title: Role of Intracellular Lipid Logistics in the Preferential Usage of Very Long Chain-Ceramides in Glucosylceramide.
abstract: Ceramide is a common precursor of sphingomyelin (SM) and glycosphingolipids (GSLs) in mammalian cells. Ceramide synthase 2 (CERS2), one of the six ceramide synthase isoforms, is responsible for the synthesis of very long chain fatty acid (C20-26 fatty acids) (VLC)-containing ceramides (VLC-Cer). It is known that the proportion of VLC species in GSLs is higher than that in SM. To address the mechanism of the VLC-preference of GSLs, we used genome editing to establish three HeLa cell mutants that expressed different amounts of CERS2 and compared the acyl chain lengths of SM and GSLs by metabolic labeling experiments. VLC-sphingolipid expression was increased along with that of CERS2, and the proportion of VLC species in glucosylceramide (GlcCer) was higher than that in SM for all expression levels of CERS2. This higher proportion was still maintained even when the proportion of C16-Cer to the total ceramides was increased by disrupting the ceramide transport protein (CERT)-dependent C16-Cer delivery pathway for SM synthesis. On the other hand, merging the Golgi apparatus and the endoplasmic reticulum (ER) by Brefeldin A decreased the proportion of VLC species in GlcCer probably due to higher accessibility of UDP-glucose ceramide glucosyltransferase (UGCG) to C16-rich ceramides. These results suggest the existence of a yet-to-be-identified mechanism rendering VLC-Cer more accessible than C16-Cer to UGCG, which is independent of CERT.
authors: Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan. tyamaji@nih.go.jp.
authors: Toshiyuki
authors: T
authors: Yamaji
authors: Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan. horietty0315@gmail.com.|Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, Chiyoda-ku, Tokyo 101-8308, Japan. horietty0315@gmail.com.
authors: Aya
authors: A
authors: Horie
authors: Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan. tachida@nih.go.jp.
authors: Yuriko
authors: Y
authors: Tachida
authors: Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan. sakumac@nih.go.jp.
authors: Chisato
authors: C
authors: Sakuma
authors: Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, Chiyoda-ku, Tokyo 101-8308, Japan. suzuki.yuusuke@nihon-u.ac.jp.
authors: Yusuke
authors: Y
authors: Suzuki
authors: Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, Chiyoda-ku, Tokyo 101-8308, Japan. kushi.yasunori@nihon-u.ac.jp.
authors: Yasunori
authors: Y
authors: Kushi
authors: Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan. hanak@nih.go.jp.
authors: Kentaro
authors: K
authors: Hanada
mesh_terms: D015153:Blotting, Western; D020126:Brefeldin A / Q000494:pharmacology; D002518:Ceramides / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D015870:Gene Expression; D005963:Glucosylceramides / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D050356:Lipid Metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013107:Sphingolipids / Q000378:metabolism; D013109:Sphingomyelins / Q000378:metabolism*; D051049:Sphingosine N-Acyltransferase / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D002518:Ceramides; D005963:Glucosylceramides; D008565:Membrane Proteins; D011500:Protein Synthesis Inhibitors; D013107:Sphingolipids; D013109:Sphingomyelins; D025521:Tumor Suppressor Proteins; D020126:Brefeldin A; C438311:CERS2 protein, human; D051049:Sphingosine N-Acyltransferase
keywords: CERT; ceramide synthase; genome editing; glucosylceramide; sphingolipid; sphingomyelin