Extended Data Figure 1: Mfsd2b is a plasma membrane protein of haematopoietic cells which does not transport LPC.
From: Mfsd2b is essential for the sphingosine-1-phosphate export in erythrocytes and platelets
a, Computational predicted model of hMfsd2b structure (http://zhanglab.ccmb.med.umich.edu/I-TASSER/). Human Mfsd2b was predicted to have common MFS fold with 12 transmembrane domains. Shown are Asp95 (D95) and Thr157 (T157). b, Expression of Mfsd2b was increased after 5FU treatment. Mfsd2b expression was higher in bone marrow and spleen (top) and peripheral young RBCs (bottom) from 5FU-treated animals. c, Mfsd2b protein is present in RBC ghost membranes. d, Limited trypsin digestion of intact RBCs. Mfsd2b protein visibly disappeared after trypsin incubation. Abbreviation ‘ns’ is non-specific protein band. e, Reticulocyte counts from WT and KO mice after phenylhydrazine treatment. The data are related to Fig. 1c (four mice per genotype). f, Transcriptional analysis of mMfsd2b in indicated cell populations isolated from mouse bone marrow. Expression level of mMfds2b was expressed as the ratio to GAPDH. g, Import assays of HEK293 cells overexpressed with empty plasmid (mock), mMfsd2b, mMfsd2b mutant D85A, or hMfsd2b with indicated lipids. h, Lipidomic analysis of major phospholipids in WT and KO RBCs (eight samples per genotype, two experiments). Total levels of phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), sphingomyelin (SM), phosphatidylglycerol (PG), phosphatidylinositol (PI), LPC, and lysophosphatidylethanolamine (LPE) were quantified from 4.46 million washed WT and KO RBCs. The amount of lipid species was normalized to internal standards and expressed as relative levels. Data are mean and s.d. (e) or s.e.m. (h).
