Fig. 3
Post-translational regulation of lipin1. Post-translational modifications of lipin 1 include phosphorylation, SUMOylation, acetylation, and ubiquitination. Phosphorylation promoted by insulin and mTOR triggers the translocation of lipin 1 protein from the ER membranes to the cytoplasm. The CTDNEP/NEP1-R1 phosphatase complex and epinephrine then dephosphorylate lipin 1 and promote its membrane association, allowing lipin 1 to react with its substrate to produce DAG. The membrane association of lipin 1 is also induced by acetylation via TIP60 acetyltransferase. The modification of lipin 1 by SUMOylation preferentially promotes lipin 1 nuclear localization, and polyubiquitination facilitates the degradation of lipin 1