Open AccessThe unusual flagellar targeting mechanism and functions of the trypanosome orthologue of the ciliary GTPase Arl13b
Author(s) -
Yiliu Zhang,
Yameng Huang,
Amrita Srivathsan,
Teck Kwang Lim,
Qingsong Lin,
Cynthia Y. He
Publication year - 2018
Publication title -
journal of cell science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.384
H-Index - 278
eISSN - 1477-9137
pISSN - 0021-9533
DOI - 10.1242/jcs.219071
Subject(s) - biology , gtpase , microbiology and biotechnology , axoneme , guanine nucleotide exchange factor , flagellum , rna interference , trypanosoma brucei , rna , biochemistry , gene
The small GTPase Arl13b is one of the most conserved and ancient ciliary proteins. In human and animals, Arl13b is primarily associated with the ciliary membrane, where it acts as a guanine-nucleotide-exchange factor (GEF) for Arl3 and is implicated in a variety of ciliary and cellular functions. We have identified and characterized Trypanosoma brucei (Tb)Arl13, the sole Arl13b homolog in this evolutionarily divergent, protozoan parasite . TbArl13 has conserved flagellar functions and exhibits catalytic activity towards two different TbArl3 homologs. However, TbArl13 is distinctly associated with the axoneme through a dimerization/docking (D/D) domain. Replacing the D/D domain with a sequence encoding a flagellar membrane protein created a viable alternative to the wild-type TbArl13 in our RNA interference (RNAi)-based rescue assay. Therefore, flagellar enrichment is crucial for TbArl13, but mechanisms to achieve this could be flexible. Our findings thus extend the understanding of the roles of Arl13b and Arl13b-Arl3 pathway in a divergent flagellate of medical importance.This article has an associated First Person interview with the first author of the paper.