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Lin KY, Gujar MR, Lin J, Ding WY, Huang J, Gao Y, Tan YS, Teng X, Christine LSL, Kanchanawong P, Toyama Y, Wang H. Astrocytes control quiescent NSC reactivation via GPCR signaling-mediated F-actin remodeling. SCIENCE ADVANCES 2024; 10:eadl4694. [PMID: 39047090 PMCID: PMC11268418 DOI: 10.1126/sciadv.adl4694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Accepted: 06/18/2024] [Indexed: 07/27/2024]
Abstract
The transitioning of neural stem cells (NSCs) between quiescent and proliferative states is fundamental for brain development and homeostasis. Defects in NSC reactivation are associated with neurodevelopmental disorders. Drosophila quiescent NSCs extend an actin-rich primary protrusion toward the neuropil. However, the function of the actin cytoskeleton during NSC reactivation is unknown. Here, we reveal the fine filamentous actin (F-actin) structures in the protrusions of quiescent NSCs by expansion and super-resolution microscopy. We show that F-actin polymerization promotes the nuclear translocation of myocardin-related transcription factor, a microcephaly-associated transcription factor, for NSC reactivation and brain development. F-actin polymerization is regulated by a signaling cascade composed of G protein-coupled receptor Smog, G protein αq subunit, Rho1 guanosine triphosphatase, and Diaphanous (Dia)/Formin during NSC reactivation. Further, astrocytes secrete a Smog ligand folded gastrulation to regulate Gαq-Rho1-Dia-mediated NSC reactivation. Together, we establish that the Smog-Gαq-Rho1 signaling axis derived from astrocytes, an NSC niche, regulates Dia-mediated F-actin dynamics in NSC reactivation.
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Affiliation(s)
- Kun-Yang Lin
- Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Mahekta R. Gujar
- Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Jiaen Lin
- Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Wei Yung Ding
- Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Jiawen Huang
- Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Yang Gao
- Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Ye Sing Tan
- Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Xiang Teng
- Mechanobiology Institute, Level 5, T-lab Building, 5A Engineering Drive 1, Singapore, 117411, Singapore
| | - Low Siok Lan Christine
- Mechanobiology Institute, Level 5, T-lab Building, 5A Engineering Drive 1, Singapore, 117411, Singapore
| | - Pakorn Kanchanawong
- Mechanobiology Institute, Level 5, T-lab Building, 5A Engineering Drive 1, Singapore, 117411, Singapore
| | - Yusuke Toyama
- Mechanobiology Institute, Level 5, T-lab Building, 5A Engineering Drive 1, Singapore, 117411, Singapore
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore
| | - Hongyan Wang
- Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
- Integrative Sciences and Engineering Programme, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore
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2
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Lin KY, Gujar MR, Lin J, Ding WY, Huang J, Gao Y, Tan YS, Teng X, Christine LSL, Kanchanawong P, Toyama Y, Wang H. Astrocytes control quiescent NSC reactivation via GPCR signaling-mediated F-actin remodeling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.11.584337. [PMID: 38903085 PMCID: PMC11188063 DOI: 10.1101/2024.03.11.584337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
The transitioning of neural stem cells (NSCs) between quiescent and proliferative states is fundamental for brain development and homeostasis. Defects in NSC reactivation are associated with neurodevelopmental disorders. Drosophila quiescent NSCs extend an actin-rich primary protrusion toward the neuropil. However, the function of the actin cytoskeleton during NSC reactivation is unknown. Here, we reveal the fine F-actin structures in the protrusions of quiescent NSCs by expansion and super-resolution microscopy. We show that F-actin polymerization promotes the nuclear translocation of Mrtf, a microcephaly-associated transcription factor, for NSC reactivation and brain development. F-actin polymerization is regulated by a signaling cascade composed of G-protein-coupled receptor (GPCR) Smog, G-protein αq subunit, Rho1 GTPase, and Diaphanous (Dia)/Formin during NSC reactivation. Further, astrocytes secrete a Smog ligand Fog to regulate Gαq-Rho1-Dia-mediated NSC reactivation. Together, we establish that the Smog-Gαq-Rho1 signaling axis derived from astrocytes, a NSC niche, regulates Dia-mediated F-actin dynamics in NSC reactivation.
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3
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Asif M, Abdullah U, Nürnberg P, Tinschert S, Hussain MS. Congenital Microcephaly: A Debate on Diagnostic Challenges and Etiological Paradigm of the Shift from Isolated/Non-Syndromic to Syndromic Microcephaly. Cells 2023; 12:cells12040642. [PMID: 36831309 PMCID: PMC9954724 DOI: 10.3390/cells12040642] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023] Open
Abstract
Congenital microcephaly (CM) exhibits broad clinical and genetic heterogeneity and is thus categorized into several subtypes. However, the recent bloom of disease-gene discoveries has revealed more overlaps than differences in the underlying genetic architecture for these clinical sub-categories, complicating the differential diagnosis. Moreover, the mechanism of the paradigm shift from a brain-restricted to a multi-organ phenotype is only vaguely understood. This review article highlights the critical factors considered while defining CM subtypes. It also presents possible arguments on long-standing questions of the brain-specific nature of CM caused by a dysfunction of the ubiquitously expressed proteins. We argue that brain-specific splicing events and organ-restricted protein expression may contribute in part to disparate clinical manifestations. We also highlight the role of genetic modifiers and de novo variants in the multi-organ phenotype of CM and emphasize their consideration in molecular characterization. This review thus attempts to expand our understanding of the phenotypic and etiological variability in CM and invites the development of more comprehensive guidelines.
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Affiliation(s)
- Maria Asif
- Cologne Center for Genomics (CCG), Faculty of Medicine, University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine, University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | - Uzma Abdullah
- University Institute of Biochemistry and Biotechnology (UIBB), PMAS-Arid Agriculture University, Rawalpindi, Rawalpindi 46300, Pakistan
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG), Faculty of Medicine, University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine, University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | - Sigrid Tinschert
- Zentrum Medizinische Genetik, Medizinische Universität, 6020 Innsbruck, Austria
| | - Muhammad Sajid Hussain
- Cologne Center for Genomics (CCG), Faculty of Medicine, University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine, University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
- Correspondence:
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4
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Chang CF, Brown KM, Yang Y, Brugmann SA. Centriolar Protein C2cd3 Is Required for Craniofacial Development. Front Cell Dev Biol 2021; 9:647391. [PMID: 34211969 PMCID: PMC8239364 DOI: 10.3389/fcell.2021.647391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 05/17/2021] [Indexed: 11/13/2022] Open
Abstract
The primary cilium is a ubiquitous, microtubule-based cellular organelle. Primary cilia dysfunction results in a group of disorders termed ciliopathies. C2 domain containing 3 centriole elongation regulator (C2cd3), encodes a centriolar protein essential for ciliogenesis. Mutations in human C2CD3 are associated with the human ciliopathy Oral-Facial-Digital syndrome type 14 (OFD14). In order to better understand the etiology of ciliopathies including OFD14, we generated numerous murine models targeting C2cd3. Initial analysis revealed several tissue-specific isoforms of C2cd3, and while the loss of C2cd3 has previously been reported to result in exencephaly, tight mesencephalic flexure, pericardial edema, abnormal heart looping and a twisted body axis, further analysis revealed that genetic background may also contribute to phenotypic variation. Additional analyses of a conditional allelic series targeting C-terminal PKC-C2 domains or the N-terminal C2CD3N-C2 domain of C2cd3 revealed a variable degree of phenotypic severity, suggesting that while the N-terminal C2CD3N-C2 domain was critical for early embryonic development as a whole, there was also a craniofacial specific role for the C2CD3N-C2 domains. Together, through generation of novel models and evaluation of C2cd3 expression, these data provide valuable insight into mechanisms of pathology for craniofacial ciliopathies that can be further explored in the future.
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Affiliation(s)
- Ching-Fang Chang
- Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Kari M Brown
- Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Yanfen Yang
- Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Samantha A Brugmann
- Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States.,Division of Plastic Surgery, Department of Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.,Shriners Children's Hospital, Cincinnati, OH, United States
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Makhdoom EUH, Waseem SS, Iqbal M, Abdullah U, Hussain G, Asif M, Budde B, Höhne W, Tinschert S, Saadi SM, Yousaf H, Ali Z, Fatima A, Kaygusuz E, Khan A, Jameel M, Khan S, Tariq M, Anjum I, Altmüller J, Thiele H, Höning S, Baig SM, Nürnberg P, Hussain MS. Modifier Genes in Microcephaly: A Report on WDR62, CEP63, RAD50 and PCNT Variants Exacerbating Disease Caused by Biallelic Mutations of ASPM and CENPJ. Genes (Basel) 2021; 12:731. [PMID: 34068194 PMCID: PMC8153008 DOI: 10.3390/genes12050731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/09/2021] [Accepted: 05/11/2021] [Indexed: 11/09/2022] Open
Abstract
Congenital microcephaly is the clinical presentation of significantly reduced head circumference at birth. It manifests as both non-syndromic-microcephaly primary hereditary (MCPH)-and syndromic forms and shows considerable inter- and intrafamilial variability. It has been hypothesized that additional genetic variants may be responsible for this variability, but data are sparse. We have conducted deep phenotyping and genotyping of five Pakistani multiplex families with either MCPH (n = 3) or Seckel syndrome (n = 2). In addition to homozygous causal variants in ASPM or CENPJ, we discovered additional heterozygous modifier variants in WDR62, CEP63, RAD50 and PCNT-genes already known to be associated with neurological disorders. MCPH patients carrying an additional heterozygous modifier variant showed more severe phenotypic features. Likewise, the phenotype of Seckel syndrome caused by a novel CENPJ variant was aggravated to microcephalic osteodysplastic primordial dwarfism type II (MOPDII) in conjunction with an additional PCNT variant. We show that the CENPJ missense variant impairs splicing and decreases protein expression. We also observed centrosome amplification errors in patient cells, which were twofold higher in MOPDII as compared to Seckel cells. Taken together, these observations advocate for consideration of additional variants in related genes for their role in modifying the expressivity of the phenotype and need to be considered in genetic counseling and risk assessment.
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Affiliation(s)
- Ehtisham Ul Haq Makhdoom
- Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (E.U.H.M.); (S.S.W.); (M.I.); (M.A.); (B.B.); (W.H.); (J.A.); (H.T.); (P.N.)
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad 38000, Pakistan; (S.M.S.); (H.Y.); (A.K.); (M.J.); (S.K.); (M.T.); (S.M.B.)
- Neurochemicalbiology and Genetics Laboratory (NGL), Department of Physiology, Faculty of Life Sciences, Government College University, Faisalabad 38000, Pakistan;
| | - Syeda Seema Waseem
- Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (E.U.H.M.); (S.S.W.); (M.I.); (M.A.); (B.B.); (W.H.); (J.A.); (H.T.); (P.N.)
- Institute of Biochemistry I, Medical Faculty, University of Cologne, 50931 Cologne, Germany;
| | - Maria Iqbal
- Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (E.U.H.M.); (S.S.W.); (M.I.); (M.A.); (B.B.); (W.H.); (J.A.); (H.T.); (P.N.)
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad 38000, Pakistan; (S.M.S.); (H.Y.); (A.K.); (M.J.); (S.K.); (M.T.); (S.M.B.)
- Institute of Biochemistry I, Medical Faculty, University of Cologne, 50931 Cologne, Germany;
| | - Uzma Abdullah
- University Institute of Biochemistry and Biotechnology (UIBB), PMAS-Arid Agriculture University, Rawalpindi 46000, Pakistan;
| | - Ghulam Hussain
- Neurochemicalbiology and Genetics Laboratory (NGL), Department of Physiology, Faculty of Life Sciences, Government College University, Faisalabad 38000, Pakistan;
| | - Maria Asif
- Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (E.U.H.M.); (S.S.W.); (M.I.); (M.A.); (B.B.); (W.H.); (J.A.); (H.T.); (P.N.)
- Institute of Biochemistry I, Medical Faculty, University of Cologne, 50931 Cologne, Germany;
| | - Birgit Budde
- Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (E.U.H.M.); (S.S.W.); (M.I.); (M.A.); (B.B.); (W.H.); (J.A.); (H.T.); (P.N.)
| | - Wolfgang Höhne
- Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (E.U.H.M.); (S.S.W.); (M.I.); (M.A.); (B.B.); (W.H.); (J.A.); (H.T.); (P.N.)
| | - Sigrid Tinschert
- Zentrum Medizinische Genetik, Medizinische Universität, 6020 Innsbruck, Austria;
| | - Saadia Maryam Saadi
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad 38000, Pakistan; (S.M.S.); (H.Y.); (A.K.); (M.J.); (S.K.); (M.T.); (S.M.B.)
| | - Hammad Yousaf
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad 38000, Pakistan; (S.M.S.); (H.Y.); (A.K.); (M.J.); (S.K.); (M.T.); (S.M.B.)
| | - Zafar Ali
- Centre for Biotechnology and Microbiology, University of Swat, Swat 19130, Pakistan;
| | - Ambrin Fatima
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi 74000, Pakistan;
| | - Emrah Kaygusuz
- Bilecik Şeyh Edebali University, Molecular Biology and Genetics, Gülümbe Campus, Bilecik 11230, Turkey;
| | - Ayaz Khan
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad 38000, Pakistan; (S.M.S.); (H.Y.); (A.K.); (M.J.); (S.K.); (M.T.); (S.M.B.)
| | - Muhammad Jameel
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad 38000, Pakistan; (S.M.S.); (H.Y.); (A.K.); (M.J.); (S.K.); (M.T.); (S.M.B.)
| | - Sheraz Khan
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad 38000, Pakistan; (S.M.S.); (H.Y.); (A.K.); (M.J.); (S.K.); (M.T.); (S.M.B.)
| | - Muhammad Tariq
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad 38000, Pakistan; (S.M.S.); (H.Y.); (A.K.); (M.J.); (S.K.); (M.T.); (S.M.B.)
| | - Iram Anjum
- Department of Biotechnology, Kinnaird College for Women, Lahore 54000, Pakistan;
| | - Janine Altmüller
- Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (E.U.H.M.); (S.S.W.); (M.I.); (M.A.); (B.B.); (W.H.); (J.A.); (H.T.); (P.N.)
| | - Holger Thiele
- Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (E.U.H.M.); (S.S.W.); (M.I.); (M.A.); (B.B.); (W.H.); (J.A.); (H.T.); (P.N.)
| | - Stefan Höning
- Institute of Biochemistry I, Medical Faculty, University of Cologne, 50931 Cologne, Germany;
| | - Shahid Mahmood Baig
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad 38000, Pakistan; (S.M.S.); (H.Y.); (A.K.); (M.J.); (S.K.); (M.T.); (S.M.B.)
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi 74000, Pakistan;
- Pakistan Science Foundation (PSF), 1- Constitution Avenue, G-5/2, Islamabad 44000, Pakistan
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (E.U.H.M.); (S.S.W.); (M.I.); (M.A.); (B.B.); (W.H.); (J.A.); (H.T.); (P.N.)
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, 50931 Cologne, Germany
| | - Muhammad Sajid Hussain
- Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (E.U.H.M.); (S.S.W.); (M.I.); (M.A.); (B.B.); (W.H.); (J.A.); (H.T.); (P.N.)
- Institute of Biochemistry I, Medical Faculty, University of Cologne, 50931 Cologne, Germany;
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, 50931 Cologne, Germany
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Barbeito P, Tachibana Y, Martin-Morales R, Moreno P, Mykytyn K, Kobayashi T, Garcia-Gonzalo FR. HTR6 and SSTR3 ciliary targeting relies on both IC3 loops and C-terminal tails. Life Sci Alliance 2020; 4:4/3/e202000746. [PMID: 33372037 PMCID: PMC7772773 DOI: 10.26508/lsa.202000746] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 12/11/2022] Open
Abstract
Ciliary accumulation of G protein–coupled receptors HTR6 and SSTR3 depends on redundant ciliary targeting sequences acting via ciliary trafficking adapters TULP3 and RABL2. G protein-coupled receptors (GPCRs) are the most common pharmacological target in human clinical practice. To perform their functions, many GPCRs must accumulate inside primary cilia, microtubule-based plasma membrane protrusions working as cellular antennae. Nevertheless, the molecular mechanisms underlying GPCR ciliary targeting remain poorly understood. Serotonin receptor 6 (HTR6) and somatostatin receptor 3 (SSTR3) are two brain-enriched ciliary GPCRs involved in cognition and pathologies such as Alzheimer’s disease and cancer. Although the third intracellular loops (IC3) of HTR6 and SSTR3 suffice to target non-ciliary GPCRs to cilia, these IC3s are dispensable for ciliary targeting of HTR6 and SSTR3 themselves, suggesting these GPCRs contain additional ciliary targeting sequences (CTSs). Herein, we discover and characterize novel CTSs in HTR6 and SSTR3 C-terminal tails (CT). These CT-CTSs (CTS2) act redundantly with IC3-CTSs (CTS1), each being sufficient for ciliary targeting. In HTR6, RKQ and LPG motifs are critical for CTS1 and CTS2 function, respectively, whereas in SSTR3 these roles are mostly fulfilled by AP[AS]CQ motifs in IC3 and juxtamembrane residues in CT. Furthermore, we shed light on how these CTSs promote ciliary targeting by modulating binding to ciliary trafficking adapters TULP3 and RABL2.
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Affiliation(s)
- Pablo Barbeito
- Department of Biochemistry, School of Medicine, Autonomous University of Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain
| | - Yuki Tachibana
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
| | - Raquel Martin-Morales
- Department of Biochemistry, School of Medicine, Autonomous University of Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain
| | - Paula Moreno
- Department of Biochemistry, School of Medicine, Autonomous University of Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain
| | - Kirk Mykytyn
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA.,Neuroscience Research Institute, The Ohio State University, Columbus, OH, USA
| | - Tetsuo Kobayashi
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
| | - Francesc R Garcia-Gonzalo
- Department of Biochemistry, School of Medicine, Autonomous University of Madrid (UAM), Madrid, Spain .,Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain
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7
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Jean F, Stuart A, Tarailo-Graovac M. Dissecting the Genetic and Etiological Causes of Primary Microcephaly. Front Neurol 2020; 11:570830. [PMID: 33178111 PMCID: PMC7593518 DOI: 10.3389/fneur.2020.570830] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/09/2020] [Indexed: 12/20/2022] Open
Abstract
Autosomal recessive primary microcephaly (MCPH; “small head syndrome”) is a rare, heterogeneous disease arising from the decreased production of neurons during brain development. As of August 2020, the Online Mendelian Inheritance in Man (OMIM) database lists 25 genes (involved in molecular processes such as centriole biogenesis, microtubule dynamics, spindle positioning, DNA repair, transcriptional regulation, Wnt signaling, and cell cycle checkpoints) that are implicated in causing MCPH. Many of these 25 genes were only discovered in the last 10 years following advances in exome and genome sequencing that have improved our ability to identify disease-causing variants. Despite these advances, many patients still lack a genetic diagnosis. This demonstrates a need to understand in greater detail the molecular mechanisms and genetics underlying MCPH. Here, we briefly review the molecular functions of each MCPH gene and how their loss disrupts the neurogenesis program, ultimately demonstrating that microcephaly arises from cell cycle dysregulation. We also explore the current issues in the genetic basis and clinical presentation of MCPH as additional avenues of improving gene/variant prioritization. Ultimately, we illustrate that the detailed exploration of the etiology and inheritance of MCPH improves the predictive power in identifying previously unknown MCPH candidates and diagnosing microcephalic patients.
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Affiliation(s)
- Francesca Jean
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Amanda Stuart
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Maja Tarailo-Graovac
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
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