Lipin Family Proteins: Structure, Functions, and Related Diseases

Lipins are enzymes that participate in the phospholipid biosynthesis pathway (Kennedy pathway) by catalyzing the dephosphorylation of phosphatidic acid to diacylglycerol. In addition, lipins can rapidly relocate within the cell and can be transported into the nucleus to serve as coactivators of gene expression. This dual function explains the strong interest in the study of these proteins. Diseases involving adipose aberrations, such as lipodystrophy and obesity, are two possible consequences of lipid metabolic dysfunction. Both lipodystrophy and obesity contribute to insulin resistance, hypertension, dysglycemia, and premature atherosclerosis. Because lipins are key regulators of lipid metabolism, it is of interest to investigate their impact on human health. The purpose of this review is to give readers a general idea regarding the structure, functions, and regulatory mechanisms of various lipin orthologs and isoforms in the tissues of eukaryotic organisms and to discuss recent advances in the understanding of lipins. A separate section is devoted to human diseases caused by an excess or deficiency of a lipin.