Dynein axonemal intermediate chain 1 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
that in humans is encoded by the ''DNAI1''
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
The inner- and outer-arm dyneins, which bridge between the doublet microtubules in axonemes, are the force-generating proteins responsible for the sliding movement in axonemes. The intermediate and light chains, thought to form the base of the dynein arm, help mediate attachment and may also participate in regulating dynein activity. This gene encodes an intermediate chain dynein, belonging to the large family of motor proteins. Mutations in this gene result in abnormal ciliary ultrastructure and function associated with primary ciliary dyskinesia (PCD) and
Kartagener syndrome
Primary ciliary dyskinesia (PCD) is a rare, autosomal recessive genetic ciliopathy, that causes defects in the action of cilia lining the upper and lower respiratory tract, sinuses, Eustachian tube, middle ear, Fallopian tube, and flagella of ...
. The ''DNAI1'' gene is involved in the development of proper respiratory function, motility of spermatozoa, and asymmetrical organization of the viscera during embryogenesis. This gene affects these three very different aspects of development because all three are dependent on proper cilia function. ''DNAI1'' codes for the development of cilia ultrastructure in the upper and lower respiratory tracts, spermatozoa flagellae, and nodal cilia (cilia of the primitive node). ''DNAI1'' specifically encodes for an intermediate chain of the outer dynein arm. Each dynein arm of the ciliary axoneme has an inner and outer dynein arm. A mutation in ''DNAI1'' can lead to defective ciliary beating. A DNAI1 gene mutation accounts for 4-10% of all cases of primary ciliary dyskensia (PCD). The most frequent structural defect in cilia of PCD patients are abnormal dynein arms. A common mutation of ''DNAI1'' leading to PCD is a hot-spot mutation in intron 1 of the gene. Mutations in coding or splicing are only found in 10% of PCD cases.
References
External links
GeneReviews/NIH/NCBI/UW entry on Primary Ciliary Dyskinesia
Further reading
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