Mutants in a macrophage-like cell line are defective in plasmalogen biosynthesis, but contain functional peroxisomes.
We have used a fluorescence-activated cytotoxicity protocol, 9-(1'-pyrene)nonanol (P9OH)/UV selection (Morand, O. H., Allen, L.-A. H., Zoeller, R. A., and Raetz, C. R. H. (1990) Biochim. Biophys. Acta 1034, 132-141), to isolate a series of plasmalogen-deficient mutants in a murine, macrophage-like cell line, RAW 264.7. Three of these mutants, RAW.7, RAW.12, and RAW.108, displayed varying degrees of plasmalogen deficiency (48, 17, and 14% of wild-type levels, respectively), and all three mutants were deficient in peroxisomal dihydroxyacetone phosphate (DHAP) acyltransferase activity (5% of wild-type). Unlike previously described Chinese hamster ovary (CHO) cell mutants, the RAW mutants contained intact, functional, peroxisomes and normal levels of alkyl-DHAP synthase activity, a peroxisomal, membrane-bound enzyme. In RAW.7 and RAW.108 cells, the loss of peroxisomal DHAP acyltransferase is the primary lesion. RAW.12 displayed not only a deficiency in the DHAP acyltransferase activity, but also displayed a second lesion in the biosynthetic pathway, a deficiency in delta 1'-desaturase activity (plasmanylethanolamine desaturase, EC 1.14.99.19), the final step in plasmenylethanolamine biosynthesis. The deficiencies expressed in the mutants represent unique lesions in plasmalogen biosynthesis. Since the RAW cell line is a macrophage-like responsive cell line, these mutants can be used to examine the role of plasmalogens in cellular functions such as arachidonic acid metabolism, prostaglandin synthesis, protein secretion, and signal transduction.
Zoeller
R A
RA
Department of Biophysics, Boston University School of Medicine, Massachusetts 02118.
Rangaswamy
S
S
Herscovitz
H
H
Rizzo
W B
WB
Hajra
A K
AK
Das
A K
AK
Moser
H W
HW
Moser
A
A
Lazarow
P B
PB
Santos
M J
MJ
D000217:Acyltransferases / Q000378:metabolism; D000818:Animals; D016466:CHO Cells; D002374:Catalase / Q000378:metabolism; D002460:Cell Line; D006224:Cricetinae; D005233:Fatty Alcohols / Q000737:chemistry; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008830:Microbodies / Q000201:enzymology / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009154:Mutation; D010955:Plasmalogens / Q000096:biosynthesis*; D011721:Pyrenes / Q000737:chemistry
D005233:Fatty Alcohols; D010955:Plasmalogens; D011721:Pyrenes; C020791:phosphatidal ethanolamines; C064596:9-(1'-pyrene)nonanol; D002374:Catalase; D000217:Acyltransferases; C020051:glycerone-phosphate O-acyltransferase