Radial spoke head protein 4 homolog A (Rsph4a)

Probable component of the axonemal radial spoke head (By similarity). Radial spokes are regularly spaced along cilia, sperm and flagella axonemes.

They consist of a thin stalk which is attached to some subfiber of the outer doublet microtubule, and a bulbous head which is attached to the stem and seems to interact with the projections in the central pair of microtubules. .