Functions as part of axonemal radial spoke complexes that play an important part in the motility of sperm and cilia. Important for male fertility. With ROPN1, involved in fibrous sheath integrity and sperm motility, plays a role in PKA-dependent signaling processes required for spermatozoa capacitation. . This is the function of Ensembl gene identifier ENSG00000145491 (ROPN1L, rhophilin associated tail protein 1 like).