RSPH4A
Encyclopedia
Radial spoke head protein 4 homolog A, also known as radial spoke head-like protein 3, is a protein
that in humans is encoded by the RSPH4A gene
.
head, as determined by homology to similar proteins in the biflagellate alga Chlamydomonas reinhardtii
and other ciliates. Radial spokes, which are regularly spaced along cilia, sperm, and flagella axoneme
s, consist of a thin 'stalk' and a bulbous 'head' that form a signal transduction scaffold between the central pair of microtubule
s and dynein
.
.
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
that in humans is encoded by the RSPH4A gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
.
Function
TRadial spoke head protein 4 homolog A appears to be a component the radial spokeRadial spoke
The radial spoke is a multi-unit protein structure found in the axonemes of eukaryotic cilia and flagella. Although experiments have determined the importance of the radial spoke in the proper function of these organelles, its structure and mode of action remain poorly understood.- Cellular...
head, as determined by homology to similar proteins in the biflagellate alga Chlamydomonas reinhardtii
Chlamydomonas reinhardtii
Chlamydomonas reinhardtii is a single celled green alga about 10 micrometres in diameter that swims with two flagella. They have a cell wall made of hydroxyproline-rich glycoproteins, a large cup-shaped chloroplast, a large pyrenoid, and an "eyespot" that senses light.Although widely distributed...
and other ciliates. Radial spokes, which are regularly spaced along cilia, sperm, and flagella axoneme
Axoneme
Numerous eukaryotic cells carry whip-like appendages whose inner core consists of a cytoskeletal structure called the axoneme....
s, consist of a thin 'stalk' and a bulbous 'head' that form a signal transduction scaffold between the central pair of microtubule
Microtubule
Microtubules are a component of the cytoskeleton. These rope-like polymers of tubulin can grow as long as 25 micrometers and are highly dynamic. The outer diameter of microtubule is about 25 nm. Microtubules are important for maintaining cell structure, providing platforms for intracellular...
s and dynein
Dynein
Dynein is a motor protein in cells which converts the chemical energy contained in ATP into the mechanical energy of movement. Dynein transports various cellular cargo by "walking" along cytoskeletal microtubules towards the minus-end of the microtubule, which is usually oriented towards the cell...
.
Clinical significance
Mutations in the RSPH4A gene are associated with primary ciliary dyskinesiaPrimary ciliary dyskinesia
Primary ciliary dyskinesia , also known as immotile ciliary syndrome or Kartagener Syndrome ', is a rare, ciliopathic, autosomal recessive genetic disorder that causes a defect in the action of the cilia lining the respiratory tract and fallopian tube, and also of the flagella of sperm in...
.