Related Experiment Video
Updated: Feb 13, 2026

A Magnetic Tether System to Investigate Visual and Olfactory Mediated Flight Control in Drosophila
Published on: November 21, 2008
The I1 dynein-associated tether and tether head complex is a conserved regulator of ciliary motility
Gang Fu1, Qian Wang1, Nhan Phan1
1Departments of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75235.
Abstract:
Motile cilia are essential for propelling cells and moving fluids across tissues. The activity of axonemal dynein motors must be precisely coordinated to generate ciliary motility, but their regulatory mechanisms are not well understood. The tether and tether head (T/TH) complex was hypothesized to provide mechanical feedback during ciliary beating because it links the motor domains of the regulatory I1 dynein to the ciliary doublet microtubule. Combining genetic and biochemical approaches with cryoelectron tomography, we identified FAP44 and FAP43 (plus the algae-specific, FAP43-redundant FAP244) as T/TH components. WT-mutant comparisons revealed that the heterodimeric T/TH complex is required for the positional stability of the I1 dynein motor domains, stable anchoring of CK1 kinase, and proper phosphorylation of the regulatory IC138-subunit. T/TH also interacts with inner dynein arm d and radial spoke 3, another important motility regulator. The T/TH complex is a conserved regulator of I1 dynein and plays an important role in the signaling pathway that is critical for normal ciliary motility.
Related Concept Videos
What is Conservation Biology?
Conservation of Small Populations
Conserved Binding Sites
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally...
Conservation of Protein Domains Over Different Proteins
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to...
Mechanism of Ciliary Motion
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
Regulated Protein Degradation
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...

