title: SIRT3 and SIRT5 regulate the enzyme activity and cardiolipin binding of very long-chain acyl-CoA dehydrogenase.
abstract: SIRT3 and SIRT5 have been shown to regulate mitochondrial fatty acid oxidation but the molecular mechanisms behind the regulation are lacking. Here, we demonstrate that SIRT3 and SIRT5 both target human very long-chain acyl-CoA dehydrogenase (VLCAD), a key fatty acid oxidation enzyme. SIRT3 deacetylates and SIRT5 desuccinylates K299 which serves to stabilize the essential FAD cofactor in the active site. Further, we show that VLCAD binds strongly to cardiolipin and isolated mitochondrial membranes via a domain near the C-terminus containing lysines K482, K492, and K507. Acetylation or succinylation of these residues eliminates binding of VLCAD to cardiolipin. SIRT3 deacetylates K507 while SIRT5 desuccinylates K482, K492, and K507. Sirtuin deacylation of recombinant VLCAD rescues membrane binding. Endogenous VLCAD from SIRT3 and SIRT5 knockout mouse liver shows reduced binding to cardiolipin. Thus, SIRT3 and SIRT5 promote fatty acid oxidation by converging upon VLCAD to promote its activity and membrane localization. Regulation of cardiolipin binding by reversible lysine acylation is a novel mechanism that is predicted to extrapolate to other metabolic proteins that localize to the inner mitochondrial membrane.
authors: Department of Pediatrics, University of Pittsburgh, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors: Yuxun
authors: Y
authors: Zhang
authors: Department of Pediatrics, University of Pittsburgh, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors: Sivakama S
authors: SS
authors: Bharathi
authors: Buck Institute for Research on Aging, Novato, California, United States of America.
authors: Matthew J
authors: MJ
authors: Rardin
authors: Department of Pediatrics, University of Pittsburgh, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors: Radha
authors: R
authors: Uppala
authors: Gladstone Institutes, University of California San Francisco, San Francisco, California, United States of America.
authors: Eric
authors: E
authors: Verdin
authors: Buck Institute for Research on Aging, Novato, California, United States of America.
authors: Bradford W
authors: BW
authors: Gibson
authors: Department of Pediatrics, University of Pittsburgh, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors: Eric S
authors: ES
authors: Goetzman
mesh_terms: D044942:Acyl-CoA Dehydrogenase, Long-Chain / Q000737:chemistry / Q000378:metabolism*; D000215:Acylation; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002308:Cardiolipins / Q000737:chemistry / Q000378:metabolism*; D020134:Catalytic Domain; D004789:Enzyme Activation; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008930:Mitochondria, Liver / Q000378:metabolism; D051336:Mitochondrial Membranes / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D016415:Sequence Alignment; D056566:Sirtuin 3 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D037761:Sirtuins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D002308:Cardiolipins; C542554:SIRT5 protein, mouse; D005182:Flavin-Adenine Dinucleotide; D044942:Acyl-CoA Dehydrogenase, Long-Chain; D056566:Sirtuin 3; D037761:Sirtuins