FIG. 1.

Model-reference adaptive control (MRAC) approach to study regulation in de novo sphingolipid synthesis. (a) Block diagram of model-reference adaptive control (MRAC); treated cells (plant) follow wild type cells (reference) to minimize the difference in sphingolipid amounts. (b) De novo sphingolipid synthesis pathway with key enzymes in italics; uni-/bi-directional arrows indicate irreversible/reversible reactions respectively; pathway intermediates, e.g., ceramide, sphingomyelin, are highly bioactive.