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-Structure paper
タイトル | Mechanism of lipid droplet formation by the yeast Sei1/Ldb16 Seipin complex. |
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ジャーナル・号・ページ | Nat Commun, Vol. 12, Issue 1, Page 5892, Year 2021 |
掲載日 | 2021年10月8日 |
著者 | Yoel A Klug / Justin C Deme / Robin A Corey / Mike F Renne / Phillip J Stansfeld / Susan M Lea / Pedro Carvalho / |
PubMed 要旨 | Lipid droplets (LDs) are universal lipid storage organelles with a core of neutral lipids, such as triacylglycerols, surrounded by a phospholipid monolayer. This unique architecture is generated ...Lipid droplets (LDs) are universal lipid storage organelles with a core of neutral lipids, such as triacylglycerols, surrounded by a phospholipid monolayer. This unique architecture is generated during LD biogenesis at endoplasmic reticulum (ER) sites marked by Seipin, a conserved membrane protein mutated in lipodystrophy. Here structural, biochemical and molecular dynamics simulation approaches reveal the mechanism of LD formation by the yeast Seipin Sei1 and its membrane partner Ldb16. We show that Sei1 luminal domain assembles a homooligomeric ring, which, in contrast to other Seipins, is unable to concentrate triacylglycerol. Instead, Sei1 positions Ldb16, which concentrates triacylglycerol within the Sei1 ring through critical hydroxyl residues. Triacylglycerol recruitment to the complex is further promoted by Sei1 transmembrane segments, which also control Ldb16 stability. Thus, we propose that LD assembly by the Sei1/Ldb16 complex, and likely other Seipins, requires sequential triacylglycerol-concentrating steps via distinct elements in the ER membrane and lumen. |
リンク | Nat Commun / PubMed:34625558 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 2.7 - 3.3 Å |
構造データ | EMDB-13103, PDB-7oxp: EMDB-13104, PDB-7oxr: |
由来 |
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キーワード | MEMBRANE PROTEIN (膜タンパク質) / Lipid droplet formation / lipid binding (脂質) / seipin |