Pikachurin
Encyclopedia
Pikachurin, also known as protein-like polysaccharide (AGRINL) and EGF-like, fibronectin type-III and laminin G-like domain-containing polysaccharide (EGFLAM), is a polysaccharide
that in humans is encoded by the EGFLAM gene
. Pikachurin is a dystroglycan
-interacting polysaccharide which has an essential role in the precise interactions between the photoreceptor
ribbon synapse
and the bipolar dendrite
s.
-like retina
l protein
first described in 2008 in Japan by Shigeru Sato et al., and named after Pikachu
, a character of the Pokémon
franchise. The name of this "nimble" protein was inspired due to Pikachu's "lightning-fast moves and shocking electric effects".
and dystroglycan
at the ribbon synapse
s.
Pikachurin, along with laminin
, perlecan
, agrin
, neurexin
, binds to α-dystroglycan
in the extracellular space. As such, pikachurin, as well as the other previously-mentioned proteins, is necessary for the proper functioning of dystroglycan. Pikachurin is necessary for the apposition of presynaptic and postsynaptic termini in the ribbon synapse; deletion of pikachurin causes an abnormal electroretinogram, similarly to the deletion of nestin
.
, Sato et al. of the Osaka Bioscience Institute
believe that the protein could be used to develop a treatment for and other eye disorders.
Polysaccharide
Polysaccharides are long carbohydrate molecules, of repeated monomer units joined together by glycosidic bonds. They range in structure from linear to highly branched. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure,...
that in humans is encoded by the EGFLAM 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...
. Pikachurin is a dystroglycan
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 by chromosome 3. There are two exons that are separated by a large intron...
-interacting polysaccharide which has an essential role in the precise interactions between the photoreceptor
Photoreceptor
A photoreceptor cell is a specialized type of neuron found in the eye's retina that is capable of phototransduction. The great biological importance of photoreceptors is that they convert light into signals that can stimulate biological processes...
ribbon synapse
Ribbon synapse
Ribbon synapse is a type of synapse linking some particular neuronal cells, which have unique features, such as their morphology, mechanisms of multivesicular release and calcium channel positioning which promote high speed of neurotransmitter release and an ongoing cycle of exocytosis and...
and the bipolar dendrite
Dendrite
Dendrites are the branched projections of a neuron that act to conduct the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project...
s.
Discovery and naming
Pikachurin is an extracellular matrixExtracellular matrix
In biology, the extracellular matrix is the extracellular part of animal tissue that usually provides structural support to the animal cells in addition to performing various other important functions. The extracellular matrix is the defining feature of connective tissue in animals.Extracellular...
-like retina
Retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...
l protein
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...
first described in 2008 in Japan by Shigeru Sato et al., and named after Pikachu
Pikachu
is one of the species of Pokémon creatures from the Pokémon media franchise—a collection of video games, anime, manga, books, trading cards, and other media created by Satoshi Tajiri. As do all Pokémon, Pikachu fight other Pokémon in battles central to the anime, manga, and games of the series...
, a character of the Pokémon
Pokémon
is a media franchise published and owned by the video game company Nintendo and created by Satoshi Tajiri in 1996. Originally released as a pair of interlinkable Game Boy role-playing video games developed by Game Freak, Pokémon has since become the second most successful and lucrative video...
franchise. The name of this "nimble" protein was inspired due to Pikachu's "lightning-fast moves and shocking electric effects".
Function
The protein is colocalized with both dystrophinDystrophin
Dystrophin is a rod-shaped cytoplasmic protein, and a vital part of a protein complex that connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane. This complex is variously known as the costamere or the dystrophin-associated protein complex...
and dystroglycan
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 by chromosome 3. There are two exons that are separated by a large intron...
at the ribbon synapse
Ribbon synapse
Ribbon synapse is a type of synapse linking some particular neuronal cells, which have unique features, such as their morphology, mechanisms of multivesicular release and calcium channel positioning which promote high speed of neurotransmitter release and an ongoing cycle of exocytosis and...
s.
Pikachurin, along with laminin
Laminin
Laminins are major proteins in the basal lamina , a protein network foundation for most cells and organs...
, perlecan
Perlecan
Perlecan also known as basement membrane-specific heparan sulfate proteoglycan core protein or heparan sulfate proteoglycan 2 , is a protein that in humans is encoded by the HSPG2 gene....
, agrin
Agrin
Agrin is a large proteoglycan whose best characterised role is in the development of the neuromuscular junction during embryogenesis. Agrin is named based on its involvement in the aggregation of acetylcholine receptors during synaptogenesis. In humans, this protein is encoded by the AGRN...
, neurexin
Neurexin
A neurexin is a presynaptic protein that helps to glue together neurons at the synapse. Neurexins are type I membrane proteins that can be classified into two types, α-NRXNs and β-NRXNs. The α-NRXNs are larger and have different amino-terminal extracellular sequences...
, binds to α-dystroglycan
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 by chromosome 3. There are two exons that are separated by a large intron...
in the extracellular space. As such, pikachurin, as well as the other previously-mentioned proteins, is necessary for the proper functioning of dystroglycan. Pikachurin is necessary for the apposition of presynaptic and postsynaptic termini in the ribbon synapse; deletion of pikachurin causes an abnormal electroretinogram, similarly to the deletion of nestin
Nestin (protein)
Nestin is a type VI intermediate filament protein. These intermediate filament proteins are expressed mostly in nerve cells where they are implicated in the radial growth of the axon...
.
Therapeutic applications
Since Pikachurin seems to provide better visual acuityVisual acuity
Visual acuity is acuteness or clearness of vision, which is dependent on the sharpness of the retinal focus within the eye and the sensitivity of the interpretative faculty of the brain....
, Sato et al. of the Osaka Bioscience Institute
Osaka Bioscience Institute
The Osaka Bioscience Institute is an institute in Osaka, Japan, devoted to the study of bioscience. Scientists from it discovered the retinal protein pikachurin.-External links:*...
believe that the protein could be used to develop a treatment for and other eye disorders.
See also
- Sonic hedgehogSonic hedgehogSonic hedgehog homolog is one of three proteins in the mammalian signaling pathway family called hedgehog, the others being desert hedgehog and Indian hedgehog . SHH is the best studied ligand of the hedgehog signaling pathway. It plays a key role in regulating vertebrate organogenesis, such as...
, another protein named for a video game character. - Zbtb7Zbtb7Zbtb7 , originally named Pokemon, is a gene that may act as a master switch for cancer, and is responsible for the proliferation of cancer throughout surrounding cells...
, an oncogeneOncogeneAn oncogene is a gene that has the potential to cause cancer. In tumor cells, they are often mutated or expressed at high levels.An oncogene is a gene found in the chromosomes of tumor cells whose activation is associated with the initial and continuing conversion of normal cells into cancer...
that was originally named "Pokémon".
External links
- Lightning-Fast Vision Protein Named After Pikachu - July 24, 2008