Dynein axonemal assembly factor 3 (DNAAF3)

Dynein axonemal assembly factor 3 (DNAAF3) is a cytoplasmic protein essential for the *preassembly* of axonemal dynein motor complexes, which are necessary for the proper function of motile cilia and flagella[1][2][3]. It is required for assembling both inner and outer dynein arms before their transport into the ciliary axoneme. DNAAF3 is evolutionarily conserved, with orthologs in vertebrates and some model organisms such as *Chlamydomonas* (PF22) and *Drosophila*. Mutations in DNAAF3 disrupt dynein arm assembly, resulting in nearly immotile or dyskinetic cilia, causing primary ciliary dyskinesia (PCD). PCD is characterized by chronic respiratory tract infections, laterality defects (such as situs inversus), and male infertility due to defective flagellar function. Structural studies show that DNAAF3 is a methyltransferase-related protein, likely acting by posttranslationally modifying dynein heavy chains, which is essential for fine-tuning ciliary motor protein activity[3]. There is presently no evidence that DNAAF3 is a direct druggable or therapeutic target, nor reports on any direct drug or ligand interaction. Loss-of-function in DNAAF3 is pathogenic, but DNAAF3 is not used as a drug therapy biomarker or as a receptor/enzyme target[1][2][3][4].

Other names

PF22C19orf51FLJ40069FLJ36139CILD2DAB1UPF0470 protein C19orf51Dynein axonemal assembly factor 3PCDDnaaf3 (zebrafish, Drosophila)DAB1 (Chlamydomonas, sometimes as PF22)dynein, axonemal, assembly factor 3