an N-(34-hydroxytetratriacontadienoyl)-sphing-4-enine + a (9Z,12Z)-octadecadienoyl-containing triacyl-sn-glycerol = an N-(34-(9Z,12Z-octadecadienoyloxy)-tetratriacontadienoyl)-sphing-4-enine + a diacylglycerol — reaction