DynAPs and cytoplasmic assembly of axonemal dyneins

Motile cilia are microtubule-based organelles that generate fluid flow through coordinated beating, a process powered by axonemal dynein motors. Dyneins are pre-assembled in the cytoplasm by a suite of proteins called dynein axonemal assembly factors (DNAAFs). Genetic variants affecting either the motors or the assembly factors cause motile ciliopathy. In recent years, DNAAFs have been found to function in conjunction with heat-shock protein (HSP) chaperone systems and organize with dynein subunits within cytoplasmic foci known as 'dynein axonemal particles' (DynAPs). In this Perspective, we provide our view on the assembly and potential function of DynAPs, as well as their place within the broader context of motile ciliated cells.