Figure 1.

Biosynthesis of Cardiolipin (CL). The biosynthesis of CL involves two pathways: de novo synthesis and remodeling steps. The de novo synthesis of CL occurs through a series of four reactions originating from phosphatidic acid (PA). PA is first transformed into CDP-DAG in the presence of CDP-DAG synthase. CDP-DAG is then converted to PGP, followed by a dephosphorylation reaction to produce PG. The combination of PG and CDP-DAG yields CL. The remodeling process is a deacylation-reacylation cycle in the presence of PLA2 and tafazzin, resulting in the replacement of the fatty acyl chains in the newly synthesized CL with polyunsaturated chains.