title: Mutations in axonemal dynein assembly factor DNAAF3 cause primary ciliary dyskinesia.
abstract: Primary ciliary dyskinesia most often arises from loss of the dynein motors that power ciliary beating. Here we show that DNAAF3 (also known as PF22), a previously uncharacterized protein, is essential for the preassembly of dyneins into complexes before their transport into cilia. We identified loss-of-function mutations in the human DNAAF3 gene in individuals from families with situs inversus and defects in the assembly of inner and outer dynein arms. Knockdown of dnaaf3 in zebrafish likewise disrupts dynein arm assembly and ciliary motility, causing primary ciliary dyskinesia phenotypes that include hydrocephalus and laterality malformations. Chlamydomonas reinhardtii PF22 is exclusively cytoplasmic, and a PF22-null mutant cannot assemble any outer and some inner dynein arms. Altered abundance of dynein subunits in mutant cytoplasm suggests that DNAAF3 (PF22) acts at a similar stage as other preassembly proteins, for example, DNAAF2 (also known as PF13 or KTU) and DNAAF1 (also known as ODA7 or LRRC50), in the dynein preassembly pathway. These results support the existence of a conserved, multistep pathway for the cytoplasmic formation of assembly competent ciliary dynein complexes.
authors.affiliation: Molecular Medicine Unit, University College London Institute of Child Health, London, UK. h.mitchison@ucl.ac.uk
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Mitchison
authors.forename: Miriam
authors.initials: M
authors.lastname: Schmidts
authors.forename: Niki T
authors.initials: NT
authors.lastname: Loges
authors.forename: Judy
authors.initials: J
authors.lastname: Freshour
authors.forename: Athina
authors.initials: A
authors.lastname: Dritsoula
authors.forename: Rob A
authors.initials: RA
authors.lastname: Hirst
authors.forename: Christopher
authors.initials: C
authors.lastname: O'Callaghan
authors.forename: Hannah
authors.initials: H
authors.lastname: Blau
authors.forename: Maha
authors.initials: M
authors.lastname: Al Dabbagh
authors.forename: Heike
authors.initials: H
authors.lastname: Olbrich
authors.forename: Philip L
authors.initials: PL
authors.lastname: Beales
authors.forename: Toshiki
authors.initials: T
authors.lastname: Yagi
authors.forename: Huda
authors.initials: H
authors.lastname: Mussaffi
authors.forename: Eddie M K
authors.initials: EM
authors.lastname: Chung
authors.forename: Heymut
authors.initials: H
authors.lastname: Omran
authors.forename: David R
authors.initials: DR
authors.lastname: Mitchell
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D056444:Axonemal Dyneins / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D016825:Chlamydomonas reinhardtii / Q000235:genetics; D002923:Cilia / Q000235:genetics; D003593:Cytoplasm / Q000235:genetics; D005260:Female; D006801:Humans; D007619:Kartagener Syndrome / Q000235:genetics*; D008297:Male; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012857:Situs Inversus / Q000235:genetics; D015027:Zebrafish / Q000235:genetics; D029961:Zebrafish Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; C572417:DNAAF3 protein, human; D008869:Microtubule-Associated Proteins; D029961:Zebrafish Proteins; D056444:Axonemal Dyneins