title: Cyclic phosphatidic acid is produced by autotaxin in blood.
abstract: Cyclic phosphatidic acid (cPA), an analog of lysophosphatidic acid (LPA), was previously identified in human serum. Although cPA possesses distinct physiological activities not elicited by LPA, its biochemical origins have scarcely been studied. In the present study, we assayed cPA formation from lysophosphatidylcholine in fetal bovine serum and found significant activity of transphosphatidylation that generated cPA. The cPA-producing enzyme was purified from fetal bovine serum using five chromatographic steps yielding a 100-kDa protein with cPA biosynthetic activity. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of its tryptic peptides revealed that the enzyme shared identical fragments with human autotaxin, a serum lysophospholipase D that produces LPA. Western blot analysis demonstrated that the 100-kDa protein was specifically recognized by an anti-human autotaxin antibody. Moreover, recombinant rat autotaxin was found to generate cPA in addition to LPA. No significant cPA- or LPA-producing activity was detected in autotaxin-depleted serum from bovine or human prepared by immunoprecipitation with an anti-autotaxin monoclonal antibody. These results indicate that the generation of cPA and LPA in serum is mainly attributed to autotaxin.
authors.affiliation: Department of Biology, Faculty of Science, Ochanomizu University, Tokyo 112-8610, Japan.
authors.forename: Satomi
authors.initials: S
authors.lastname: Tsuda
authors.forename: Shinichi
authors.initials: S
authors.lastname: Okudaira
authors.forename: Keiko
authors.initials: K
authors.lastname: Moriya-Ito
authors.forename: Chie
authors.initials: C
authors.lastname: Shimamoto
authors.forename: Masayuki
authors.initials: M
authors.lastname: Tanaka
authors.forename: Junken
authors.initials: J
authors.lastname: Aoki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Arai
authors.forename: Kimiko
authors.initials: K
authors.lastname: Murakami-Murofushi
authors.forename: Tetsuyuki
authors.initials: T
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D001769:Blood / Q000378:metabolism*; D002417:Cattle; D004986:Ether / Q000378:metabolism; D006801:Humans; D008244:Lysophosphatidylcholines / Q000378:metabolism; D008246:Lysophospholipids / Q000096:biosynthesis / Q000737:chemistry; D008670:Metals / Q000378:metabolism; D009097:Multienzyme Complexes / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D043264:Phosphodiesterase I / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011755:Pyrophosphatases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism; D000099189:Lysophospholipase D
chemical_list: D000911:Antibodies, Monoclonal; D004986:Ether; D008244:Lysophosphatidylcholines; D008246:Lysophospholipids; D008670:Metals; D009097:Multienzyme Complexes; D010446:Peptide Fragments; D043264:Phosphodiesterase I; D010727:Phosphoric Diester Hydrolases; D011755:Pyrophosphatases; D011994:Recombinant Proteins; D012965:Sodium Chloride; D000099189:Lysophospholipase D; C032881:lysophosphatidic acid