The LIPIN1 gene encodes Lipin-1, a Mg(++)-dependent phosphatidic acid phosphatase. The latter protein is 890 amino acid long, with two conserved domains; an N-terminal domain encompassing the first 114 residues, and a catalytic domain LNS2 (Lipin/Ned1/Smp2) at amino acids 674-830. Lipin-1 catalyzes the conversion of phosphatidic acid to diacylglycerol in the triacylglycerol synthesis pathway.
LPIN1 expression is most prominent in skeletal muscle and adipose tissue in humans. Lipin mRNA levels in human adipose tissue have a strong negative correlation with fasting glucose and insulin levels, and they can serve as an indicator of insulin resistance.