Appears to be involved in myelination. Could also participate in ion transport events as addition of plasmolipin to lipid bilayers induces the formation of ion channels, which are voltage-dependent and K(+)-selective. Hexamer arranged as a trimer of two plasmolipin subunits. Expression restricted to the sciatic nerve, brain and kidney. In the sciatic nerve, found in Schwann cells; in the brain, in developing oligodendrocytes, especially of the corpus callosum, of cortical white matter, in the optic nerve and in the stratum radiatum and stratum oriens of the hippocampus. In kidney, segregated to the apical surface of renal tubular epithelia. In the sciatic nerve, first detected at postnatal day P4, increases to a maximum at day P14 and then declines to moderate levels in adulthood. In the brain, onset of expression is at day P1, levels increase to reach a maximum at P20 and decline slightly to adulthood. Belongs to the MAL family.