1
|
Perry JA, Werner ME, Omi S, Heck BW, Maddox PS, Mavrakis M, Maddox AS. Animal septins contain functional transmembrane domains. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.20.567915. [PMID: 38045322 PMCID: PMC10690161 DOI: 10.1101/2023.11.20.567915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Septins, a conserved family of filament-forming proteins, contribute to eukaryotic cell division, polarity, and membrane trafficking. Septins scaffold other proteins to cellular membranes, but it is unknown how septins associate with membranes. We identified and characterized an isoform of Caenorhabditis elegans septin UNC-61 that was predicted to contain a transmembrane domain (TMD). The TMD isoform is expressed in a subset of tissues where the known septins were known to act, and TMD function was required for tissue integrity of the egg-laying apparatus. We found TMD-containing septins across opisthokont phylogeny and demonstrated that the TMD-containing sequence of a primate TMD-septin is sufficient for localization to cellular membranes. Together, our findings reveal a novel mechanism of septin-membrane association with profound implications for septin dynamics and regulation.
Collapse
Affiliation(s)
- Jenna A. Perry
- Department of Biology, The University of North Carolina at Chapel Hill; Chapel Hill, North Carolina, 27599 USA
| | - Michael E. Werner
- Department of Biology, The University of North Carolina at Chapel Hill; Chapel Hill, North Carolina, 27599 USA
| | - Shizue Omi
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Med, 13013 Marseille, France
| | - Bryan W. Heck
- Department of Biology, The University of North Carolina at Chapel Hill; Chapel Hill, North Carolina, 27599 USA
| | - Paul S. Maddox
- Department of Biology, The University of North Carolina at Chapel Hill; Chapel Hill, North Carolina, 27599 USA
| | - Manos Mavrakis
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Med, 13013 Marseille, France
| | - Amy S. Maddox
- Department of Biology, The University of North Carolina at Chapel Hill; Chapel Hill, North Carolina, 27599 USA
| |
Collapse
|
2
|
Nagoshi R, Sakamoto A, Imai T, Uchiyama T, Kaname T, Kunishima S, Ishiguro A. Bernard-Soulier syndrome caused by a novel GP1BB variant and 22q11.2 deletion. Int J Hematol 2024; 120:142-145. [PMID: 38625506 DOI: 10.1007/s12185-024-03768-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 03/25/2024] [Accepted: 03/28/2024] [Indexed: 04/17/2024]
Abstract
Bernard-Soulier syndrome (BSS) is caused by defects in GP1BA, GP1BB, or GP9 genes. Patients with 22q11.2 deletion syndrome (22q11.2DS) are obligate carriers of BSS because GP1BB resides on chromosome 22q11.2. A 15-month-old girl without bleeding symptoms had giant platelets and thrombocytopenia. Physical findings and macrothrombocytopenia suggested 22q11.2DS, which was confirmed by fluorescence in situ hybridization. Flow cytometry showed decreased GPIbα on the platelets. Gene panel testing revealed a novel variant in GP1BB, p.(Val169_Leu172del). These findings confirmed that the patient had BSS. This case suggests that any patient with 22q11.2DS and macrothrombocytopenia should be further tested for BSS.
Collapse
Affiliation(s)
- Rintaro Nagoshi
- Center for Postgraduate Education and Training, National Center for Child Health and Development (NCCHD), Tokyo, Japan
| | - Atsushi Sakamoto
- Division of Hematology, Center for Postgraduate Education and Training, NCCHD, 2-10-1 Okura, Setagaya-Ku, Tokyo, 157-8535, Japan.
| | - Tsuyoshi Imai
- Department of Pediatric Hematology and Oncology, National Hospital Organization Shikoku Medical Center for Children and Adults, Kagawa, Japan
| | | | | | - Shinji Kunishima
- Department of Medical Technology, School of Health Sciences, Gifu University of Medical Science, Gifu, Japan
| | - Akira Ishiguro
- Center for Postgraduate Education and Training, National Center for Child Health and Development (NCCHD), Tokyo, Japan
- Division of Hematology, Center for Postgraduate Education and Training, NCCHD, 2-10-1 Okura, Setagaya-Ku, Tokyo, 157-8535, Japan
| |
Collapse
|
3
|
Grupp B, Gronemeyer T. A biochemical view on the septins, a less known component of the cytoskeleton. Biol Chem 2023; 404:1-13. [PMID: 36423333 DOI: 10.1515/hsz-2022-0263] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 10/30/2022] [Indexed: 11/25/2022]
Abstract
The septins are a conserved family of guanine nucleotide binding proteins, often named the fourth component of the cytoskeleton. They self-assemble into non-polar filaments and further into higher ordered structures. Properly assembled septin structures are required for a wide range of indispensable intracellular processes such as cytokinesis, vesicular transport, polarity establishment and cellular adhesion. Septins belong structurally to the P-Loop NTPases. However, unlike the small GTPases like Ras, septins do not mediate signals to effectors through GTP binding and hydrolysis. The role of nucleotide binding and subsequent GTP hydrolysis by the septins is rather controversially debated. We compile here the structural features from the existing septin crystal- and cryo-EM structures regarding protofilament formation, inter-subunit interface architecture and nucleotide binding and hydrolysis. These findings are supplemented with a summary of available biochemical studies providing information regarding nucleotide binding and hydrolysis of fungal and mammalian septins.
Collapse
Affiliation(s)
- Benjamin Grupp
- Institute of Molecular Genetics and Cell Biology, Ulm University, James Franck Ring N27, 89081 Ulm, Germany
| | - Thomas Gronemeyer
- Institute of Molecular Genetics and Cell Biology, Ulm University, James Franck Ring N27, 89081 Ulm, Germany
| |
Collapse
|
4
|
Neubauer K, Zieger B. Role of Septins in Endothelial Cells and Platelets. Front Cell Dev Biol 2021; 9:768409. [PMID: 34858990 PMCID: PMC8632023 DOI: 10.3389/fcell.2021.768409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Septins are conserved cytoskeletal GTP-binding proteins identified in almost all eukaryotes except higher plants. Mammalian septins comprise 13 family members with either ubiquitous or organ- and tissue-specific expression patterns. They form filamentous oligomers and complexes with other proteins to serve as diffusions barrier and/or multi-molecular scaffolds to function in a physiologically regulated manner. Diverse septins are highly expressed in endothelial cells and platelets, which play an important role in hemostasis, a process to prevent blood loss after vascular injury. Endothelial septins are involved in cellular processes such as exocytosis and in processes concerning organismal level, like angiogenesis. Septins are additionally found in endothelial cell-cell junctions where their presence is required to maintain the integrity of the barrier function of vascular endothelial monolayers. In platelets, septins are important for activation, degranulation, adhesion, and aggregation. They have been identified as mediators of distinct platelet functions and being essential in primary and secondary hemostatic processes. Septin-knockout mouse studies show the relevance of septins in several aspects of hemostasis. This is in line with reports that dysregulation of septins is clinically relevant in human bleeding disorders. The precise function of septins in the biology of endothelial cells and platelets remains poorly understood. The following mini-review highlights the current knowledge about the role of septin cytoskeleton in regulating critical functions in these two cell types.
Collapse
Affiliation(s)
- Katharina Neubauer
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Barbara Zieger
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| |
Collapse
|
5
|
Neubauer K, Jurk K, Petermann V, Kumm E, Zieger B. Impaired Platelet Function in Sept8-Deficient Mice In Vitro. Thromb Haemost 2021; 121:484-494. [PMID: 33202444 DOI: 10.1055/s-0040-1718733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Septins (Septs) are a widely expressed protein family of 13 mammalian members, recognized as a unique component of the cytoskeleton. In human platelets, we previously described that SEPT4 and SEPT8 are localized surrounding α-granules and move to the platelet surface after activation, indicating a possible role in platelet physiology. In this study, we investigated the impact of Sept8 on platelet function in vitro using Sept8-deficient mouse platelets. Deletion of Sept8 in mouse platelets caused a pronounced defect in activation of the fibrinogen receptor integrin αIIbβ3, α-granule exocytosis, and aggregation, especially in response to the glycoprotein VI agonist convulxin. In contrast, δ-granule and lysosome exocytosis of Sept8-deficient platelets was comparable to wild-type platelets. Sept8-deficient platelet binding to immobilized fibrinogen under static conditions was diminished and spreading delayed. The procoagulant activity of Sept8-deficient platelets was reduced in response to convulxin as determined by lactadherin binding. Also thrombin generation was decreased relative to controls. Thus, Sept8 is required for efficient integrin αIIbβ3 activation, α-granule release, platelet aggregation, and contributes to platelet-dependent thrombin generation. These results revealed Sept8 as a modulator of distinct platelet functions involved in primary and secondary hemostatic processes.
Collapse
Affiliation(s)
- Katharina Neubauer
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Kerstin Jurk
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Victoria Petermann
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Elena Kumm
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Barbara Zieger
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| |
Collapse
|
6
|
Septins in Infections: Focus on Viruses. Pathogens 2021; 10:pathogens10030278. [PMID: 33801245 PMCID: PMC8001386 DOI: 10.3390/pathogens10030278] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/17/2021] [Accepted: 02/25/2021] [Indexed: 11/17/2022] Open
Abstract
Human septins comprise a family of 13 genes that encode conserved GTP-binding proteins. They form nonpolar complexes, which assemble into higher-order structures, such as bundles, scaffolding structures, or rings. Septins are counted among the cytoskeletal elements. They interact with the actin and microtubule networks and can bind to membranes. Many cellular functions with septin participation have been described in the literature, including cytokinesis, motility, forming of scaffolding platforms or lateral diffusion barriers, vesicle transport, exocytosis, and recognition of micron-scale curvature. Septin dysfunction has been implicated in diverse human pathologies, including neurodegeneration and tumorigenesis. Moreover, septins are thought to affect the outcome of host–microbe interactions. Implication of septins has been demonstrated in fungal, bacterial, and viral infections. Knowledge on the precise function of a particular septin in the different steps of the virus infection and replication cycle is still limited. Published data for vaccinia virus (VACV), hepatitis C virus (HCV), influenza A virus (H1N1 and H5N1), human herpesvirus 8 (HHV-8), and Zika virus (ZIKV), all of major concern for public health, will be discussed here.
Collapse
|
7
|
Hiroi N, Yamauchi T. Modeling and Predicting Developmental Trajectories of Neuropsychiatric Dimensions Associated With Copy Number Variations. Int J Neuropsychopharmacol 2019; 22:488-500. [PMID: 31135887 PMCID: PMC6672556 DOI: 10.1093/ijnp/pyz026] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/20/2019] [Accepted: 05/24/2019] [Indexed: 01/23/2023] Open
Abstract
Copy number variants, such as duplications and hemizygous deletions at chromosomal loci of up to a few million base pairs, are highly associated with psychiatric disorders. Hemizygous deletions at human chromosome 22q11.2 were found to be associated with elevated instances of schizophrenia and autism spectrum disorder in 1992 and 2002, respectively. Following these discoveries, many mouse models have been developed and tested to analyze the effects of gene dose alterations in small chromosomal segments and single genes of 22q11.2. Despite several limitations to modeling mental illness in mice, mouse models have identified several genes on 22q11.2-Tbx1, Dgcr8, Comt, Sept5, and Prodh-that contribute to dimensions of autism spectrum disorder and schizophrenia, including working memory, social communication and interaction, and sensorimotor gating. Mouse studies have identified that heterozygous deletion of Tbx1 results in defective social communication during the neonatal period and social interaction deficits during adolescence/adulthood. Overexpression of Tbx1 or Comt in adult neural progenitor cells in the hippocampus delays the developmental maturation of working memory capacity. Collectively, mouse models of variants of these 4 genes have revealed several potential neuronal mechanisms underlying various aspects of psychiatric disorders, including adult neurogenesis, microRNA processing, catecholamine metabolism, and synaptic transmission. The validity of the mouse data would be ultimately tested when therapies or drugs based on such potential mechanisms are applied to humans.
Collapse
Affiliation(s)
- Noboru Hiroi
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York
| | - Takahira Yamauchi
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York
| |
Collapse
|
8
|
Motahari Z, Moody SA, Maynard TM, LaMantia AS. In the line-up: deleted genes associated with DiGeorge/22q11.2 deletion syndrome: are they all suspects? J Neurodev Disord 2019; 11:7. [PMID: 31174463 PMCID: PMC6554986 DOI: 10.1186/s11689-019-9267-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 04/21/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND 22q11.2 deletion syndrome (22q11DS), a copy number variation (CNV) disorder, occurs in approximately 1:4000 live births due to a heterozygous microdeletion at position 11.2 (proximal) on the q arm of human chromosome 22 (hChr22) (McDonald-McGinn and Sullivan, Medicine 90:1-18, 2011). This disorder was known as DiGeorge syndrome, Velo-cardio-facial syndrome (VCFS) or conotruncal anomaly face syndrome (CTAF) based upon diagnostic cardiovascular, pharyngeal, and craniofacial anomalies (McDonald-McGinn and Sullivan, Medicine 90:1-18, 2011; Burn et al., J Med Genet 30:822-4, 1993) before this phenotypic spectrum was associated with 22q11.2 CNVs. Subsequently, 22q11.2 deletion emerged as a major genomic lesion associated with vulnerability for several clinically defined behavioral deficits common to a number of neurodevelopmental disorders (Fernandez et al., Principles of Developmental Genetics, 2015; Robin and Shprintzen, J Pediatr 147:90-6, 2005; Schneider et al., Am J Psychiatry 171:627-39, 2014). RESULTS The mechanistic relationships between heterozygously deleted 22q11.2 genes and 22q11DS phenotypes are still unknown. We assembled a comprehensive "line-up" of the 36 protein coding loci in the 1.5 Mb minimal critical deleted region on hChr22q11.2, plus 20 protein coding loci in the distal 1.5 Mb that defines the 3 Mb typical 22q11DS deletion. We categorized candidates based upon apparent primary cell biological functions. We analyzed 41 of these genes that encode known proteins to determine whether haploinsufficiency of any single 22q11.2 gene-a one gene to one phenotype correspondence due to heterozygous deletion restricted to that locus-versus complex multigenic interactions can account for single or multiple 22q11DS phenotypes. CONCLUSIONS Our 22q11.2 functional genomic assessment does not support current theories of single gene haploinsufficiency for one or all 22q11DS phenotypes. Shared molecular functions, convergence on fundamental cell biological processes, and related consequences of individual 22q11.2 genes point to a matrix of multigenic interactions due to diminished 22q11.2 gene dosage. These interactions target fundamental cellular mechanisms essential for development, maturation, or homeostasis at subsets of 22q11DS phenotypic sites.
Collapse
Affiliation(s)
- Zahra Motahari
- The Institute for Neuroscience, and Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington DC, 20037 USA
| | - Sally Ann Moody
- The Institute for Neuroscience, and Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington DC, 20037 USA
| | - Thomas Michael Maynard
- The Institute for Neuroscience, and Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington DC, 20037 USA
| | - Anthony-Samuel LaMantia
- The Institute for Neuroscience, and Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington DC, 20037 USA
| |
Collapse
|
9
|
Zwifelhofer NMJ, Bercovitz RS, Weik LA, Moroi A, LaRose S, Newman PJ, Newman DK. Hemizygosity for the gene encoding glycoprotein Ibβ is not responsible for macrothrombocytopenia and bleeding in patients with 22q11 deletion syndrome. J Thromb Haemost 2019; 17:295-305. [PMID: 30549403 PMCID: PMC6410711 DOI: 10.1111/jth.14357] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Indexed: 12/17/2022]
Abstract
Essentials How thrombocytopenia relates to bleeding in 22q11 deletion syndrome (22q11DS) is not clear. Bleeding severity, platelet count and volume, and GPIBB were examined in patients with 22q11DS. Macrothrombocytopenia and bleeding typified imperfectly overlapping subsets of 22q11DS patients. GPIBB hemizygosity does not cause macrothrombocytopenia or bleeding in patients with 22q11DS. SUMMARY: Background and objectives Macrothrombocytopenia and bleeding are frequently associated with 22q11 deletion syndrome (22q11DS). GPIBB, which encodes the glycoprotein (GP) Ibβ subunit of GPIb-IX-V, is commonly deleted in patients with 22q11DS. Absence of functional GPIb-IX-V causes Bernard-Soulier syndrome, which is a severe bleeding disorder characterized by macrothrombocytopenia. Patients with 22q11DS are often obligate hemizygotes for GPIBB, and those with only a pathogenically disrupted copy of GPIBB present with Bernard-Soulier syndrome. The objective of this study was to determine how GPIBB hemizygosity and sequence variation relate to macrothrombocytopenia and bleeding in patients with 22q11DS who do not have Bernard-Soulier syndrome. Patients/methods We thoroughly characterized bleeding severity, mean platelet volume, platelet count and GPIBB copy number and sequence in patients with 22q11DS. Results and conclusions Macrothrombocytopenia and mild bleeding were observed in incompletely overlapping subsets of patients, and GPIBB copy number and sequence variation did not correlate with either macrothrombocytopenia or bleeding in patients with 22q11DS. These findings indicate that GPIBB hemizygosity does not result in either macrothrombocytopenia or bleeding in these patients. Alternative genetic causes of macrothrombocytopenia, potential causes of acquired thrombocytopenia and bleeding and ways in which platelet size, platelet count and GPIBB sequence information can be used to aid in the diagnosis and management of patients with 22q11DS are discussed.
Collapse
Affiliation(s)
- N M J Zwifelhofer
- Blood Research Institute, BloodCenter of Wisconsin - part of Versiti, Milwaukee, WI, USA
| | - R S Bercovitz
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
- Department of Pediatrics, Division of Hematology and Oncology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - L A Weik
- Children's Hospital of Wisconsin, Milwaukee, WI, USA
| | - A Moroi
- Blood Research Institute, BloodCenter of Wisconsin - part of Versiti, Milwaukee, WI, USA
| | - S LaRose
- Blood Research Institute, BloodCenter of Wisconsin - part of Versiti, Milwaukee, WI, USA
| | - P J Newman
- Blood Research Institute, BloodCenter of Wisconsin - part of Versiti, Milwaukee, WI, USA
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - D K Newman
- Blood Research Institute, BloodCenter of Wisconsin - part of Versiti, Milwaukee, WI, USA
- Department of Pharmacology & Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
- Department of Microbiology & Immunology, Medical College of Wisconsin, Milwaukee, WI, USA
| |
Collapse
|
10
|
Cattaneo M. Inherited Disorders of Platelet Function. Platelets 2019. [DOI: 10.1016/b978-0-12-813456-6.00048-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
11
|
Acute Pre-B Lymphoblastic Leukemia and Congenital Anomalies in a Child with a de Novo 22q11.1q11.22 Duplication. Balkan J Med Genet 2018; 21:87-91. [PMID: 30425917 PMCID: PMC6231321 DOI: 10.2478/bjmg-2018-0002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Microdeletions and microduplications are recurrent in the q11.2 region of chromosome 22. The 22q11.2 duplication syndrome is an extremely variable disorder with a phenotype ranging from severe intellectual disability, facial dysmorphism, heart defects, and urogenital abnormalities to very mild symptoms. Both benign and malignant hematological entities are rare. A male patient was diagnosed with mild facial dysmorphia, congenital heart anomalies shortly after birth and acute bowel obstruction due to malrotation of the intestine at the age of 3 years. A whole-genome single nucleotide polymorphism (SNP) array revealed a de novo 6.6 Mb duplication in the 22q11.1q11.22 chromosomal region. A year later, the patient was diagnosed with acute pre-B lymphoblastic leukemia (pre-B ALL). Five genes, CDC45, CLTCL1, DGCR2, GP1BB and SEPT5, in the 22q11.1q11.22 region are potentially responsible for cell cycle division. We hypothesized that dosage imbalance of genes implicated in the rearrangement could have disrupted the balance between cell growth and differentiation and played a role in the initiation of malignancy with a hyperdiploid leukemic clone, whereas over-expression of the TBX1 gene might have been responsible for congenital heart defects and mild facial dysmorphia.
Collapse
|
12
|
Neubauer K, Boeckelmann D, Koehler U, Kracht J, Kirschner J, Pendziwiat M, Zieger B. Hereditary neuralgic amyotrophy in childhood caused by duplication within the SEPT9 gene: A family study. Cytoskeleton (Hoboken) 2018; 76:131-136. [PMID: 30019529 PMCID: PMC6585727 DOI: 10.1002/cm.21479] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 06/28/2018] [Accepted: 07/10/2018] [Indexed: 01/24/2023]
Abstract
Hereditary neuralgic amyotrophy (HNA) is an autosomal dominant disorder associated with episodic, recurrent, and painful neuropathies affecting the nerves of the brachial plexus. In this study, we report on a family of Lebanese descent with HNA onset in early childhood. The affected family members presented with platelet dysfunction. Platelet aggregation was reduced after stimulation with the agonists ADP and epinephrine in all affected family members. Flow cytometric analyses revealed impaired platelet δ‐secretion. The index patient and one brother suffered from kidney cysts. Molecular genetic analysis revealed a heterozygous duplication of exon 2 within the septin 9 (SEPT9) gene in all the affected family members. Such a young child with HNA (aged 2 years) caused by SEPT9 duplication has not been described so far.
Collapse
Affiliation(s)
- Katharina Neubauer
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, University Medical Center, Medical Faculty, University of Freiburg, Freiburg, Germany
| | - Doris Boeckelmann
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, University Medical Center, Medical Faculty, University of Freiburg, Freiburg, Germany
| | - Udo Koehler
- Department of Medical Genetics, MGZ - Medical Genetics Center, Munich, Germany
| | - Julia Kracht
- Division of General Pediatrics, Department of Pediatrics and Adolescent Medicine, University Medical Center, Medical Faculty, University of Freiburg, Freiburg, Germany
| | - Janbernd Kirschner
- Department of Neuropediatrics and Muscle Disorders, University Medical Center, Faculty of Medicine, University of Freiburg, Germany
| | - Manuela Pendziwiat
- Department of Neuropediatrics, Christian-Albrechts-University of Kiel and University Medical Center Schleswig-Holstein, Kiel, Germany
| | - Barbara Zieger
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, University Medical Center, Medical Faculty, University of Freiburg, Freiburg, Germany
| |
Collapse
|
13
|
Wasik AA, Dash SN, Lehtonen S. Septins in kidney: A territory little explored. Cytoskeleton (Hoboken) 2018; 76:154-162. [PMID: 30004646 PMCID: PMC6585700 DOI: 10.1002/cm.21477] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/15/2018] [Accepted: 07/03/2018] [Indexed: 12/15/2022]
Abstract
Septins are a conserved family of GTP‐binding proteins that assemble into cytoskeletal filaments to function in a highly sophisticated and physiologically regulated manner. Originally septins were discovered in the budding yeast as membrane‐associated filaments that affect cell polarity and cytokinesis. In the last decades, much progress has been made in understanding the biochemical properties and cell biological functions of septins. In line with this, mammalian septins have been shown to be involved in various cellular processes, including regulation of cell polarity, cytoskeletal organization, vesicle trafficking, ciliogenesis, and cell–pathogen interactions. A growing number of studies have shown that septins play important roles in tissue and organ development and physiology; yet, little is known about their role in the kidney. In the following review, we discuss the structure and functions of septins in general and summarize the evidence for their presence and roles in the kidney.
Collapse
Affiliation(s)
- Anita A Wasik
- Department of Pathology, University of Helsinki, Helsinki, Finland
| | - Surjya N Dash
- Department of Pathology, University of Helsinki, Helsinki, Finland
| | - Sanna Lehtonen
- Department of Pathology, University of Helsinki, Helsinki, Finland
| |
Collapse
|
14
|
Honorat JA, Lopez-Chiriboga AS, Kryzer TJ, Fryer JP, Devine M, Flores A, Lennon VA, Pittock SJ, McKeon A. Autoimmune septin-5 cerebellar ataxia. NEUROLOGY-NEUROIMMUNOLOGY & NEUROINFLAMMATION 2018; 5:e474. [PMID: 29998156 PMCID: PMC6039209 DOI: 10.1212/nxi.0000000000000474] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/21/2018] [Indexed: 01/08/2023]
Abstract
Objective To report a form of autoimmune cerebellar ataxia in which antibodies target septin-5, a guanosine triphosphate (GTP)-binding neural protein involved in neurotransmitter exocytosis. Methods Archived sera and CSF specimens with unclassified synaptic antibodies were re-evaluated by tissue-based indirect immunofluorescence assay. Autoantigens were identified by Western blot and mass spectrometry. Recombinant protein assays (Western blot, cell based, and protein screening array) confirmed antigen specificity. Results Serum and CSF from 6 patients produced identical synaptic immunoglobulin G (IgG) staining patterns of synaptic regions (neuropil) of the mouse cerebrum and cerebellum. The molecular layer of the cerebellum and the thalamus demonstrated stronger immunoreactivity than the midbrain, hippocampus, cortex, and basal ganglia. The antigen revealed by mass spectrometry analysis of immunoprecipitated cerebellar proteins and confirmed by recombinant protein assays was septin-5. All 4 patients with records available had subacute onset of cerebellar ataxia with prominent eye movement symptoms (oscillopsia or vertigo). None had cancer detected. Improvements occurred after immunotherapies (2) or spontaneously (1). One patient died. Conclusion Septin-5 IgG represents a biomarker for a potentially fatal but treatable autoimmune ataxia.
Collapse
Affiliation(s)
- Josephe A Honorat
- Department of Laboratory Medicine and Pathology (J.A.H., T.J.K., J.P.F., V.A.L., S.J.P., A.M.), the Department of Neurology (A.S.L.-C., V.A.L., S.J.P., A.M.), and the Department of Immunology (V.A.L.), College of Medicine, Mayo Clinic, Rochester, MN; and Department of Neurology (M.D., A.F.), University of Texas, Southwestern, Dallas
| | - A Sebastian Lopez-Chiriboga
- Department of Laboratory Medicine and Pathology (J.A.H., T.J.K., J.P.F., V.A.L., S.J.P., A.M.), the Department of Neurology (A.S.L.-C., V.A.L., S.J.P., A.M.), and the Department of Immunology (V.A.L.), College of Medicine, Mayo Clinic, Rochester, MN; and Department of Neurology (M.D., A.F.), University of Texas, Southwestern, Dallas
| | - Thomas J Kryzer
- Department of Laboratory Medicine and Pathology (J.A.H., T.J.K., J.P.F., V.A.L., S.J.P., A.M.), the Department of Neurology (A.S.L.-C., V.A.L., S.J.P., A.M.), and the Department of Immunology (V.A.L.), College of Medicine, Mayo Clinic, Rochester, MN; and Department of Neurology (M.D., A.F.), University of Texas, Southwestern, Dallas
| | - James P Fryer
- Department of Laboratory Medicine and Pathology (J.A.H., T.J.K., J.P.F., V.A.L., S.J.P., A.M.), the Department of Neurology (A.S.L.-C., V.A.L., S.J.P., A.M.), and the Department of Immunology (V.A.L.), College of Medicine, Mayo Clinic, Rochester, MN; and Department of Neurology (M.D., A.F.), University of Texas, Southwestern, Dallas
| | - Michelle Devine
- Department of Laboratory Medicine and Pathology (J.A.H., T.J.K., J.P.F., V.A.L., S.J.P., A.M.), the Department of Neurology (A.S.L.-C., V.A.L., S.J.P., A.M.), and the Department of Immunology (V.A.L.), College of Medicine, Mayo Clinic, Rochester, MN; and Department of Neurology (M.D., A.F.), University of Texas, Southwestern, Dallas
| | - Angela Flores
- Department of Laboratory Medicine and Pathology (J.A.H., T.J.K., J.P.F., V.A.L., S.J.P., A.M.), the Department of Neurology (A.S.L.-C., V.A.L., S.J.P., A.M.), and the Department of Immunology (V.A.L.), College of Medicine, Mayo Clinic, Rochester, MN; and Department of Neurology (M.D., A.F.), University of Texas, Southwestern, Dallas
| | - Vanda A Lennon
- Department of Laboratory Medicine and Pathology (J.A.H., T.J.K., J.P.F., V.A.L., S.J.P., A.M.), the Department of Neurology (A.S.L.-C., V.A.L., S.J.P., A.M.), and the Department of Immunology (V.A.L.), College of Medicine, Mayo Clinic, Rochester, MN; and Department of Neurology (M.D., A.F.), University of Texas, Southwestern, Dallas
| | - Sean J Pittock
- Department of Laboratory Medicine and Pathology (J.A.H., T.J.K., J.P.F., V.A.L., S.J.P., A.M.), the Department of Neurology (A.S.L.-C., V.A.L., S.J.P., A.M.), and the Department of Immunology (V.A.L.), College of Medicine, Mayo Clinic, Rochester, MN; and Department of Neurology (M.D., A.F.), University of Texas, Southwestern, Dallas
| | - Andrew McKeon
- Department of Laboratory Medicine and Pathology (J.A.H., T.J.K., J.P.F., V.A.L., S.J.P., A.M.), the Department of Neurology (A.S.L.-C., V.A.L., S.J.P., A.M.), and the Department of Immunology (V.A.L.), College of Medicine, Mayo Clinic, Rochester, MN; and Department of Neurology (M.D., A.F.), University of Texas, Southwestern, Dallas
| |
Collapse
|
15
|
Gothwal M, Sandrock-Lang K, Zieger B. Genetics of inherited platelet disorders. Hamostaseologie 2017; 34:133-41. [DOI: 10.5482/hamo-13-09-0049] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 12/11/2013] [Indexed: 11/05/2022] Open
Abstract
SummaryThe current review describes inherited platelet disorders, illustrates their clinical phenotype and molecular genetic defects. Platelets are the key molecules mediating haemostasis via adhesion, activation and clot formation at the site of injury. The inherited platelet disorders can be classified according to their platelet defects: receptor/cytoskeleton defects, secretion disorder, and signal transduction defect.Patients with inherited thrombocytopathia present with mucous membrane bleedings (epistaxis, gingival bleeding) and may present with serious life threatening bleedings following surgery or trauma. Therefore, biochemical and molecular genetic characterization of inherited platelet disorders is important to understand these disorders and to support an efficient therapy.
Collapse
|
16
|
Patients with Bernard-Soulier syndrome and different severity of the bleeding phenotype. Blood Cells Mol Dis 2017; 67:69-74. [DOI: 10.1016/j.bcmd.2017.01.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 01/17/2017] [Accepted: 01/19/2017] [Indexed: 11/16/2022]
|
17
|
Abstract
Septins are GTP-binding and membrane-interacting proteins with a highly conserved domain structure involved in various cellular processes, including cytoskeleton organization, cytokinesis, and membrane dynamics. To date, 13 different septin genes have been identified in mammals (SEPT1 to SEPT12 and SEPT14), which can be classified into four distinct subgroups based on the sequence homology of their domain structure (SEPT2, SEPT3, SEPT6, and SEPT7 subgroup). The family members of these subgroups have a strong affinity for other septins and form apolar tri-, hexa-, or octameric complexes consisting of multiple septin polypeptides. The first characterized core complex is the hetero-trimer SEPT2-6-7. Within these complexes single septins can be exchanged in a subgroup-specific manner. Hexamers contain SEPT2 and SEPT6 subgroup members and SEPT7 in two copies each whereas the octamers additionally comprise two SEPT9 subgroup septins. The various isoforms seem to determine the function and regulation of the septin complex. Septins self-assemble into higher-order structures, including filaments and rings in orders, which are typical for different cell types. Misregulation of septins leads to human diseases such as neurodegenerative and bleeding disorders. In non-dividing cells such as neuronal tissue and platelets septins have been associated with exocytosis. However, many mechanistic details and roles attributed to septins are poorly understood. We describe here some important mammalian septin interactions with a special focus on the clinically relevant septin interactions.
Collapse
Affiliation(s)
- Katharina Neubauer
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Faculty of Medicine, Medical Center-University of Freiburg Freiburg, Germany
| | - Barbara Zieger
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Faculty of Medicine, Medical Center-University of Freiburg Freiburg, Germany
| |
Collapse
|
18
|
Rakonjac M, Cuturilo G, Stevanovic M, Jelicic L, Subotic M, Jovanovic I, Drakulic D. Differences in speech and language abilities between children with 22q11.2 deletion syndrome and children with phenotypic features of 22q11.2 deletion syndrome but without microdeletion. RESEARCH IN DEVELOPMENTAL DISABILITIES 2016; 55:322-329. [PMID: 27235769 DOI: 10.1016/j.ridd.2016.05.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Revised: 05/07/2016] [Accepted: 05/09/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND 22q11.2DS is the most common microdeletion syndrome in humans, usually associated with speech and language delay (SLD). Approximately 75% of children with 22q11.2 microdeletion have congenital heart malformations (CHM) which after infant open-heart surgery might lead to SLD. AIMS The purpose of this study was to determine whether factors associated with microdeletion contribute to SLD in children with 22q11.2DS. METHODS AND PROCEDURES We compared speech and language abilities of two groups of school-aged children: those with 22q11.2 microdeletion (E1) and those with the phenotype resembling 22q11.2DS but without the microdeletion (E2). An age-matched group of typically developing children was also tested. OUTCOMES AND RESULTS The obtained results revealed that children from group E1 have lower level of speech and language abilities compared to children from group E2 and control group. Additionally, mild to moderate SLD was detected in children from group E2 compared to children from the control group. CONCLUSIONS AND IMPLICATIONS The obtained results imply that both CHM after infant open-heart surgery and other factors associated with 22q11.2 microdeletion, contribute to SLD in patients with 22q11.2 microdeletion. Based on this, we could postulate that there is/are some potential candidate gene(s), located in the 22q11.2 region, whose function could be important for speech and language development.
Collapse
Affiliation(s)
- Marijana Rakonjac
- Institute for Experimental Phonetics and Speech Pathology, Jovanova 35, Belgrade, Serbia; Life Activities Advancement Center, Jovanova 35, Belgrade, Serbia.
| | - Goran Cuturilo
- Faculty of Medicine, University of Belgrade, Dr Subotica 8, 11000 Belgrade, Serbia; University Children's Hospital, Tirsova 10, 11000 Belgrade, Serbia.
| | - Milena Stevanovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010 Belgrade, Serbia.
| | - Ljiljana Jelicic
- Institute for Experimental Phonetics and Speech Pathology, Jovanova 35, Belgrade, Serbia; Life Activities Advancement Center, Jovanova 35, Belgrade, Serbia.
| | - Misko Subotic
- Institute for Experimental Phonetics and Speech Pathology, Jovanova 35, Belgrade, Serbia; Life Activities Advancement Center, Jovanova 35, Belgrade, Serbia.
| | - Ida Jovanovic
- Faculty of Medicine, University of Belgrade, Dr Subotica 8, 11000 Belgrade, Serbia; University Children's Hospital, Tirsova 10, 11000 Belgrade, Serbia.
| | - Danijela Drakulic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010 Belgrade, Serbia.
| |
Collapse
|
19
|
Menon MB, Gaestel M. Sep(t)arate or not – how some cells take septin-independent routes through cytokinesis. J Cell Sci 2015; 128:1877-86. [PMID: 25690008 DOI: 10.1242/jcs.164830] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Cytokinesis is the final step of cell division, and is a process that requires a precisely coordinated molecular machinery to fully separate the cytoplasm of the parent cell and to establish the intact outer cell barrier of the daughter cells. Among various cytoskeletal proteins involved, septins are known to be essential mediators of cytokinesis. In this Commentary, we present recent observations that specific cell divisions can proceed in the absence of the core mammalian septin SEPT7 and its Drosophila homolog Peanut (Pnut) and that thus challenge the view that septins have an essential role in cytokinesis. In the pnut mutant neuroepithelium, orthogonal cell divisions are successfully completed. Similarly, in the mouse, Sept7-null mutant early embryonic cells and, more importantly, planktonically growing adult hematopoietic cells undergo productive proliferation. Hence, as discussed here, mechanisms must exist that compensate for the lack of SEPT7 and the other core septins in a cell-type-specific manner. Despite there being crucial non-canonical immune-relevant functions of septins, septin depletion is well tolerated by the hematopoietic system. Thus differential targeting of cytokinesis could form the basis for more specific anti-proliferative therapies to combat malignancies arising from cell types that require septins for cytokinesis, such as carcinomas and sarcomas, without impairing hematopoiesis that is less dependent on septin.
Collapse
Affiliation(s)
- Manoj B Menon
- Institute of Physiological Chemistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Matthias Gaestel
- Institute of Physiological Chemistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| |
Collapse
|
20
|
Wesseling H, Gottschalk MG, Bahn S. Targeted multiplexed selected reaction monitoring analysis evaluates protein expression changes of molecular risk factors for major psychiatric disorders. Int J Neuropsychopharmacol 2014; 18:pyu015. [PMID: 25539505 PMCID: PMC4368865 DOI: 10.1093/ijnp/pyu015] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Extensive research efforts have generated genomic, transcriptomic, proteomic, and functional data hoping to elucidate psychiatric pathophysiology. Selected reaction monitoring, a recently developed targeted proteomic mass spectrometric approach, has made it possible to evaluate previous findings and hypotheses with high sensitivity, reproducibility, and quantitative accuracy. METHODS Here, we have developed a labelled multiplexed selected reaction monitoring assay, comprising 56 proteins previously implicated in the aetiology of major psychiatric disorders, including cell type markers or targets and effectors of known psychopharmacological interventions. We analyzed postmortem anterior prefrontal cortex (Brodmann area 10) tissue of patients diagnosed with schizophrenia (n=22), bipolar disorder (n=23), and major depressive disorder with (n=11) and without (n=11) psychotic features compared with healthy controls (n=22). RESULTS Results agreed with several previous studies, with the finding of alterations of Wnt-signalling and glutamate receptor abundance predominately in bipolar disorder and abnormalities in energy metabolism across the neuropsychiatric disease spectrum. Calcium signalling was predominantly affected in schizophrenia and affective psychosis. Interestingly, we were able to show a decrease of all 4 tested oligodendrocyte specific proteins (MOG, MBP, MYPR, CNPase) in bipolar disorder and to a lesser extent in schizophrenia and affective psychosis. Finally, we provide new evidence linking ankyrin 3 specifically to affective psychosis and the 22q11.2 deletion syndrome-associated protein septin 5 to schizophrenia. CONCLUSIONS Our study highlights the potential of selected reaction monitoring to evaluate the protein abundance levels of candidate markers of neuropsychiatric spectrum disorders, providing a high throughput multiplex platform for validation of putative disease markers and drug targets.
Collapse
Affiliation(s)
| | | | - Sabine Bahn
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB2 1QT, United Kingdom (Wesseling, Gottschalk, and Bahn); Department of Neuroscience, Erasmus Medical Center, 3000 CA Rotterdam, The Netherlands (Dr Bahn).H.W. and M.G.G. contributed equally to this work.
| |
Collapse
|
21
|
Septins arrange F-actin-containing fibers on the Chlamydia trachomatis inclusion and are required for normal release of the inclusion by extrusion. mBio 2014; 5:e01802-14. [PMID: 25293760 PMCID: PMC4196233 DOI: 10.1128/mbio.01802-14] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular human pathogen that grows inside a membranous, cytosolic vacuole termed an inclusion. Septins are a group of 13 GTP-binding proteins that assemble into oligomeric complexes and that can form higher-order filaments. We report here that the septins SEPT2, -9, -11, and probably -7 form fibrillar structures around the chlamydial inclusion. Colocalization studies suggest that these septins combine with F actin into fibers that encase the inclusion. Targeting the expression of individual septins by RNA interference (RNAi) prevented the formation of septin fibers as well as the recruitment of actin to the inclusion. At the end of the developmental cycle of C. trachomatis, newly formed, infectious elementary bodies are released, and this release occurs at least in part through the organized extrusion of intact inclusions. RNAi against SEPT9 or against the combination of SEPT2/7/9 substantially reduced the number of extrusions from a culture of infected HeLa cells. The data suggest that a higher-order structure of four septins is involved in the recruitment or stabilization of the actin coat around the chlamydial inclusion and that this actin recruitment by septins is instrumental for the coordinated egress of C. trachomatis from human cells. The organization of F actin around parasite-containing vacuoles may be a broader response mechanism of mammalian cells to the infection by intracellular, vacuole-dwelling pathogens. Chlamydia trachomatis is a frequent bacterial pathogen throughout the world, causing mostly eye and genital infections. C. trachomatis can develop only inside host cells; it multiplies inside a membranous vacuole in the cytosol, termed an inclusion. The inclusion is covered by cytoskeletal “coats” or “cages,” whose organization and function are poorly understood. We here report that a relatively little-characterized group of proteins, septins, is required to organize actin fibers on the inclusion and probably through actin the release of the inclusion. Septins are a group of GTP-binding proteins that can organize into heteromeric complexes and then into large filaments. Septins have previously been found to be involved in the interaction of the cell with bacteria in the cytosol. Our observation that they also organize a reaction to bacteria living in vacuoles suggests that they have a function in the recognition of foreign compartments by a parasitized human cell.
Collapse
|
22
|
Dolat L, Hu Q, Spiliotis ET. Septin functions in organ system physiology and pathology. Biol Chem 2014; 395:123-41. [PMID: 24114910 DOI: 10.1515/hsz-2013-0233] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 10/08/2013] [Indexed: 02/07/2023]
Abstract
Human septins comprise a family of 13 genes that encode for >30 protein isoforms with ubiquitous and tissue-specific expressions. Septins are GTP-binding proteins that assemble into higher-order oligomers and filamentous polymers, which associate with cell membranes and the cytoskeleton. In the last decade, much progress has been made in understanding the biochemical properties and cell biological functions of septins. In parallel, a growing number of studies show that septins play important roles for the development and physiology of specific tissues and organs. Here, we review the expression and function of septins in the cardiovascular, immune, nervous, urinary, digestive, respiratory, endocrine, reproductive, and integumentary organ systems. Furthermore, we discuss how the tissue-specific functions of septins relate to the pathology of human diseases that arise from aberrations in septin expression.
Collapse
|
23
|
Serotonergic, noradrenergic and dopaminergic markers are related to cognitive function in adults with 22q11 deletion syndrome. Int J Neuropsychopharmacol 2014; 17:1159-65. [PMID: 24713114 DOI: 10.1017/s1461145714000376] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Patients with 22q11 deletion syndrome (22q11DS) have a high prevalence of psychiatric disorders and intellectual disability. At present the neurobiology underlying psychopathology in 22q11DS is still not understood. In the present study, we analyzed urinary serotonergic, dopaminergic and noradrenergic markers in 67 adults with 22q11DS. Levels of serotonin and the catecholamine metabolite homovanillic acid were significantly lower in the 22q11DS subjects compared to healthy controls. Within the 22q11DS group, levels of dopamine, homovanillic acid, norepinephrine, vanillyl mandelic acid and serotonin positively correlated with Full Scale Intelligence Quotient scores. Our results suggest that cognitive deficits in 22q11DS are associated with abnormal function of several neurotransmitters.
Collapse
|
24
|
Savoia A, Kunishima S, De Rocco D, Zieger B, Rand ML, Pujol-Moix N, Caliskan U, Tokgoz H, Pecci A, Noris P, Srivastava A, Ward C, Morel-Kopp MC, Alessi MC, Bellucci S, Beurrier P, de Maistre E, Favier R, Hézard N, Hurtaud-Roux MF, Latger-Cannard V, Lavenu-Bombled C, Proulle V, Meunier S, Négrier C, Nurden A, Randrianaivo H, Fabris F, Platokouki H, Rosenberg N, HadjKacem B, Heller PG, Karimi M, Balduini CL, Pastore A, Lanza F. Spectrum of the mutations in Bernard-Soulier syndrome. Hum Mutat 2014; 35:1033-45. [PMID: 24934643 DOI: 10.1002/humu.22607] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Accepted: 06/06/2014] [Indexed: 01/05/2023]
Abstract
Bernard-Soulier syndrome (BSS) is a rare autosomal recessive bleeding disorder characterized by defects of the GPIb-IX-V complex, a platelet receptor for von Willebrand factor (VWF). Most of the mutations identified in the genes encoding for the GP1BA (GPIbα), GP1BB (GPIbβ), and GP9 (GPIX) subunits prevent expression of the complex at the platelet membrane or more rarely its interaction with VWF. As a consequence, platelets are unable to adhere to the vascular subendothelium and agglutinate in response to ristocetin. In order to collect information on BSS patients, we established an International Consortium for the study of BSS, allowing us to enrol and genotype 132 families (56 previously unreported). With 79 additional families for which molecular data were gleaned from the literature, the 211 families characterized so far have mutations in the GP1BA (28%), GP1BB (28%), or GP9 (44%) genes. There is a wide spectrum of mutations with 112 different variants, including 22 novel alterations. Consistent with the rarity of the disease, 85% of the probands carry homozygous mutations with evidence of founder effects in some geographical areas. This overview provides the first global picture of the molecular basis of BSS and will lead to improve patient diagnosis and management.
Collapse
Affiliation(s)
- Anna Savoia
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy; Department of Medical Sciences, University of Trieste, Trieste, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Zimman A, Titz B, Komisopoulou E, Biswas S, Graeber TG, Podrez EA. Phosphoproteomic analysis of platelets activated by pro-thrombotic oxidized phospholipids and thrombin. PLoS One 2014; 9:e84488. [PMID: 24400094 PMCID: PMC3882224 DOI: 10.1371/journal.pone.0084488] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 11/15/2013] [Indexed: 11/19/2022] Open
Abstract
Specific oxidized phospholipids (oxPCCD36) promote platelet hyper-reactivity and thrombosis in hyperlipidemia via the scavenger receptor CD36, however the signaling pathway(s) induced in platelets by oxPCCD36 are not well defined. We have employed mass spectrometry-based tyrosine, serine, and threonine phosphoproteomics for the unbiased analysis of platelet signaling pathways induced by oxPCCD36 as well as by the strong physiological agonist thrombin. oxPCCD36 and thrombin induced differential phosphorylation of 115 proteins (162 phosphorylation sites) and 181 proteins (334 phosphorylation sites) respectively. Most of the phosphoproteome changes induced by either agonist have never been reported in platelets; thus they provide candidates in the study of platelet signaling. Bioinformatic analyses of protein phosphorylation dependent responses were used to categorize preferential motifs for (de)phosphorylation, predict pathways and kinase activity, and construct a phosphoproteome network regulating integrin activation. A putative signaling pathway involving Src-family kinases, SYK, and PLCγ2 was identified in platelets activated by oxPCCD36. Subsequent ex vivo studies in human platelets demonstrated that this pathway is downstream of the scavenger receptor CD36 and is critical for platelet activation by oxPCCD36. Our results provide multiple insights into the mechanism of platelet activation and specifically in platelet regulation by oxPCCD36.
Collapse
Affiliation(s)
- Alejandro Zimman
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Bjoern Titz
- Crump Institute for Molecular Imaging, Department of Molecular and Medical Pharmacology, Institute for Molecular Medicine, Jonsson Comprehensive Cancer Center and California NanoSystems Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Evangelia Komisopoulou
- Crump Institute for Molecular Imaging, Department of Molecular and Medical Pharmacology, Institute for Molecular Medicine, Jonsson Comprehensive Cancer Center and California NanoSystems Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Sudipta Biswas
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Thomas G. Graeber
- Crump Institute for Molecular Imaging, Department of Molecular and Medical Pharmacology, Institute for Molecular Medicine, Jonsson Comprehensive Cancer Center and California NanoSystems Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Eugene A. Podrez
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- * E-mail:
| |
Collapse
|
26
|
Copy number variation at 22q11.2: from rare variants to common mechanisms of developmental neuropsychiatric disorders. Mol Psychiatry 2013; 18:1153-65. [PMID: 23917946 PMCID: PMC3852900 DOI: 10.1038/mp.2013.92] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 05/13/2013] [Accepted: 06/24/2013] [Indexed: 11/08/2022]
Abstract
Recently discovered genome-wide rare copy number variants (CNVs) have unprecedented levels of statistical association with many developmental neuropsychiatric disorders, including schizophrenia, autism spectrum disorders, intellectual disability and attention deficit hyperactivity disorder. However, as CNVs often include multiple genes, causal genes responsible for CNV-associated diagnoses and traits are still poorly understood. Mouse models of CNVs are in use to delve into the precise mechanisms through which CNVs contribute to disorders and associated traits. Based on human and mouse model studies on rare CNVs within human chromosome 22q11.2, we propose that alterations of a distinct set of multiple, noncontiguous genes encoded in this chromosomal region, in concert with modulatory impacts of genetic background and environmental factors, variably shift the probabilities of phenotypes along a predetermined developmental trajectory. This model can be further extended to the study of other CNVs and may serve as a guide to help characterize the impact of genes in developmental neuropsychiatric disorders.
Collapse
|
27
|
Goubau C, Buyse GM, Di Michele M, Van Geet C, Freson K. Regulated granule trafficking in platelets and neurons: a common molecular machinery. Eur J Paediatr Neurol 2013; 17:117-25. [PMID: 22951324 DOI: 10.1016/j.ejpn.2012.08.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 08/03/2012] [Accepted: 08/11/2012] [Indexed: 01/25/2023]
Abstract
Platelet function in primary hemostasis involves the secretion of granules upon activation, providing the localized delivery of effector proteins at sites of vascular injury. The sequential process of regulated secretion in platelets, from the biogenesis of the granules, through their transport and up to the exocytotic fusion process at the acceptor membrane, involves a complex molecular machinery conserved between some other specialized cells such as neurons. Mutations in genes encoding proteins involved in this process of granule trafficking have helped towards demystification of the underlying secretory mechanisms. Human diseases of trafficking encompass a broad symptomatology including a platelet-related bleeding diathesis and neuronal problems. In this review, we want to highlight the similarities in granule biology between platelets and neurons and further focus on some granule trafficking disorders that result in bleeding and neuropathology. This review provides evidence that platelet research can be expanded from traditional studies of isolated thrombopathies to the field of neuropathologies that include a platelet secretion defect.
Collapse
Affiliation(s)
- Christophe Goubau
- Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | | | | | | | | |
Collapse
|
28
|
Cattaneo M. Congenital Disorders of Platelet Function. Platelets 2013. [DOI: 10.1016/b978-0-12-387837-3.00050-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
29
|
Harper KM, Hiramoto T, Tanigaki K, Kang G, Suzuki G, Trimble W, Hiroi N. Alterations of social interaction through genetic and environmental manipulation of the 22q11.2 gene Sept5 in the mouse brain. Hum Mol Genet 2012; 21:3489-99. [PMID: 22589251 DOI: 10.1093/hmg/dds180] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Social behavior dysfunction is a symptomatic element of schizophrenia and autism spectrum disorder (ASD). Although altered activities in numerous brain regions are associated with defective social cognition and perception, the causative relationship between these altered activities and social cognition and perception-and their genetic underpinnings-are not known in humans. To address these issues, we took advantage of the link between hemizygous deletion of human chromosome 22q11.2 and high rates of social behavior dysfunction, schizophrenia and ASD. We genetically manipulated Sept5, a 22q11.2 gene, and evaluated its role in social interaction in mice. Sept5 deficiency, against a high degree of homogeneity in a congenic genetic background, selectively impaired active affiliative social interaction in mice. Conversely, virally guided overexpression of Sept5 in the hippocampus or, to a lesser extent, the amygdala elevated levels of active affiliative social interaction in C57BL/6J mice. Congenic knockout mice and mice overexpressing Sept5 in the hippocampus or amygdala were indistinguishable from control mice in novelty and olfactory responses, anxiety or motor activity. Moreover, post-weaning individual housing, an environmental condition designed to reduce stress in male mice, selectively raised levels of Sept5 protein in the amygdala and increased active affiliative social interaction in C57BL/6J mice. These findings identify this 22q11.2 gene in the hippocampus and amygdala as a determinant of social interaction and suggest that defective social interaction seen in 22q11.2-associated schizophrenia and ASD can be genetically and environmentally modified by altering this 22q11.2 gene.
Collapse
Affiliation(s)
- Kathryn M Harper
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | | | | | | | | | | | | |
Collapse
|
30
|
Hiroi N, Hiramoto T, Harper KM, Suzuki G, Boku S. Mouse Models of 22q11.2-Associated Autism Spectrum Disorder. ACTA ACUST UNITED AC 2012; Suppl 1:001. [PMID: 25089229 PMCID: PMC4118685 DOI: 10.4172/2165-7890.s1-001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Copy number variation (CNV) of human chromosome 22q11.2 is associated with an elevated rate of autism spectrum disorder (ASD) and represents one of syndromic ASDs with rare genetic variants. However, the precise genetic basis of this association remains unclear due to its relatively large hemizygous and duplication region, including more than 30 genes. Previous studies using genetic mouse models suggested that although not all 22q11.2 genes contribute to ASD symptomatology, more than one 22q11.2 genes have distinct phenotypic targets for ASD symptoms. Our data show that deficiency of the two 22q11.2 genesTbx1 and Sept5 causes distinct phenotypic sets of ASD symptoms.
Collapse
Affiliation(s)
- Noboru Hiroi
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Golding 104, 1300 Morris Park Avenue, Bronx, NY, 10461 USA ; Department of Neuroscience, Albert Einstein College of Medicine, Golding 104, 1300 Morris Park Avenue, Bronx, NY, 10461 USA ; Department of Genetics, Albert Einstein College of Medicine, Golding 104, 1300 Morris Park Avenue, Bronx, NY, 10461 USA
| | - Takeshi Hiramoto
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Golding 104, 1300 Morris Park Avenue, Bronx, NY, 10461 USA
| | - Kathryn M Harper
- Department of Psychiatry & Behavioral Sciences, Northwestern University, Ward Building Room 9-258, 303 E. Chicago Ave. Chicago, IL 60611, USA
| | - Go Suzuki
- Department of Psychiatry, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Shuken Boku
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Golding 104, 1300 Morris Park Avenue, Bronx, NY, 10461 USA
| |
Collapse
|