Institute for Mathematical Modeling of Biological Systems, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany; Systems Biology of Lipid Metabolism, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany.
Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Str. 56, Münster, 48149, Germany; Cells in Motion Interfaculty Centre (CiM), University of Münster, Münster, 48149, Germany.
Insect Biochem Mol Biol. 2021 Jun;133:103512. doi: 10.1016/j.ibmb.2020.103512. Epub 2020 Dec 9.
The Seipin protein is a conserved key component in the biogenesis of lipid droplets (LDs). Recently, a cooperation between human Seipin and the Lipid droplet assembly factor 1 (LDAF1) was described. LDAF1 physically interacts with Seipin and the holocomplex safeguards regular LD biogenesis. The function of LDAF1 proteins outside mammals is less clear. In yeast, the lipid droplet organization (LDO) proteins, which also cooperate with Seipin, are the putative homologs of LDAF1. While certain functional aspects are shared between the LDO and mammalian LDAF1 proteins, the relationship between the proteins is under debate. Here, we identify the Drosophila melanogaster protein CG32803, which we re-named to dmLDAF1, as an insect member of this protein family. dmLDAF1 decorates LDs in cultured cells and in vivo and the protein is linked to the fly and mouse Seipin proteins. Altering the dmLDAF1 abundance affects LD size, number and overall lipid storage amounts. Our results suggest that the LDAF1 proteins thus fulfill an evolutionarily conserved function in the biogenesis and biology of LDs.
Seipin 蛋白是脂滴（LDs）生物发生的保守关键组成部分。最近，描述了人 Seipin 与脂滴组装因子 1（LDAF1）之间的合作。LDAF1 与 Seipin 物理相互作用，完整复合物可保护正常的 LD 生物发生。LDAF1 蛋白在哺乳动物以外的功能不太清楚。在酵母中，与 Seipin 合作的脂滴组织（LDO）蛋白也是 LDAF1 的假定同源物。虽然 LDO 和哺乳动物 LDAF1 蛋白具有某些功能方面的共享，但这些蛋白之间的关系存在争议。在这里，我们鉴定出果蝇的 CG32803 蛋白，将其重新命名为 dmLDAF1，作为该蛋白家族的昆虫成员。dmLDAF1 在培养细胞和体内装饰 LD，并且该蛋白与果蝇和小鼠的 Seipin 蛋白相连。改变 dmLDAF1 的丰度会影响 LD 的大小、数量和整体脂质储存量。我们的结果表明，LDAF1 蛋白在 LD 的生物发生和生物学中具有保守的功能。
