Degradation of human Lipin-1 by BTRC E3 ubiquitin ligase.

Lipin-1 has dual functions in the regulation of lipid and energy metabolism according to its subcellular localization, which is tightly controlled. However, it is unclear how Lipin-1 degradation is regulated. Here, we demonstrate that Lipin-1 is degraded through its DSGXXS motif. We show that Lipin-1 interacts with either of two E3 ubiquitin ligases, BTRC or FBXW11, and that this interaction is DSGXXS-dependent and mediates the attachment of polyubiquitin chains. Further, we demonstrate that degradation of Lipin-1 is regulated by BTRC in the cytoplasm and on membranes. These novel insights into the regulation of human Lipin-1 stability will be useful in planning further studies to elucidate its metabolic processes.