scholarly journals Flagellar adhesion in Trypanosoma brucei relies on interactions between different skeletal structures in the flagellum and cell body

2013 ◽  
Vol 127 (1) ◽  
pp. 204-215 ◽  
Author(s):  
B. Rotureau ◽  
T. Blisnick ◽  
I. Subota ◽  
D. Julkowska ◽  
N. Cayet ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Cell Body ◽  
Skeletal Structures

scholarly journals Resolving Trypanosoma brucei Flagellar Structure by Cryo-Electron Tomography

2019 ◽  
Vol 131 ◽  
pp. 01012
Author(s):  
Jennifer Dai
Keyword(s):  
Cell Motility ◽  
Internal Structure ◽  
Trypanosoma Brucei ◽  
Cell Body ◽  
Human African Trypanosomiasis ◽  
Electron Tomography ◽  
Unicellular Eukaryote ◽  
African Trypanosomiasis ◽  
Detailed Structure ◽  
Cryo Electron Tomography

Trypanosoma brucei is a unicellular eukaryote that can cause human African trypanosomiasis, which has continued to evolve and spread. The key feature of these parasites is that they have a flagellum consists of a typical 9 + 2 axoneme and a lattice-like paraflagellar rod (PFR). It attached to the cell body and is responsible for cell motility, cytokinesis, and morphogenesis. The present study demonstrates the detailed structure and defines the length of the axoneme and three domains of the paraflagellar rod (PFR) using cryo-electron tomography of Trypanosoma brucei flagella. The performed analysis revealed the double-headed structure of the outer-arm dynein, the internal structure of PFR and identified repeating structure in the flagella. Since these structures are critical to the pathogenicity of Trypanosoma brucei, and understanding their organization would help in finding treatments against African trypanosomiasis.

scholarly journals Trypanosomes have divergent kinesin-2 proteins that function differentially in IFT, cell division, and motility

2018 ◽  
Author(s):  
Robert L. Douglas ◽  
Brett M. Haltiwanger ◽  
Haiming Wu ◽  
Robert L. Jeng ◽  
Joel Mancuso ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Division ◽  
Trypanosoma Brucei ◽  
Cell Body ◽  
Basal Body ◽  
Protein Function ◽  
Intraflagellar Transport ◽  
Tail Domain ◽  
Specialized Structure ◽  
Attachment Zone

SummaryTrypanosoma brucei, the causative agent of African sleeping sickness, has a flagellum that is crucial for motility, pathogenicity, and viability. In most eukaryotes, the intraflagellar transport (IFT) machinery drives flagellum biogenesis, and anterograde IFT requires kinesin-2 motor proteins. In this study, we investigated the function of the two T. brucei kinesin-2 proteins, TbKin2a and TbKin2b, in bloodstream form trypanosomes. We found that compared to other kinesin-2 proteins, TbKin2a and TbKin2b show greater variation in neck, stalk, and tail domain sequences. Both kinesins contributed additively to flagellar lengthening. Surprisingly, silencing TbKin2a inhibited cell proliferation, cytokinesis and motility, whereas silencing TbKin2b did not. TbKin2a was localized on the flagellum and colocalized with IFT components near the basal body, consistent with it performing a role in IFT. TbKin2a was also detected on the flagellar attachment zone, a specialized structure in trypanosome cells that connects the flagellum to the cell body. Our results indicate that kinesin-2 proteins in trypanosomes play conserved roles in IFT and exhibit a specialized localization, emphasizing the evolutionary flexibility of motor protein function in an organism with a large complement of kinesins.

scholarly journals The N Terminus of Phosphodiesterase TbrPDEB1 of Trypanosoma brucei Contains the Signal for Integration into the Flagellar Skeleton

2010 ◽  
Vol 9 (10) ◽  
pp. 1466-1475 ◽  
Author(s):  
Edith Luginbuehl ◽  
Damaris Ryter ◽  
Judith Schranz-Zumkehr ◽  
Michael Oberholzer ◽  
Stefan Kunz ◽  
...  
Keyword(s):  
Subcellular Localization ◽  
Trypanosoma Brucei ◽  
Cell Body ◽  
Intracellular Signaling ◽  
Fluorescent Protein ◽  
Sequence Similarity ◽  
Single Amino Acid ◽  
Content Type ◽  
Gfp Reporter ◽  
Camp Levels

ABSTRACT The precise subcellular localization of the components of the cyclic AMP (cAMP) signaling pathways is a crucial aspect of eukaryotic intracellular signaling. In the human pathogen Trypanosoma brucei, the strict control of cAMP levels by cAMP-specific phosphodiesterases is essential for parasite survival, both in cell culture and in the infected host. Among the five cyclic nucleotide phosphodiesterases identified in this organism, two closely related isoenzymes, T. brucei PDEB1 (TbrPDEB1) (PDEB1) and TbrPDEB2 (PDEB2) are predominantly responsible for the maintenance of cAMP levels. Despite their close sequence similarity, they are distinctly localized in the cell. PDEB1 is mostly located in the flagellum, where it forms an integral part of the flagellar skeleton. PDEB2 is mainly located in the cell body, and only a minor part of the protein localizes to the flagellum. The current study, using transfection of procyclic trypanosomes with green fluorescent protein (GFP) reporters, demonstrates that the N termini of the two enzymes are essential for determining their final subcellular localization. The first 70 amino acids of PDEB1 are sufficient to specifically direct a GFP reporter to the flagellum and to lead to its detergent-resistant integration into the flagellar skeleton. In contrast, the analogous region of PDEB2 causes the GFP reporter to reside predominantly in the cell body. Mutagenesis of selected residues in the N-terminal region of PDEB2 demonstrated that single amino acid changes are sufficient to redirect the reporter from a cell body location to stable integration into the flagellar skeleton.

Evidence for a Mr 88,000 glycoprotein with a transmembrane association to a unique flagellum attachment region in Trypanosoma brucei

1989 ◽  
Vol 93 (3) ◽  
pp. 501-508
Author(s):  
A. Woods ◽  
A.J. Baines ◽  
K. Gull
Keyword(s):  
Trypanosoma Brucei ◽  
Cell Body ◽  
Outer Surface ◽  
Fluorescein Isothiocyanate ◽  
Surface Glycoprotein ◽  
Narrow Line ◽  
Variable Surface ◽  
Attachment Region ◽  
Relationship Of ◽  
Attachment Zone

We have examined the relationship of externally accessible proteins associated with the internal cytoskeleton of procyclic Trypanosoma brucei. Two approaches were taken. First, externally disposed glycoproteins were identified with lectins and examined for their persistence and location in isolated cytoskeletons. Second, proteins containing tyrosine residues available for chemical modification on the outer surface were identified in isolated cytoskeletons and probed for glycosylation. The procyclic form of T. brucei that was employed does not express the variable surface glycoprotein. The lectin concanavalin A (ConA) bound to the outer surface of T. brucei in two discrete locations; one a narrow line close to the flagellum attachment zone on the cell body, the other at the distal tip of the flagellum itself. Of these, only the cell body labelling was detected when isolated cytoskeletons were probed with fluorescein isothiocyanate-labelled ConA. When cytoskeletons were prepared from cells labelled with gold-conjugated ConA, a narrow line of label was detected parallel to the flagellum attachment zone but was distinct from it. Only one cytoskeletal protein, of Mr 88,000, could be labelled at the cell surface by the 125I/iodogen procedure. This protein could be precipitated from SDS-solubilized cytoskeletons with ConA-agarose. These data indicate the existence of a previously undetected cytoskeletal structure, situated in the cell body, close to the point of flagellum attachment, which has a transmembrane association with an external Mr 88,000 glycoprotein.

scholarly journals A cell-body groove housing the new flagellum tip suggests an adaptation of cellular morphogenesis for parasitism in the bloodstream form of Trypanosoma brucei

2013 ◽  
Vol 126 (24) ◽  
pp. 5748-5757 ◽  
Author(s):  
Louise Hughes ◽  
Katie Towers ◽  
Tobias Starborg ◽  
Keith Gull ◽  
Sue Vaughan
Keyword(s):  
Trypanosoma Brucei ◽  
Cell Body ◽  
Bloodstream Form ◽  
Cellular Morphogenesis ◽  
A Cell

scholarly journals In situ structural analysis of the flagellum attachment zone in Trypanosoma brucei using cryo-scanning transmission electron tomography

2020 ◽  
Author(s):  
Sylvain Trépout
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Trypanosoma Brucei ◽  
Cell Body ◽  
Electron Tomography ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Attachment Zone

SummaryThe flagellum of Trypanosoma brucei is a 20 µm-long organelle responsible for locomotion and cell morphogenesis. The flagellum attachment zone (FAZ) is a multi-protein complex whose function is to attach the flagellum to the cell body but also to guide cytokinesis. Cryo-transmission electron microscopy is a tool of choice to access the structure of the FAZ in a close-to-native state. However, because of the large dimension of the cell body, the whole FAZ cannot be structurally studied in situ at high resolution in 3D using classical transmission electron microscopy approaches. In the present work, cryo-scanning transmission electron tomography, a new method capable of investigating cryo-fixed thick biological samples, has been used to study whole T. brucei cells at the bloodstream stage. The method has been used to visualise and characterise the structure and organisation of the FAZ filament. It is composed of an array of cytoplasmic stick-like structures. These sticks are heterogeneously distributed between the posterior part and the anterior tip of the cell. This cryo-STET investigation provides new insights in the structure the FAZ filament. In combination with protein structure predictions, this work proposes a new model for the elongation of the FAZ.HighlightsFlagellar and cellular membranes are in close contact next to the FAZ filamentSticks are heterogeneously distributed along the FAZ filament lengthThin appendages are present between the FAZ filament sticks to neighbouring microtubulesFAZ elongation could originate from the force exerted by dynein motors on subpellicular microtubules

Screening of some Asteraceae to discover new active compounds against Trypanosoma brucei by metabolite profiling and PLS analysis

Planta Medica ◽  
2013 ◽  
Vol 79 (13) ◽  
Author(s):  
MS Nogueira ◽  
FB da Costa ◽  
MA Magenta ◽  
M Kaiser ◽  
R Brun ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Metabolite Profiling ◽  
Active Compounds ◽  
Pls Analysis

Body Effect Measurement in DRAM Cell Transistor Using Memory Test System

2016 ◽  
Author(s):  
Ilwoo Jung ◽  
Byoungdeok Choi ◽  
Bonggu Sung ◽  
Daejung Kim ◽  
Ilgweon Kim ◽  
...  
Keyword(s):  
Conventional Method ◽  
Cell Body ◽  
Test System ◽  
Memory Test ◽  
Effect Measurement ◽  
Nondestructive Measurement ◽  
Individual Values ◽  
Body Effect ◽  
Sample Damage ◽  
Viable Method

Abstract Body effect is the key characteristic of DRAM cell transistor. Conventional method uses a TEG structure for body effect measurement. But this measurement is not accurate, because TEG structure has only several transistors and it is located outside of the DRAM die. This paper suggests a viable method for measuring DRAM cell transistor body effect. It uses a memory test system for fast, massive, nondestructive measurement. Newly developed method can measure 100,000 DRAM cell body effects in two minute, without sample damage. The test gives one median value and 100,000 individual values of body effects. Median value of measured body effects is equal to the TEG body effect. An individual DRAM cell body effect has a correlation with the fin height.

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