Faculty, Staff and Student Publications
Publication Date
7-1-2022
Journal
Journal of Biological Chemistry
Abstract
The human parasite Trypanosoma brucei contains a motile flagellum that determines the plane of cell division, controls cell morphology, and mediates cell-cell communication. During the cell cycle, inheritance of the newly formed flagellum requires its correct positioning toward the posterior of the cell, which depends on the faithful segregation of multiple flagellum-associated cytoskeletal structures including the basal body, the flagellar pocket collar, the flagellum attachment zone, and the hook complex. A specialized group of four microtubules termed the microtubule quartet (MtQ) originates from the basal body and runs through the flagellar pocket collar and the hook complex to extend, along the flagellum attachment zone, toward the anterior of the cell. However, the physiological function of the MtQ is poorly understood, and few MtQ-associated proteins have been identified and functionally characterized. We report here that an MtQ-localized protein named NHL1 interacts with the microtubule-binding protein TbSpef1 and depends on TbSpef1 for its localization to the MtQ. We show that RNAi-mediated knockdown of NHL1 impairs the segregation of flagellum-associated cytoskeletal structures, resulting in mispositioning of the new flagellum. Furthermore, knockdown of NHL1 also causes misplacement of the cell division plane in dividing trypanosome cells, halts cleavage furrow ingression, and inhibits completion of cytokinesis. These findings uncover a crucial role for the MtQ-associated protein NHL1 in regulating basal body segregation to promote flagellar inheritance in T. brucei.
Keywords
Basal Bodies, Chromosome Segregation, Flagella, Humans, Microtubules, Protozoan Proteins, Trypanosoma brucei brucei, Trypanosoma brucei, microtubule quartet, flagellum inheritance, basal body
DOI
10.1016/j.jbc.2022.102125
PMID
35697071
PMCID
PMC9257412
PubMedCentral® Posted Date
6-10-2022
PubMedCentral® Full Text Version
Post-print
Published Open-Access
yes