Trypanosomatid Flagellar Pocket from Structure to Function

Flagellar Attachment in Selected Trypanosomes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072927 ◽

1973 ◽

Vol 31 ◽

pp. 496-497

Author(s):

J. J. Paulin

Keyword(s):

Cell Membrane ◽

Lateral Surface ◽

The Body ◽

Flagellar Pocket ◽

Integral Component ◽

Free Flagellum ◽

Flagellar Axoneme

Movement in epimastigote and trypomastigote stages of trypanosomes is accomplished by planar sinusoidal beating of the anteriorly directed flagellum and associated undulating membrane. The flagellum emerges from a bottle-shaped depression, the flagellar pocket, opening on the lateral surface of the cell. The limiting cell membrane envelopes not only the body of the trypanosome but is continuous with and insheathes the flagellar axoneme forming the undulating membrane. In some species a paraxial rod parallels the axoneme from its point of emergence at the flagellar pocket and is an integral component of the undulating membrane. A portion of the flagellum may extend beyond the anterior apex of the cell as a free flagellum; the length is variable in different species of trypanosomes.

Download Full-text

The Trypanosome Flagellar Pocket Collar and Its Ring Forming Protein—TbBILBO1

Cells ◽

10.3390/cells5010009 ◽

2016 ◽

Vol 5 (1) ◽

pp. 9 ◽

Cited By ~ 9

Author(s):

Doranda Perdomo ◽

Mélanie Bonhivers ◽

Derrick Robinson

Keyword(s):

Flagellar Pocket

Download Full-text

Dependency relationships between IFT-dependent flagellum elongation and cell morphogenesis in Leishmania

Open Biology ◽

10.1098/rsob.180124 ◽

2018 ◽

Vol 8 (11) ◽

pp. 180124 ◽

Cited By ~ 3

Author(s):

Jack Daniel Sunter ◽

Flavia Moreira-Leite ◽

Keith Gull

Keyword(s):

Fluorescence Microscopy ◽

Cell Shape ◽

Electron Tomography ◽

Intraflagellar Transport ◽

Flagellar Pocket ◽

Cell Morphogenesis ◽

Multiple Functions ◽

Cell Shape Changes ◽

Shape Changes

Flagella have multiple functions that are associated with different axonemal structures. Motile flagella typically have a 9 + 2 arrangement of microtubules, whereas sensory flagella normally have a 9 + 0 arrangement. Leishmania exhibits both of these flagellum forms and differentiation between these two flagellum forms is associated with cytoskeletal and cell shape changes. We disrupted flagellum elongation in Leishmania by deleting the intraflagellar transport (IFT) protein IFT140 and examined the effects on cell morphogenesis. Δift140 cells have no external flagellum, having only a very short flagellum within the flagellar pocket. This short flagellum had a collapsed 9 + 0 (9v) axoneme configuration reminiscent of that in the amastigote and was not attached to the pocket membrane. Although amastigote-like changes occurred in the flagellar cytoskeleton, the cytoskeletal structures of Δift140 cells retained their promastigote configurations, as examined by fluorescence microscopy of tagged proteins and serial electron tomography. Thus, Leishmania promastigote cell morphogenesis does not depend on the formation of a long flagellum attached at the neck. Furthermore, our data show that disruption of the IFT system is sufficient to produce a switch from the 9 + 2 to the collapsed 9 + 0 (9v) axonemal structure, echoing the process that occurs during the promastigote to amastigote differentiation.

Download Full-text

Characterization of a cDNA encoding a cysteine-rich cell surface protein located in the flagellar pocket of the protozoan Trypanosoma brucei.

Molecular and Cellular Biology ◽

10.1128/mcb.10.9.4506 ◽

1990 ◽

Vol 10 (9) ◽

pp. 4506-4517 ◽

Cited By ~ 52

Author(s):

M G Lee ◽

B E Bihain ◽

D G Russell ◽

R J Deckelbaum ◽

L H Van der Ploeg

Keyword(s):

Amino Acid ◽

Cell Surface ◽

Trypanosoma Brucei ◽

Transmembrane Domain ◽

Density Lipoprotein ◽

Surface Protein ◽

Integral Membrane Protein ◽

Cell Surface Receptor ◽

Flagellar Pocket ◽

Cytoplasmic Extension

We have characterized a cDNA encoding a cysteine-rich, acidic integral membrane protein (CRAM) of the parasitic protozoa Trypanosoma brucei and Trypanosoma equiperdum. Unlike other membrane proteins of T. brucei, which are distributed throughout the cell surface, CRAM is concentrated in the flagellar pocket, an invagination of the cell surface of the trypanosome where endocytosis has been documented. Accordingly, CRAM also locates to vesicles located underneath the pocket, providing evidence of its internalization. CRAM has a predicted molecular mass of 130 kilodaltons and has a signal peptide, a transmembrane domain, and a 41-amino-acid cytoplasmic extension. A characteristic feature of CRAM is a large extracellular domain with a roughly 66-fold acidic, cysteine-rich 12-amino-acid repeat. CRAM is conserved among different protozoan species, including Trypanosoma cruzi, and CRAM has structural similarities with eucaryotic cell surface receptors. The most striking homology of CRAM is to the human low-density-lipoprotein receptor. We propose that CRAM functions as a cell surface receptor of different trypanosome species.

Download Full-text

Interaction between the flagellar pocket collar and the hook complex via a novel microtubule-binding protein in Trypanosoma brucei

PLoS Pathogens ◽

10.1371/journal.ppat.1006710 ◽

2017 ◽

Vol 13 (11) ◽

pp. e1006710 ◽

Cited By ~ 11

Author(s):

Anna Albisetti ◽

Célia Florimond ◽

Nicolas Landrein ◽

Keni Vidilaseris ◽

Marie Eggenspieler ◽

...

Keyword(s):

Trypanosoma Brucei ◽

Binding Protein ◽

Flagellar Pocket ◽

Microtubule Binding

Download Full-text

Flagellar Pocket

Encyclopedia of Parasitology ◽

10.1007/978-3-642-27769-6_1204-2 ◽

2016 ◽

pp. 1-1

Author(s):

Heinz Mehlhorn

Keyword(s):

Flagellar Pocket

Download Full-text

Crystal structure of the N-terminal domain of the trypanosome flagellar protein BILBO1 reveals a ubiquitin fold with a long structured loop for protein binding

Journal of Biological Chemistry ◽

10.1074/jbc.ra119.010768 ◽

2019 ◽

Vol 295 (6) ◽

pp. 1489-1499

Author(s):

Keni Vidilaseris ◽

Nicolas Landrein ◽

Yulia Pivovarova ◽

Johannes Lesigang ◽

Niran Aeksiri ◽

...

Keyword(s):

Crystal Structure ◽

Rational Drug Design ◽

Sub Saharan Africa ◽

Flagellar Pocket ◽

Terminal Domain ◽

Rational Drug ◽

Cytoplasmic Face ◽

Flagellar Protein ◽

Sub Saharan ◽

Single Flagellum

Trypanosoma brucei is a protist parasite causing sleeping sickness and nagana in sub-Saharan Africa. T. brucei has a single flagellum whose base contains a bulblike invagination of the plasma membrane called the flagellar pocket (FP). Around the neck of the FP on its cytoplasmic face is a structure called the flagellar pocket collar (FPC), which is essential for FP biogenesis. BILBO1 was the first characterized component of the FPC in trypanosomes. BILBO1's N-terminal domain (NTD) plays an essential role in T. brucei FPC biogenesis and is thus vital for the parasite's survival. Here, we report a 1.6-Å resolution crystal structure of TbBILBO1-NTD, which revealed a conserved horseshoe-like hydrophobic pocket formed by an unusually long loop. Results from mutagenesis experiments suggested that another FPC protein, FPC4, interacts with TbBILBO1 by mainly contacting its three conserved aromatic residues Trp-71, Tyr-87, and Phe-89 at the center of this pocket. Our findings disclose the binding site of TbFPC4 on TbBILBO1-NTD, which may provide a basis for rational drug design targeting BILBO1 to combat T. brucei infections.

Download Full-text