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Thorn HI, Guruceaga X, Martin-Vicente A, Nywening AV, Xie J, Ge W, Fortwendel JR. MOB-mediated regulation of septation initiation network (SIN) signaling is required for echinocandin-induced hyperseptation in Aspergillus fumigatus. mSphere 2024; 9:e0069523. [PMID: 38349166 DOI: 10.1128/msphere.00695-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 01/17/2024] [Indexed: 03/27/2024] Open
Abstract
Aspergillus fumigatus is a major invasive mold pathogen and the most frequent etiologic agent of invasive aspergillosis. The currently available treatments for invasive aspergillosis are limited in both number and efficacy. Our recent work has uncovered that the β-glucan synthase inhibitors, the echinocandins, are fungicidal against strains of A. fumigatus with defects in septation initiation network (SIN) kinase activity. These drugs are known to be fungistatic against strains with normal septation. Surprisingly, SIN kinase mutant strains also failed to invade lung tissue and were significantly less virulent in immunosuppressed mouse models. Inhibiting septation in filamentous fungi is therefore an exciting therapeutic prospect to both reduce virulence and improve current antifungal therapy. However, the SIN remains understudied in pathogenic fungi. To address this knowledge gap, we characterized the putative regulatory components of the A. fumigatus SIN. These included the GTPase, SpgA, it's two-component GTPase-activating protein, ByrA/BubA, and the kinase activators, SepM and MobA. Deletion of spgA, byrA, or bubA resulted in no overt septation or echinocandin susceptibility phenotypes. In contrast, our data show that deletion of sepM or mobA largely phenocopies disruption of their SIN kinase binding partners, sepL and sidB, respectively. Reduced septum formation, echinocandin hypersusceptibility, and reduced virulence were generated by loss of either gene. These findings provide strong supporting evidence that septa are essential not only for withstanding the cell wall disrupting effects of echinocandins but are also critical for the establishment of invasive disease. Therefore, pharmacological SIN inhibition may be an exciting strategy for future antifungal drug development.IMPORTANCESepta are important structural determinants of echinocandin susceptibility and tissue invasive growth for the ubiquitous fungal pathogen Aspergillus fumigatus. Components of the septation machinery therefore represent promising novel antifungal targets to improve echinocandin activity and reduce virulence. However, little is known about septation regulation in A. fumigatus. Here, we characterize the predicted regulatory components of the A. fumigatus septation initiation network. We show that the kinase activators SepM and MobA are vital for proper septation and echinocandin resistance, with MobA playing an essential role. Null mutants of mobA displayed significantly reduced virulence in a mouse model, underscoring the importance of this pathway for A. fumigatus pathogenesis.
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Affiliation(s)
- Harrison I Thorn
- Graduate Program in Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Xabier Guruceaga
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Adela Martin-Vicente
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Ashley V Nywening
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Integrated Program in Biomedical Sciences, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Jinhong Xie
- Graduate Program in Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Wenbo Ge
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Jarrod R Fortwendel
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
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2
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Zawy Alsofy S, Lewitz M, Meyer K, Fortmann T, Wilbers E, Nakamura M, Ewelt C. Retrospective Analysis of Risk Factors for Recurrence of Chronic Subdural Haematoma after Surgery. J Clin Med 2024; 13:805. [PMID: 38337502 PMCID: PMC10856185 DOI: 10.3390/jcm13030805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 02/12/2024] Open
Abstract
(1) Background: In this study, epidemiological, clinical, therapeutical, and haemostaseological variables were investigated regarding their correlation with the recurrence of chronic subdural haematomas to assess the risk of recurrence more reliably in everyday clinical practice. (2) Methods: In our retrospective study, the electronic records of 90 patients who underwent surgery for a chronic subdural haematoma at our institute between 1 January 2017 and 31 May 2021 were analysed regarding previously defined variables. (3) Results: In the patient collective, 33.33% of the 90 patients experienced a recurrence requiring treatment. The occurrence of a recurrence was not statistically significantly related to age, gender, known alcohol abuse, a specific location, extension over one or both hemispheres, the surgical method, or anticoagulant medication. However, the recurrence was statistically significantly related to haematoma width (p = 0.000007), septation (p = 0.005), and the existence of a coagulation disorder not treated with medication (p = 0.04). (4) Conclusions: In our study, the width of the haematoma, septation, and coagulation disorders not treated with medication were documented as risk factors for the occurrence of a chronic subdural haematoma. Identifying of these risk factors could help in adapting individual therapeutic concepts for chronic subdural haematomas.
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Affiliation(s)
- Samer Zawy Alsofy
- Department of Medicine, Faculty of Health, Witten/Herdecke University, 58448 Witten, Germany; (M.L.); (T.F.); (E.W.)
- Department of Neurosurgery, St. Barbara-Hospital, Academic Hospital of Westfaelische Wilhelms-University Muenster, 59073 Hamm, Germany; (K.M.); (C.E.)
| | - Marc Lewitz
- Department of Medicine, Faculty of Health, Witten/Herdecke University, 58448 Witten, Germany; (M.L.); (T.F.); (E.W.)
- Department of Neurosurgery, St. Barbara-Hospital, Academic Hospital of Westfaelische Wilhelms-University Muenster, 59073 Hamm, Germany; (K.M.); (C.E.)
| | - Kyra Meyer
- Department of Neurosurgery, St. Barbara-Hospital, Academic Hospital of Westfaelische Wilhelms-University Muenster, 59073 Hamm, Germany; (K.M.); (C.E.)
| | - Thomas Fortmann
- Department of Medicine, Faculty of Health, Witten/Herdecke University, 58448 Witten, Germany; (M.L.); (T.F.); (E.W.)
- Department of Neurosurgery, St. Barbara-Hospital, Academic Hospital of Westfaelische Wilhelms-University Muenster, 59073 Hamm, Germany; (K.M.); (C.E.)
| | - Eike Wilbers
- Department of Medicine, Faculty of Health, Witten/Herdecke University, 58448 Witten, Germany; (M.L.); (T.F.); (E.W.)
- Department of Neurosurgery, St. Barbara-Hospital, Academic Hospital of Westfaelische Wilhelms-University Muenster, 59073 Hamm, Germany; (K.M.); (C.E.)
| | - Makoto Nakamura
- Department of Neurosurgery, Academic Hospital Koeln-Merheim, Witten/Herdecke University, 51109 Koeln, Germany;
| | - Christian Ewelt
- Department of Neurosurgery, St. Barbara-Hospital, Academic Hospital of Westfaelische Wilhelms-University Muenster, 59073 Hamm, Germany; (K.M.); (C.E.)
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Nguyen SN, Quaegebeur JM, Farooqi K, Bacha EA, Goldstone AB. Staged Ventricular Septation of the Double-Inlet Ventricle: How-I-Do-It. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2024; 27:86-91. [PMID: 38522878 DOI: 10.1053/j.pcsu.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/18/2023] [Accepted: 01/12/2024] [Indexed: 03/26/2024]
Abstract
Ventricular septation of the double-inlet ventricle is a largely abandoned operation due to poor historical outcomes. However, there has been renewed interest in septation as an alternative to Fontan palliation given its long-term sequelae. As one of the few centers to revisit septation in the early 1990s, our institution has long-term data on a series of patients with a double-inlet ventricle who underwent biventricular repair. This manuscript is a summary of our approach to staged septation of the double-inlet ventricle, with a focus on patient selection criteria, surgical techniques, perioperative considerations on timing of interventions, and long-term results. We believe that septation of the double-inlet ventricle should be reconsidered in patients with suitable anatomy in light of the known complications of Fontan palliation.
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Affiliation(s)
- Stephanie N Nguyen
- Section of Pediatric and Congenital Cardiac Surgery, New York Presbyterian-Morgan Stanley Children's Hospital, Columbia University Irving Medical Center, New York, New York
| | - Jan M Quaegebeur
- Section of Pediatric and Congenital Cardiac Surgery, New York Presbyterian-Morgan Stanley Children's Hospital, Columbia University Irving Medical Center, New York, New York
| | - Kanwal Farooqi
- Division of Pediatric Cardiology, New York Presbyterian-Morgan Stanley Children's Hospital, Columbia University Irving Medical Center, New York, New York
| | - Emile A Bacha
- Section of Pediatric and Congenital Cardiac Surgery, New York Presbyterian-Morgan Stanley Children's Hospital, Columbia University Irving Medical Center, New York, New York
| | - Andrew B Goldstone
- Section of Pediatric and Congenital Cardiac Surgery, New York Presbyterian-Morgan Stanley Children's Hospital, Columbia University Irving Medical Center, New York, New York..
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4
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Lamża Ł. Diversity of 'simple' multicellular eukaryotes: 45 independent cases and six types of multicellularity. Biol Rev Camb Philos Soc 2023; 98:2188-2209. [PMID: 37475165 DOI: 10.1111/brv.13001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 07/10/2023] [Accepted: 07/13/2023] [Indexed: 07/22/2023]
Abstract
Multicellularity evolved multiple times in the history of life, with most reviewers agreeing that it appeared at least 20 times in eukaryotes. However, a specific list of multicellular eukaryotes with clear criteria for inclusion has not yet been published. Herein, an updated critical review of eukaryotic multicellularity is presented, based on current understanding of eukaryotic phylogeny and new discoveries in microbiology, phycology and mycology. As a result, 45 independent multicellular lineages are identified that fall into six distinct types. Functional criteria, as distinct from a purely topological definition of a cell, are introduced to bring uniformity and clarity to the existing definitions of terms such as colony, multicellularity, thallus or plasmodium. The category of clonal multicellularity is expanded to include: (i) septated multinucleated thalli found in Pseudofungi and early-branching Fungi such as Chytridiomycota and Blastocladiomycota; and (ii) multicellular reproductive structures formed by plasmotomy in intracellular parasites such as Phytomyxea. Furthermore, (iii) endogeneous budding, as found in Paramyxida, is described as a form of multicellularity. The best-known case of clonal multicellularity, i.e. (iv) non-separation of cells after cell division, as known from Metazoa and Ochrophyta, is also discussed. The category of aggregative multicellularity is expanded to include not only (v) pseudoplasmodial forms, such a sorocarp-forming Acrasida, but also (vi) meroplasmodial organisms, such as members of Variosea or Filoreta. A common set of topological, geometric, genetic and life-cycle criteria are presented that form a coherent, philosophically sound framework for discussing multicellularity. A possibility of a seventh type of multicellularity is discussed, that of multi-species superorganisms formed by protists with obligatory bacterial symbionts, such as some members of Oxymonada or Parabasalia. Its inclusion is dependent on the philosophical stance taken towards the concepts of individuality and organism in biology. Taxa that merit special attention are identified, such as colonial Centrohelea, and a new speculative form of multicellularity, possibly present in some reticulopodial amoebae, is briefly described. Because of insufficient phylogenetic and morphological data, not all lineages could be unequivocally identified, and the true total number of all multicellular eukaryotic lineages is therefore higher, likely close to a hundred.
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Affiliation(s)
- Łukasz Lamża
- Copernicus Center for Interdisciplinary Studies, Jagiellonian University, Szczepanska 1, Kraków, 31-011, Poland
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5
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Milholland KL, AbdelKhalek A, Baker KM, Hoda S, DeMarco AG, Naughton NH, Koeberlein AN, Lorenz GR, Anandasothy K, Esperilla-Muñoz A, Narayanan SK, Correa-Bordes J, Briggs SD, Hall MC. Cdc14 phosphatase contributes to cell wall integrity and pathogenesis in Candida albicans. Front Microbiol 2023; 14:1129155. [PMID: 36876065 PMCID: PMC9977832 DOI: 10.3389/fmicb.2023.1129155] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 01/26/2023] [Indexed: 02/18/2023] Open
Abstract
The Cdc14 phosphatase family is highly conserved in fungi. In Saccharomyces cerevisiae, Cdc14 is essential for down-regulation of cyclin-dependent kinase activity at mitotic exit. However, this essential function is not broadly conserved and requires only a small fraction of normal Cdc14 activity. Here, we identified an invariant motif in the disordered C-terminal tail of fungal Cdc14 enzymes that is required for full enzyme activity. Mutation of this motif reduced Cdc14 catalytic rate and provided a tool for studying the biological significance of high Cdc14 activity. A S. cerevisiae strain expressing the reduced-activity hypomorphic mutant allele (cdc14hm ) as the sole source of Cdc14 proliferated like the wild-type parent strain but exhibited an unexpected sensitivity to cell wall stresses, including chitin-binding compounds and echinocandin antifungal drugs. Sensitivity to echinocandins was also observed in Schizosaccharomyces pombe and Candida albicans strains lacking CDC14, suggesting this phenotype reflects a novel and conserved function of Cdc14 orthologs in mediating fungal cell wall integrity. In C. albicans, the orthologous cdc14hm allele was sufficient to elicit echinocandin hypersensitivity and perturb cell wall integrity signaling. It also caused striking abnormalities in septum structure and the same cell separation and hyphal differentiation defects previously observed with cdc14 gene deletions. Since hyphal differentiation is important for C. albicans pathogenesis, we assessed the effect of reduced Cdc14 activity on virulence in Galleria mellonella and mouse models of invasive candidiasis. Partial reduction in Cdc14 activity via cdc14hm mutation severely impaired C. albicans virulence in both assays. Our results reveal that high Cdc14 activity is important for C. albicans cell wall integrity and pathogenesis and suggest that Cdc14 may be worth future exploration as an antifungal drug target.
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Affiliation(s)
- Kedric L Milholland
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Ahmed AbdelKhalek
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, United States
| | - Kortany M Baker
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Smriti Hoda
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Andrew G DeMarco
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Noelle H Naughton
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Angela N Koeberlein
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Gabrielle R Lorenz
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Kartikan Anandasothy
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | | | - Sanjeev K Narayanan
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, United States
| | - Jaime Correa-Bordes
- Department of Biomedical Sciences, Universidad de Extremadura, Badajoz, Spain
| | - Scott D Briggs
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States.,Institute for Cancer Research, Purdue University, West Lafayette, IN, United States
| | - Mark C Hall
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States.,Institute for Cancer Research, Purdue University, West Lafayette, IN, United States
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6
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Rocha LIQ, Oliveira MFDS, Dias LC, Franco de Oliveira M, de Moura CEB, Magalhães MDS. Heart morphology during the embryonic development of Podocnemis unifilis Trosquel 1948 (Testudines: Podocnemididae). Anat Rec (Hoboken) 2023; 306:193-212. [PMID: 35808951 DOI: 10.1002/ar.25041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/09/2022] [Accepted: 06/27/2022] [Indexed: 01/29/2023]
Abstract
Cardiogenesis is similar in all vertebrates, but differences in the valvuloseptal morphogenesis among non-crocodilian reptiles, birds, and mammals are noted. The origin of mesenchymal structures such as valves that regulate the passage of blood and the formation of partial septa that prevent the complete mixing of oxygen-rich and low-oxygen blood present in adult chelonians are essential in the evolutionary understanding of complete septation, endothermy and malformations, even in mammals. In this context, this study analyzed the heart morphogenesis of Podocnemis unifilis (Testudines: Podocnemididae) from the 4th to the 60th day of incubation. We identified the tubular heart stage, folding of the cardiac tube and expansion of the atrial and ventricular compartments followed by atrial septation by the septum primum, ventricle septation by partial septa, outflow tract septation and the formation of bicuspid valves with cartilage differentiation at the base. The formation of the first atrial septum with the mesenchymal cap is noted during the development of the atrial septum, joining the atrioventricular cushion on the 17th day and completely dividing the atria. Small secondary perforations appeared in the mid-cranial part, observed up to the 45th day. Partial ventricle septation into the pulmonary, venous, and arterial subcompartments takes place by trabeculae carneae thickening and grouping on the 15th day. The outflow tract forms the aorticopulmonary and interaortic septa on the 16th day and the bicuspid valves, on the 20th day. Therefore, after the first 20 days, the heart exhibits a general anatomical conformation similar to that of adult turtles.
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Affiliation(s)
- Layla Ianca Queiroz Rocha
- Programa de Pós-graduação em Biologia de Água Doce e Pesca Interior, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brazil
| | - Maria Fabiele da Silva Oliveira
- Programa de Pós-graduação em Biologia de Água Doce e Pesca Interior, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brazil
| | - Lucas Castanhola Dias
- Laboratório Temático de Microscopia e Nanotecnologia, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brazil
| | - Moacir Franco de Oliveira
- Departamento de Ciências Animais, Universidade Federal Rural do Semi-Árido, Mossoró, Rio Grande do Norte, Brazil
| | | | - Marcela Dos Santos Magalhães
- Programa de Pós-graduação em Biologia de Água Doce e Pesca Interior, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brazil.,Departamento de Morfologia, Universidade Federal do Amazonas, Manaus, Amazonas, Brazil
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7
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Kang KN, Boll JM. PBP1A Directly Interacts with the Divisome Complex to Promote Septal Peptidoglycan Synthesis in Acinetobacter baumannii. J Bacteriol 2022; 204:e0023922. [PMID: 36317921 DOI: 10.1128/jb.00239-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The class A penicillin-binding proteins (aPBPs), PBP1A and PBP1B, are major peptidoglycan synthases that synthesize more than half of the peptidoglycan per generation in Escherichia coli. Whereas aPBPs have distinct roles in peptidoglycan biosynthesis during growth (i.e., elongation and division), they are semiredundant; disruption of either is rescued by the other to maintain envelope homeostasis and promote proper growth. Acinetobacter baumannii is a nosocomial pathogen that has a high propensity to overcome antimicrobial treatment. A. baumannii contains both PBP1A and PBP1B (encoded by mrcA and mrcB, respectively), but only mrcA deletion decreased fitness and contributed to colistin resistance through inactivation of lipooligosaccharide biosynthesis, indicating that PBP1B was not functionally redundant with the PBP1A activity. While previous studies suggested a distinct role for PBP1A in division, it was unknown whether its role in septal peptidoglycan biosynthesis was direct. Here, we show that A. baumannii PBP1A has a direct role in division through interactions with divisome components. PBP1A localizes to septal sites during growth, where it interacts with the transpeptidase PBP3, an essential division component that regulates daughter cell formation. PBP3 overexpression was sufficient to rescue the division defect in ΔmrcA A. baumannii; however, PBP1A overexpression was not sufficient to rescue the septal defect when PBP3 was inhibited, suggesting that their activity is not redundant. Overexpression of a major dd-carboxypeptidase, PBP5, also restored the canonical A. baumannii coccobacilli morphology in ΔmrcA cells. Together, these data support a direct role for PBP1A in A. baumannii division and highlights its role as a septal peptidoglycan synthase. IMPORTANCE Peptidoglycan biosynthesis is a validated target of β-lactam antibiotics, and it is critical that we understand essential processes in multidrug-resistant pathogens such as Acinetobacter baumannii. While model systems such as Escherichia coli have shown that PBP1A is associated with side wall peptidoglycan synthesis, we show herein that A. baumannii PBP1A directly interacts with the divisome component PBP3 to promote division, suggesting a unique role for the enzyme in this highly drug-resistant nosocomial pathogen. A. baumannii demonstrated unanticipated resistance and tolerance to envelope-targeting antibiotics, which may be driven by rewired peptidoglycan machinery and may underlie therapeutic failure during antibiotic treatment.
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Moshayedi A, Lee RB, Tisdale L, Crimmins J. Angioinvasive mucormycosis in a patient with aplastic anemia. JAAD Case Rep 2022; 32:71-73. [PMID: 36691587 PMCID: PMC9860379 DOI: 10.1016/j.jdcr.2022.11.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Aref Moshayedi
- Virginia Commonwealth University, School of Medicine, Richmond, Virginia
- Correspondence to: Aref Moshayedi, BS, Virginia Commonwealth University, School of Medicine, 1201 E Marshall St, Richmond, VA 23298.
| | - Rachel B. Lee
- Department of Dermatology, Virginia Commonwealth University, Richmond, Virginia
| | - Lauren Tisdale
- Department of Dermatology, Virginia Commonwealth University, Richmond, Virginia
| | - Jennifer Crimmins
- Department of Dermatopathology, Virginia Commonwealth University, Richmond, Virginia
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9
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Kvasilova A, Gregorovicova M, Olejnickova V, Kolesova H, Sedmera D. Myocardial development in crocodylians. Dev Dyn 2022; 251:2029-2047. [PMID: 36045487 DOI: 10.1002/dvdy.527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 08/20/2022] [Accepted: 08/20/2022] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Recent reports confirmed the notion that there exists a rudimentary cardiac conduction system (CCS) in the crocodylian heart, and development of its ventricular part is linked to septation. We thus analyzed myocardial development with the emphasis on the CCS components and vascularization in two different crocodylian species. RESULTS Using optical mapping and HNK-1 immunostaining, pacemaker activity was localized to the right-sided sinus venosus. The atrioventricular conduction was restricted to dorsal part of the atrioventricular canal. Within the ventricle, the impulse was propagated from base-to-apex initially by the trabeculae, later by the ventricular septum, in which strands of HNK-1 positivity were temporarily observed. Completion of ventricular septation correlated with transition of ventricular epicardial activation pattern to mature apex-to-base direction from two periapical foci. Despite a gradual thickening of the ventricular wall, no morphological differentiation of the Purkinje network was observed. Thin-walled coronary vessels with endothelium positive for QH1 obtained a smooth muscle coat after septation. Intramyocardial vessels were abundant especially in the rapidly thickening left ventricular wall. CONCLUSIONS Most of the CCS components present in the homeiotherm hearts can be identified in the developing crocodylian heart, with a notable exception of the Purkinje network distinct from the trabeculae carneae.
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Affiliation(s)
- Alena Kvasilova
- Institute of Anatomy, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Martina Gregorovicova
- Institute of Anatomy, First Faculty of Medicine, Charles University, Prague, Czech Republic.,Institute of Physiology, The Czech Academy of Sciences, Prague, Czech Republic
| | - Veronika Olejnickova
- Institute of Anatomy, First Faculty of Medicine, Charles University, Prague, Czech Republic.,Institute of Physiology, The Czech Academy of Sciences, Prague, Czech Republic
| | - Hana Kolesova
- Institute of Anatomy, First Faculty of Medicine, Charles University, Prague, Czech Republic.,Institute of Physiology, The Czech Academy of Sciences, Prague, Czech Republic
| | - David Sedmera
- Institute of Anatomy, First Faculty of Medicine, Charles University, Prague, Czech Republic.,Institute of Physiology, The Czech Academy of Sciences, Prague, Czech Republic
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10
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Deepe RN, Drummond JR, Wolters RA, Fitzgerald EA, Tarolli HG, Harvey AB, Wessels A. Sox9 Expression in the Second Heart Field; A Morphological Assessment of the Importance to Cardiac Development with Emphasis on Atrioventricular Septation. J Cardiovasc Dev Dis 2022; 9. [PMID: 36354775 DOI: 10.3390/jcdd9110376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/26/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022] Open
Abstract
Failure to form the septal structures that separate the left and right cardiac chambers results in defects that allow shunting of blood from one side of the heart to the other, leading to the mixing of oxygenated and de-oxygenated blood. The atrioventricular (AV) mesenchymal complex, consisting of the AV cushions, the Dorsal Mesenchymal Protrusion (DMP), and the mesenchymal cap, plays a crucial role in AV septation. Cells found in these structures derive from different cell lineages. In this study we have investigated the role of the transcription factor Sox9 in the Second Heart Field (SHF) with the emphasis on the formation of the atrioventricular septal complex. Using a mouse model in which Sox9 is conditionally deleted from the SHF we demonstrate that in this model virtually all mouse embryos develop septal abnormalities, including complete atrioventricular septal defects (cAVSDs) and isolated ventricular septal defects. Our morphological analyses indicate that perturbation of the development of the mesenchymal cap appears to play a crucial role in the pathogenesis of the atrial septal defects observed in the AVSDs and suggests that this component of the AV mesenchymal complex might play a more important role in AV septation than previously appreciated.
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Abstract
To explore the value of ultrasonography in the auxiliary diagnosis of pleural effusion, we retrospectively analyzed the ultrasonographic findings of 275 exudates and 307 transudates and summarized the ultrasonographic image features of pleural effusion according to patients' primary diseases. The findings of thoracic ultrasonography performed before the initial thoracentesis in 582 patients with subsequently confirmed exudative/transudative pleural effusion were analyzed with regard to the sonographic features of pleural effusion. In 275 cases with exudates, thoracic ultrasonography showed a complex septate appearance in 19 cases (6.9%), complex nonseptate appearance in 100 cases (36.4%), complex homogenous sign in 46 cases (16.7%), and pleural thickness > 3 mm in 105 cases. In contrast, in 307 patients with transudates, most patients (97.1%) had bilateral pleural effusion. Ultrasonographic images displayed anechoic appearance and absence of pleural thickening in a vast majority of cases (306, 99.7%; 301, 98%). These positive findings in the exudate were statistically higher than those in their counterparts (P < .05). In the empyema subgroup, the proportion of complex septate appearance, complex nonseptate appearance, complex homogenous sign, and pleural thickening was the highest, at 19/41, 12/41, 10/41, and 30/41, respectively. Ultrasonography is valuable in defining the nature of pleural effusion. Some sonographic features of pleural effusion, such as echogenicity, septation, and pleural thickening, may indicate a high risk of exudative pleural effusion.
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Affiliation(s)
- Ting Wang
- Department of Respiratory Medicine, Xi’an People’s Hospital (Xi’an No. 4 Hospital), Xi’an 710004, China
| | - Ge Du
- Department of Rehabilitation Center for Elderly, Beijing Rehabilitation Hospital Affiliated to Capital Medical University, Beijing 100144, China
| | - Liping Fang
- Department of Respiratory Medicine, Xi’an People’s Hospital (Xi’an No. 4 Hospital), Xi’an 710004, China
| | - Yang Bai
- Department of Medical Ultrasonics, Xi’an People’s Hospital (Xi’an No. 4 Hospital), Xi’an 710004, China
| | - Zishuang Liu
- Department of Rehabilitation Center for Elderly, Beijing Rehabilitation Hospital Affiliated to Capital Medical University, Beijing 100144, China
- *Correspondence: Zishuang Liu, Department of Rehabilitation Center for Elderly, Beijing Rehabilitation Hospital Affiliated to Capital Medical University, Beijing 100144, China (e-mail: ); or Li Wang, Department of Radiology, Xi’an People’s Hospital (Xi’an No.4 Hospital), Xi’an 710004, China, Xi’an 710004, China (e-mail: )
| | - Li Wang
- Department of Radiology, Xi’an People’s Hospital (Xi’an No. 4 Hospital), Xi’an 710004, China
- *Correspondence: Zishuang Liu, Department of Rehabilitation Center for Elderly, Beijing Rehabilitation Hospital Affiliated to Capital Medical University, Beijing 100144, China (e-mail: ); or Li Wang, Department of Radiology, Xi’an People’s Hospital (Xi’an No.4 Hospital), Xi’an 710004, China, Xi’an 710004, China (e-mail: )
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12
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Spence RN, Huso W, Edwards H, Doan A, Reese S, Harris SD, Srivastava R, Marten MR. Aspergillus nidulans Septa Are Indispensable for Surviving Cell Wall Stress. Microbiol Spectr 2022;:e0206321. [PMID: 35107348 DOI: 10.1128/spectrum.02063-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Septation in filamentous fungi is a normal part of development, which involves the formation of cross-hyphal bulkheads, typically containing pores, allowing cytoplasmic streaming between compartments. Based on previous findings regarding septa and cell wall stress, we hypothesized that septa are critical for survival during cell wall stress. To test this hypothesis, we used known Aspergillus nidulans septation-deficient mutants (ΔsepH, Δbud3, Δbud4, and Δrho4) and six antifungal compounds. Three of these compounds (micafungin, Congo red, and calcofluor white) are known cell wall stressors which activate the cell wall integrity signaling pathway (CWIS), while the three others (cycloheximide, miconazole, and 2,3-butanedione monoxime) perturb specific cellular processes not explicitly related to the cell wall. Our results show that deficiencies in septation lead to fungi which are more susceptible to cell wall-perturbing compounds but are no more susceptible to other antifungal compounds than a control. This implies that septa play a critical role in surviving cell wall stress. IMPORTANCE The ability to compartmentalize potentially lethal damage via septation appears to provide filamentous fungi with a facile means to tolerate diverse forms of stress. However, it remains unknown whether this mechanism is deployed in response to all forms of stress or is limited to specific perturbations. Our results support the latter possibility by showing that presence of septa promotes survival in response to cell wall damage but plays no apparent role in coping with other unrelated forms of stress. Given that cell wall damage is a primary effect caused by exposure to the echinocandin class of antifungal agents, our results emphasize the important role that septa might play in enabling resistance to these drugs. Accordingly, the inhibition of septum formation could conceivably represent an attractive approach to potentiating the effects of echinocandins and mitigating resistance in human fungal pathogens.
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Wernet V, Wäckerle J, Fischer R. The STRIPAK component SipC is involved in morphology and cell-fate determination in the nematode-trapping fungus Duddingtonia flagrans. Genetics 2022; 220:iyab153. [PMID: 34849851 PMCID: PMC8733638 DOI: 10.1093/genetics/iyab153] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/20/2021] [Indexed: 11/29/2022] Open
Abstract
The striatin-interacting phosphatase and kinase (STRIPAK) complex is a highly conserved eukaryotic signaling hub involved in the regulation of many cellular processes. In filamentous fungi, STRIPAK controls multicellular development, hyphal fusion, septation, and pathogenicity. In this study, we analyzed the role of the STRIPAK complex in the nematode-trapping fungus Duddingtonia flagrans which forms three-dimensional, adhesive trapping networks to capture Caenorhabditis elegans. Trap networks consist of several hyphal loops which are morphologically and functionally different from vegetative hyphae. We show that lack of the STRIPAK component SipC (STRIP1/2/HAM-2/PRO22) results in incomplete loop formation and column-like trap structures with elongated compartments. The misshapen or incomplete traps lost their trap identity and continued growth as vegetative hyphae. The same effect was observed in the presence of the actin cytoskeleton drug cytochalasin A. These results could suggest a link between actin and STRIPAK complex functions.
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Affiliation(s)
- Valentin Wernet
- Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT)—South Campus, D-76131 Karlsruhe, Germany
| | - Jan Wäckerle
- Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT)—South Campus, D-76131 Karlsruhe, Germany
| | - Reinhard Fischer
- Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT)—South Campus, D-76131 Karlsruhe, Germany
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Yagüe N, Gómez-Delgado L, Curto MÁ, Carvalho VSD, Moreno MB, Pérez P, Ribas JC, Cortés JCG. Echinocandin Drugs Induce Differential Effects in Cytokinesis Progression and Cell Integrity. Pharmaceuticals (Basel) 2021; 14:ph14121332. [PMID: 34959732 PMCID: PMC8706178 DOI: 10.3390/ph14121332] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022] Open
Abstract
Fission yeast contains three essential β(1,3)-D-glucan synthases (GSs), Bgs1, Bgs3, and Bgs4, with non-overlapping roles in cell integrity and morphogenesis. Only the bgs4+ mutants pbr1-8 and pbr1-6 exhibit resistance to GS inhibitors, even in the presence of the wild-type (WT) sequences of bgs1+ and bgs3+. Thus, Bgs1 and Bgs3 functions seem to be unaffected by those GS inhibitors. To learn more about echinocandins' mechanism of action and resistance, cytokinesis progression and cell death were examined by time-lapse fluorescence microscopy in WT and pbr1-8 cells at the start of treatment with sublethal and lethal concentrations of anidulafungin, caspofungin, and micafungin. In WT, sublethal concentrations of the three drugs caused abundant cell death that was either suppressed (anidulafungin and micafungin) or greatly reduced (caspofungin) in pbr1-8 cells. Interestingly, the lethal concentrations induced differential phenotypes depending on the echinocandin used. Anidulafungin and caspofungin were mostly fungistatic, heavily impairing cytokinesis progression in both WT and pbr1-8. As with sublethal concentrations, lethal concentrations of micafungin were primarily fungicidal in WT cells, causing cell lysis without impairing cytokinesis. The lytic phenotype was suppressed again in pbr1-8 cells. Our results suggest that micafungin always exerts its fungicidal effect by solely inhibiting Bgs4. In contrast, lethal concentrations of anidulafungin and caspofungin cause an early cytokinesis arrest, probably by the combined inhibition of several GSs.
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Kumar A, Zendel A, Batres M, Gerber DA, Desai CS. Radiologic Reporting of Simple Hepatic Cyst Versus Biliary Cystadenoma May Lead to Unnecessary Surgery. Am Surg 2021:31348211054077. [PMID: 34806934 DOI: 10.1177/00031348211054077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND AIMS Simple liver cyst (SHC) is a benign condition with no malignant potential. They are typically discovered incidentally due to the increased use of abdominal imaging, but some patients may present with abdominal pain. A radiologist's differential diagnosis in cases of SHC will often include "rule out biliary cystadenoma." Under these circumstances, patients and surgeons are more likely to pursue surgical options even in asymptomatic cases. The aim of this study is to conduct a retrospective analysis of presentation, radiologic reporting, management plan, and histopathology of patients referred to a tertiary hospital in order to determine the correlation between radiology and histology. METHODS We retrospectively analyzed the clinical, radiological, and histopathological data of 20 patients operated for a diagnosis of a cystic lesion in the liver. RESULT The CT/MRI of 6 (30%) patients was reported as a biliary cystadenoma, 13 (65%) were reported as a simple hepatic cyst and 1 patient (5%) had hepatocellular carcinoma (HCC) with the additional diagnosis of multiple hepatic cysts. The lesion reported as HCC on the scan was separate from the cystic lesions. The modality of imaging for these cysts was evenly split, 50% of patients had a CT scan, and 50% had an MRI performed. All imaging studies were interpreted by an attending radiologist and most of them were discussed in multidisciplinary meetings. Nineteen patients (95%) had an intraoperative diagnosis of a simple liver cyst based on its visual appearance and clear fluid within the cyst. These patients underwent cyst wall fenestration and de-roofing with the cyst wall sent for histopathology. One patient (5%) with HCC underwent a non-anatomical liver resection. Histopathology was conclusive for a benign hepatic cystic lesion from the cyst wall biopsy. All 20 patients in this study underwent surgery, either due to symptoms or due to radiologic diagnosis of BCA. Four of the 20 cases (20%) were asymptomatic and out of these four cases, 3 (75%) were diagnosed as cystadenoma on the preoperative imaging studies. All 19 cases were diagnosed as a simple liver cyst on pathology. CONCLUSION In summary, there is a growing trend of "ruling-out the diagnosis of biliary cystadenoma" in patients who present with liver cysts. Patients are appropriately more anxious after this preoperative diagnosis and the treating surgeons have medico-legal concerns regarding conservative management in asymptomatic patients diagnosed as BCA. This single center experience draws attention to the radiology criteria utilized for diagnosing a biliary cystadenoma and suggests that it is time to revisit the imaging interpretation and differential diagnosis.
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Affiliation(s)
- Aman Kumar
- Division of Abdominal Transplant, Department of Surgery, 2332University of North Carolina, Chapel Hill, NC, USA
| | - Alex Zendel
- Division of Abdominal Transplant, Department of Surgery, 2332University of North Carolina, Chapel Hill, NC, USA
| | - Michael Batres
- Division of Abdominal Transplant, Department of Surgery, 2332University of North Carolina, Chapel Hill, NC, USA
| | - David A Gerber
- Division of Abdominal Transplant, Department of Surgery, 2332University of North Carolina, Chapel Hill, NC, USA
| | - Chirag S Desai
- Division of Abdominal Transplant, Department of Surgery, 2332University of North Carolina, Chapel Hill, NC, USA
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16
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Cantlay S, Sen BC, Flärdh K, McCormick JR. Influence of core divisome proteins on cell division in Streptomyces venezuelae ATCC 10712. Microbiology (Reading) 2021; 167. [PMID: 33400639 DOI: 10.1099/mic.0.001015] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The sporulating, filamentous soil bacterium Streptomyces venezuelae ATCC 10712 differentiates under submerged and surface growth conditions. In order to lay a solid foundation for the study of development-associated division for this organism, a congenic set of mutants was isolated, individually deleted for a gene encoding either a cytoplasmic (i.e. ftsZ) or core inner membrane (i.e. divIC, ftsL, ftsI, ftsQ, ftsW) component of the divisome. While ftsZ mutants are completely blocked for division, single mutants in the other core divisome genes resulted in partial, yet similar, blocks in sporulation septum formation. Double and triple mutants for core divisome membrane components displayed phenotypes that were similar to those of the single mutants, demonstrating that the phenotypes were not synergistic. Division in this organism is still partially functional without multiple core divisome proteins, suggesting that perhaps other unknown lineage-specific proteins perform redundant functions. In addition, by isolating an ftsZ2p mutant with an altered -10 region, the conserved developmentally controlled promoter was also shown to be required for sporulation-associated division. Finally, microscopic observation of FtsZ-YFP dynamics in the different mutant backgrounds led to the conclusion that the initial assembly of regular Z rings does not per se require the tested divisome membrane proteins, but the stability of Z rings is dependent on the divisome membrane components tested. The observation is consistent with the interpretation that Z ring instability likely results from and further contributes to the observed defects in sporulation septation in mutants lacking core divisome proteins.
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Affiliation(s)
- Stuart Cantlay
- Present address: Department of Biological Sciences, West Liberty University, West Liberty, WV 26074, USA
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA 15282, USA
| | | | - Klas Flärdh
- Department of Biology, Lund University, 223 62 Lund, Sweden
| | - Joseph R McCormick
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA 15282, USA
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Kang KN, Kazi MI, Biboy J, Gray J, Bovermann H, Ausman J, Boutte CC, Vollmer W, Boll JM. Septal Class A Penicillin-Binding Protein Activity and ld-Transpeptidases Mediate Selection of Colistin-Resistant Lipooligosaccharide-Deficient Acinetobacter baumannii. mBio 2021; 12:e02185-20. [PMID: 33402533 DOI: 10.1128/mBio.02185-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Despite dogma suggesting that lipopolysaccharide/lipooligosaccharide (LOS) was essential for viability of Gram-negative bacteria, several Acinetobacter baumannii clinical isolates produced LOS− colonies after colistin selection. Inactivation of the conserved class A penicillin-binding protein, PBP1A, was a compensatory mutation that supported isolation of LOS−A. baumannii, but the impact of PBP1A mutation was not characterized. Here, we show that the absence of PBP1A causes septation defects and that these, together with ld-transpeptidase activity, support isolation of LOS−A. baumannii. PBP1A contributes to proper cell division in A. baumannii, and its absence induced cell chaining. Only isolates producing three or more septa supported selection of colistin-resistant LOS−A. baumannii. PBP1A was enriched at the midcell, where the divisome complex facilitates daughter cell formation, and its localization was dependent on glycosyltransferase activity. Transposon mutagenesis showed that genes encoding two putative ld-transpeptidases (LdtJ and LdtK) became essential in the PBP1A mutant. Both LdtJ and LdtK were required for selection of LOS−A. baumannii, but each had distinct enzymatic activities in the cell. Together, these findings demonstrate that defects in PBP1A glycosyltransferase activity and ld-transpeptidase activity remodel the cell envelope to support selection of colistin-resistant LOS−A. baumannii.
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18
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Abstract
A critical step in bacterial cytokinesis is the activation of septal peptidoglycan synthesis at the Z ring. Although FtsN is the trigger and acts through FtsQLB and FtsA to activate FtsWI the mechanism is unclear. Spatiotemporal regulation of septal peptidoglycan (PG) synthesis is achieved by coupling assembly and activation of the synthetic enzymes (FtsWI) to the Z ring, a cytoskeletal element that is required for division in most bacteria. In Escherichia coli, the recruitment of the FtsWI complex is dependent upon the cytoplasmic domain of FtsL, a component of the conserved FtsQLB complex. Once assembled, FtsWI is activated by the arrival of FtsN, which acts through FtsQLB and FtsA, which are also essential for their recruitment. However, the mechanism of activation of FtsWI by FtsN is not clear. Here, we identify a region of FtsL that plays a key role in the activation of FtsWI which we designate AWI (activation of FtsWI) and present evidence that FtsL acts through FtsI. Our results suggest that FtsN switches FtsQLB from a recruitment complex to an activator with FtsL interacting with FtsI to activate FtsW. Since FtsQLB and FtsWI are widely conserved in bacteria, this mechanism is likely to be also widely conserved.
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Degaga TK, Zenebe AM, Wirtu AT, Woldehawariat TD, Dellie ST, Gemechu JM. Anatomographic Variants of Sphenoid Sinus in Ethiopian Population. Diagnostics (Basel) 2020; 10:E970. [PMID: 33227888 DOI: 10.3390/diagnostics10110970] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/07/2020] [Accepted: 10/14/2020] [Indexed: 11/16/2022] Open
Abstract
Neurosurgeons often neglect the sphenoid sinus due to its deep location and difficulties in accessing during surgical interventions. Disease of the sphenoid sinus is difficult to diagnose since its presenting symptoms are difficult to recognize. Moreover, compared with other paranasal sinuses, the sphenoid sinus is considered the most variable air sinus in terms of its degree of pneumatization, number and position of inter-sinus septa, and its relationship with the surrounding anatomical structures. Anatomical variations of the sphenoid sinus are significant from a neurosurgical point of view. Understanding of these variations and its relationships with surrounding structures such as the internal carotid artery, optic nerve, and pituitary gland are clinically relevant to minimize injuries associated with surgical procedures that involve sphenoid sinus. We implemented principles of imaging using computed tomography to elucidate any anatomical variations of the sphenoid sinus in the Ethiopian population. We conducted a prospective study in 200 patients with ages 18-79, who underwent scans of the sphenoid sinus at the Tikur Anbessa Referral Teaching Hospital in 2017-2018. Our findings revealed an incidence of anatomographical variations in terms of pneumatization that varied between 2-50%. These variants include 2% conchal, 25.5% presellar, 50% sellar, and 22.5% postsellar pneumatization. We also demonstrated anatomographic variants in terms of septation, 77.5% single complete septa, 11.5% single incomplete, 10% double septa, and 1% absence of septa. In summary, the sellar pneumatization was found to be the most clinically relevant anatomographic variant among Ethiopians participating in the study, of which 90% were tomographically single septated. These variants must be taken into consideration during trans-sphenoidal surgery and knowledge of the variations has clinical implication in minimizing injuries during invasive surgical procedures involving the sphenoid sinus.
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20
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Pickford H, Alcock E, Singh A, Kelemen G, Bhatt A. A mycobacterial DivIVA domain-containing protein involved in cell length and septation. Microbiology (Reading) 2020; 166:817-825. [PMID: 32678058 PMCID: PMC7654743 DOI: 10.1099/mic.0.000952] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mycobacterial cells elongate via polar deposition of cell wall material, similar to the filamentous Streptomyces species, which contain a tip-organizing centre. Coiled-coiled proteins such as DivIVA play an important role in this process. The genome of Mycobacterium tuberculosis, the causative agent of tuberculosis, encodes many coiled-coil proteins that are homologous to DivIVA with a potential role in mycobacterial cell elongation. Here we describe studies on Mycobacterium smegmatis MSMEG_2416, a homologue of M. tuberculosis Rv2927c. Two previous independent studies showed that MSMEG_2416 was involved in septation (subsequently referred to as sepIVA). Contrary to these previous reports, we found sepIVA to be dispensable for growth in laboratory media by generating a viable null mutant. The mutant strain did, however, show a number of differences, including a change in colony morphology and biofilm formation that could be reversed on complementation with sepIVA as well as Rv2927c, the sepIVA homologue from M. tuberculosis. However, analysis of cell wall lipids did not reveal any alterations in lipid profiles of the mutant strain. Microscopic examination of the mutant revealed longer cells with more septa, which occurred at irregular intervals, often generating mini-compartments, a profile similar to that observed in the previous studies following conditional depletion, highlighting a role for sepIVA in mycobacterial growth.
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Affiliation(s)
- Hayleah Pickford
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, UK
| | - Emily Alcock
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Albel Singh
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, UK
| | - Gabriella Kelemen
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Apoorva Bhatt
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, UK
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Zhou X, Zheng L, Guan L, Ye J, Virag A, Harris SD, Lu L. The Scaffold Proteins Paxillin B and α-Actinin Regulate Septation in Aspergillus nidulans via Control of Actin Ring Contraction. Genetics 2020; 215:449-461. [PMID: 32317285 PMCID: PMC7268981 DOI: 10.1534/genetics.120.303234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/12/2020] [Indexed: 11/29/2022] Open
Abstract
Cytokinesis, as the final step of cell division, plays an important role in fungal growth and proliferation. In the filamentous fungus Aspergillus nidulans, defective cytokinesis is able to induce abnormal multinuclear or nonnucleated cells and then result in reduced hyphal growth and abolished sporulation. Previous studies have reported that a conserved contractile actin ring (CAR) protein complex and the septation initiation network (SIN) signaling kinase cascade are required for cytokinesis and septation; however, little is known about the role(s) of scaffold proteins involved in these two important cellular processes. In this study, we show that a septum-localized scaffold protein paxillin B (PaxB) is essential for cytokinesis/septation in A. nidulans The septation defects observed in a paxB deletion strain resemble those caused by the absence of another identified scaffold protein, α-actinin (AcnA). Deletion of α-actinin (AcnA) leads to undetectable PaxB at the septation site, whereas deletion of paxB does not affect the localization of α-actinin at septa. However, deletion of either α-actinin (acnA) or paxB causes the actin ring to disappear at septation sites during cytokinesis. Notably, overexpression of α-actinin acnA partially rescues the septum defects of the paxB mutant but not vice versa, suggesting AcnA may play a dominant role over that of PaxB for cytokinesis and septation. In addition, PaxB and α-actinin affect the septal dynamic localization of MobA, a conserved component of the SIN pathway, suggesting they may affect the SIN protein complex function at septa. Protein pull-down assays combined with liquid chromatography-mass spectrometry identification indicate that α-actinin AcnA and PaxB likely do not directly interact, but presumably belong to an actin cytoskeleton protein network that is required for the assembly and contraction of the CAR. Taken together, findings in this study provide novel insights into the roles of conserved scaffold proteins during fungal septation in A. nidulans.
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Affiliation(s)
- Xiaogang Zhou
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, China
| | - Likun Zheng
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, China
| | - Luyu Guan
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, China
| | - Jing Ye
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, China
| | | | - Steven D Harris
- Department of Biological Sciences, University of Manitoba, Winnipeg, Canada
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, China
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Beutel BG, Doscher ME, Melone CP. Prevalence of a Septated First Dorsal Compartment Among Patients With and Without De Quervain Tenosynovitis: An In Vivo Anatomical Study. Hand (N Y) 2020; 15:348-352. [PMID: 30428712 PMCID: PMC7225884 DOI: 10.1177/1558944718810864] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Background: The reported prevalence of a subcompartment housing the extensor pollicis brevis (EPB) tendon within the first dorsal compartment varies widely in the literature, especially regarding the rates of occurrence between genders and among those with and without De Quervain. Based on direct intraoperative observation, we hypothesized that the prevalence of a septated compartment is far greater than previously reported, particularly in those with De Quervain disease. Methods: A prospective analysis of consecutive patients who underwent first dorsal compartment release was carried out. Patients were divided into 2 groups: those with De Quervain tenosynovitis ("De Quervain" group) and a control cohort without a primary diagnosis of De Quervain ("non-De Quervain" group). The intraoperative findings of a single compartment or a separate subcompartment were recorded. The prevalence of a septated compartment was calculated and compared between genders and both patient groups. Results: A total of 102 consecutive patients were included, with a female predominance (74.5%). Overall, 79.4% of patients had a separate subcompartment for the EPB. In the De Quervain cohort, 89.1% had 2 compartments, while 71.4% of non-De Quervain patients had a subcompartment. Men and women had a similar rate of double compartments (80% and 82.4%, respectively). Conclusions: The prevalence of a septated first dorsal compartment is considerably higher than previously reported, most notably in patients afflicted with De Quervain tenosynovitis. This higher rate of septation occurs with a similar prevalence in both men and women. Owing to its consistent presence, the dual first dorsal compartment should be regarded as an expectant anatomical component of the normal wrist.
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Affiliation(s)
- Bryan G. Beutel
- Mount Sinai Beth Israel, New York, NY, USA,Bryan G. Beutel, Department of Orthopaedic Surgery, The Hand Surgery Center, Mount Sinai Beth Israel, 321 East 34th Street, New York, NY 10016, USA.
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Milner DS, Ray LJ, Saxon EB, Lambert C, Till R, Fenton AK, Sockett RE. DivIVA Controls Progeny Morphology and Diverse ParA Proteins Regulate Cell Division or Gliding Motility in Bdellovibrio bacteriovorus. Front Microbiol 2020; 11:542. [PMID: 32373080 PMCID: PMC7186360 DOI: 10.3389/fmicb.2020.00542] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/12/2020] [Indexed: 01/12/2023] Open
Abstract
The predatory bacterium B. bacteriovorus grows and divides inside the periplasm of Gram-negative bacteria, forming a structure known as a bdelloplast. Cell division of predators inside the dead prey cell is not by binary fission but instead by synchronous division of a single elongated filamentous cell into odd or even numbers of progeny cells. Bdellovibrio replication and cell division processes are dependent on the finite level of nutrients available from inside the prey bacterium. The filamentous growth and division process of the predator maximizes the number of progeny produced by the finite nutrients in a way that binary fission could not. To learn more about such an unusual growth profile, we studied the role of DivIVA in the growing Bdellovibrio cell. This protein is well known for its link to polar cell growth and spore formation in Gram-positive bacteria, but little is known about its function in a predatory growth context. We show that DivIVA is expressed in the growing B. bacteriovorus cell and controls cell morphology during filamentous cell division, but not the number of progeny produced. Bacterial Two Hybrid (BTH) analysis shows DivIVA may interact with proteins that respond to metabolic indicators of amino-acid biosynthesis or changes in redox state. Such changes may be relevant signals to the predator, indicating the consumption of prey nutrients within the sealed bdelloplast environment. ParA, a chromosome segregation protein, also contributes to bacterial septation in many species. The B. bacteriovorus genome contains three ParA homologs; we identify a canonical ParAB pair required for predatory cell division and show a BTH interaction between a gene product encoded from the same operon as DivIVA with the canonical ParA. The remaining ParA proteins are both expressed in Bdellovibrio but are not required for predator cell division. Instead, one of these ParA proteins coordinates gliding motility, changing the frequency at which the cells reverse direction. Our work will prime further studies into how one bacterium can co-ordinate its cell division with the destruction of another bacterium that it dwells within.
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Affiliation(s)
- David S Milner
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Luke J Ray
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Emma B Saxon
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Carey Lambert
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Rob Till
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Andrew K Fenton
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Renee Elizabeth Sockett
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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Abstract
In 2014, an extensive review discussing the major steps of cardiac development focusing on growth, formation of primary and chamber myocardium and the development of the cardiac electrical system, was published. Molecular genetic lineage analyses have since furthered our insight in the developmental origin of the various component parts of the heart, which currently can be unambiguously identified by their unique molecular phenotype. Moreover, genetic, molecular and cell biological analyses have driven insights into the mechanisms underlying the development of the different cardiac components. Here, we build on our previous review and provide an insight into the molecular mechanistic revelations that have forwarded the field of cardiac development. Despite the enormous advances in our knowledge over the last decade, the development of congenital cardiac malformations remains poorly understood. The challenge for the next decade will be to evaluate the different developmental processes using newly developed molecular genetic techniques to further unveil the gene regulatory networks operational during normal and abnormal cardiac development.
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Affiliation(s)
| | - Phil Barnett
- Department of Medical BiologyAmsterdamUMC location AMCAmsterdamThe Netherlands
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25
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Liang HH, Chen CY, Chen WY, Chen TM, Chan WP. Solitary cystic metastatic lymph node of occult human papillomavirus-related oropharyngeal cancer mimicking second branchial cleft cyst: A case report. Medicine (Baltimore) 2019; 98:e17800. [PMID: 31689859 PMCID: PMC6946570 DOI: 10.1097/md.0000000000017800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
RATIONALE Human papillomavirus (HPV)-related oropharyngeal cancer is becoming more common, the primary cancer AQ4 usually occult and appearing only as cystic cervical lymph node (LN) metastasis. Distinguishing between a benign cystic lesion and cystic LN metastasis is challenging given their similar radiologic and histologic appearances. PATIENT CONCERNS A 54-year-old man presented with a bulging cystic mass measuring 6.4cm on the right side of neck. DIAGNOSES Postexcision diagnosis was second branchial cleft cyst. After 2 years, the cystic mass recurred, and HPV-related tonsillar squamous cell carcinoma with cystic metastatic LNs was confirmed after wide tonsillectomy and neck dissection. The previous cystic lesion proved to be a cystic metastatic LN from the same malignancy with additional p16 immunostain. INTERVENTIONS The patient was treated with adjuvant concurrent chemoradiation therapy. OUTCOMES The patient was followed up in the outpatient department with no evidence of recurrence after 1 year. LESSONS When an adult has a cystic mass in the upper neck, we must rigorously exclude it as a cystic metastatic LN of occult HPV-related oropharyngeal cancer. Additional p16 staining might be helpful.
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MESH Headings
- Branchioma/diagnosis
- Carcinoma, Squamous Cell/diagnosis
- Carcinoma, Squamous Cell/secondary
- Carcinoma, Squamous Cell/virology
- Diagnosis, Differential
- Humans
- Lymph Nodes/pathology
- Lymph Nodes/virology
- Lymphatic Metastasis/diagnosis
- Male
- Middle Aged
- Neck/pathology
- Neck/virology
- Neck Dissection
- Neoplasms, Cystic, Mucinous, and Serous/diagnosis
- Neoplasms, Cystic, Mucinous, and Serous/secondary
- Neoplasms, Cystic, Mucinous, and Serous/virology
- Neoplasms, Unknown Primary/diagnosis
- Neoplasms, Unknown Primary/pathology
- Neoplasms, Unknown Primary/virology
- Oropharyngeal Neoplasms/diagnosis
- Oropharyngeal Neoplasms/secondary
- Oropharyngeal Neoplasms/virology
- Papillomaviridae
- Papillomavirus Infections/complications
- Papillomavirus Infections/virology
- Tonsillar Neoplasms/diagnosis
- Tonsillar Neoplasms/pathology
- Tonsillar Neoplasms/virology
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Affiliation(s)
- Han-Hsuan Liang
- Department of Radiology, Wan Fang Hospital
- Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University
| | - Chia-Yuen Chen
- Department of Radiology, Wan Fang Hospital
- Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University
| | - Wei-Yu Chen
- Department of Pathology, Wan Fang Hospital
- Department of Pathology, School of Medicine, College of Medicine, Taipei Medical University, Taipei
| | - Tsung-Ming Chen
- Department of Otolaryngology, Shuang Ho Hospital, New Taipei City, Taiwan
| | - Wing P. Chan
- Department of Radiology, Wan Fang Hospital
- Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University
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26
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Abstract
The atrial septum enables efficient oxygen transport by separating the systemic and pulmonary venous blood returning to the heart. Only in placental mammals will the atrial septum form by the coming-together of the septum primum and the septum secundum. In up to one of four placental mammals, this complex morphogenesis is incomplete and yields patent foramen ovale. The incidence of incomplete atrial septum is unknown for groups with the septum primum only, such as birds and reptiles. We found a low incidence of incomplete atrial septum in 11 species of bird (0% of specimens) and 13 species of reptiles (3% of specimens). In reptiles, there was a trabecular interface between the atrial septum and the atrial epicardium which was without a clear boundary between left and right atrial cavities. In developing reptiles (four squamates and one crocodylian), the septum primum initiated as a sheet that acquired perforations and the trabecular interface developed late. We conclude that atrial septation from the septum primum only results in a low incidence of incompleteness. In reptiles, the atrial septum and atrial wall develop a trabecular interface, but previous studies on atrial hemodynamics suggest this interface has a very limited capacity for shunting.
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Affiliation(s)
- Bjarke Jensen
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - William Joyce
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, The Netherlands.,Department of Bioscience, Zoophysiology, Aarhus University, Aarhus, Denmark
| | - Martina Gregorovicova
- Institute of Anatomy, First Medical Faculty, Czech Academy of Sciences, Charles University and Institute of Physiology, Prague, Czech Republic
| | - David Sedmera
- Institute of Anatomy, First Medical Faculty, Czech Academy of Sciences, Charles University and Institute of Physiology, Prague, Czech Republic
| | - Tobias Wang
- Department of Bioscience, Zoophysiology, Aarhus University, Aarhus, Denmark
| | - Vincent M Christoffels
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, The Netherlands
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Fukada F, Kodama S, Nishiuchi T, Kajikawa N, Kubo Y. Plant pathogenic fungi Colletotrichum and Magnaporthe share a common G 1 phase monitoring strategy for proper appressorium development. New Phytol 2019; 222:1909-1923. [PMID: 30715740 DOI: 10.1111/nph.15728] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Accepted: 01/24/2019] [Indexed: 06/09/2023]
Abstract
To breach the plant cuticle, many plant pathogenic fungi differentiate specialized infection structures (appressoria). In Colletotrichum orbiculare (cucumber anthracnose fungus), this differentiation requires unique proper G1 /S phase progression, regulated by two-component GTPase activating protein CoBub2/CoBfa1 and GTPase CoTem1. Since their homologues regulate mitotic exit, cytokinesis, or septum formation from yeasts to mammals, we asked whether the BUB2 function in G1 /S progression is specific to plant pathogenic fungi. Colletotrichum higginsianum and Magnaporthe oryzae were genetically analyzed to investigate conservation of BUB2 roles in cell cycle regulation, septum formation, and virulence. Expression profile of cobub2Δ was analyzed using a custom microarray. In bub2 mutants of both fungi, S phase initiation was earlier, and septum formation coordinated with a septation initiation network protein and contractile actin ring was impaired. Earlier G1 /S transition in cobub2Δ results in especially high expression of DNA replication genes and differing regulation of virulence-associated genes that encode proteins such as carbohydrate-active enzymes and small secreted proteins. The virulence of chbub2Δ and mobub2Δ was significantly reduced. Our evidence shows that BUB2 regulation of G1 /S transition and septum formation supports its specific requirement for appressorium development in plant pathogenic fungi.
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Affiliation(s)
- Fumi Fukada
- Laboratory of Plant Pathology, Life and Environmental Sciences, Graduate School of Kyoto Prefectural University, Sakyo, Kyoto, 606-8522, Japan
| | - Sayo Kodama
- Laboratory of Plant Pathology, Life and Environmental Sciences, Graduate School of Kyoto Prefectural University, Sakyo, Kyoto, 606-8522, Japan
| | - Takumi Nishiuchi
- Division of Functional Genomics, Advanced Science Research Centre, Kanazawa University, Kanazawa, 920-0934, Japan
| | - Naoki Kajikawa
- Laboratory of Plant Pathology, Life and Environmental Sciences, Graduate School of Kyoto Prefectural University, Sakyo, Kyoto, 606-8522, Japan
| | - Yasuyuki Kubo
- Laboratory of Plant Pathology, Life and Environmental Sciences, Graduate School of Kyoto Prefectural University, Sakyo, Kyoto, 606-8522, Japan
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28
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Poelmann RE, Gittenberger-de Groot AC. Development and evolution of the metazoan heart. Dev Dyn 2019; 248:634-656. [PMID: 31063648 PMCID: PMC6767493 DOI: 10.1002/dvdy.45] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/25/2019] [Accepted: 04/29/2019] [Indexed: 12/19/2022] Open
Abstract
The mechanisms of the evolution and development of the heart in metazoans are highlighted, starting with the evolutionary origin of the contractile cell, supposedly the precursor of cardiomyocytes. The last eukaryotic common ancestor is likely a combination of several cellular organisms containing their specific metabolic pathways and genetic signaling networks. During evolution, these tool kits diversified. Shared parts of these conserved tool kits act in the development and functioning of pumping hearts and open or closed circulations in such diverse species as arthropods, mollusks, and chordates. The genetic tool kits became more complex by gene duplications, addition of epigenetic modifications, influence of environmental factors, incorporation of viral genomes, cardiac changes necessitated by air‐breathing, and many others. We evaluate mechanisms involved in mollusks in the formation of three separate hearts and in arthropods in the formation of a tubular heart. A tubular heart is also present in embryonic stages of chordates, providing the septated four‐chambered heart, in birds and mammals passing through stages with first and second heart fields. The four‐chambered heart permits the formation of high‐pressure systemic and low‐pressure pulmonary circulation in birds and mammals, allowing for high metabolic rates and maintenance of body temperature. Crocodiles also have a (nearly) separated circulation, but their resting temperature conforms with the environment. We argue that endothermic ancestors lost the capacity to elevate their body temperature during evolution, resulting in ectothermic modern crocodilians. Finally, a clinically relevant paragraph reviews the occurrence of congenital cardiac malformations in humans as derailments of signaling pathways during embryonic development. The cardiac regulatory toolkit contains many factors including epigenetic, genetic, viral, hemodynamic, and environmental factors, but also transcriptional activators, repressors, duplicated genes, redundancies and dose‐dependancies. Numerous toolkits regulate mechanisms including cell‐cell interactions, EMT, mitosis patterns, cell migration and differentiation and left/right sidedness involved in the development of endocardial cushions, looping, septum complexes, pharyngeal arch arteries, chamber and valve formation and conduction system. Evolutionary development of the yolk sac circulation likely preceded the advent of endothermy in amniotes. Parallel evolutionary traits regulate the development of contractile pumps in various taxa often in conjunction with the gut, lungs and excretory organs.
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Affiliation(s)
- Robert E Poelmann
- Institute of Biology, Department of Animal Sciences and Health, Leiden University, Leiden, The Netherlands.,Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
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29
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Sanders WB, de Los Ríos A. The cellular cortex in Collemataceae (lichenized Ascomycota) participates in thallus growth and morphogenesis via parenchymatous cell divisions. Mycologia 2019; 111:206-216. [PMID: 30888911 DOI: 10.1080/00275514.2019.1566810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
According to a widely held view, fungi do not produce parenchymatous tissues. Following up on recent transmission electron microscopy (TEM) evidence that challenged this paradigm in several lichens, we employed scanning electron microscopy (SEM) to investigate the orientation of new anticlinal walls in the single-layered fungal cortex of six species of Collemataceae, a family of gelatinous cyanolichens with diverse surface morphologies. Examination of thallus surfaces in four species of Leptogium (L. austromericanum, L. burnetiae, L. chloromelum, L. marginellum) and two species of Scytinium (S. gelatinosum, S. lichenoides) revealed that recently formed septa adjoin to preceding septa in parenchymatous division. These cortical divisions were evident in the formation and development of thallus wrinkles, folds, isidia, and lobules in the six morphologically distinct taxa. Tomentum, by contrast, arose as filamentous outgrowths of the cortical cells. We conclude that the monostromatic cellular cortex in Collemataceae participates in surface growth and morphogenesis by means of parenchymatous cell divisions, in a remarkable parallel to plant meristems. Cortical cell divisions do not appear to drive morphogenesis, however, as very similar morphologies are achieved in the closely related genus Collema, which lacks a cortex altogether. These results provide evidence that parenchymatous cell division can indeed play a role in morphogenesis of fungal structures and show that SEM is a useful tool for distinguishing the orientation of anticlinal divisions in the cortex of gelatinous lichens.
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Affiliation(s)
- William B Sanders
- a Department of Biological Sciences , Florida Gulf Coast University , Fort Myers , Florida 33965
| | - Asunción de Los Ríos
- b Departamento de Bioquímica y Ecología Microbiana , Museo Nacional de Ciencias Naturales (CSIC) , C/Serrano 115-dpdo, E-28006 , Madrid , Spain
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30
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Radchenko D, Teichert I, Pöggeler S, Kück U. A Hippo Pathway-Related GCK Controls Both Sexual and Vegetative Developmental Processes in the Fungus Sordaria macrospora. Genetics 2018; 210:137-153. [PMID: 30012560 PMCID: PMC6116960 DOI: 10.1534/genetics.118.301261] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 06/25/2018] [Indexed: 11/18/2022] Open
Abstract
The supramolecular striatin-interacting phosphatases and kinases (STRIPAK) complex is conserved from yeast to human, and regulates a variety of key biological processes. In animals, this complex consists of the scaffold protein striatin, the protein phosphatase 2A, and kinases, such as germinal center kinase (GCK) III and GCKIV family members, as well as other associated proteins. The STRIPAK complex was identified as a negative regulator of the Hippo pathway, a large eukaryotic signaling network with a core composed of a GCK and a nuclear Dbf2-related kinase. The signaling architecture of the Hippo core resembles the fungal septation initiation network (SIN) that regulates cytokinesis in fission yeast as well as septation in filamentous fungi. In the filamentous model fungus Sordaria macrospora, core components of the STRIPAK complex have been functionally described and the striatin homolog PRO11 has been shown to interact with the GCK SmKIN3. However, the exact role of SmKIN3 in fungal development has not yet been fully elucidated. Here, we provide comprehensive genetic and functional analysis of SmKIN3 from S. macrospora Using deletion mutants and site-directed mutagenesis, along with phenotypic and phylogenetic analysis, we provide compelling evidence that SmKIN3 is involved in fruiting body formation, hyphal fusion, and septation. Strains carrying the ATP-binding mutant SmKIN3K39R, as well as a double-deletion strain lacking SmKIN3 and the core STRIPAK subunit PRO11, also revealed severe developmental defects. Collectively, this study suggests that SmKIN3 links both the SIN and STRIPAK complex, thereby regulating multiple key cellular processes.
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Affiliation(s)
- Daria Radchenko
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, 44780, Germany
| | - Ines Teichert
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, 44780, Germany
| | - Stefanie Pöggeler
- Genetik Eukaryotischer Mikroorganismen, Institut für Mikrobiologie und Genetik, Universität Göttingen, 37077, Germany
| | - Ulrich Kück
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, 44780, Germany
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31
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Masilamani R, Cian MB, Dalebroux ZD. Salmonella Tol-Pal Reduces Outer Membrane Glycerophospholipid Levels for Envelope Homeostasis and Survival during Bacteremia. Infect Immun 2018; 86:e00173-18. [PMID: 29735519 DOI: 10.1128/IAI.00173-18] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 04/27/2018] [Indexed: 12/22/2022] Open
Abstract
Salmonellae regulate membrane lipids during infection, but the exact proteins and mechanisms that promote their survival during bacteremia remain largely unknown. Mutations in genes encoding the conserved Salmonella enterica serovar Typhimurium (S. Typhimurium) Tol-Pal apparatus caused the outer membrane (OM) sensor lipoprotein, RcsF, to become activated. The capsule activation phenotype for the mutants suggested that Tol-Pal might influence envelope lipid homeostasis. The mechanism involves reducing OM glycerophospholipid (GPL) levels, since the mutant salmonellae similarly accumulated phosphatidylglycerols (PGl) and phosphatidylethanolamines (PE) within the OM in comparison to the wild type. The data support the Escherichia coli model, whereby Tol-Pal directs retrograde GPL translocation across the periplasm. The S. Typhimurium mechanism involves contributions from YbgC, a cytoplasmic acyl coenzyme A (acyl-CoA) thioesterase, and CpoB, a periplasmic TolA-binding protein. The functional relationship between Tol-Pal and YbgC and CpoB was previously unresolved. The S. Typhimurium Tol-Pal proteins contribute similarly toward promoting OM-GPL homeostasis and Rcs signaling inactivity but differently toward promoting bacterial morphology, rifampin resistance, survival in macrophages, and survival in mice. For example, tolQ, tolR, tolA, and cpoB mutants were significantly more attenuated than ybgC, tolB, and pal mutants in a systemic mouse model of disease. Therefore, key roles exist for TolQ, TolR, TolA, and CpoB during murine bacteremia, which are independent of maintaining GPL homeostasis. The ability of TolQR to channel protons across the inner membrane (IM) is necessary for S. Typhimurium TolQRA function, since mutating conserved channel-facing residues rendered TolQ ineffective at rescuing deletion mutant phenotypes. Therefore, Tol-Pal promotes S. Typhimurium survival during bacteremia, in part, by reducing OM GPL concentrations, while TolQRA and CpoB enhance systemic virulence by additional mechanisms.
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32
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Jain P, Malakar B, Khan MZ, Lochab S, Singh A, Nandicoori VK. Delineating FtsQ-mediated regulation of cell division in Mycobacterium tuberculosis. J Biol Chem 2018; 293:12331-12349. [PMID: 29903917 DOI: 10.1074/jbc.ra118.003628] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 05/31/2018] [Indexed: 11/06/2022] Open
Abstract
Identifying and characterizing the individual contributors to bacterial cellular elongation and division will improve our understanding of their impact on cell growth and division. Here, we delineated the role of ftsQ, a terminal gene of the highly conserved division cell wall (dcw) operon, in growth, survival, and cell length maintenance in the human pathogen Mycobacterium tuberculosis (Mtb). We found that FtsQ overexpression significantly increases the cell length and number of multiseptate cells. FtsQ depletion in Mtb resulted in cells that were shorter than WT cells during the initial growth stages (4 days after FtsQ depletion) but were longer than WT cells at later stages (10 days after FtsQ depletion) and compromised the survival in vitro and in differentiated THP1 macrophages. Overexpression of N- and C-terminal FtsQ regions altered the cell length, and the C-terminal domain alone complemented the FtsQ depletion phenotype. MS analyses suggested robust FtsQ phosphorylation on Thr-24, and although phosphoablative and -mimetic mutants rescued the FtsQ depletion-associated cell viability defects, they failed to complement the cell length defects. MS and coimmunoprecipitation experiments identified 63 FtsQ-interacting partners, and we show that the interaction of FtsQ with the recently identified cell division protein SepIVA is independent of FtsQ phosphorylation and suggests a role of FtsQ in modulating cell division. FtsQ exhibited predominantly septal localization in both the presence and absence of SepIVA. Our results suggest a role for FtsQ in modulating the length, division, and survival of Mtb cells both in vitro and in the host.
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Affiliation(s)
- Preeti Jain
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067 and
| | - Basanti Malakar
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067 and
| | - Mehak Zahoor Khan
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067 and
| | - Savita Lochab
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067 and
| | - Archana Singh
- Council of Scientific and Industrial Research-Institute of Genomics and Integrative Biology, New Delhi 110025, India
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33
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Jiang P, Zheng S, Lu L. Mitotic-Spindle Organizing Protein MztA Mediates Septation Signaling by Suppressing the Regulatory Subunit of Protein Phosphatase 2A-ParA in Aspergillus nidulans. Front Microbiol 2018; 9:988. [PMID: 29774021 PMCID: PMC5951981 DOI: 10.3389/fmicb.2018.00988] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 04/27/2018] [Indexed: 12/20/2022] Open
Abstract
The proper timing and positioning of cytokinesis/septation is crucial for hyphal growth and conidiation in Aspergillus nidulans. The septation initiation network (SIN) components are a conserved spindle pole body (SPB) localized signaling cascade and the terminal kinase complex SidB-MobA, which must localize on the SPB in this pathway to trigger septation/cytokinesis. The regulatory subunit of phosphatase PP2A-ParA has been identified to be a negative regulator capable of inactivating the SIN. However, little is known about how ParA regulates the SIN pathway and whether ParA regulates the septum formation process through affecting the SPB-localized SIN proteins. In this study, through RNA-Seq and genetic approaches, we identified a new positive septation regulator, a putative mitotic-spindle organizing protein and a yeast Mzt1 homolog MztA, which acts antagonistically toward PP2A-ParA to coordinately regulate the SPB-localized SIN proteins SidB-MobA during septation. These findings imply that regulators, phosphatase PP2A-ParA and MztA counteract the septation function probably through balancing the polymerization and depolymerization of microtubules at the SPB.
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Affiliation(s)
- Ping Jiang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Shujun Zheng
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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34
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Tsujino K, Li JT, Tsukui T, Ren X, Bakiri L, Wagner E, Sheppard D. Fra-2 negatively regulates postnatal alveolar septation by modulating myofibroblast function. Am J Physiol Lung Cell Mol Physiol 2017; 313:L878-L888. [PMID: 28818870 DOI: 10.1152/ajplung.00062.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 08/03/2017] [Accepted: 08/11/2017] [Indexed: 01/12/2023] Open
Abstract
Mice that globally overexpress the transcription factor Fos-related antigen-2 (Fra-2) develop extensive pulmonary fibrosis and pulmonary vascular remodeling. To determine if these phenotypes are a consequence of ectopic Fra-2 expression in vascular smooth muscle cells and myofibroblasts, we generated mice that overexpress Fra-2 specifically in these cell types (α-SMA-rtTA;tetO-Fra-2). Surprisingly, these mice did not develop vascular remodeling or pulmonary fibrosis but did develop a spontaneous emphysema-like phenotype characterized by alveolar enlargement. Secondary septa formation is an important step in the normal development of lung alveoli, and α-smooth muscle actin (SMA)-expressing fibroblasts (myofibroblasts) play a crucial role in this process. The mutant mice showed reduced numbers of secondary septa at postnatal day 7 and enlarged alveolae starting at postnatal day 12, suggesting impairment of secondary septa formation. Lineage tracing using α-SMA-rtTA mice crossed to a floxed TdTomato reporter revealed that embryonic expression of α-SMA Cre marked a population of cells that gave rise to nearly all alveolar myofibroblasts. Comprehensive transcriptome analyses (RNA sequencing) demonstrated that the overwhelming majority of genes whose expression was significantly altered by overexpression of Fra-2 in myofibroblasts encoded secreted proteins, components of the extracellular matrix (ECM), and cell adhesion-associated genes, including coordinate upregulation of pairs of integrins and their principal ECM ligands. In addition, primary myofibroblasts isolated from the mutant mice showed reduced migration capacity. These findings suggest that Fra-2 overexpression might impair myofibroblast functions crucial for secondary septation, such as myofibroblast migration across alveoli, by perturbing interactions between integrins and locally produced components of the ECM.
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Affiliation(s)
- Kazuyuki Tsujino
- Department of Medicine, University of California, San Francisco, California
| | - John T Li
- Department of Medicine, University of California, San Francisco, California.,Department of Pediatrics, University of California, San Francisco, California; and
| | - Tatsuya Tsukui
- Department of Medicine, University of California, San Francisco, California
| | - Xin Ren
- Department of Medicine, University of California, San Francisco, California
| | - Latifa Bakiri
- BBVA Foundation-CNIO Cancer Cell Biology Program, Spanish National Cancer Research Centre, Madrid, Spain
| | - Erwin Wagner
- BBVA Foundation-CNIO Cancer Cell Biology Program, Spanish National Cancer Research Centre, Madrid, Spain
| | - Dean Sheppard
- Department of Medicine, University of California, San Francisco, California;
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Yu D, Zhang S, Li X, Xu JR, Schultzhaus Z, Jin Q. A Gin4-Like Protein Kinase GIL1 Involvement in Hyphal Growth, Asexual Development, and Pathogenesis in Fusarium graminearum. Int J Mol Sci 2017; 18:E424. [PMID: 28212314 DOI: 10.3390/ijms18020424] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 02/02/2017] [Accepted: 02/04/2017] [Indexed: 11/23/2022] Open
Abstract
Fusarium graminearum is the main causal agent of Fusarium head blight (FHB) on wheat and barley. In a previous study, a GIN4-like protein kinase gene, GIL1, was found to be important for plant infection and sexual reproduction. In this study we further characterized the functions of GIL1 kinase in different developmental processes. The Δgil1 mutants were reduced in growth, conidiation, and virulence, and formed whitish and compact colonies. Although phialide formation was rarely observed in the mutants, deletion of GIL1 resulted in increased hyphal branching and increased tolerance to cell wall and cell membrane stresses. The Δgil1 mutants produced straight, elongated conidia lacking of distinct foot cells and being delayed in germination. Compared with the wild type, some compartments in the vegetative hyphae of Δgil1 mutants had longer septal distances and increased number of nuclei, suggesting GIL1 is related to cytokinesis and septation. Localization of the GIL1-GFP fusion proteins to the septum and hyphal branching and fusion sites further supported its roles in septation and branching. Overall, our results indicate that GIL1 plays a role in vegetative growth and plant infection in F. graminearum, and is involved in septation and hyphal branching.
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Juvvadi PR, Steinbach WJ. Calcineurin Orchestrates Hyphal Growth, Septation, Drug Resistance and Pathogenesis of Aspergillus fumigatus: Where Do We Go from Here? Pathogens 2015; 4:883-93. [PMID: 26694470 PMCID: PMC4693169 DOI: 10.3390/pathogens4040883] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/07/2015] [Accepted: 12/11/2015] [Indexed: 12/27/2022] Open
Abstract
Studies on fungal pathogens belonging to the ascomycota phylum are critical given the ubiquity and frequency with which these fungi cause infections in humans. Among these species, Aspergillus fumigatus causes invasive aspergillosis, a leading cause of death in immunocompromised patients. Fundamental to A. fumigatus pathogenesis is hyphal growth. However, the precise mechanisms underlying hyphal growth and virulence are poorly understood. Over the past 10 years, our research towards the identification of molecular targets responsible for hyphal growth, drug resistance and virulence led to the elucidation of calcineurin as a key signaling molecule governing these processes. In this review, we summarize our salient findings on the significance of calcineurin for hyphal growth and septation in A. fumigatus and propose future perspectives on exploiting this pathway for designing new fungal-specific therapeutics.
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Affiliation(s)
- Praveen R Juvvadi
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA.
| | - William J Steinbach
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA.
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
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Ntokou A, Klein F, Dontireddy D, Becker S, Bellusci S, Richardson WD, Szibor M, Braun T, Morty RE, Seeger W, Voswinckel R, Ahlbrecht K. Characterization of the platelet-derived growth factor receptor-α-positive cell lineage during murine late lung development. Am J Physiol Lung Cell Mol Physiol 2015; 309:L942-58. [PMID: 26320158 DOI: 10.1152/ajplung.00272.2014] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 08/20/2015] [Indexed: 12/11/2022] Open
Abstract
A reduced number of alveoli is the structural hallmark of diseases of the neonatal and adult lung, where alveoli either fail to develop (as in bronchopulmonary dysplasia), or are progressively destroyed (as in chronic obstructive pulmonary disease). To correct the loss of alveolar septa through therapeutic regeneration, the mechanisms of septa formation must first be understood. The present study characterized platelet-derived growth factor receptor-α-positive (PDGFRα(+)) cell populations during late lung development in mice. PDGFRα(+) cells (detected using a PDGFRα(GFP) reporter line) were noted around the proximal airways during the pseudoglandular stage. In the canalicular stage, PDGFRα(+) cells appeared in the more distal mesenchyme, and labeled α-smooth muscle actin-positive tip cells in the secondary crests and lipofibroblasts in the primary septa during alveolarization. Some PDGFRα(+) cells appeared in the mesenchyme of the adult lung. Over the course of late lung development, PDGFRα(+) cells consistently expressed collagen I, and transiently expressed markers of mesenchymal stem cells. With the use of both, a constitutive and a conditional PDGFRα(Cre) line, it was observed that PDGFRα(+) cells generated alveolar myofibroblasts including tip cells of the secondary crests, and lipofibroblasts. These lineages were committed before secondary septation. The present study provides new insights into the time-dependent commitment of the PDGFRα(+) cell lineage to lipofibroblasts and myofibroblasts during late lung development that is needed to better understand the cellular contribution to the process of alveolarization.
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Affiliation(s)
- Aglaia Ntokou
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research [Deutsches Zentrum für Lungenforschung (DZL)], Bad Nauheim, Germany
| | - Friederike Klein
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research [Deutsches Zentrum für Lungenforschung (DZL)], Bad Nauheim, Germany
| | - Daria Dontireddy
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research [Deutsches Zentrum für Lungenforschung (DZL)], Bad Nauheim, Germany
| | - Sven Becker
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research [Deutsches Zentrum für Lungenforschung (DZL)], Bad Nauheim, Germany
| | - Saverio Bellusci
- Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - William D Richardson
- Wolfson Institute for Biomedical Research, University College London, London, United Kingdom; and
| | - Marten Szibor
- Department of Cardiac Development and Remodelling, Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research (DZL), Bad Nauheim, Germany
| | - Thomas Braun
- Department of Cardiac Development and Remodelling, Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research (DZL), Bad Nauheim, Germany
| | - Rory E Morty
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research [Deutsches Zentrum für Lungenforschung (DZL)], Bad Nauheim, Germany; Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Werner Seeger
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research [Deutsches Zentrum für Lungenforschung (DZL)], Bad Nauheim, Germany; Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Robert Voswinckel
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research [Deutsches Zentrum für Lungenforschung (DZL)], Bad Nauheim, Germany
| | - Katrin Ahlbrecht
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research [Deutsches Zentrum für Lungenforschung (DZL)], Bad Nauheim, Germany; Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, Member of the German Center for Lung Research (DZL), Giessen, Germany;
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Lu YT, Qi ST, Xu JM, Pan J, Shi J. A membranous structure separating the adenohypophysis and neurohypophysis: an anatomical study and its clinical application for craniopharyngioma. J Neurosurg Pediatr 2015; 15:630-7. [PMID: 25745951 DOI: 10.3171/2014.10.peds143] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT This study aimed to identify the membranous septation between the adeno- and neurohypophysis. The clinical impact of this septation in the surgical removal of infradiaphragmatic craniopharyngioma (Id-CP) is also clarified. METHODS The sellar regions from 8 fetal and 6 adult cadavers were dissected. After staining first with H & E and then with picro-Sirius red, the membranous structures were observed and measured under normal light and polarization microscopy. The pre- and postsurgical images and intraoperative procedures in 28 cases of childhood Id-CP were reviewed and analyzed. RESULTS There is a significant membranous septation (termed the adenoneurohypophysis septation [ANHS]) lying behind the intermediate lobe to separate the adeno- and neurohypophysis. The average thicknesses are 21.9 ± 16.9 μm and 79.1 ± 43.2 μm in fetal and adult heads, respectively. The median segment of the septation is significantly thicker than the upper and lower segments. The ANHS extends from the suprasellar pars tuberalis to the sellar floor, where it is fused with the pituitary capsule. During Id-CP surgery performed via a transcranial approach, the ANHS can be identified to reserve the neurohypophysis. Moreover, by understanding the anatomy of this membrane, the pituitary stalk was preserved in 3 patients (10.7%). CONCLUSIONS There is a significant membrane separating the anterior and posterior lobes of the pituitary gland, which lies behind the intermediate lobe. Understanding the anatomy of this septation is important for identifying and preserving the neurohypophysis and pituitary stalk during Id-CP surgery.
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Affiliation(s)
- Yun-Tao Lu
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Song-Tao Qi
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Jia-Ming Xu
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Jun Pan
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Jin Shi
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
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Jackson-Hayes L, Hill TW, Loprete DM, DelBove CE, Shapiro JA, Henley JL, Dawodu OO. Two amino acid sequences direct Aspergillus nidulans protein kinase C (PkcA) localization to hyphal apices and septation sites. Mycologia 2015; 107:452-9. [PMID: 25724996 DOI: 10.3852/14-217] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 01/18/2015] [Indexed: 11/10/2022]
Abstract
The Aspergillus nidulans ortholog of protein kinase C (pkcA) is involved in the organism's putative cell wall integrity (CWI) pathway, and PkcA also is highly localized at growing tips and forming septa. In the present work we identify the regions within PkcA that are responsible for its localization to hyphal tips and septation sites. To this end, we used serially truncated pkcA constructs and expressed them as green fluorescent protein (GFP) chimeras and identified two regions that direct PkcA localization. The first region is a 10 amino-acid sequence near the carboxyl end of the C2 domain that is required for localization to hyphal tips. Proteins containing this sequence also localize to septation sites. A second region between C2 and C1B (encompassing C1A) is sufficient for localization to septation sites but not to hyphal tips. We also report that localization to hyphal tips and septation sites alone is not sufficient for truncated constructs to complement hypersensitivity to the cell wall compromising agent calcofluor white in a strain bearing a mutation in the pkcA gene. Taken together, these results suggest that localization and stress response might be independent.
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Affiliation(s)
| | - Terry W Hill
- Departments of Chemistry and Biology, Rhodes College, Memphis, Tennessee 38112
| | - Darlene M Loprete
- Departments of Chemistry and Biology, Rhodes College, Memphis, Tennessee 38112
| | - Claire E DelBove
- Departments of Chemistry and Biology, Rhodes College, Memphis, Tennessee 38112
| | - Justin A Shapiro
- Departments of Chemistry and Biology, Rhodes College, Memphis, Tennessee 38112
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Luo Y, Zhang H, Qi L, Zhang S, Zhou X, Zhang Y, Xu JR. FgKin1 kinase localizes to the septal pore and plays a role in hyphal growth, ascospore germination, pathogenesis, and localization of Tub1 beta-tubulins in Fusarium graminearum. New Phytol 2014; 204:943-54. [PMID: 25078365 DOI: 10.1111/nph.12953] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 06/20/2014] [Indexed: 05/20/2023]
Abstract
The Kin1/Par-1/MARK kinases regulate various cellular processes in eukaryotic organisms. Kin1 orthologs are well conserved in fungal pathogens but none of them have been functionally characterized. Here, we show that KIN1 is important for pathogenesis and growth in two phytopathogenic fungi and that FgKin1 regulates ascospore germination and the localization of Tub1 β-tubulins in Fusarium graminearum. The Fgkin1 mutant and putative FgKIN1(S172A) kinase dead (nonactivatable) transformants were characterized for defects in plant infection, sexual and asexual reproduction, and stress responses. The localization of FgKin1 and two β-tubulins were examined in the wild-type and mutant backgrounds. Deletion of FgKIN1 resulted in reduced virulence and defects in ascospore germination and release. FgKin1 localized to the center of septal pores. FgKIN1 deletion had no effect on Tub2 microtubules but disrupted Tub1 localization. In the mutant, Tub1 appeared to be enriched in the nucleolus. In Magnaporthe oryzae, MoKin1 has similar functions in growth and infection and it also localizes to septal pores. The S172A mutation had no effect on the localization and function of FgKIN1 during sexual reproduction. These results indicate that FgKIN1 has kinase-dependent and independent functions and it specifically regulates Tub1 β-tubulins. FgKin1 plays a critical role in ascospore discharge, germination, and plant infection.
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Affiliation(s)
- Yongping Luo
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
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Gupta C, Kurian P, Seva KN, Kalthur SG, D'Souza AS. A morphological and morphometric study of jugular foramen in dry skulls with its clinical implications. J Craniovertebr Junction Spine 2014; 5:118-21. [PMID: 25336833 PMCID: PMC4201011 DOI: 10.4103/0974-8237.142305] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE Jugular foramen of human skull is one of the most interesting foramina. It is a complex bony canal, numerous vital structures, including nerves and vessels are transmitted through it. Most of the intracranial and extra cranial lesions of posterior cranial fossa might affect the structures in jugular foramen in addition to intrinsic abnormalities. As the neurosurgeons have become courageous in approaching this area, so there is a need to become familiar with this area. Hence, the present study was done to examine the anatomy of jugular foramen, including its morphological features and dimensions. MATERIALS AND METHODS The study was carried out on 50 dried skulls. 100 jugular foramina were studied on both right and left side of skulls. The length, width of jugular foramen and width and depth of jugular fossa were measured using vernier calipers. Presence of dome, complete and incomplete septation was also looked for. RESULTS The mean right and left anteroposterior diameter, latero-medial diameter, area, jugular fossa width, depth in our study was 11.22, 16.52, 187.34, 6.83, 11.58 mm and 9.52, 16.02, 153.2, 5.69, 11.13 mm. Dome was present in jugular foramen in 74% on the right side and 58% on the left side. Complete septation in jugular foramen is seen in 44% on the right side and 42% on the left side. CONCLUSION This study will help the neurosurgeons while doing surgery in this region.
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Affiliation(s)
- Chandni Gupta
- Department of Anatomy, Kasturba Medical College, Manipal University, Manipal, Karnataka, India
| | - Punnose Kurian
- Department of Anatomy, Kasturba Medical College, Manipal University, Manipal, Karnataka, India
| | - Kantharaj Naik Seva
- Department of Anatomy, Kasturba Medical College, Manipal University, Manipal, Karnataka, India
| | | | - Antony Sylvan D'Souza
- Department of Anatomy, Kasturba Medical College, Manipal University, Manipal, Karnataka, India
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Stockstill KE, Park J, Wille R, Bay G, Joseph A, Shannon KB. Mutation of Hof1 PEST motif phosphorylation sites leads to retention of Hof1 at the bud neck and a decrease in the rate of myosin contraction. Cell Biol Int 2013; 37:314-25. [PMID: 23359466 DOI: 10.1002/cbin.10042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 12/31/2012] [Indexed: 11/07/2022]
Abstract
Regulation of actomyosin ring contraction is important for the coordination of cytokinesis with mitosis. Hof1, a member of the Pombe Cdc15 homology (PCH) family of proteins, is required for efficient cytokinesis in budding yeast. Phosphorylation of Hof1 depends on the mitotic exit network (MEN), and its degradation at the end of mitosis depends on its PEST motif and interaction with the E3 ligase Grr1. To test the hypothesis that targeted destruction of Hof1 temporally couples mitotic exit with contraction of the actomyosin ring, we mutated the Hof1 PEST motif to prevent phosphorylation and subsequent degradation. These mutations increased the amount of Hof1 at the bud neck during cytokinesis, resulted in smaller bud neck diameter, and slowed the rate of myosin contraction. However, Hof1 PEST motif phosphorylation site mutants did not have cytokinesis defects, indicating that regulation of Hof1 levels does not control the onset of actomyosin ring contraction as predicted.
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Affiliation(s)
- Katherine E Stockstill
- Department of Biological Sciences, Missouri University of Science and Technology, 105 Schrenk Hall, 400 W. 11th St., Rolla, Missouri, 65401, USA.
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Affiliation(s)
- Robert H Anderson
- Cardiac Unit, Institute of Child Health, University College, London, UK.
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Abstract
The developmental anatomy of the ventricular outlets and intrapericardial arterial trunks is a source of considerable confusion. First, major problems exist because of the multiple names and definitions used to describe this region of the heart as it develops. Second, there is no agreement on the boundaries of the described components, nor on the number of ridges or cushions to be found dividing the outflow tract, and the pattern of their fusion. Evidence is also lacking concerning the role of the fused cushions relative to that of the so-called aortopulmonary septum in separating the intrapericardial components of the great arterial trunks. In this review, we discuss the existing problems, as we see them, in the context of developmental and postnatal morphology. We concentrate, in particular, on the changes in the nature of the wall of the outflow tract, which is initially myocardial throughout its length. Key features that, thus far, do not seem to have received appropriate attention are the origin, and mode of separation, of the intrapericardial portions of the arterial trunks, and the formation of the walls of the aortic and pulmonary valvar sinuses. Also as yet undetermined is the formation of the free-standing muscular subpulmonary infundibulum, the mechanism of its separation from the aortic valvar sinuses, and its differentiation, if any, from the muscular ventricular outlet septum.
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Affiliation(s)
- Sandra Webb
- Department of Anatomy and Developmental Biology, St George's Hospital Medical School, Cranmer Terrace, London SW17 ORE, UK.
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Abstract
Cell-specific activation of transcription factor sigmaF during sporulation in Bacillus subtilis requires the formation of the polar septum and the activity of a serine phosphatase (SpoIIE) located in the septum. The SpoIIE phosphatase indirectly activates sigmaF by dephosphorylating a protein (SpoIIAA-P) in the pathway that controls the activity of the transcription factor. By use of a SpoIIE-GFP fusion protein in time-course and time-lapse experiments and by direct visualization of septa in living cells, we show that SpoIIE is present in the predivisional sporangium, where it often localizes near both cell poles in structures known as E-rings. We also present evidence consistent with the view that SpoIIE is present in both progeny cells after polar division. These findings are incompatible with a model for the control of sigmaF activity in which the phosphatase is simply sequestered to one cell. Instead, we conclude that the function of SpoIIE is subject to regulation, and we present evidence that this occurs in two stages. The first stage, which involves the phosphatase function of SpoIIE, depends on the cell division protein FtsZ and could correspond to the FtsZ-dependent assembly of SpoIIE into E-rings. The second stage occurs after the dephosphorylation of SpoIIAA-P and is dependent on the later-acting, cell-division protein DivIC. Evidence based on the use of modified and mutant forms of the phosphatase protein indicates that SpoIIE blocks the capacity of unphosphorylated SpoIIAA to activate sigmaF until formation of the polar septum is completed.
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Affiliation(s)
- N King
- Department of Molecular and Cellular Biology, The Biological Laboratories, Harvard University, Cambridge, Massachusetts 02138, USA
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Abstract
The budding yeast lyt1 mutation causes cell lysis. We report here that lyt1 is an allele of cdc15, a gene which encodes a protein kinase that functions late in the cell cycle. Neither cdc15-1 nor cdc15-lyt1 strains are able to septate at 37 degreesC, even though they may manage to rebud. Cells lyse after a shmoo-like projection appears at the distal pole of the daughter cell. Actin polarizes towards the distal pole but the septins remain at the mother-daughter neck. This morphogenetic response reflects entry into a new round of the cell cycle: the preference for polarization from the distal pole was lost in bud1 cdc15 double mutants; double cdc15-lyt1 cdc28-4 mutants, defective for START, did not develop apical projections and apical polarization was accompanied by DNA replication. The same phenomena were caused by mutations in the genes CDC14, DBF2, and TEM1, which are functionally related to CDC15. Apical polarization was delayed in cdc15 mutants as compared with budding in control cells and this delay was abolished in a septin mutant. Our results suggest that the delayed M/G1 transition in cdc15 mutants is due to a septin-dependent checkpoint that couples initiation of the cell cycle to the completion of cytokinesis.
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Affiliation(s)
- J Jiménez
- Departamento de Microbiología II, Facultad de Farmacia
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Abstract
Cytokinesis is the part of the cell cycle in which the cell is cleaved to form two daughter cells. The unicellular yeast, Schizosaccharomyces pombe is an excellent model organism in which to study cell division, since it shows the general features of eukaryotic cell division and is amenable to genetic analysis. In this manuscript we describe the isolation and characterization of a new protein, imp2, which is required for normal septation in fission yeast. imp2, which colocalizes with the medial ring during septation, is structurally similar to a group of proteins including the S. pombe cdc15 and the mouse PSTPIP that are localized to, and thought to be involved in actin ring organization. Cells in which the imp2 gene is deleted or overexpressed have septation and cell separation defects. An analysis of the actin cytoskeleton shows the lack of a medial ring in septating cells that overexpress imp2, and the appearance of abnormal medial ring structures in septated cells that lack imp2. These observations suggest that imp2 destabilizes the medial ring during septation. imp2 also shows genetic interactions with several, previously characterized septation genes, strengthening the conclusion that it plays a role in normal fission yeast septation.
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Affiliation(s)
- J Demeter
- Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, Texas 77030, USA
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