Unsaturated fatty acids are essential lipid components of Mucor rouxii. g-Linolenic acid (GLA) is synthesized via the desaturase enzymes: D9-desaturase catalyzes mono-unsaturated fatty acids that are utilized as substrate for GLA biosynthesis. We cloned and characterized a M. rouxii gene highly homologous to D9-desaturase genes. This sequence encodes for a protein of 452 amino acids and contains two introns of 60 and 61 nucleotides. D9-desaturase of M. rouxii is expressed during cell growth when cells are subjected to temperature shifts. At 30°C, the mRNA level of late log phase is about 6.4-fold higher than that of early log phase. A shift from 30 to 15°C induced transcription of D9-desaturase gene in both early and late log phases. However, the pattern of increased transcription by cold induction varied depending on growth conditions: transcription of late log phase is higher than that of early log phase. These results indicate that cell growth and low temperature influence the expression of D9-desaturase gene and fatty acid composition of M. rouxii.
Mucor rouxii Δ9-desaturase gene is transcriptionally regulated during cell growth and by low temperature
MARESCA, Bruno;
1999-01-01
Abstract
Unsaturated fatty acids are essential lipid components of Mucor rouxii. g-Linolenic acid (GLA) is synthesized via the desaturase enzymes: D9-desaturase catalyzes mono-unsaturated fatty acids that are utilized as substrate for GLA biosynthesis. We cloned and characterized a M. rouxii gene highly homologous to D9-desaturase genes. This sequence encodes for a protein of 452 amino acids and contains two introns of 60 and 61 nucleotides. D9-desaturase of M. rouxii is expressed during cell growth when cells are subjected to temperature shifts. At 30°C, the mRNA level of late log phase is about 6.4-fold higher than that of early log phase. A shift from 30 to 15°C induced transcription of D9-desaturase gene in both early and late log phases. However, the pattern of increased transcription by cold induction varied depending on growth conditions: transcription of late log phase is higher than that of early log phase. These results indicate that cell growth and low temperature influence the expression of D9-desaturase gene and fatty acid composition of M. rouxii.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
