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The selective utilization of substrates in vivo by the phosphatidylethanolamine and phosphatidylcholine biosynthetic enzymes Ept1p and Cpt1p in yeast
Author(s) -
Boumann Henry A,
de Kruijff Ben,
Heck Albert J.R,
de Kroon Anton I.P.M
Publication year - 2004
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2004.05.043
Subject(s) - phosphatidylethanolamine , phosphatidylcholine , biochemistry , chemistry , choline , phospholipid , in vivo , enzyme , ethanolamine , phosphocholine , yeast , biology , membrane , microbiology and biotechnology
In yeast, the aminoalcohol phosphotransferases Ept1p and Cpt1p catalyze the final steps in the CDP‐ethanolamine and CDP‐choline routes leading to phosphatidylethanolamine (PE) and phosphatidylcholine (PC), respectively. To determine how these enzymes contribute to the molecular species profiles of PE and PC in vivo, wild‐type, cpt1 Δ, and ept1 Δ cells were pulse labeled with deuterated ethanolamine and choline. Analysis of newly synthesized PE and PC using electrospray ionization tandem mass spectrometry revealed that PE and PC produced by Ept1p and Cpt1p have different species compositions, demonstrating that the enzymes consume distinct sets of diacylglycerol species in vivo. Using the characteristic phospholipid species profiles produced by Ept1p and Cpt1p as molecular fingerprints, it was also shown that in vivo CDP‐monomethylethanolamine is preferentially used as substrate by Ept1p, whereas CDP‐dimethylethanolamine and CDP‐propanolamine are converted by Cpt1p.