Yeast ceramide synthase component Lag1 has a paralog, Lac1. This entry includes Lac1, Lag1 and their homologues from plants and animals [, , ], involved in sphingolipid synthesis.LAG1 and LAC1 contain multiple membrane-spanning domains and are localised to the endoplasmic reticulum (ER) []. They are essential subunits of the acyl-CoA-dependent ceramide synthase that is involved in synthesis of ceramide from C26(acyl)-coenzyme A and dihydrosphingosine or phytosphingosine [, , ].Human Lac1/Lag1 homologue CERS2 (ceramide synthase 2) is a tumour metastasis suppressor that can inhibit breast cancer cell invasion []. Tomato Lac1/Lag1 homologue ASC1 can mediate resistance to sphinganine-analog mycotoxins (SAMs) by restoring the sphingolipid biosynthesis [].Arabidopsis thaliana contains three ceramide synthases with distinct substrate specificities: LOH1 and LOH3 (LONGEVITY ASSURANCE GENE ONE HOMOLOG1 At3g25540 and 3 At1g19260) use very-long-chain fatty acyl-CoA and trihydroxy LCB substrates, and LOH2 (At3g19260) uses palmitoyl-CoA and dihydroxy LCB substrates [].
