Fukutin is a eukaryotic protein necessary for the maintenance of
muscle integrity,
cortical histogenesis Histogenesis is the formation of different tissues from undifferentiated cells. These cells are constituents of three primary germ layers, the endoderm, mesoderm, and ectoderm. The science of the microscopic structures of the tissues formed wi ...
, and normal
ocular
Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and con ...
development. Mutations in the fukutin gene have been shown to result in
Fukuyama congenital muscular dystrophy
Fukuyama congenital muscular dystrophy (FCMD) is a rare, autosomal recessive form of muscular dystrophy (weakness and breakdown of muscular tissue) mainly described in Japan but also identified in Turkish and Ashkenazi Jewish patients; fifteen case ...
(FCMD) characterised by brain malformation - one of the most common autosomal-recessive disorders in Japan.
In humans this protein is encoded by the ''FCMD''
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 ...
(also named ''FKTN''), located on
chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...
9q31.
Human fukutin exhibits a length of 461 amino acids and a predicted molecular mass of 53.7 kDa.
Function
Although its function is mostly unknown, fukutin is a putative transmembrane protein that is ubiquitously expressed, although at higher levels in skeletal muscle, heart and brain.
It is localized to the cis-
Golgi compartment, where it may be involved in the
glycosylation of α-
dystroglycan
Dystroglycan is a protein that in humans is encoded by the ''DAG1'' gene.
Dystroglycan is one of the dystrophin-associated glycoproteins, which is encoded by a 5.5 kb transcript in ''Homo sapiens'' on chromosome 3. There are two exons that are s ...
in skeletal muscle. The encoded protein is thought to be a
glycosyltransferase
Glycosyltransferases (GTFs, Gtfs) are enzymes (EC 2.4) that establish natural glycosidic linkages. They catalyze the transfer of saccharide moieties from an activated nucleotide sugar (also known as the "glycosyl donor") to a nucleophilic glyco ...
and could play a role in brain development.
Fukutin is expressed in the mammalian retina and is located in the Golgi complex of retinal neurons.
[Haro, C., Uribe, M.L., Quereda, C., Cruces, J. and Martín-Nieto, J. (2018) Expression in retinal neurons of fukutin and FKRP, the protein products of two dystroglycanopathy-causative genes. Molecular Vision ''24'', 43-58.]
Clinical significance
Defects in this gene are a cause of
Fukuyama congenital muscular dystrophy
Fukuyama congenital muscular dystrophy (FCMD) is a rare, autosomal recessive form of muscular dystrophy (weakness and breakdown of muscular tissue) mainly described in Japan but also identified in Turkish and Ashkenazi Jewish patients; fifteen case ...
(FCMD),
Walker-Warburg syndrome (WWS),
limb-girdle muscular dystrophy type 2M (LGMD2M), and
dilated cardiomyopathy
Dilated cardiomyopathy (DCM) is a condition in which the heart becomes enlarged and cannot pump blood effectively. Symptoms vary from none to feeling tired, leg swelling, and shortness of breath. It may also result in chest pain or fainting. Co ...
type 1X (CMD1X).
See also
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Fukutin-related protein
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Congenital Muscular Dystrophy Overview*
LOVD The Leiden Open Variation Database (LOVD) is a free, flexible web-based open source database developed in the Leiden University Medical Center in the Netherlands, designed to collect and display variants in the DNA sequence. The focus of an LOVD i ...
mutation database
FKTN
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