Nipa‐Like Domain‐Containing 4, also known as ''NIPAL4'' or ''Ichthyin'', is a

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 ...

that is predicted to

code In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communication ...

for a

transmembrane protein A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequentl ...

with nine

transmembrane domains A transmembrane domain (TMD) is a membrane-spanning protein domain. TMDs generally adopt an alpha helix topological conformation, although some TMDs such as those in porins can adopt a different conformation. Because the interior of the lipid bil ...

. ''NIPAL4'' codes for the protein

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

transporter NIPA4, which acts as a transporter.

Expression

''NIPAL4'' is mainly expressed in the skin, specifically in the granular layer of the

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...

Function

''NIPAL4'' codes for a magnesium transporter that can also transport other

divalent cation In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with other atoms when it forms chemical compounds or molecules. Description The combining capacity, or affinity of an ...

s such as Ba²⁺, Mn²⁺, Sr²⁺ and Co²⁺, though to a much less extent than Mg²⁺. There is also evidence that ''NIPAL4'' is involved in the synthesis of

very long chain fatty acids A very-long-chain fatty acid (VLCFA) is a fatty acid with 22 or more carbons. Their biosynthesis occurs in the endoplasmic reticulum. VLCFA's can represent up to a few percent of the total fatty acid content of a cell. Unlike most fatty acids, VL ...

involved in the epidermal

lipid metabolism Lipid metabolism is the synthesis and degradation of lipids in cells, involving the breakdown or storage of fats for energy and the synthesis of structural and functional lipids, such as those involved in the construction of cell membranes. In anim ...

. Disruptions to this pathway results in impaired skin function, causing the symptoms of ARCI.

Pathology

Mutations in this gene account for 16% of autosomal recessive congenital ichthyosis (ARCI) cases, making it the 2nd most common gene involved with this disease. Since its first identification in 2004, 18 disease‐causing mutations have been reported in ''NIPAL4''.

References

{{reflist Genes Genes on human chromosome 5 Genetics

Expression

Function

Pathology

See also

References