1. Non-esterified fatty acids (NEFA) are transported into the cell
2. they're converted to acyl coenzyme A (CoA) by acyl CoA synthetase (ACS).
3. The acyl CoA can be oxidized
4. can be esterified into complex lipids : like TGs, PLs, or DAGs, which can also replenish the cellular fatty acid stores as necessary.
5. or can give rise to leukotrienes, prostaglandins, and thromboxanes, which are secondary metabolites who in addition to complex lipids such as DAG, can increase cellular concentrations of 2nd messengers like cAMP, IP3, and Calcium.
(these 2nd messengers or their lipid precursors can all have effects on gene expression).
6. Alternatively, free FAs and Fatty acyl CoAs can act directly at the nuclear level
7. in the nucleus, signaling through fatty acids or their metabolites can lead to changes in nuclear receptor activation (like in the case of peroxisome proliferator activated receptors and liver X receptors.
8. can lead to changes in transcription factor abundance (like in the case of sterol regulatory element binding protein-1c, leading to upregulation, or downregulation of target genes.