Arachidonate 12-lipoxygenase, 12R-type (ALOX12B)

Arachidonate 12-lipoxygenase, 12R-type (ALOX12B) is a member of the lipoxygenase enzyme family responsible for regio- and stereospecific oxidation of polyunsaturated fatty acids, most notably linoleic acid and arachidonic acid. Expressed predominantly in epithelial tissues such as the skin, ALOX12B catalyzes the incorporation of molecular oxygen into fatty acid substrates, creating hydroperoxide products critical for the lipid modifications that build and maintain the epidermal water barrier. ALOX12B acts upstream of ALOXE3 in a cascade that enables the formation of the corneocyte lipid envelope by converting lipid intermediates for attachment to corneocyte proteins, thus preventing dehydration. Loss-of-function mutations in the gene cause autosomal recessive congenital ichthyosis (ARCI), resulting in defective keratinization and severely dry skin. The enzyme’s activity also contributes to lipid-mediated signaling, epidermal differentiation, and immunomodulation by suppressing antigen presentation. There is ongoing research regarding its role in cancer and its utility as a molecular biomarker for epidermal disorders and certain cancers. Pharmaceutical targeting is primarily in early research as there are no current therapies directly approved for modulation of ALOX12B activity.

Other names

ALOX12B12R-lipoxygenase12R-LOXEpidermis-type lipoxygenase 12arachidonate lipoxygenase 3ARCI2

Drugs acting on this enzyme would primarily act as enzymatic inhibitors of fatty acid dioxygenase activity, blocking the formation of lipid hydroperoxide intermediates; potential downstream effects would include interruption of epidermal barrier lipid formation and changes in lipid-mediated signaling.