Crystal structure of a lipin/Pah phosphatidic acid phosphatase

• Published in: Nature communications Vol. 11; no. 1; p. 1309
• Main Authors: Khayyo, Valerie I., Hoffmann, Reece M., Wang, Huan, Bell, Justin A., Burke, John E., Reue, Karen, Airola, Michael V.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.03.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 631/1647/296; 631/45/287/1192; 631/45/607/1164; 631/45/612/1237; 631/535/1266; Acid phosphatase; Architecture; BASIC BIOLOGICAL SCIENCES; Catalysis; Catalytic Domain - genetics; Cellular structure; Crystal structure; Crystallography, X-Ray; Diglycerides; Domains; Fish oils; HEK293 Cells; Humanities and Social Sciences; Humans; Hydrolases; Mass spectrometry; Membrane lipids; Membrane proteins; Membranes; multidisciplinary; Mutation; Phosphatase; Phosphatidate Phosphatase - genetics; Phosphatidate Phosphatase - isolation & purification; Phosphatidate Phosphatase - metabolism; Phosphatidate Phosphatase - ultrastructure; Phosphatidic acid; Protein Conformation, alpha-Helical; Protein folding; Protozoan Proteins - genetics; Protozoan Proteins - isolation & purification; Protozoan Proteins - ultrastructure; Recombinant Proteins - genetics; Recombinant Proteins - isolation & purification; Recombinant Proteins - ultrastructure; Rhabdomyolysis; Science; Science (multidisciplinary); Signaling; Synthesis; Tetrahymena thermophila; Tetrahymena thermophila - enzymology; Transfection; Triglycerides; X-ray crystallography
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-15124-z

Lipin/Pah phosphatidic acid phosphatases (PAPs) generate diacylglycerol to regulate triglyceride synthesis and cellular signaling. Inactivating mutations cause rhabdomyolysis, autoinflammatory disease, and aberrant fat storage. Disease-mutations cluster within the conserved N-Lip and C-Lip regions that are separated by 500-residues in humans. To understand how the N-Lip and C-Lip combine for PAP function, we determined crystal structures of Tetrahymena thermophila Pah2 ( Tt Pah2) that directly fuses the N-Lip and C-Lip. Tt Pah2 adopts a two-domain architecture where the N-Lip combines with part of the C-Lip to form an immunoglobulin-like domain and the remaining C-Lip forms a HAD-like catalytic domain. An N-Lip C-Lip fusion of mouse lipin-2 is catalytically active, which suggests mammalian lipins function with the same domain architecture as Tt Pah2. HDX-MS identifies an N-terminal amphipathic helix essential for membrane association. Disease-mutations disrupt catalysis or destabilize the protein fold. This illustrates mechanisms for lipin/Pah PAP function, membrane association, and lipin-related pathologies. Lipin/Pah phosphatidic acid phosphatases generate diacylglycerol to regulate triglyceride synthesis and cellular signaling. Here authors determine structures of Tetrahymena thermophila Pah2 and identify an N-terminal amphipathic helix essential for membrane association.