BILBO1 is a scaffold protein of the flagellar pocket collar in the pathogen Trypanosoma brucei.

The flagellar pocket (FP) of the pathogen Trypanosoma brucei is an important single copy structure that is formed by the invagination of the pellicular membrane. It is the unique site of endo- and exocytosis and is required for parasite pathogenicity. The FP consists of distinct structural sub-domai...

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Main Authors: Célia Florimond, Annelise Sahin, Keni Vidilaseris, Gang Dong, Nicolas Landrein, Denis Dacheux, Anna Albisetti, Edward H Byard, Mélanie Bonhivers, Derrick R Robinson
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2015-03-01
Series:PLoS Pathogens
Online Access:https://doi.org/10.1371/journal.ppat.1004654
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author Célia Florimond
Annelise Sahin
Keni Vidilaseris
Gang Dong
Nicolas Landrein
Denis Dacheux
Anna Albisetti
Edward H Byard
Mélanie Bonhivers
Derrick R Robinson
author_facet Célia Florimond
Annelise Sahin
Keni Vidilaseris
Gang Dong
Nicolas Landrein
Denis Dacheux
Anna Albisetti
Edward H Byard
Mélanie Bonhivers
Derrick R Robinson
author_sort Célia Florimond
collection DOAJ
description The flagellar pocket (FP) of the pathogen Trypanosoma brucei is an important single copy structure that is formed by the invagination of the pellicular membrane. It is the unique site of endo- and exocytosis and is required for parasite pathogenicity. The FP consists of distinct structural sub-domains with the least explored being the annulus/horseshoe shaped flagellar pocket collar (FPC). To date the only known component of the FPC is the protein BILBO1, a cytoskeleton protein that has a N-terminus that contains an ubiquitin-like fold, two EF-hand domains, plus a large C-terminal coiled-coil domain. BILBO1 has been shown to bind calcium, but in this work we demonstrate that mutating either or both calcium-binding domains prevents calcium binding. The expression of deletion or mutated forms of BILBO1 in trypanosomes and mammalian cells demonstrate that the coiled-coil domain is necessary and sufficient for the formation of BILBO1 polymers. This is supported by Yeast two-hybrid analysis. Expression of full-length BILBO1 in mammalian cells induces the formation of linear polymers with comma and globular shaped termini, whereas mutation of the canonical calcium-binding domain resulted in the formation of helical polymers and mutation in both EF-hand domains prevented the formation of linear polymers. We also demonstrate that in T. brucei the coiled-coil domain is able to target BILBO1 to the FPC and to form polymers whilst the EF-hand domains influence polymers shape. This data indicates that BILBO1 has intrinsic polymer forming properties and that binding calcium can modulate the form of these polymers. We discuss whether these properties can influence the formation of the FPC.
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spelling doaj.art-9f36e33b67ef408494190715810d45882022-12-21T23:36:24ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742015-03-01113e100465410.1371/journal.ppat.1004654BILBO1 is a scaffold protein of the flagellar pocket collar in the pathogen Trypanosoma brucei.Célia FlorimondAnnelise SahinKeni VidilaserisGang DongNicolas LandreinDenis DacheuxAnna AlbisettiEdward H ByardMélanie BonhiversDerrick R RobinsonThe flagellar pocket (FP) of the pathogen Trypanosoma brucei is an important single copy structure that is formed by the invagination of the pellicular membrane. It is the unique site of endo- and exocytosis and is required for parasite pathogenicity. The FP consists of distinct structural sub-domains with the least explored being the annulus/horseshoe shaped flagellar pocket collar (FPC). To date the only known component of the FPC is the protein BILBO1, a cytoskeleton protein that has a N-terminus that contains an ubiquitin-like fold, two EF-hand domains, plus a large C-terminal coiled-coil domain. BILBO1 has been shown to bind calcium, but in this work we demonstrate that mutating either or both calcium-binding domains prevents calcium binding. The expression of deletion or mutated forms of BILBO1 in trypanosomes and mammalian cells demonstrate that the coiled-coil domain is necessary and sufficient for the formation of BILBO1 polymers. This is supported by Yeast two-hybrid analysis. Expression of full-length BILBO1 in mammalian cells induces the formation of linear polymers with comma and globular shaped termini, whereas mutation of the canonical calcium-binding domain resulted in the formation of helical polymers and mutation in both EF-hand domains prevented the formation of linear polymers. We also demonstrate that in T. brucei the coiled-coil domain is able to target BILBO1 to the FPC and to form polymers whilst the EF-hand domains influence polymers shape. This data indicates that BILBO1 has intrinsic polymer forming properties and that binding calcium can modulate the form of these polymers. We discuss whether these properties can influence the formation of the FPC.https://doi.org/10.1371/journal.ppat.1004654
spellingShingle Célia Florimond
Annelise Sahin
Keni Vidilaseris
Gang Dong
Nicolas Landrein
Denis Dacheux
Anna Albisetti
Edward H Byard
Mélanie Bonhivers
Derrick R Robinson
BILBO1 is a scaffold protein of the flagellar pocket collar in the pathogen Trypanosoma brucei.
PLoS Pathogens
title BILBO1 is a scaffold protein of the flagellar pocket collar in the pathogen Trypanosoma brucei.
title_full BILBO1 is a scaffold protein of the flagellar pocket collar in the pathogen Trypanosoma brucei.
title_fullStr BILBO1 is a scaffold protein of the flagellar pocket collar in the pathogen Trypanosoma brucei.
title_full_unstemmed BILBO1 is a scaffold protein of the flagellar pocket collar in the pathogen Trypanosoma brucei.
title_short BILBO1 is a scaffold protein of the flagellar pocket collar in the pathogen Trypanosoma brucei.
title_sort bilbo1 is a scaffold protein of the flagellar pocket collar in the pathogen trypanosoma brucei
url https://doi.org/10.1371/journal.ppat.1004654
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