scholarly journals Research on Initial Lightning Attachment Zone for Aircraft

2013 ◽  
Author(s):  
Xiang-Ru Teng ◽  
Guang-Bin Liu ◽  
Zhi-Yong Yu ◽  
Yu-Long Zhao
Keyword(s):  
Attachment Zone

Definition of individual components within the cytoskeleton of Trypanosoma brucei by a library of monoclonal antibodies

1989 ◽  
Vol 93 (3) ◽  
pp. 491-500 ◽  
Author(s):  
A. Woods ◽  
T. Sherwin ◽  
R. Sasse ◽  
T.H. MacRae ◽  
A.J. Baines ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Monoclonal Antibodies ◽  
Trypanosoma Brucei ◽  
Immunofluorescence Microscopy ◽  
Complex Mixtures ◽  
Immunogold Electron Microscopy ◽  
Basal Bodies ◽  
Tubulin Isotypes ◽  
Definition Of ◽  
Attachment Zone

The detergent-insoluble T. brucei cytoskeleton consists of several morphologically distinct regions and organelles, many of which are detectable only by electron microscopy. We have produced a set of monoclonal antibodies that define each structural component of this highly ordered cytoskeleton. The monoclonal antibodies were selected by cloning of hybridomas produced from mice injected with complex mixtures of proteins of either the cytoskeleton itself or salt extracts thereof. Four antibodies define particular tubulin isotypes and locate the microtubules of the axoneme and sub-pellicular array; two antibodies recognize the flagellum attachment zone; one recognizes the paraflagellar rod and another the basal bodies. Finally, one antibody defines a detergent-insoluble component of the nucleus. The antigens detected by each monoclonal antibody have been analysed by immunofluorescence microscopy, immunogold electron microscopy and Western blotting.

scholarly journals Maintenance of hook complex integrity and centrin arm assembly facilitates flagellum inheritance in Trypanosoma brucei

2020 ◽  
Vol 295 (37) ◽  
pp. 12962-12974 ◽  
Author(s):  
Kieu T. M. Pham ◽  
Huiqing Hu ◽  
Ziyin Li
Keyword(s):  
Trypanosoma Brucei ◽  
Essential Role ◽  
Biological Functions ◽  
Human Parasite ◽  
Attachment Zone

Inheritance of the newly assembled flagellum in the human parasite Trypanosoma brucei depends on the faithful duplication and segregation of multiple flagellum-associated cytoskeletal structures, including the hook complex and its associated centrin arm. The biological functions of this unique hook complex–centrin arm assembly remain poorly understood. Here, we report a hook complex–associated protein named BOH2 that plays an essential role in promoting flagellum inheritance. BOH2 localizes to the hooked part of the hook complex by bridging the hook complex, the centrin arm, and the flagellum attachment zone filament. Depletion of BOH2 caused the loss of the shank part of the hook complex and its associated protein TbSmee1, disrupted the assembly of the centrin arm and the recruitment of centrin arm–associated protein CAAP1, inhibited the assembly of the flagellum attachment zone, and caused flagellum mispositioning and detachment. These results demonstrate crucial roles of BOH2 in maintaining hook complex integrity and promoting centrin arm formation and suggest that proper assembly of the hook complex–centrin arm structure facilitates flagellum inheritance.

scholarly journals Novel Bilobe Components in Trypanosoma brucei Identified Using Proximity-Dependent Biotinylation

2012 ◽  
Vol 12 (2) ◽  
pp. 356-367 ◽  
Author(s):  
Brooke Morriswood ◽  
Katharina Havlicek ◽  
Lars Demmel ◽  
Sevil Yavuz ◽  
Marco Sealey-Cardona ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Protein Identification ◽  
Affinity Purification ◽  
Bioinformatic Analysis ◽  
Test Subject ◽  
Content Type ◽  
Interaction Partners ◽  
Nonionic Detergent ◽  
Protein Components ◽  
Attachment Zone

ABSTRACT The trypanosomes are a family of parasitic protists of which the African trypanosome, Trypanosoma brucei , is the best characterized. The complex and highly ordered cytoskeleton of T. brucei has been shown to play vital roles in its biology but remains difficult to study, in large part owing to the intractability of its constituent proteins. Existing methods of protein identification, such as bioinformatic analysis, generation of monoclonal antibody panels, proteomics, affinity purification, and yeast two-hybrid screens, all have drawbacks. Such deficiencies—troublesome proteins and technical limitations—are common not only to T. brucei but also to many other protists, many of which are even less well studied. Proximity-dependent biotin identification (BioID) is a recently developed technique that allows forward screens for interaction partners and near neighbors in a native environment with no requirement for solubility in nonionic detergent. As such, it is extremely well suited to the exploration of the cytoskeleton. In this project, BioID was adapted for use in T. brucei . The trypanosome bilobe, a discrete cytoskeletal structure with few known protein components, represented an excellent test subject. Use of the bilobe protein TbMORN1 as a probe resulted in the identification of seven new bilobe constituents and two new flagellum attachment zone proteins. This constitutes the first usage of BioID on a largely uncharacterized structure, and demonstrates its utility in identifying new components of such a structure. This remarkable success validates BioID as a new tool for the study of unicellular eukaryotes in particular and the eukaryotic cytoskeleton in general.

Kinetic Numerical Simulation of the Cathode Attachment Zone of Constricted High-Current Vacuum Arcs

2013 ◽  
Vol 41 (2) ◽  
pp. 384-390 ◽  
Author(s):  
Dmitry L. Shmelev ◽  
Thierry Delachaux ◽  
Ekkehard Schade
Keyword(s):  
Numerical Simulation ◽  
High Current ◽  
Attachment Zone

Immunological characterization of cytoskeletal proteins associated with the basal body, axoneme and flagellum attachment zone of Trypanosoma brucei

Parasitology ◽  
1995 ◽  
Vol 111 (1) ◽  
pp. 77-85 ◽  
Author(s):  
R. Woodward ◽  
M. J. Carden ◽  
K. Gull
Keyword(s):  
Monoclonal Antibody ◽  
Trypanosoma Brucei ◽  
Basal Body ◽  
Complex Mixture ◽  
Cytoskeletal Proteins ◽  
Bovine Sperm ◽  
Phosphatase Treatment ◽  
Body Complex ◽  
Attachment Zone

SUMMARYThe monoclonal antibody BS7, raised to bovine sperm flagellum cytoskeletal antigens in a previous study, is here reported to detect flagellum-associated structures in Trypanosoma brucei and Crithidia fasciculata. Immunoblotting showed that BS7 cross-reacts with several cytoskeletal T. brucei proteins but phosphatase treatment did not diminish this complex immunoblot reactivity. To characterize further the cross-reactive proteins recognized in T. brucei-cytoskeletons by BS7 each was excised from preparative gels and used as an immunogen for antiserum production. Two proteins, with apparent sizes around 43 and 47 kDa, produced antisera shown to be monospecific by immunoblotting total T. brucei flagellum preparations. Each of these detected the basal body-associated immunofluorescence in T. brucei. Identification of the smaller, 43 kDa, component as a basal body-associated product was supported by the behaviour of a second monoclonal antibody, BBA4, which was also shown to detect the T. brucei basal body complex by immunofluorescence and immunoblots the 43 kDa polypeptide. These observations reveal new components of the trypanosome cytoskeleton. Also, they provide a further example of an immunological approach for identification of interesting, rare components of the T. brucei cytoskeleton starting from a complex mixture of proteins.

scholarly journals Microtubule polarity and dynamics in the control of organelle positioning, segregation, and cytokinesis in the trypanosome cell cycle.

1995 ◽  
Vol 128 (6) ◽  
pp. 1163-1172 ◽  
Author(s):  
D R Robinson ◽  
T Sherwin ◽  
A Ploubidou ◽  
E H Byard ◽  
K Gull
Keyword(s):  
Cell Cycle ◽  
Trypanosoma Brucei ◽  
Daughter Nucleus ◽  
Basal Bodies ◽  
Cortical Microtubules ◽  
Cell Extension ◽  
Microtubule Polarity ◽  
Check Points ◽  
High Degree ◽  
Attachment Zone

Trypanosoma brucei has a precisely ordered microtubule cytoskeleton whose morphogenesis is central to cell cycle events such as organelle positioning, segregation, mitosis, and cytokinesis. We have defined microtubule polarity and show the + ends of the cortical microtubules to be at the posterior end of the cell. Measurements of organelle positions through the cell cycle reveal a high degree of coordinate movement and a relationship with overall cell extension. Quantitative analysis of the segregation of the replicated mitochondrial genome (the kinetoplast) by the flagellar basal bodies identifies a new G2 cell cycle event marker. The subsequent mitosis then positions one "daughter" nucleus into the gap between the segregated basal bodies/kinetoplasts. The anterior daughter nucleus maintains its position relative to the anterior of the cell, suggesting an effective yet cryptic nuclear positioning mechanism. Inhibition of microtubule dynamics by rhizoxin results in a phenomenon whereby cells, which have segregated their kinetoplasts yet are compromised in mitosis, cleave into a nucleated portion and a flagellated, anucleate, cytoplast. We term these cytoplasts "zoids" and show that they contain the posterior (new) flagellum and associated basal-body/kinetoplast complex. Examination of zoids suggests a role for the flagellum attachment zone (FAZ) in defining the position for the axis of cleavage in trypanosomes. Progression through cytokinesis, (zoid formation) while mitosis is compromised, suggests that the dependency relationships leading to the classical cell cycle check points may be altered in trypanosomes, to take account of the need to segregate two unit genomes (nuclear and mitochondrial) in this cell.

scholarly journals Functional analyses of the CIF1-CIF2 complex in Trypanosoma brucei identify the structural motifs required for complex formation and cytokinesis

2017 ◽  
Author(s):  
Huiqing Hu ◽  
Paul Majneri ◽  
Dielan Li ◽  
Yasuhiro Kurasawa ◽  
Tai An ◽  
...  
Keyword(s):  
Zinc Finger ◽  
Coiled Coil ◽  
Longitudinal Axis ◽  
Zinc Finger Motif ◽  
Structural Motifs ◽  
Zinc Finger Motifs ◽  
Ef Hand ◽  
Functional Analyses ◽  
Attachment Zone ◽  
Structural Insights

ABSTRACTCytokinesis in trypanosome occurs uni-directionally along the longitudinal axis from the cell anterior towards the cell posterior and requires a trypanosome-specific CIF1-CIF2 protein complex. However, little is known about the contribution of the structural motifs in CIF1 and CIF2 to complex assembly and cytokinesis. Here, we demonstrated that the two zinc-finger motifs but not the coiled-coil motif in CIF1 are required for interaction with the EF-hand motifs in CIF2. We further showed that localization of CIF1 depends on the coiled-coil motif and the first zinc-finger motif and that localization of CIF2 depends on the EF-hand motifs. Deletion of the coiled-coil motif and mutation of either zinc-finger motifs in CIF1 disrupted cytokinesis. Further, mutation of either zinc-finger motif in CIF1 mis-localized CIF2 to the cytosol and destabilized CIF2, whereas deletion of the coiled-coil motif in CIF1 spread CIF2 over to the new flagellum attachment zone and stabilized CIF2. Together, these results uncovered the requirement of the coiled-coil motif and zinc-finger motifs for CIF1 function in cytokinesis and for CIF2 localization and stability, providing structural insights into the functional interplay between the two cytokinesis regulators.

scholarly journals Bovine Cryptosporidiosis: A Transmission and Scanning Electron Microscopic Study of Some Stages in the Life Cycle and of the Host-Parasite Relationship

1978 ◽  
Vol 15 (3) ◽  
pp. 417-427 ◽  
Author(s):  
J. Pohlenz ◽  
W. J. Bemrick ◽  
H. W. Moon ◽  
N. F. Cheville
Keyword(s):  
Epithelial Cells ◽  
Diarrheal Disease ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic Study ◽  
Attachment Sites ◽  
Scanning Electron Microscopic ◽  
Parasite Relationship ◽  
Host Parasite ◽  
Attachment Zone ◽  
Scanning Electron

Transmission and scanning electron microscopy of the ileal mucosae from 12 calves infected with Cryptosporidium sp. showed cryptosporidia free in the lumen and attached to epithelium. The attached parasites were interpreted to be extracellular and adherent to the microvillous border of epithelial cells. Stages of the organism included crescentic-free merozoites, trophozoites, schizonts, gametes and oocysts. Attached parasites were detected chiefly at villous tips and all stages were present on a single villus. Attachment sites were characterized by absence or disintegration of microvilli, disorganization of the terminal web and development of a specialized attachment zone. There were increased numbers of lysosomes and irregularities in the nuclear membrane of parasitized epithelial cells. It was concluded that cryptosporidia exist in bovine intestine as extracellular parasites and cause epithelial changes that in turn probably cause or contribute to diarrheal disease.

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