Acts as a Mg(2+) transporter. Can also transport other divalent cations such as Ba(2+), Mn(2+), Sr(2+) and Co(2+) but to a much less extent than Mg(2+) (By similarity). May be a receptor for ligands (trioxilins A3 and B3) from the hepoxilin pathway.
Highly expressed in brain, lung, stomach, keratinocytes and leukocytes, and in all other tissues tested except liver, thyroid and fetal brain.
Defects in NIPAL4 are the cause of ichthyosis congenital autosomal recessive ichthyin-related (ARCII) [MIM:612281]. ARCII is a disorder of keratinization with abnormal differentiation and desquamation of the epidermis. The phenotype usually presents as non-bullous congenital ichthyosiform erythroderma (NCIE) with fine whitish scaling on an erythrodermal background; larger brownish scales are present on the buttocks, neck and legs. Some of the families may show a more lamellar phenotype (lamellar ichthyosis).