Conversion of palmitate to unsaturated fatty acids differs in a Neurospora crassa mutant with impaired fatty acid synthase activity.
The Neurospora crassa cel (fatty acid chain elongation) mutant has impaired fatty acid synthase activity. The cel mutant requires exogenous 16:0 for growth and converts 16:0 to other fatty acids. In contrast to wild-type N. crassa, which converted only 42% of the exogenous [7,7,8,8-(2)H4]16:0 that was incorporated into cell lipids to unsaturated fatty acids, cel converted 72%. In addition, cel contains higher levels of 18:3(delta 9,12,15) than wild-type, and synthesizes two fatty acids, 20:2(delta 11,14 and 20:3(delta 11,14,17, found at only trace levels in wild-type. Thus, the delta 15-desaturase activity and elongation activity on 18-carbon polyunsaturated fatty acids are higher for cel than wild-type. This altered metabolism of exogenous 16:0 may be directly due to impaired flux through the endogenous fatty acid biosynthetic pathway, or may result from altered regulation of the synthesis of unsaturated fatty acids in the mutant.
Stafford
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USDA, ARS, Western Regional Research Center, Albany, California 94710, USA.
McKeon
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TA
Goodrich-Tanrikulu
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M
D044943:Fatty Acid Desaturases / Q000378:metabolism; D064429:Fatty Acid Synthases / Q000172:deficiency* / Q000235:genetics; D005227:Fatty Acids / Q000096:biosynthesis*; D009492:Neurospora crassa / Q000201:enzymology* / Q000235:genetics; D019308:Palmitic Acid / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism
D005227:Fatty Acids; D014280:Triglycerides; D019308:Palmitic Acid; D044943:Fatty Acid Desaturases; D064429:Fatty Acid Synthases