Giant FAZ10 is required for flagellum attachment zone stabilization and furrow positioning in <i>Trypanosoma brucei</i>

Moreira, Bernardo Pereira; Fonseca, Carol Kobori da; Hammarton, Tansy C.; Baqui, Munira Muhammad Abdel

doi:10.1242/jcs.194308

Cited by 27 publications

(30 citation statements)

References 58 publications

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“…This association is particularly relevant for FAZ filament proteins that display a 305 punctuated pattern in fluorescence. Following this idea, the absence of sticks at proximal locations as 306 observed in the present study does not agree with immunofluorescence data in which most of the FAZ 307 filament proteins were found to be present at equivalent proximal locations (Kohl et of FAZ10 is weaker than that of FAZ1 at proximal locations (Moreira et al, 2017). Since FAZ10 is a 310 giant protein (0.5 MDa) it is likely to have a significant contribution in the structure observed in electron 311 microscopy.…”

Section: Sticks Are Heterogeneously Distributed Along the Faz Filamencontrasting

confidence: 53%

In situstructural analysis of the flagellum attachment zone inTrypanosoma bruceiusing cryo-scanning transmission electron tomography

Trépout

2020

Preprint

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In situ structural analysis of the flagellum 1 attachment zone in Trypanosoma brucei using 2 cryo-scanning transmission electron tomography 3 4 Sylvain Trépout 5Highlights 30  Flagellar and cellular membranes are in close contact next to the FAZ filament 31  Sticks are heterogeneously distributed along the FAZ filament length 32  Thin appendages connect the FAZ filament sticks to neighbouring microtubules 33 Abbreviations 34Transmission Electron Tomography (TET); Transmission Electron Microscopy (TEM); Scanning 35Transmission Electron Microscopy (STEM); Scanning Transmission Electron Tomography (STET); 36Flagellum Attachment Zone (FAZ) 37

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Section: Sticks Are Heterogeneously Distributed Along the Faz Filamencontrasting

confidence: 53%

In situstructural analysis of the flagellum attachment zone inTrypanosoma bruceiusing cryo-scanning transmission electron tomography

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2020

Preprint

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“…2C,D). This complicated the potential role of BOH1 in regulating cytokinesis, as flagellum detachment is known to also inhibit cytokinesis in T. brucei (LaCount et al, 2002;Moreira et al, 2017;Zhou et al, 2015Zhou et al, , 2011. Nonetheless, our finding that BOH1 deficiency disrupted TbPLK localization to the FAZ tip (Fig.…”

Section: Boh1 Is Required For the Localization Of The Cytokinesis Regmentioning

confidence: 82%

“…The flagellum and its associated cytoskeletal structures, including the basal body, the FAZ, the flagellar pocket and the bilobe structure consisting of a hook complex and a centrin arm, are duplicated during the S phase of the cell cycle, and are segregated thereafter during G2 and mitotic phases. While the assembly of the new flagellum requires duplication of the basal body (Dang et al, 2017;Hu et al, 2015a), correct positioning and attachment of the newly assembled flagellum is impacted by the faithful duplication and segregation of other flagellum-associated cytoskeletal structures, such as the FAZ and the bilobe structure (Lacomble et al, 2012;Moreira et al, 2017;Rotureau et al, 2014;Sun et al, 2013;Vaughan et al, 2008;Zhou et al, 2010Zhou et al, , 2015Zhou et al, , 2011. This important cellular process is governed by reversible protein phosphorylation mediated by the Polo-like kinase homolog TbPLK (Ikeda and de Graffenried, 2012) and the putative protein phosphatase kinetoplastid-specific protein phosphatase 1 named KPP1 (Zhou et al, 2018b), both of which localize to the basal body, the hook complex and the distal tip of the new FAZ, and may regulate certain downstream factors at these cytoskeletal structures.…”

Section: Introductionmentioning

confidence: 99%

BOH1 cooperates with Polo-like kinase to regulate flagellum inheritance and cytokinesis initiation in Trypanosoma brucei

Pham¹,

Zhou²,

Kurasawa³

et al. 2019

Journal of Cell Science

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Trypanosoma brucei possesses a motile flagellum that determines cell morphology and the cell division plane. Inheritance of the newly assembled flagellum during the cell cycle is controlled by the Polo-like kinase homolog TbPLK, which also regulates cytokinesis initiation. How TbPLK is targeted to its subcellular locations remains poorly understood. Here we report the trypanosome-specific protein BOH1 that cooperates with TbPLK to regulate flagellum inheritance and cytokinesis initiation in the procyclic form of T. brucei. BOH1 localizes to an unusual sub-domain in the flagellum-associated hook complex, bridging the hook complex, the centrin arm and the flagellum attachment zone. Depletion of BOH1 disrupts hook-complex morphology, inhibits centrin-arm elongation and abolishes flagellum attachment zone assembly, leading to flagellum mis-positioning and detachment. Further, BOH1 deficiency impairs the localization of TbPLK and the cytokinesis regulator CIF1 to the cytokinesis initiation site, providing a molecular mechanism for its role in cytokinesis initiation. These findings reveal the roles of BOH1 in maintaining hookcomplex morphology and regulating flagellum inheritance, and establish BOH1 as an upstream regulator of the TbPLK-mediated cytokinesis regulatory pathway.

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“…The molecular mechanism for the unidirectional, longitudinal binary cell fission in trypanosome remains poorly understood. Based on the observed cell cycle defects through RNAimediated gene ablation, many proteins have been reported to be involved in cytokinesis, which localize to various subcellular structures and possess diverse biochemical functions (5,(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23). However, many of these proteins localize to the cytosol, raising the question of whether they play a direct role in cytokinesis.…”

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confidence: 99%

Functional analyses of the CIF1-CIF2 complex inTrypanosoma bruceiidentify the structural motifs required for complex formation and cytokinesis

Hu¹,

Majneri

Li³

et al. 2017

Preprint

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Cytokinesis in trypanosome occurs unidirectionally 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 zincfinger 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.Trypanosoma brucei, an early branching parasitic protozoan, causes lethal infections in humans and animals in sub-Saharan Africa. The parasite has a complex life cycle by alternating between insect vectors and mammalian hosts, and proliferates through binary cell fission in the midgut of insects and the bloodstream of mammals. Cell division occurs uni-directionally along the longitudinal axis from the cell anterior to the cell posterior, as visualized by time-lapse video microscopy of dividing cells (1), and the division plane appears to be determined by the length of the new flagellum and a proteinaceous filament termed flagellum attachment zone (FAZ) (2,3). The anterior tip of the newly assembled FAZ filament constitutes the site from which cytokinesis cleavage furrow starts to ingress towards the posterior cell end along the division fold, which is formed through membrane invagination by unknown mechanisms (4,5). Due to the apparent lack of involvement of actin in cytokinesis (6), trypanosome likely does not assemble an actomyosin contractile ring, the evolutionarily conserved machinery for cleavage furrow ingression found in amoebas, fungi, and animals (7,8).The molecular mechanism for the unidirectional, longitudinal binary cell fission in trypanosome remains poorly understood. Based on the observed cell cycle defects through RNAimediated gene ablation, many proteins have been reported to be involved in cytokinesis, which localize to various subcellular structures and possess diverse biochemical functions (5,9-23). However, many of these proteins localize to the cytosol, raising the question of whether they play a . CC-BY-NC-ND 4.0 International license peer-reviewed) is the author/funder. It is made available under a The copyright holder for this preprint (which was ...

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Giant FAZ10 is required for flagellum attachment zone stabilization and furrow positioning in Trypanosoma brucei

Cited by 27 publications

References 58 publications

In situstructural analysis of the flagellum attachment zone inTrypanosoma bruceiusing cryo-scanning transmission electron tomography

In situstructural analysis of the flagellum attachment zone inTrypanosoma bruceiusing cryo-scanning transmission electron tomography

BOH1 cooperates with Polo-like kinase to regulate flagellum inheritance and cytokinesis initiation in Trypanosoma brucei

Functional analyses of the CIF1-CIF2 complex inTrypanosoma bruceiidentify the structural motifs required for complex formation and cytokinesis

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