- De novo phosphatidylcholine (PC) biosynthesis via the Kennedy pathway involves highly endergonic biochemical reactions that must be fine-tuned with energy homeostasis. Previous studies have shown that CTP:phosphocholine cytidylyltransferase (CCT) is an important regulatory enzyme in this pathway and that its activity can be controlled at both transcriptional and posttranslational levels. Here we identified an important additional mechanism regulating plant CCT1 activity. Comparative analysis revealed that Arabidopsis CCT1 (AtCCT1) contains catalytic and membrane-binding domains that are homologous to those of rat CCT1.
- Polyunsaturated fatty acids (PUFAs) such as α-linolenic acid (ALA, 18:3Δ9cis,12cis,15cis) have high nutritiol and industrial values. In oilseed crops, PUFAs are synthesized on phosphatidylcholine (PC) and accumulated in triacylglycerol (TAG). Therefore, exploring the mechanisms that route PC-derived PUFA to TAG is essential for understanding and improving PUFA production. The seed oil of flax (Linum usitatissimum) is enriched in ALA, and this plant has many lipid biosynthetic enzymes that prefer ALA-containing substrates.
- Background Plant polyunsaturated fatty acids (PUFAs) are mainly synthesized on phosphatidylcholine (PC). Results Diacylglycerol acyltransferase (DGAT) produced higher amount of PUFA-containing TAG in the presence of acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT). Conclusion The LPCAT-catalyzed reverse reaction can be coupled to the DGAT reaction for PUFA accumulation. Significance A mechanism for enhancing the transfer of PUFAs from PC into TAG has been confirmed.