7YJ2

Cryo-EM structure of SPT-ORMDL3 (ORMDL3-N13A) complex

7YJ2 の概要

• エントリーDOI: 10.2210/pdb7yj2/pdb
• EMDBエントリー: 33869
• 分子名称: Serine palmitoyltransferase 2, Serine palmitoyltransferase 1, ORM1-like protein 3, ... (6 entities in total)
• 機能のキーワード: ceramide, transferase-inhibitor complex, transferase/inhibitor
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 144288.10

構造登録者

Xie, T.,Liu, P.,Gong, X. (登録日: 2022-07-19, 公開日: 2023-07-05, 最終更新日: 2025-06-25)

主引用文献

Xie, T.,Liu, P.,Wu, X.,Dong, F.,Zhang, Z.,Yue, J.,Mahawar, U.,Farooq, F.,Vohra, H.,Fang, Q.,Liu, W.,Wattenberg, B.W.,Gong, X.
Ceramide sensing by human SPT-ORMDL complex for establishing sphingolipid homeostasis.
Nat Commun, 14:3475-3475, 2023

PubMed Abstract: The ORM/ORMDL family proteins function as regulatory subunits of the serine palmitoyltransferase (SPT) complex, which is the initiating and rate-limiting enzyme in sphingolipid biosynthesis. This complex is tightly regulated by cellular sphingolipid levels, but the sphingolipid sensing mechanism is unknown. Here we show that purified human SPT-ORMDL complexes are inhibited by the central sphingolipid metabolite ceramide. We have solved the cryo-EM structure of the SPT-ORMDL3 complex in a ceramide-bound state. Structure-guided mutational analyses reveal the essential function of this ceramide binding site for the suppression of SPT activity. Structural studies indicate that ceramide can induce and lock the N-terminus of ORMDL3 into an inhibitory conformation. Furthermore, we demonstrate that childhood amyotrophic lateral sclerosis (ALS) variants in the SPTLC1 subunit cause impaired ceramide sensing in the SPT-ORMDL3 mutants. Our work elucidates the molecular basis of ceramide sensing by the SPT-ORMDL complex for establishing sphingolipid homeostasis and indicates an important role of impaired ceramide sensing in disease development.

PubMed: 37308477
DOI: 10.1038/s41467-023-39274-y

実験手法

ELECTRON MICROSCOPY (2.9 Å)