Cilia- and flagella-associated protein 61 (CFAP61)

Cilia- and flagella-associated protein 61 (CFAP61) is an evolutionarily conserved, testis-expressed structural protein integral to the assembly and stability of the axonemal radial spoke and calmodulin- and spoke-associated complex (CSC) in sperm flagella[1][2]. It is required for normal sperm flagellum morphology and motility but appears non-essential in respiratory cilia, distinguishing it from other ciliary proteins[1][2]. Biallelic variants in CFAP61 cause multiple morphological abnormalities of the flagella (MMAF), leading to severe male infertility due to impaired sperm motility and axoneme defects[1][2]. CFAP61 interacts with other structural components of the axoneme and CSC, regulating the assembly of radial spoke clusters and associated protein networks; however, it is not a classic receptor, enzyme, or pharmacological target[1][2]. There are currently no drugs targeting CFAP61, though its genetic defects serve as biomarkers for MMAF diagnosis.

Other names

C20orf26DKFZP434K156dJ1002M8.3CaM-IP3hypothetical protein LOC26074SPGF84dJ1178H5.4