HGNC Approved Gene Symbol: CEPT1
Cytogenetic location: 1p13.3 Genomic coordinates (GRCh38): 1:111,139,499-111,185,104 (from NCBI)
CEPT1 is a dual-specificity enzyme that catalyzes ethanolaminephosphotransferase (EC 2.7.8.1) and cholinephosphotransferase (EC 2.7.8.2) reactions for the synthesis of phosphatidylethanolamine and phosphatidylcholine, respectively (Henneberry and McMaster, 1999).
By searching an EST database using S. cerevisiae Cpt1 (CHPT1; 616747) as query, Henneberry and McMaster (1999) identified human CEPT1. The deduced 416-amino acid protein has a calculated molecular mass of 46.6 kD. CEPT1 has 7 membrane-spanning domains and an active-site CDP-alcohol phosphotransferase motif, which lies on the cytoplasmic face between transmembrane domains 1 and 2. The 2 catalytic asp residues are on the exposed side of an amphipathic helix that contacts the lipid bilayer. Northern blot analysis detected a 2.3-kb CEPT1 transcript in all 16 human tissues examined.
Henneberry and McMaster (1999) found that human CEPT1 displayed broad substrate specificity in vitro and used both CDP-choline and CDP-ethanolamine as phosphobase donors for a broad range of diacylglycerol substrates, resulting in synthesis of both phosphatidylcholine and phosphatidylethanolamine. CEPT1 showed an absolute requirement for Mg(2+) or Mn(2+). Expression of human CEPT1 increased production of radiolabeled phosphatidylcholine and phosphatidylethanolamine in S. cerevisiae.
Henneberry et al. (2000) found that CEPT1 synthesized platelet-activating factor (PAF) and PAF precursor via its cholinephosphotransferase activity.
Henneberry et al. (2000) stated that the CEPT1 gene maps to chromosome 1, between microsatellite markers D1S2865 and D1S418.
Hartz (2016) mapped the CEPT1 gene to chromosome 1p13.3 based on an alignment of the CEPT1 sequence (GenBank AF068302) with the genomic sequence (GRCh38).
Hartz, P. A. Personal Communication. Baltimore, Md. 1/13/2016.
Henneberry, A. L., McMaster, C. R. Cloning and expression of a human choline/ethanolaminephosphotransferase: synthesis of phosphatidylcholine and phosphatidylethanolamine. Biochem. J. 339: 291-298, 1999. [PubMed: 10191259]
Henneberry, A. L., Wistow, G., McMaster, C. R. Cloning, genomic organization, and characterization of a human cholinephosphotransferase. J. Biol. Chem. 275: 29808-29815, 2000. [PubMed: 10893425] [Full Text: https://doi.org/10.1074/jbc.M005786200]