As component of a spoke-associated complex, regulates ciliary mobility by mediating a stable and functional assembly of the radial spoke 3 (RS3). Knockout cells show deficiencies in cell multiplication and ciliary functions. Mutants move with greatly reduced velocities, have disturbed waveform of beating cilia and have stiffer cilia (PubMed:25694453). Mutant cilia lack an adjacent portion of the radial spoke 3 stem region (PubMed:25694453).