Fatty acid transport protein 4 is required for incorporation of saturated ultralong-chain fatty acids into epidermal ceramides and monoacylglycerols

Fatty acid transport protein 4 (FATP4) is an acyl-CoA synthetase that is required for normal permeability barrier in mammalian skin. FATP4 ( SLC27A4 ) mutations cause ichthyosis prematurity syndrome, a nonlethal disorder. In contrast, Fatp4 −/− mice die neonatally from a defective barrier. Here we used electron microscopy and lipidomics to characterize defects in Fatp4 −/− mice. Mutants showed lamellar body, corneocyte lipid envelope, and...