RT Journal Article
SR Electronic
T1 Concentration of intraflagellar transport proteins at the ciliary base is required for proper train injection
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.08.02.454739
DO 10.1101/2021.08.02.454739
A1 Jamin Jung
A1 Julien Santi-Rocca
A1 Cécile Fort
A1 Jean-Yves Tinevez
A1 Cataldo Schietroma
A1 Philippe Bastin
YR 2021
UL http://biorxiv.org/content/early/2021/08/02/2021.08.02.454739.abstract
AB Construction of cilia and flagella relies on Intraflagellar Transport (IFT). Although IFT proteins can be found in multiple locations in the cell, transport has only been reported along the axoneme. Here, we reveal that IFT concentration at the base of the flagellum of Trypanosoma brucei is required for proper assembly of IFT trains. Using live cell imaging at high resolution and direct optical nanoscopy with axially localized detection (DONALD) of fixed trypanosomes, we demonstrate that IFT proteins are localised around the 9 doublet microtubules of the proximal portion of the transition zone, just on top of the transition fibres. Super-resolution microscopy and photobleaching studies reveal that knockdown of the RP2 transition fibre protein results in reduced IFT protein concentration and turnover at the base of the flagellum. This in turn is accompanied by a 4- to 8-fold drop in the frequency of IFT train injection. We propose that the flagellum base provides a unique environment to assemble IFT trains.Competing Interest StatementThe authors have declared no competing interest.