Radial spoke head protein 4 homolog A, also known as radial spoke head-like protein 3, 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, res ...
that in humans is encoded by the ''RSPH4A''
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 b ...
.
Function
TRadial spoke head protein 4 homolog A appears to be a component the
radial spoke head, as determined by homology to similar proteins in the biflagellate alga ''
Chlamydomonas reinhardtii
''Chlamydomonas reinhardtii'' is a single-cell green alga about 10 micrometres in diameter that swims with two flagella. It has a cell wall made of hydroxyproline-rich glycoproteins, a large cup-shaped chloroplast, a large pyrenoid, and an eye ...
'' and other ciliates. Radial spokes, which are regularly spaced along
cilia, sperm, and flagella
axoneme
An axoneme, also called an axial filament is the microtubule-based cytoskeletal structure that forms the core of a cilium or flagellum. Cilia and flagella are found on many cells, organisms, and microorganisms, to provide motility. The axo ...
s, consist of a thin 'stalk' and a bulbous 'head' that form a signal transduction scaffold between the central pair of
microtubules and
dynein.
Clinical significance
Mutations in the RSPH4A gene are associated with
primary ciliary dyskinesia
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 sper ...
.
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Primary Ciliary Dyskinesia
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