehog (Hh) signaling. siRNA-mediated loss of RP2 or Arl3 reduced the level of Kif7 at the cilia tip. This was further validated by reduced levels of Kif7 at cilia tips detected in fibroblasts and induced pluripotent stem cell (iPSC) 3D optic cups derived from a patient carrying an RP2 nonsense mutation c.519C > T (p.R120X), which lack detectable RP2 protein. Translational read-through inducing drugs (TRIDs), such as PTC124, were able to restore Kif7 levels at the ciliary tip of RP2 null cells. Collectively, our findings suggest that RP2 and Arl3 regulate the trafficking of specific kinesins to cilia tips and provide additional evidence that TRIDs could be clinically beneficial for patients with this retinal degeneration.
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Affiliation(s)
- Nele Schwarz
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Amelia Lane
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | | | | | | | - Clare L. Thompson
- Institute of Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, UK
| | - Lyndon da Cruz
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Moorfields Eye Hospital, London EC1V 2PD, UK
| | | | - J. Paul Chapple
- William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, London EC1M 6BQ, UK
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60
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Pak E, Segal RA. Hedgehog Signal Transduction: Key Players, Oncogenic Drivers, and Cancer Therapy. Dev Cell 2017; 38:333-44. [PMID: 27554855 DOI: 10.1016/j.devcel.2016.07.026] [Citation(s) in RCA: 227] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Hedgehog (Hh) signaling pathway governs complex developmental processes, including proliferation and patterning within diverse tissues. These activities rely on a tightly regulated transduction system that converts graded Hh input signals into specific levels of pathway activity. Uncontrolled activation of Hh signaling drives tumor initiation and maintenance. However, recent entry of pathway-specific inhibitors into the clinic reveals mixed patient responses and thus prompts further exploration of pathway activation and inhibition. In this review, we share emerging insights into regulated and oncogenic Hh signaling, supplemented with updates on the development and use of Hh pathway-targeted therapies.
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Affiliation(s)
- Ekaterina Pak
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Rosalind A Segal
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA.
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61
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Bangs F, Anderson KV. Primary Cilia and Mammalian Hedgehog Signaling. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a028175. [PMID: 27881449 DOI: 10.1101/cshperspect.a028175] [Citation(s) in RCA: 400] [Impact Index Per Article: 57.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
It has been a decade since it was discovered that primary cilia have an essential role in Hedgehog (Hh) signaling in mammals. This discovery came from screens in the mouse that identified a set of genes that are required for both normal Hh signaling and for the formation of primary cilia. Since then, dozens of mouse mutations have been identified that disrupt cilia in a variety of ways and have complex effects on Hedgehog signaling. Here, we summarize the genetic and developmental studies used to deduce how Hedgehog signal transduction is linked to cilia and the complex effects that perturbation of cilia structure can have on Hh signaling. We conclude by describing the current status of our understanding of the cell-type-specific regulation of ciliogenesis and how that determines the ability of cells to respond to Hedgehog ligands.
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Affiliation(s)
- Fiona Bangs
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York 10065
| | - Kathryn V Anderson
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York 10065
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62
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Wu F, Zhang Y, Sun B, McMahon AP, Wang Y. Hedgehog Signaling: From Basic Biology to Cancer Therapy. Cell Chem Biol 2017; 24:252-280. [PMID: 28286127 DOI: 10.1016/j.chembiol.2017.02.010] [Citation(s) in RCA: 218] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/29/2016] [Accepted: 02/10/2017] [Indexed: 02/07/2023]
Abstract
The Hedgehog (HH) signaling pathway was discovered originally as a key pathway in embryonic patterning and development. Since its discovery, it has become increasingly clear that the HH pathway also plays important roles in a multitude of cancers. Therefore, HH signaling has emerged as a therapeutic target of interest for cancer therapy. In this review, we provide a brief overview of HH signaling and the key molecular players involved and offer an up-to-date summary of our current knowledge of endogenous and exogenous small molecules that modulate HH signaling. We discuss experiences and lessons learned from the decades-long efforts toward the development of cancer therapies targeting the HH pathway. Challenges to develop next-generation cancer therapies are highlighted.
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Affiliation(s)
- Fujia Wu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bo Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Andrew P McMahon
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad-CIRM Center for Regenerative Medicine and Stem Cell Research, W.M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Yu Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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63
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He M, Agbu S, Anderson KV. Microtubule Motors Drive Hedgehog Signaling in Primary Cilia. Trends Cell Biol 2017; 27:110-125. [PMID: 27765513 PMCID: PMC5258846 DOI: 10.1016/j.tcb.2016.09.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 09/08/2016] [Accepted: 09/23/2016] [Indexed: 01/05/2023]
Abstract
The mammalian Hedgehog (Hh) signaling pathway is required for development and for maintenance of adult stem cells, and overactivation of the pathway can cause tumorigenesis. All responses to Hh family ligands in mammals require the primary cilium, an ancient microtubule-based organelle that extends from the cell surface. Genetic studies in mice and humans have defined specific functions for cilium-associated microtubule motor proteins: they act in the construction and disassembly of the primary cilium, they control ciliary length and stability, and some have direct roles in mammalian Hh signal transduction. These studies highlight how integrated genetic and cell biological studies can define the molecular mechanisms that underlie cilium-associated health and disease.
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Affiliation(s)
- Mu He
- Department of Physiology and Department of Biochemistry and Biophysics, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Stephanie Agbu
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Biochemistry, Cell, and Molecular Biology Program, Weill Graduate School of Medical Sciences of Cornell University, 1300 York Avenue, New York, NY 10065, USA
| | - Kathryn V Anderson
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
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64
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Abstract
The casein kinase 1 (CK1) family of serine (Ser)/threonine (Thr) protein kinases participates in a myriad of cellular processes including developmental signaling. Hedgehog (Hh) and Wnt pathways are two major and evolutionarily conserved signaling pathways that control embryonic development and adult tissue homeostasis. Deregulation of these pathways leads to many human disorders including birth defects and cancer. Here, I review the role of CK1 in the regulation of Hh and Wnt signal transduction cascades from the membrane reception systems to the transcriptional effectors. In both Hh and Wnt pathways, multiple CK1 family members regulate signal transduction at several levels of the pathways and play either positive or negative roles depending on the signaling status, individual CK1 isoforms involved, and the specific substrates they phosphorylate. A common mechanism underlying the control of CK1-mediated phosphorylation of Hh and Wnt pathway components is the regulation of CK1/substrate interaction within large protein complexes. I will highlight this feature in the context of Hh signaling and draw interesting parallels between the Hh and Wnt pathways.
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Affiliation(s)
- Jin Jiang
- University of Texas Southwestern Medical Center at Dallas, Dallas, TX, United States.
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65
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Jin Z, Schwend T, Fu J, Bao Z, Liang J, Zhao H, Mei W, Yang J. Members of the Rusc protein family interact with Sufu and inhibit vertebrate Hedgehog signaling. Development 2016; 143:3944-3955. [PMID: 27633991 DOI: 10.1242/dev.138917] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 09/01/2016] [Indexed: 12/20/2022]
Abstract
Hedgehog (Hh) signaling is fundamentally important for development and adult tissue homeostasis. It is well established that in vertebrates Sufu directly binds and inhibits Gli proteins, the downstream mediators of Hh signaling. However, it is unclear how the inhibitory function of Sufu towards Gli is regulated. Here we report that the Rusc family of proteins, the biological functions of which are poorly understood, form a heterotrimeric complex with Sufu and Gli. Upon Hh signaling, Rusc is displaced from this complex, followed by dissociation of Gli from Sufu. In mammalian fibroblast cells, knockdown of Rusc2 potentiates Hh signaling by accelerating signaling-induced dissociation of the Sufu-Gli protein complexes. In Xenopus embryos, knockdown of Rusc1 or overexpression of a dominant-negative Rusc enhances Hh signaling during eye development, leading to severe eye defects. Our study thus uncovers a novel regulatory mechanism controlling the response of cells to Hh signaling in vertebrates.
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Affiliation(s)
- Zhigang Jin
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, 2001 S Lincoln Avenue, Urbana, IL 61802, USA
| | - Tyler Schwend
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, 2001 S Lincoln Avenue, Urbana, IL 61802, USA
| | - Jia Fu
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, 2001 S Lincoln Avenue, Urbana, IL 61802, USA
| | - Zehua Bao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USA
| | - Jing Liang
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USA
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USA
| | - Wenyan Mei
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, 2001 S Lincoln Avenue, Urbana, IL 61802, USA
| | - Jing Yang
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, 2001 S Lincoln Avenue, Urbana, IL 61802, USA
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66
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Control of Hedgehog Signalling by the Cilia-Regulated Proteasome. J Dev Biol 2016; 4:jdb4030027. [PMID: 29615591 PMCID: PMC5831775 DOI: 10.3390/jdb4030027] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 08/25/2016] [Accepted: 08/29/2016] [Indexed: 12/31/2022] Open
Abstract
The Hedgehog signalling pathway is evolutionarily highly conserved and essential for embryonic development of invertebrates and vertebrates. Consequently, impaired Hedgehog signalling results in very severe human diseases, ranging from holoprosencephaly to Pallister-Hall syndrome. Due to this great importance for human health, the focus of numerous research groups is placed on the investigation of the detailed mechanisms underlying Hedgehog signalling. Today, it is known that tiny cell protrusions, known as primary cilia, are necessary to mediate Hedgehog signalling in vertebrates. Although the Hedgehog pathway is one of the best studied signalling pathways, many questions remain. One of these questions is: How do primary cilia control Hedgehog signalling in vertebrates? Recently, it was shown that primary cilia regulate a special kind of proteasome which is essential for proper Hedgehog signalling. This review article will cover this novel cilia-proteasome association in embryonic Hedgehog signalling and discuss the possibilities provided by future investigations on this topic.
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67
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Torrado B, Graña M, Badano JL, Irigoín F. Ciliary Entry of the Hedgehog Transcriptional Activator Gli2 Is Mediated by the Nuclear Import Machinery but Differs from Nuclear Transport in Being Imp-α/β1-Independent. PLoS One 2016; 11:e0162033. [PMID: 27579771 PMCID: PMC5007031 DOI: 10.1371/journal.pone.0162033] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 08/16/2016] [Indexed: 01/20/2023] Open
Abstract
Gli2 is the primary transcriptional activator of Hedgehog signalling in mammals. Upon stimulation of the pathway, Gli2 moves into the cilium before reaching the nucleus. However, the mechanisms underlying its entry into the cilium are not completely understood. Since several similarities have been reported between nuclear and ciliary import, we investigated if the nuclear import machinery participates in Gli2 ciliary entry. Here we show that while two conserved classical nuclear localization signals mediate Gli2 nuclear localization via importin (Imp)-α/β1, these sequences are not required for Gli2 ciliary import. However, blocking Imp-mediated transport through overexpression of GTP-locked Ran reduced the percentage of Gli2 positive cilia, an effect that was not explained by increased CRM1-dependent export of Gli2 from the cilium. We explored the participation of Imp-β2 in Gli2 ciliary traffic and observed that this transporter is involved in moving Gli2 into the cilium, as has been described for other ciliary proteins. In addition, our data indicate that Imp-β2 might also collaborate in Gli2 nuclear entry. How does Imp-β2 determine the final destination of a protein that can localize to two distinct subcellular compartments remains an open question. Therefore, our data shows that the nuclear-cytoplasmic shuttling machinery plays a critical role mediating the subcellular distribution of Gli2 and the activation of the pathway, but distinct importins likely play a differential role mediating its ciliary and nuclear translocation.
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Affiliation(s)
- Belén Torrado
- Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo CP11400, Uruguay
| | - Martín Graña
- Bioinformatics Unit, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo CP11400, Uruguay
| | - José L. Badano
- Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo CP11400, Uruguay
| | - Florencia Irigoín
- Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo CP11400, Uruguay
- Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Gral. Flores 2125, Montevideo CP11800, Uruguay
- * E-mail:
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68
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Paige Taylor S, Kunova Bosakova M, Varecha M, Balek L, Barta T, Trantirek L, Jelinkova I, Duran I, Vesela I, Forlenza KN, Martin JH, Hampl A, Bamshad M, Nickerson D, Jaworski ML, Song J, Ko HW, Cohn DH, Krakow D, Krejci P. An inactivating mutation in intestinal cell kinase, ICK, impairs hedgehog signalling and causes short rib-polydactyly syndrome. Hum Mol Genet 2016; 25:3998-4011. [PMID: 27466187 DOI: 10.1093/hmg/ddw240] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 06/27/2016] [Accepted: 06/29/2016] [Indexed: 12/30/2022] Open
Abstract
The short rib polydactyly syndromes (SRPS) are a group of recessively inherited, perinatal-lethal skeletal disorders primarily characterized by short ribs, shortened long bones, varying types of polydactyly and concomitant visceral abnormalities. Mutations in several genes affecting cilia function cause SRPS, revealing a role for cilia function in skeletal development. To identify additional SRPS genes and discover novel ciliary molecules required for normal skeletogenesis, we performed exome sequencing in a cohort of patients and identified homozygosity for a missense mutation, p.E80K, in Intestinal Cell Kinase, ICK, in one SRPS family. The p.E80K mutation abolished serine/threonine kinase activity, resulting in altered ICK subcellular and ciliary localization, increased cilia length, aberrant cartilage growth plate structure, defective Hedgehog and altered ERK signalling. These data identify ICK as an SRPS-associated gene and reveal that abnormalities in signalling pathways contribute to defective skeletogenesis.
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Affiliation(s)
- S Paige Taylor
- Department of Human Genetics, University of California Los Angeles, Los Angeles, CA 90095, USA
| | | | - Miroslav Varecha
- Department of Biology, Faculty of Medicine, Masaryk University, 62500 Brno, Czech Republic
| | - Lukas Balek
- Department of Biology, Faculty of Medicine, Masaryk University, 62500 Brno, Czech Republic
| | - Tomas Barta
- Department of Histology and Embryology, Faculty of Medicine, Masaryk University, 62500 Brno, Czech Republic
| | - Lukas Trantirek
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500 Brno, Czech Republic
| | - Iva Jelinkova
- Department of Biology, Faculty of Medicine, Masaryk University, 62500 Brno, Czech Republic
| | - Ivan Duran
- Department of Orthopaedic Surgery.,Department of Human Genetics.,Department of Obstetrics and Gynecology, Orthopaedic Institute for Children, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Iva Vesela
- Institute of Experimental Biology, Masaryk University, 62500 Brno, Czech Republic
| | - Kimberly N Forlenza
- Department of Orthopaedic Surgery.,Department of Human Genetics.,Department of Obstetrics and Gynecology, Orthopaedic Institute for Children, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Jorge H Martin
- Department of Orthopaedic Surgery.,Department of Human Genetics.,Department of Obstetrics and Gynecology, Orthopaedic Institute for Children, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Ales Hampl
- Department of Histology and Embryology, Faculty of Medicine, Masaryk University, 62500 Brno, Czech Republic
| | | | - Michael Bamshad
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA.,Division of Genetic Medicine, Seattle Children's Hospital, Seattle, WA 98105, USA.,Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Deborah Nickerson
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | | | - Jieun Song
- College of Pharmacy, Dongguk University-Seoul, Goyang 410-820, Korea
| | - Hyuk Wan Ko
- College of Pharmacy, Dongguk University-Seoul, Goyang 410-820, Korea
| | - Daniel H Cohn
- Department of Orthopaedic Surgery.,International Skeletal Dysplasia Registry, University of California Los Angeles, Los Angeles, CA 90095, USA.,Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Deborah Krakow
- Department of Human Genetics, University of California Los Angeles, Los Angeles, CA 90095, USA .,Department of Orthopaedic Surgery.,International Skeletal Dysplasia Registry, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Pavel Krejci
- Department of Biology, Faculty of Medicine, Masaryk University, 62500 Brno, Czech Republic.,Department of Orthopaedic Surgery.,International Clinical Research Center, St. Anne's University Hospital, 65691 Brno, Czech Republic
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69
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Li T, Fan J, Blanco-Sánchez B, Giagtzoglou N, Lin G, Yamamoto S, Jaiswal M, Chen K, Zhang J, Wei W, Lewis MT, Groves AK, Westerfield M, Jia J, Bellen HJ. Ubr3, a Novel Modulator of Hh Signaling Affects the Degradation of Costal-2 and Kif7 through Poly-ubiquitination. PLoS Genet 2016; 12:e1006054. [PMID: 27195754 PMCID: PMC4873228 DOI: 10.1371/journal.pgen.1006054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 04/25/2016] [Indexed: 12/21/2022] Open
Abstract
Hedgehog (Hh) signaling regulates multiple aspects of metazoan development and tissue homeostasis, and is constitutively active in numerous cancers. We identified Ubr3, an E3 ubiquitin ligase, as a novel, positive regulator of Hh signaling in Drosophila and vertebrates. Hh signaling regulates the Ubr3-mediated poly-ubiquitination and degradation of Cos2, a central component of Hh signaling. In developing Drosophila eye discs, loss of ubr3 leads to a delayed differentiation of photoreceptors and a reduction in Hh signaling. In zebrafish, loss of Ubr3 causes a decrease in Shh signaling in the developing eyes, somites, and sensory neurons. However, not all tissues that require Hh signaling are affected in zebrafish. Mouse UBR3 poly-ubiquitinates Kif7, the mammalian homologue of Cos2. Finally, loss of UBR3 up-regulates Kif7 protein levels and decreases Hh signaling in cultured cells. In summary, our work identifies Ubr3 as a novel, evolutionarily conserved modulator of Hh signaling that boosts Hh in some tissues.
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Affiliation(s)
- Tongchao Li
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Junkai Fan
- Markey Cancer Center and Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | | | - Nikolaos Giagtzoglou
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, United States of America
| | - Guang Lin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Shinya Yamamoto
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, United States of America
| | - Manish Jaiswal
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas, United States of America
| | - Kuchuan Chen
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Jie Zhang
- Markey Cancer Center and Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Wei Wei
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas, United States of America
| | - Michael T. Lewis
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas, United States of America
| | - Andrew K. Groves
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
| | - Monte Westerfield
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, United States of America
| | - Jianhang Jia
- Markey Cancer Center and Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Hugo J. Bellen
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, United States of America
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
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70
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Emechebe U, Kumar P P, Rozenberg JM, Moore B, Firment A, Mirshahi T, Moon AM. T-box3 is a ciliary protein and regulates stability of the Gli3 transcription factor to control digit number. eLife 2016; 5. [PMID: 27046536 PMCID: PMC4829432 DOI: 10.7554/elife.07897] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 03/05/2016] [Indexed: 12/17/2022] Open
Abstract
Crucial roles for T-box3 in development are evident by severe limb malformations and other birth defects caused by T-box3 mutations in humans. Mechanisms whereby T-box3 regulates limb development are poorly understood. We discovered requirements for T-box at multiple stages of mouse limb development and distinct molecular functions in different tissue compartments. Early loss of T-box3 disrupts limb initiation, causing limb defects that phenocopy Sonic Hedgehog (Shh) mutants. Later ablation of T-box3 in posterior limb mesenchyme causes digit loss. In contrast, loss of anterior T-box3 results in preaxial polydactyly, as seen with dysfunction of primary cilia or Gli3-repressor. Remarkably, T-box3 is present in primary cilia where it colocalizes with Gli3. T-box3 interacts with Kif7 and is required for normal stoichiometry and function of a Kif7/Sufu complex that regulates Gli3 stability and processing. Thus, T-box3 controls digit number upstream of Shh-dependent (posterior mesenchyme) and Shh-independent, cilium-based (anterior mesenchyme) Hedgehog pathway function. DOI:http://dx.doi.org/10.7554/eLife.07897.001 Mutations in the gene that encodes a protein called T-box3 cause serious birth defects, including deformities of the hands and feet, via poorly understood mechanisms. Several other proteins are also important for ensuring that limbs develop correctly. These include the Sonic Hedgehog protein, which controls a signaling pathway that determines whether a protein called Gli3 is converted into its “repressor” form. The hair-like structures called primary cilia that sit on the surface of animal cells also contain Gli3, and processes within these structures control the production of the Gli3-repressor. Emechebe, Kumar et al. have now studied genetically engineered mice in which the production of the T-box3 protein was stopped at different stages of mouse development. This revealed that turning off T-box3 production early in development causes many parts of the limb not to form. This type of defect appears to be the same as that seen in mice that lack the Sonic Hedgehog protein. If the production of T-box3 is turned off later in mouse development in the rear portion of the developing limb, the limb starts to develop but doesn’t develop enough rear toes. When T-box3 production is turned off in the front portion of the developing limbs, mice are born with too many front toes. This latter problem mimics the effects seen in mice that are unable to produce Gli3-repressor or that have defective primary cilia. Further investigation unexpectedly revealed that T-box3 is found in primary cilia and localizes to the same regions of the cilia as the Gli3-repressor. Furthermore, T-box3 also interacts with a protein complex that controls the stability of Gli3 and processes it into the Gli3-repressor form. In the future, it will be important to determine how T-box3 controls the stability of Gli3 and whether that process occurs in the primary cilia or in other parts of the cell where T-box3 and Gli3 coexist, such as the nucleus. This could help us understand how T-box3 and Sonic Hedgehog signaling contribute to other aspects of development and to certain types of cancer. DOI:http://dx.doi.org/10.7554/eLife.07897.002
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Affiliation(s)
- Uchenna Emechebe
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, United States
| | - Pavan Kumar P
- Weis Center for Research, Geisinger Clinic, Danville, United States
| | | | - Bryn Moore
- Weis Center for Research, Geisinger Clinic, Danville, United States
| | - Ashley Firment
- Weis Center for Research, Geisinger Clinic, Danville, United States
| | - Tooraj Mirshahi
- Weis Center for Research, Geisinger Clinic, Danville, United States
| | - Anne M Moon
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, United States.,Weis Center for Research, Geisinger Clinic, Danville, United States.,Department of Human Genetics, University of Utah, Salt Lake City, United States.,Department of Pediatrics, University of Utah, Salt Lake City, United States
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71
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Zhao Z, Lee RTH, Pusapati GV, Iyu A, Rohatgi R, Ingham PW. An essential role for Grk2 in Hedgehog signalling downstream of Smoothened. EMBO Rep 2016; 17:739-52. [PMID: 27113758 PMCID: PMC5341524 DOI: 10.15252/embr.201541532] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 03/07/2016] [Indexed: 01/28/2023] Open
Abstract
The G‐protein‐coupled receptor kinase 2 (adrbk2/GRK2) has been implicated in vertebrate Hedgehog (Hh) signalling based on the effects of its transient knock‐down in mammalian cells and zebrafish embryos. Here, we show that the response to Hh signalling is effectively abolished in the absence of Grk2 activity. Zebrafish embryos lacking all Grk2 activity are refractory to both Sonic hedgehog (Shh) and oncogenic Smoothened (Smo) activity, but remain responsive to inhibition of cAMP‐dependent protein kinase (PKA) activity. Mutation of the kinase domain abrogates the rescuing activity of grk2 mRNA, suggesting that Grk2 acts in a kinase‐dependent manner to regulate the response to Hh. Previous studies have suggested that Grk2 potentiates Smo activity by phosphorylating its C‐terminal tail (CTT). In the zebrafish embryo, however, phosphomimetic Smo does not display constitutive activity, whereas phospho‐null mutants retain activity, implying phosphorylation is neither sufficient nor necessary for Smo function. Since Grk2 rescuing activity requires the integrity of domains essential for its interaction with GPCRs, we speculate that Grk2 may regulate Hh pathway activity by downregulation of a GPCR.
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Affiliation(s)
- Zhonghua Zhao
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore Developmental and Biomedical Genetics Laboratory, Institute of Molecular and Cell Biology, Agency of Science, Technology and Research (A-STAR), Singapore, Singapore
| | - Raymond Teck Ho Lee
- Developmental and Biomedical Genetics Laboratory, Institute of Molecular and Cell Biology, Agency of Science, Technology and Research (A-STAR), Singapore, Singapore
| | - Ganesh V Pusapati
- Departments of Medicine and Biochemistry, School of Medicine, Stanford University, Stanford, CA, USA
| | - Audrey Iyu
- Developmental and Biomedical Genetics Laboratory, Institute of Molecular and Cell Biology, Agency of Science, Technology and Research (A-STAR), Singapore, Singapore
| | - Rajat Rohatgi
- Departments of Medicine and Biochemistry, School of Medicine, Stanford University, Stanford, CA, USA
| | - Philip W Ingham
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore Developmental and Biomedical Genetics Laboratory, Institute of Molecular and Cell Biology, Agency of Science, Technology and Research (A-STAR), Singapore, Singapore
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72
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Gorojankina T. Hedgehog signaling pathway: a novel model and molecular mechanisms of signal transduction. Cell Mol Life Sci 2016; 73:1317-32. [PMID: 26762301 PMCID: PMC11108571 DOI: 10.1007/s00018-015-2127-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 12/23/2015] [Accepted: 12/23/2015] [Indexed: 12/21/2022]
Abstract
The Hedgehog (Hh) signaling pathway has numerous roles in the control of cell proliferation, tissue patterning and stem cell maintenance. In spite of intensive study, the mechanisms of Hh signal transduction are not completely understood. Here I review published data and present a novel model of vertebrate Hh signaling suggesting that Smoothened (Smo) functions as a G-protein-coupled receptor in cilia. This is the first model to propose molecular mechanisms for the major steps of Hh signaling, including inhibition of Smo by Patched, Smo activation, and signal transduction from active Smo to Gli transcription factors. It also suggests a novel role for the negative pathway regulators Sufu and PKA in these processes.
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Affiliation(s)
- Tatiana Gorojankina
- Neuroscience Paris-Saclay Institute (Neuro-PSI), UMR 9197, CNRS, Université Paris-Sud, Bât. 32/33, CNRS, 91190, Gif-sur-Yvette, France.
- Institut Curie, Centre de Recherche, Orsay, France.
- CNRS UMR3347, 91400, Orsay, France.
- Univ. Paris Sud, Université Paris Saclay, Orsay, France.
- INSERM U1021, 91400, Orsay, France.
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73
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Song Z, Zhang X, Jia S, Yelick PC, Zhao C. Zebrafish as a Model for Human Ciliopathies. J Genet Genomics 2016; 43:107-20. [DOI: 10.1016/j.jgg.2016.02.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 12/22/2022]
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74
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Xavier GM, Seppala M, Barrell W, Birjandi AA, Geoghegan F, Cobourne MT. Hedgehog receptor function during craniofacial development. Dev Biol 2016; 415:198-215. [PMID: 26875496 DOI: 10.1016/j.ydbio.2016.02.009] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 02/09/2016] [Accepted: 02/10/2016] [Indexed: 01/20/2023]
Abstract
The Hedgehog signalling pathway plays a fundamental role in orchestrating normal craniofacial development in vertebrates. In particular, Sonic hedgehog (Shh) is produced in three key domains during the early formation of the head; neuroectoderm of the ventral forebrain, facial ectoderm and the pharyngeal endoderm; with signal transduction evident in both ectodermal and mesenchymal tissue compartments. Shh signalling from the prechordal plate and ventral midline of the diencephalon is required for appropriate division of the eyefield and forebrain, with mutation in a number of pathway components associated with Holoprosencephaly, a clinically heterogeneous developmental defect characterized by a failure of the early forebrain vesicle to divide into distinct halves. In addition, signalling from the pharyngeal endoderm and facial ectoderm plays an essential role during development of the face, influencing cranial neural crest cells that migrate into the early facial processes. In recent years, the complexity of Shh signalling has been highlighted by the identification of multiple novel proteins that are involved in regulating both the release and reception of this protein. Here, we review the contributions of Shh signalling during early craniofacial development, focusing on Hedgehog receptor function and describing the consequences of disruption for inherited anomalies of this region in both mouse models and human populations.
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Affiliation(s)
- Guilherme M Xavier
- Department of Craniofacial Development and Stem Cell Biology, King's College London Dental Institute, Floor 27, Guy's Hospital, London SE1 9RT, UK; Department of Orthodontics, King's College London Dental Institute, Floor 27, Guy's Hospital, London SE1 9RT, UK
| | - Maisa Seppala
- Department of Craniofacial Development and Stem Cell Biology, King's College London Dental Institute, Floor 27, Guy's Hospital, London SE1 9RT, UK; Department of Orthodontics, King's College London Dental Institute, Floor 27, Guy's Hospital, London SE1 9RT, UK
| | - William Barrell
- Department of Craniofacial Development and Stem Cell Biology, King's College London Dental Institute, Floor 27, Guy's Hospital, London SE1 9RT, UK
| | - Anahid A Birjandi
- Department of Craniofacial Development and Stem Cell Biology, King's College London Dental Institute, Floor 27, Guy's Hospital, London SE1 9RT, UK
| | - Finn Geoghegan
- Department of Craniofacial Development and Stem Cell Biology, King's College London Dental Institute, Floor 27, Guy's Hospital, London SE1 9RT, UK
| | - Martyn T Cobourne
- Department of Craniofacial Development and Stem Cell Biology, King's College London Dental Institute, Floor 27, Guy's Hospital, London SE1 9RT, UK; Department of Orthodontics, King's College London Dental Institute, Floor 27, Guy's Hospital, London SE1 9RT, UK.
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75
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Sanchez GM, Alkhori L, Hatano E, Schultz SW, Kuzhandaivel A, Jafari S, Granseth B, Alenius M. Hedgehog Signaling Regulates the Ciliary Transport of Odorant Receptors in Drosophila. Cell Rep 2016; 14:464-470. [PMID: 26774485 DOI: 10.1016/j.celrep.2015.12.059] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 10/26/2015] [Accepted: 12/10/2015] [Indexed: 01/20/2023] Open
Abstract
Hedgehog (Hh) signaling is a key regulatory pathway during development and also has a functional role in mature neurons. Here, we show that Hh signaling regulates the odor response in adult Drosophila olfactory sensory neurons (OSNs). We demonstrate that this is achieved by regulating odorant receptor (OR) transport to and within the primary cilium in OSN neurons. Regulation relies on ciliary localization of the Hh signal transducer Smoothened (Smo). We further demonstrate that the Hh- and Smo-dependent regulation of the kinesin-like protein Cos2 acts in parallel to the intraflagellar transport system (IFT) to localize ORs within the cilium compartment. These findings expand our knowledge of Hh signaling to encompass chemosensory modulation and receptor trafficking.
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Affiliation(s)
- Gonzalo M Sanchez
- Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden
| | - Liza Alkhori
- Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden
| | - Eduardo Hatano
- Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden
| | - Sebastian W Schultz
- Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden
| | | | - Shadi Jafari
- Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden
| | - Björn Granseth
- Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden
| | - Mattias Alenius
- Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden.
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76
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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.
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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
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77
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Jiang S, Du J, Kong Q, Li C, Li Y, Sun H, Pu J, Mao B. A Group of ent-Kaurane Diterpenoids Inhibit Hedgehog Signaling and Induce Cilia Elongation. PLoS One 2015; 10:e0139830. [PMID: 26439749 PMCID: PMC4595341 DOI: 10.1371/journal.pone.0139830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 09/17/2015] [Indexed: 01/20/2023] Open
Abstract
The Hedgehog (Hh) signaling pathway plays important roles in the tumorigenesis of multiple cancers and is a key target for drug discovery. In a screen of natural products extracted from Chinese herbs, we identified eight ent-Kaurane diterpenoids and two triterpene dilactones as novel Hh pathway antagonists. Epistatic analyses suggest that these compounds likely act at the level or downstream of Smoothened (Smo) and upstream of Suppressor of Fused (Sufu). The ent-Kauranoid-treated cells showed elongated cilia, suppressed Smo trafficking to cilia, and mitotic defects, while the triterpene dilactones had no effect on the cilia and ciliary Smo. These ent-Kaurane diterpenoids provide new prototypes of Hh inhibitors, and are valuable probes for deciphering the mechanisms of Smo ciliary transport and ciliogenesis.
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Affiliation(s)
- Shiyou Jiang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China
| | - Jiacheng Du
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China
| | - Qinghua Kong
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Chaocui Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yan Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Handong Sun
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Jianxin Pu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- * E-mail: (BM); (JP)
| | - Bingyu Mao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- * E-mail: (BM); (JP)
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78
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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.
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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.
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79
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Oh S, Kato M, Zhang C, Guo Y, Beachy PA. A Comparison of Ci/Gli Activity as Regulated by Sufu in Drosophila and Mammalian Hedgehog Response. PLoS One 2015; 10:e0135804. [PMID: 26271100 PMCID: PMC4536226 DOI: 10.1371/journal.pone.0135804] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 07/27/2015] [Indexed: 01/20/2023] Open
Abstract
Suppressor of fused (Su(fu)/Sufu), one of the most conserved components of the Hedgehog (Hh) signaling pathway, binds Ci/Gli transcription factors and impedes activation of target gene expression. In Drosophila, the Su(fu) mutation has a minimal phenotype, and we show here that Ci transcriptional activity in large part is regulated independently of Su(fu) by other pathway components. Mutant mice lacking Sufu in contrast show excessive pathway activity and die as embryos with patterning defects. Here we show that in cultured cells Hh stimulation can augment transcriptional activity of a Gli2 variant lacking Sufu interaction and, surprisingly, that regulation of Hh pathway targets is nearly normal in the neural tube of Sufu-/- mutant embryos that also lack Gli1 function. Some degree of Hh-induced transcriptional activation of Ci/Gli thus can occur independently of Sufu in both flies and mammals. We further note that Sufu loss can also reduce Hh induction of high-threshold neural tube fates, such as floor plate, suggesting a possible positive pathway role for Sufu.
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Affiliation(s)
- Sekyung Oh
- Department of Developmental Biology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Masaki Kato
- Department of Developmental Biology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Chi Zhang
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Yurong Guo
- Division of Pulmonary and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Philip A. Beachy
- Department of Developmental Biology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Biochemistry, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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80
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Tunovic S, Barañano KW, Barkovich JA, Strober JB, Jamal L, Slavotinek AM. Novel KIF7 missense substitutions in two patients presenting with multiple malformations and features of acrocallosal syndrome. Am J Med Genet A 2015; 167A:2767-76. [PMID: 26174511 DOI: 10.1002/ajmg.a.37249] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 06/28/2015] [Indexed: 12/22/2022]
Abstract
We present two children who both had two missense mutations in the Kinesin Family Member 7 (KIF7) gene. A seven year old female with severe developmental delays, failure to thrive and growth retardation, infantile spasms, a cardiac vascular ring and right-sided aortic arch, imperforate anus, hydronephrosis with a right renal cyst, syndactyly and abnormal white matter was a compound heterozygote for c.3365C > G, predicting p.(Ser1122Trp) that was maternally inherited and c.2482G > A, predicting p.(Val828Met) that was paternally inherited. An eight year old female with severe developmental delays, epilepsy, left postaxial polydactyly of the hand and abnormalities of brain development including hydrocephalus, pachygyria and absence of the body and splenium of the corpus callous was a compound heterozygote for c.461G > A, predicting p.(Arg154Gln) and c.2959 G > A, predicting p.(Glu987Lys) that was maternally inherited and her father was unavailable for testing. The presentations in these children include features of acrocallosal syndrome, such as hypoplasia of the corpus callosum, enlarged ventricles, facial dysmorphism with a prominent forehead and broad halluces in the first child, but included atypical findings for individuals previously reported to have truncating mutations in KIF7, including imperforate anus, infantile spasms and severe growth retardation. We conclude that these phenotypes may result from the KIF7 sequence variants and abnormal hedgehog signaling, but that the full spectrum of KIF7-associated features remains to be determined.
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Affiliation(s)
- Sanjin Tunovic
- Division of Genetics, Department of Pediatrics, University of California, San Francisco, California
| | - Kristin W Barañano
- Department of Pediatric Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - James A Barkovich
- Department of Radiology and Biomolecular Imaging, University of California, San Francisco, California
| | - Jonathan B Strober
- Department of Pediatric Neurology, University of California, San Francisco, California
| | - Leila Jamal
- Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Anne M Slavotinek
- Division of Genetics, Department of Pediatrics, University of California, San Francisco, California
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81
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Abstract
The Hedgehog (Hh) signalling pathway plays many important roles in development, homeostasis and tumorigenesis. The critical function of Hh signalling in bone formation has been identified in the past two decades. Here, we review the evolutionarily conserved Hh signalling mechanisms with an emphasis on the functions of the Hh signalling pathway in bone development, homeostasis and diseases. In the early stages of embryonic limb development, Sonic Hedgehog (Shh) acts as a major morphogen in patterning the limb buds. Indian Hedgehog (Ihh) has an essential function in endochondral ossification and induces osteoblast differentiation in the perichondrium. Hh signalling is also involved intramembrane ossification. Interactions between Hh and Wnt signalling regulate cartilage development, endochondral bone formation and synovial joint formation. Hh also plays an important role in bone homeostasis, and reducing Hh signalling protects against age-related bone loss. Disruption of Hh signalling regulation leads to multiple bone diseases, such as progressive osseous heteroplasia. Therefore, understanding the signalling mechanisms and functions of Hh signalling in bone development, homeostasis and diseases will provide important insights into bone disease prevention, diagnoses and therapeutics.
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82
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Liu J, Zeng H, Liu A. The loss of Hh responsiveness by a non-ciliary Gli2 variant. Development 2015; 142:1651-60. [PMID: 25834022 DOI: 10.1242/dev.119669] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Accepted: 03/09/2015] [Indexed: 01/07/2023]
Abstract
Hedgehog signaling is crucial for vertebrate development and physiology. Gli2, the primary effector of Hedgehog signaling, localizes to the tip of the primary cilium, but the importance of its ciliary localization remains unclear. We address the roles of Gli2 ciliary localization by replacing endogenous Gli2 with Gli2(ΔCLR), a Gli2 variant not localizing to the cilium. The resulting Gli2(ΔCLRKI) and Gli2(ΔCLRKI);Gli3 double mutants resemble Gli2-null and Gli2;Gli3 double mutants, respectively, suggesting the lack of Gli2(ΔCLR) activation in development. Significantly, Gli2(ΔCLR) cannot be activated either by pharmacochemical activation of Smo in vitro or by loss of Ptch1 in vivo. Finally, Gli2(ΔCLR) exhibits strong transcriptional activator activity in the absence of Sufu, suggesting that the lack of its activation in vivo results from a specific failure in relieving the inhibitory function of Sufu. Our results provide strong evidence that the ciliary localization of Gli2 is crucial for cilium-dependent activation of Hedgehog signaling.
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Affiliation(s)
- Jinling Liu
- Department of Biology, Eberly College of Science, The Pennsylvania State University, University Park, PA 16802, USA
| | - Huiqing Zeng
- Department of Biology, Eberly College of Science, The Pennsylvania State University, University Park, PA 16802, USA
| | - Aimin Liu
- Department of Biology, Eberly College of Science, The Pennsylvania State University, University Park, PA 16802, USA Center for Cellular Dynamics, Huck Institute of Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
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83
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Barakeh D, Faqeih E, Anazi S, S Al-Dosari M, Softah A, Albadr F, Hassan H, Alazami AM, Alkuraya FS. The many faces of KIF7. Hum Genome Var 2015; 2:15006. [PMID: 27081521 PMCID: PMC4785560 DOI: 10.1038/hgv.2015.6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 12/22/2014] [Accepted: 12/23/2014] [Indexed: 11/17/2022] Open
Abstract
Mutations in KIF7, the gene that encodes a component of the kinesin complex of anterograde intraflagellar transport in the cilia, have been reported to cause a range of phenotypes including hydrolethalis, acrocallosal syndrome and Joubert syndrome. In a cohort of patients with various neurogenetic phenotypes, we identified novel KIF7 mutations in two families that span the known phenotypic spectrum of KIF7-related disorders. Surprisingly, we also identified a novel truncating KIF7 mutation in a third consanguineous family, in which the index presented with intellectual disability but no overt signs of ciliopathy, and his brain magnetic resonance imaging revealed an isolated dysgenesis of corpus callosum. This small cohort contributes novel pathogenic alleles of KIF7 and suggests that KIF7-related phenotypes can include isolated dysgenesis of corpus callosum with intellectual disability, thus expanding the range of phenotypes that warrant sequencing of this gene.
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Affiliation(s)
- Duna Barakeh
- Department of Genetics, King Faisal Specialist Hospital and Research Center , Riyadh, Saudi Arabia
| | - Eissa Faqeih
- Department of Pediatric Subspecialties, Children's Specialist Hospital, King Fahad Medical City , Riyadh, Saudi Arabia
| | - Shams Anazi
- Department of Genetics, King Faisal Specialist Hospital and Research Center , Riyadh, Saudi Arabia
| | - Mohammed S Al-Dosari
- Department of Pharmacognosy, College of Pharmacy, King Saud University , Riyadh, Saudi Arabia
| | - Ameen Softah
- Department of Pediatrics, King Fahad Armed Forces Hospital , Jeddah, Saudi Arabia
| | - Fahad Albadr
- Department of Radiology, College of Medicine, King Saud University , Riyadh, Saudi Arabia
| | - Hamdy Hassan
- Department of Radiology, College of Medicine, King Saud University , Riyadh, Saudi Arabia
| | - Anas M Alazami
- Department of Genetics, King Faisal Specialist Hospital and Research Center , Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia; Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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84
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Hedgehog signaling: From basic research to clinical applications. J Formos Med Assoc 2015; 114:569-76. [PMID: 25701396 DOI: 10.1016/j.jfma.2015.01.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/01/2015] [Indexed: 01/20/2023] Open
Abstract
Studies of the major signaling pathways have revealed a connection between development, regeneration, and cancer, highlighting common signaling networks in these processes. The Hedgehog (Hh) pathway plays a central role in the development of most tissues and organs in mammals. Hh signaling is also required for tissue homeostasis and regeneration in adults, while perturbed Hh signaling is associated with human cancers. A fundamental understanding of Hh signaling will not only enhance our knowledge of how the embryos are patterned but also provide tools to treat diseases related to aberrant Hh signaling. Studies have yielded a basic framework of Hh signaling, which establishes the foundation for addressing unresolved issues of Hh signaling. A detailed characterization of the biochemical interactions between Hh components will help explain the production of graded Hh responses required for tissue patterning. Additional cell biological and genetic studies will offer new insight into the role of Hh signaling in homeostasis and regeneration. Finally, drugs that are capable of manipulating the Hh pathway can be used to treat human diseases caused by disrupted Hh signaling. These investigations will serve as a paradigm for studying signal transduction/integration in homeostasis and disease, and for translating discovery from bench to bedside.
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85
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Cooperative integration between HEDGEHOG-GLI signalling and other oncogenic pathways: implications for cancer therapy. Expert Rev Mol Med 2015; 17:e5. [PMID: 25660620 PMCID: PMC4836208 DOI: 10.1017/erm.2015.3] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The HEDGEHOG-GLI (HH-GLI) signalling is a key pathway critical in embryonic development, stem cell biology and tissue homeostasis. In recent years, aberrant activation of HH-GLI signalling has been linked to several types of cancer, including those of the skin, brain, lungs, prostate, gastrointestinal tract and blood. HH-GLI signalling is initiated by binding of HH ligands to the transmembrane receptor PATCHED and is mediated by transcriptional effectors that belong to the GLI family, whose activity is finely tuned by a number of molecular interactions and post-translation modifications. Several reports suggest that the activity of the GLI proteins is regulated by several proliferative and oncogenic inputs, in addition or independent of upstream HH signalling. The identification of this complex crosstalk and the understanding of how the major oncogenic signalling pathways interact in cancer is a crucial step towards the establishment of efficient targeted combinatorial treatments. Here we review recent findings on the cooperative integration of HH-GLI signalling with the major oncogenic inputs and we discuss how these cues modulate the activity of the GLI proteins in cancer. We then summarise the latest advances on SMO and GLI inhibitors and alternative approaches to attenuate HH signalling through rational combinatorial therapies.
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86
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Jia Y, Wang Y, Xie J. The Hedgehog pathway: role in cell differentiation, polarity and proliferation. Arch Toxicol 2015; 89:179-91. [PMID: 25559776 PMCID: PMC4630008 DOI: 10.1007/s00204-014-1433-1] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 12/04/2014] [Indexed: 02/07/2023]
Abstract
Hedgehog (Hh) is first described as a genetic mutation that has "spiked" phenotype in the cuticles of Drosophila in later 1970s. Since then, Hh signaling has been implicated in regulation of differentiation, proliferation, tissue polarity, stem cell population and carcinogenesis. The first link of Hh signaling to cancer was established through discovery of genetic mutations of Hh receptor gene PTCH1 being responsible for Gorlin syndrome in 1996. It was later shown that Hh signaling is associated with many types of cancer, including skin, leukemia, lung, brain and gastrointestinal cancers. Another important milestone for the Hh research field is the FDA approval for the clinical use of Hh inhibitor Erivedge/Vismodegib for treatment of locally advanced and metastatic basal cell carcinomas. However, recent clinical trials of Hh signaling inhibitors in pancreatic, colon and ovarian cancer all failed, indicating a real need for further understanding of Hh signaling in cancer. In this review, we will summarize recent progress in the Hh signaling mechanism and its role in human cancer.
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Affiliation(s)
- Yanfei Jia
- Central Laboratory, Jinan Central Hospital Affiliated to Shandong, University, Jinan, China
- Division of Hematology and Oncology, Department of Pediatrics, Wells Center for Pediatric Research, Indiana University Simon Cancer Center, Indiana University, Indianapolis, IN 46202, USA
| | - Yunshan Wang
- Central Laboratory, Jinan Central Hospital Affiliated to Shandong, University, Jinan, China
| | - Jingwu Xie
- Division of Hematology and Oncology, Department of Pediatrics, Wells Center for Pediatric Research, Indiana University Simon Cancer Center, Indiana University, Indianapolis, IN 46202, USA
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87
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Chong YC, Mann RK, Zhao C, Kato M, Beachy PA. Bifurcating action of Smoothened in Hedgehog signaling is mediated by Dlg5. Genes Dev 2015; 29:262-76. [PMID: 25644602 PMCID: PMC4318143 DOI: 10.1101/gad.252676.114] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 12/29/2014] [Indexed: 12/19/2022]
Abstract
Binding of the Hedgehog (Hh) protein signal to its receptor, Patched, induces accumulation of the seven-pass transmembrane protein Smoothened (Smo) within the primary cilium and of the zinc finger transcription factor Gli2 at the ciliary tip, resulting ultimately in Gli-mediated changes in nuclear gene expression. However, the mechanism by which pathway activation is communicated from Smo to Gli2 is not known. In an effort to elucidate this mechanism, we identified Dlg5 (Discs large, homolog 5) in a biochemical screen for proteins that preferentially interact with activated Smo. We found that disruption of Smo-Dlg5 interactions or depletion of endogenous Dlg5 leads to diminished Hh pathway response without a significant impact on Smo ciliary accumulation. We also found that Dlg5 is localized at the basal body, where it associates with another pathway component, Kif7. We show that Dlg5 is required for Hh-induced enrichment of Kif7 and Gli2 at the tip of the cilium but is dispensable for Gpr161 exit from the cilium and the consequent suppression of Gli3 processing into its repressor form. Our findings suggest a bifurcation of Smo activity in Hh response, with a Dlg5-independent arm for suppression of Gli repressor formation and a second arm involving Smo interaction with Dlg5 for Gli activation.
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Affiliation(s)
- Yong Chun Chong
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California 94305, USA; Department of Developmental Biology, Stanford University, Stanford, California 94305, USA; Department of Biochemistry, Stanford University, Stanford, California 94305, USA
| | - Randall K Mann
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California 94305, USA; Department of Developmental Biology, Stanford University, Stanford, California 94305, USA; Department of Biochemistry, Stanford University, Stanford, California 94305, USA
| | - Chen Zhao
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California 94305, USA; Department of Developmental Biology, Stanford University, Stanford, California 94305, USA; Department of Biochemistry, Stanford University, Stanford, California 94305, USA
| | - Masaki Kato
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California 94305, USA; Department of Developmental Biology, Stanford University, Stanford, California 94305, USA
| | - Philip A Beachy
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California 94305, USA; Department of Developmental Biology, Stanford University, Stanford, California 94305, USA; Department of Biochemistry, Stanford University, Stanford, California 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
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88
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Zhulyn O, Hui CC. Sufu and Kif7 in limb patterning and development. Dev Dyn 2015; 244:468-78. [PMID: 25581370 DOI: 10.1002/dvdy.24249] [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: 08/31/2014] [Revised: 12/23/2014] [Accepted: 12/24/2014] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND The vertebrate digit pattern is defined by the morphogen Sonic hedgehog (Shh), which controls the activity of Gli transcription factors. Gli1, 2 and 3 are dynamically expressed during patterning. Downstream of Shh, their activity is regulated by Sufu and Kif7, core components of the Shh signaling cascade. The precise roles of these regulators during limb development have not been fully described. We analyze the role of Sufu and Kif7 in the limb and demonstrate that their loss has distinct and synergistic effects on Gli activity and digit pattern. RESULTS Using a series of mouse mutants, we show that Sufu and Kif7 are expressed throughout limb development and their deletion has distinct effects on Gli levels and limb formation. Concomitant deletion of Sufu and Kif7 results in constitutive pathway activity and severe limb truncation. This is consistent with the recently published two-population model, which suggests that precocious activation of Shh signaling inhibits organizing center formation and limb outgrowth. CONCLUSIONS Together, our findings demonstrate that perturbations of Sufu and Kif7 affect Gli activity and recapitulate the full spectrum of vertebrate limb defects, ranging from severe truncation to polydactyly.
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Affiliation(s)
- Olena Zhulyn
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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89
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Carpenter BS, Barry RL, Verhey KJ, Allen BL. The heterotrimeric kinesin-2 complex interacts with and regulates GLI protein function. J Cell Sci 2015; 128:1034-50. [PMID: 25588831 DOI: 10.1242/jcs.162552] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
GLI transport to the primary cilium and nucleus is required for proper Hedgehog (HH) signaling; however, the mechanisms that mediate these trafficking events are poorly understood. Kinesin-2 motor proteins regulate ciliary transport of cargo, yet their role in GLI protein function remains unexplored. To examine a role for the heterotrimeric KIF3A-KIF3B-KAP3 kinesin-2 motor complex in regulating GLI activity, we performed a series of structure-function analyses using biochemical, cell signaling and in vivo approaches that define novel specific interactions between GLI proteins and two components of this complex, KAP3 and KIF3A. We find that all three mammalian GLI proteins interact with KAP3 and we map specific interaction sites in both proteins. Furthermore, we find that GLI proteins interact selectively with KIF3A, but not KIF3B, and that GLI interacts synergistically with KAP3 and KIF3A. Using a combination of cell signaling assays and chicken in ovo electroporation, we demonstrate that KAP3 interactions restrict GLI activator function but not GLI repressor function. These data suggest that GLI interactions with KIF3A-KIF3B-KAP3 complexes are essential for proper GLI transcriptional activity.
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Affiliation(s)
- Brandon S Carpenter
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Renee L Barry
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Kristen J Verhey
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Benjamin L Allen
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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90
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Lin C, Yao E, Wang K, Nozawa Y, Shimizu H, Johnson JR, Chen JN, Krogan NJ, Chuang PT. Regulation of Sufu activity by p66β and Mycbp provides new insight into vertebrate Hedgehog signaling. Genes Dev 2015; 28:2547-63. [PMID: 25403183 PMCID: PMC4233246 DOI: 10.1101/gad.249425.114] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Control of Gli function by Sufu, a major negative regulator, is a key step in mammalian Hedgehog (Hh) signaling. Lin et al. identified several Sufu-interacting proteins, including p66β and Mycbp. Sufu recruits p66β to block Gli-mediated Hh target gene expression. Meanwhile, Mycbp forms a complex with Gli and Sufu without Hh stimulation but remains inactive. Hh pathway activation leads to dissociation of Sufu/p66β from Gli, enabling Mycbp to promote Gli protein activity and Hh target gene expression. Control of Gli function by Suppressor of Fused (Sufu), a major negative regulator, is a key step in mammalian Hedgehog (Hh) signaling, but how this is achieved in the nucleus is unknown. We found that Hh signaling results in reduced Sufu protein levels and Sufu dissociation from Gli proteins in the nucleus, highlighting critical functions of Sufu in the nucleus. Through a proteomic approach, we identified several Sufu-interacting proteins, including p66β (a member of the NuRD [nucleosome remodeling and histone deacetylase] repressor complex) and Mycbp (a Myc-binding protein). p66β negatively and Mycbp positively regulate Hh signaling in cell-based assays and zebrafish. They function downstream from the membrane receptors, Patched and Smoothened, and the primary cilium. Sufu, p66β, Mycbp, and Gli are also detected on the promoters of Hh targets in a dynamic manner. Our results support a new model of Hh signaling in the nucleus. Sufu recruits p66β to block Gli-mediated Hh target gene expression. Meanwhile, Mycbp forms a complex with Gli and Sufu without Hh stimulation but remains inactive. Hh pathway activation leads to dissociation of Sufu/p66β from Gli, enabling Mycbp to promote Gli protein activity and Hh target gene expression. These studies provide novel insight into how Sufu controls Hh signaling in the nucleus.
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Affiliation(s)
- Chuwen Lin
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, California 94158, USA
| | - Erica Yao
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, California 94158, USA
| | - Kevin Wang
- Department of Molecular, Cell, and Developmental Biology, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Yoko Nozawa
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, California 94158, USA
| | - Hirohito Shimizu
- Department of Molecular, Cell, and Developmental Biology, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Jeffrey R Johnson
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California 94158
| | - Jau-Nian Chen
- Department of Molecular, Cell, and Developmental Biology, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California 94158
| | - Pao-Tien Chuang
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, California 94158, USA;
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91
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Abstract
A rare disease is defined as a condition that affects less than 1 in 2000 individuals. Currently more than 7000 rare diseases have been documented, and most are thought to be of genetic origin. Rare diseases primarily affect children, and congenital craniofacial syndromes and disorders constitute a significant proportion of rare diseases, with over 700 having been described to date. Modeling craniofacial disorders in animal models has been instrumental in uncovering the etiology and pathogenesis of numerous conditions and in some cases has even led to potential therapeutic avenues for their prevention. In this chapter, we focus primarily on two general classes of rare disorders, ribosomopathies and ciliopathies, and the surprising finding that the disruption of fundamental, global processes can result in tissue-specific craniofacial defects. In addition, we discuss recent advances in understanding the pathogenesis of an extremely rare and specific craniofacial condition known as syngnathia, based on the first mouse models for this condition. Approximately 1% of all babies are born with a minor or major developmental anomaly, and individuals suffering from rare diseases deserve the same quality of treatment and care and attention to their disease as other patients.
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Affiliation(s)
- Annita Achilleos
- Stowers Institute for Medical Research, Kansas City, Missouri, USA
| | - Paul A Trainor
- Stowers Institute for Medical Research, Kansas City, Missouri, USA; Department of Anatomy & Cell Biology, University of Kansas Medical Center, Kansas City, Kansas, USA.
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92
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Liu YC, Couzens AL, Deshwar AR, B McBroom-Cerajewski LD, Zhang X, Puviindran V, Scott IC, Gingras AC, Hui CC, Angers S. The PPFIA1-PP2A protein complex promotes trafficking of Kif7 to the ciliary tip and Hedgehog signaling. Sci Signal 2014; 7:ra117. [PMID: 25492966 DOI: 10.1126/scisignal.2005608] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The primary cilium is required for Hedgehog (Hh) signaling in vertebrates. Hh leads to ciliary accumulation and activation of the transmembrane protein Smoothened (Smo) and affects the localization of several pathway components, including the Gli family of transcriptional regulators, within different regions of primary cilia. Genetic analysis indicates that the kinesin protein Kif7 both promotes and inhibits mouse Hh signaling. Using mass spectrometry, we identified liprin-α1 (PPFIA1) and the protein phosphatase PP2A as Kif7-interacting proteins, and we showed that they were important for the trafficking of Kif7 and Gli proteins to the tips of cilia and for the transcriptional output of Hh signaling. Our results suggested that PPFIA1 functioned with PP2A to promote the dephosphorylation of Kif7, triggering Kif7 localization to the tips of primary cilia and promoting Gli transcriptional activity.
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Affiliation(s)
- Yulu C Liu
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Amber L Couzens
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | - Ashish R Deshwar
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | | | - Xiaoyun Zhang
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Vijitha Puviindran
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Ian C Scott
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada. Program in Developmental and Stem Cell Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada. Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Chi-Chung Hui
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada. Program in Developmental and Stem Cell Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Stephane Angers
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada. Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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93
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Investigation of genetic factors underlying typical orofacial clefts: mutational screening and copy number variation. J Hum Genet 2014; 60:17-25. [PMID: 25391604 DOI: 10.1038/jhg.2014.96] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 10/01/2014] [Accepted: 10/10/2014] [Indexed: 12/13/2022]
Abstract
Typical orofacial clefts (OFCs) comprise cleft lip, cleft palate and cleft lip and palate. The complex etiology has been postulated to involve chromosome rearrangements, gene mutations and environmental factors. A group of genes including IRF6, FOXE1, GLI2, MSX2, SKI, SATB2, MSX1 and FGF has been implicated in the etiology of OFCs. Recently, the role of the copy number variations (CNVs) has been studied in genetic defects and diseases. CNVs act by modifying gene expression, disrupting gene sequence or altering gene dosage. The aims of this study were to screen the above-mentioned genes and to investigate CNVs in patients with OFCs. The sample was composed of 23 unrelated individuals who were grouped according to phenotype (associated with other anomalies or isolated) and familial recurrence. New sequence variants in GLI2, MSX1 and FGF8 were detected in patients, but not in their parents, as well as in 200 control chromosomes, indicating that these were rare variants. CNV screening identified new genes that can influence OFC pathogenesis, particularly highlighting TCEB3 and KIF7, that could be further analyzed. The findings of the present study suggest that the mechanism underlying CNV associated with sequence variants may play a role in the etiology of OFC.
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94
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Ho J, Du Y, Wong OGW, Siu MKY, Chan KKL, Cheung ANY. Downregulation of the gli transcription factors regulator Kif7 facilitates cell survival and migration of choriocarcinoma cells. PLoS One 2014; 9:e108248. [PMID: 25265279 PMCID: PMC4180749 DOI: 10.1371/journal.pone.0108248] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 08/26/2014] [Indexed: 12/21/2022] Open
Abstract
The kinesin protein Kif7 has been recognized as an integral component of hedgehog signalling. Aberrant activation of hedgehog signalling has been implicated in many human solid tumours. Gestational trophoblastic disease includes frankly malignant choriocarcinoma and potentially malignant hydatidiform mole. Here we investigated the hedgehog signalling components expression profiles in gestational trophoblastic disease. Downregulation of Gli1, Gli2, Gli3 and Kif7 was demonstrated in clinical samples of choriocarcinoma and hydatidiform moles as well as choriocarcinoma cell lines when compared with normal placentas. Ectopic expression of Kif7 in two choriocarcinoma cell lines JAR and JEG-3 led to a decrease in cell growth and increase in apoptosis demonstrated by MTT and TUNEL assays, respectively. Overexpression of Kif7 also led to suppressed cell migration through transwell assay. In contrast, knocking down Kif7 in HTR-8/SVneo, an immortalized trophoblast cell line, increased cell number over time and increased the migratory ability of the cells. Taken together, Kif7 may contribute to pathogenesis of gestational trophoblastic disease through enhancing survival and promoting dissemination of trophoblasts.
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Affiliation(s)
- Joanna Ho
- Department of Pathology, The University of Hong Kong, HKSAR, China
| | - Yanan Du
- Department of Pathology, The University of Hong Kong, HKSAR, China
| | | | - Michelle K. Y. Siu
- Department of Obstetrics and Gynaecology, The University of Hong Kong, HKSAR, China
| | - Karen K. L. Chan
- Department of Obstetrics and Gynaecology, The University of Hong Kong, HKSAR, China
| | - Annie N. Y. Cheung
- Department of Pathology, The University of Hong Kong, HKSAR, China
- Department of Pathology, The University of Hong Kong – Shenzhen Hospital, Shenzhen, China
- * E-mail:
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95
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Abstract
The kinesin-4 motor protein Kif7 regulates Hedgehog signalling at cilia in mammals by controlling the activity of Gli transcription factors. Kif7 is now found to inhibit microtubule growth to restrict and coordinate the length of axonemal microtubules at the ciliary tip. Such Kif7-mediated organization of the ciliary tip compartment regulates Gli activity and is proposed to be required for correct Hedgehog signalling.
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96
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Pusapati GV, Rohatgi R. Location, location, and location: compartmentalization of Hedgehog signaling at primary cilia. EMBO J 2014; 33:1852-4. [PMID: 25037564 DOI: 10.15252/embj.201489294] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Ganesh V Pusapati
- Departments of Medicine and Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Rajat Rohatgi
- Departments of Medicine and Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
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97
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Li S, Ma G, Wang B, Jiang J. Hedgehog induces formation of PKA-Smoothened complexes to promote Smoothened phosphorylation and pathway activation. Sci Signal 2014; 7:ra62. [PMID: 24985345 PMCID: PMC4621970 DOI: 10.1126/scisignal.2005414] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Hedgehog (Hh) is a secreted glycoprotein that binds its receptor Patched to activate the G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptor-like protein Smoothened (Smo). In Drosophila, protein kinase A (PKA) phosphorylates and activates Smo in cells stimulated with Hh. In unstimulated cells, PKA phosphorylates and inhibits the transcription factor Cubitus interruptus (Ci). We found that in cells exposed to Hh, the catalytic subunit of PKA (PKAc) bound to the juxtamembrane region of the carboxyl terminus of Smo. PKA-mediated phosphorylation of Smo further enhanced its association with PKAc to form stable kinase-substrate complexes that promoted the PKA-mediated transphosphorylation of Smo dimers. We identified multiple basic residues in the carboxyl terminus of Smo that were required for interaction with PKAc, Smo phosphorylation, and Hh pathway activation. Hh induced a switch from the association of PKAc with a cytosolic complex of Ci and the kinesin-like protein Costal2 (Cos2) to a membrane-bound Smo-Cos2 complex. Thus, our study uncovers a previously uncharacterized mechanism for regulation of PKA activity and demonstrates that the signal-regulated formation of kinase-substrate complexes plays a central role in Hh signal transduction.
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Affiliation(s)
- Shuang Li
- Department of Developmental Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Guoqiang Ma
- Department of Developmental Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Bing Wang
- Department of Developmental Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Jin Jiang
- Department of Developmental Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA. Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA.
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98
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He M, Subramanian R, Bangs F, Omelchenko T, Liem KF, Kapoor TM, Anderson KV. The kinesin-4 protein Kif7 regulates mammalian Hedgehog signalling by organizing the cilium tip compartment. Nat Cell Biol 2014; 16:663-72. [PMID: 24952464 PMCID: PMC4085576 DOI: 10.1038/ncb2988] [Citation(s) in RCA: 214] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 05/13/2014] [Indexed: 12/12/2022]
Abstract
Mammalian Hedgehog (Hh) signal transduction requires a primary cilium, a microtubule-based organelle, and the Gli-Sufu complexes that mediate Hh signalling, which are enriched at cilia tips. Kif7, a kinesin-4 family protein, is a conserved regulator of the Hh signalling pathway and a human ciliopathy protein. Here we show that Kif7 localizes to the cilium tip, the site of microtubule plus ends, where it limits cilium length and controls cilium structure. Purified recombinant Kif7 binds the plus ends of growing microtubules in vitro, where it reduces the rate of microtubule growth and increases the frequency of microtubule catastrophe. Kif7 is not required for normal intraflagellar transport or for trafficking of Hh pathway proteins into cilia. Instead, a central function of Kif7 in the mammalian Hh pathway is to control cilium architecture and to create a single cilium tip compartment, where Gli-Sufu activity can be correctly regulated.
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Affiliation(s)
- Mu He
- 1] Developmental Biology Program, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue New York, New York 10065, USA [2] Program in Biochemistry and Structural Biology, Cell and Developmental Biology, and Molecular Biology, Weill Cornell Graduate School of Medical Sciences, Cornell University, 1300 York Avenue New York, New York 10065, USA
| | - Radhika Subramanian
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, 1230 York Avenue New York, New York 10065, USA
| | - Fiona Bangs
- Developmental Biology Program, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue New York, New York 10065, USA
| | - Tatiana Omelchenko
- Cell Biology Program, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue New York, New York 10065, USA
| | - Karel F Liem
- 1] Developmental Biology Program, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue New York, New York 10065, USA [2]
| | - Tarun M Kapoor
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, 1230 York Avenue New York, New York 10065, USA
| | - Kathryn V Anderson
- Developmental Biology Program, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue New York, New York 10065, USA
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99
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Lodh S, O’Hare EA, Zaghloul NA. Primary cilia in pancreatic development and disease. BIRTH DEFECTS RESEARCH. PART C, EMBRYO TODAY : REVIEWS 2014; 102:139-58. [PMID: 24864023 PMCID: PMC4213238 DOI: 10.1002/bdrc.21063] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 03/30/2014] [Accepted: 03/30/2014] [Indexed: 01/04/2023]
Abstract
Primary cilia and their anchoring basal bodies are important regulators of a growing list of signaling pathways. Consequently, dysfunction in proteins associated with these structures results in perturbation of the development and function of a spectrum of tissue and cell types. Here, we review the role of cilia in mediating the development and function of the pancreas. We focus on ciliary regulation of major pathways involved in pancreatic development, including Shh, Wnt, TGF-β, Notch, and fibroblast growth factor. We also discuss pancreatic phenotypes associated with ciliary dysfunction, including pancreatic cysts and defects in glucose homeostasis, and explore the potential role of cilia in such defects.
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Affiliation(s)
- Sukanya Lodh
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Elizabeth A. O’Hare
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Norann A. Zaghloul
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
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100
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G-protein-coupled receptors, Hedgehog signaling and primary cilia. Semin Cell Dev Biol 2014; 33:63-72. [PMID: 24845016 DOI: 10.1016/j.semcdb.2014.05.002] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 05/12/2014] [Indexed: 12/21/2022]
Abstract
The Hedgehog (Hh) pathway has become an important model to study the cell biology of primary cilia, and reciprocally, the study of ciliary processes provides an opportunity to solve longstanding mysteries in the mechanism of vertebrate Hh signal transduction. The cilium is emerging as an unique compartment for G-protein-coupled receptor (GPCR) signaling in many systems. Two members of the GPCR family, Smoothened and Gpr161, play important roles in the Hh pathway. We review the current understanding of how these proteins may function to regulate Hh signaling and also highlight some of the critical unanswered questions being tackled by the field. Uncovering GPCR-regulated mechanisms important in Hh signaling may provide therapeutic strategies against the Hh pathway that plays important roles in development, regeneration and cancer.
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