Biosynthesis of platelet activating factor (PAF) via alternate pathways: subcellular distribution of products in HL-60 cells

Conference · Thu May 01 00:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5233773

Record, M; Snyder, F

Final steps in the biosynthesis of PAF can be catalyzed by two different routes: CDP-choline:1-alkyl-2-acetyl-Gro cholinephosphotransferase (dithiothrietol (DTT)-insensitive) or acetyl-CoA:1-alkyl-2-lyso-GroPCho acetyltransferase. The authors have investigated the conversion of tritium-labeled 1-alkyl-2-acetyl-Gro and 1-alkyl-2-lyso-GroPCho (lyso-PAF) to PAF and other lipid products in HL-60 cells and in subcellular organelles isolated by centrifugation in a Percoll gradient. When cells are incubated with the labeled precursors (2 ..mu..M) the total amount of labeled PAF and 1-alkyl-2-acyl-GroPCho formed was similar from both precursors (60 pmol from 1-alkyl-2-acetyl-Gro and 50 pmol from lyso-PAF). However, PAF formed from 1-alkyl-2-acetyl-Gro represented 70% of the total products, whereas with lyso-PAF the major labeled product was 1-alkyl-2-acyl-GroPCho. Formation of PAF from 1-(/sup 3/H)alkyl-2-acetyl-Gro was linear to at least 30 min at 20/sup 0/C. After a 15-min incubation of this neutral lipid with HL-60 cells, the labeled PAF produced was located exclusively in the plasma membrane fraction as opposed to the label in the 1-alkyl-2-acyl-GroPCho, which was found only in the endoplasmic reticulum; none of the labeled PAF product was released to the media. The authors results suggest PAF might be synthesized by the DTT-insensitive cholinephosphotransferase at the site of the plasma membrane in HL-60 cells.

• Research Organization: Oak Ridge Associated Universities, TN
• DOE Contract Number: AC05-76OR00033
• OSTI ID: 5233773
• Report Number(s): CONF-8606151-; TRN: 86-031436
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BLOOD COAGULATION FACTORS
BIOSYNTHESIS
TRANSFERASES
ENZYME ACTIVITY
ANIMAL CELLS
BIOLOGICAL PATHWAYS
CATALYSTS
CELL MEMBRANES
LIPIDS
PRECURSOR
TRACER TECHNIQUES
TRITIUM COMPOUNDS
CELL CONSTITUENTS
COAGULANTS
DRUGS
ENZYMES
HEMATOLOGIC AGENTS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MEMBRANES
ORGANIC COMPOUNDS
SYNTHESIS
550201* - Biochemistry- Tracer Techniques