2. Academic Validation
  3. LDAF1 and Seipin Form a Lipid Droplet Assembly Complex

LDAF1 and Seipin Form a Lipid Droplet Assembly Complex

  • Dev Cell. 2019 Dec 2;51(5):551-563.e7. doi: 10.1016/j.devcel.2019.10.006.
Jeeyun Chung 1,  Xudong Wu 2,  Talley J Lambert 3,  Zon Weng Lai 4,  Tobias C Walther 5,  Robert V Farese Jr 6
Affiliations

Affiliations

  • 1 Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
  • 2 Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
  • 3 Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
  • 4 Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Harvard Chan Advanced Multi-omics Platform, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
  • 5 Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Harvard Chan Advanced Multi-omics Platform, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02124, USA; Howard Hughes Medical Institute, Boston, MA 02115, USA. Electronic address: [email protected].
  • 6 Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02124, USA. Electronic address: [email protected].
PMID: 31708432 DOI: 10.1016/j.devcel.2019.10.006
Abstract

Lipid droplets (LDs) originate from the endoplasmic reticulum (ER) to store triacylglycerol (TG) and Cholesterol esters. The ER protein seipin was shown to localize to ER-LD contacts soon after LDs form, but what determines the sites of initial LD biogenesis in the ER is unknown. Here, we identify TMEM159, now re-named lipid droplet assembly factor 1 (LDAF1), as an interaction partner of seipin. Together, LDAF1 and seipin form an ∼600 kDa oligomeric complex that copurifies with TG. LDs form at LDAF1-seipin complexes, and re-localization of LDAF1 to the plasma membrane co-recruits seipin and redirects LD formation to these sites. Once LDs form, LDAF1 dissociates from seipin and moves to the LD surface. In the absence of LDAF1, LDs form only at significantly higher cellular TG concentrations. Our data suggest that the LDAF1-seipin complex is the core protein machinery that facilitates LD biogenesis and determines the sites of their formation in the ER.

Keywords

Berardinelli-Seip congenital lipodystrophy type 2; TMEM159; endoplasmic reticulum; fat; lipid droplets; lipodystrophy; organelle biogenesis; promethin; triacylglycerol.

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