PDF(Pubmed)
Abstract：
Seipin (BSCL2), a conserved endoplasmic reticulum protein, plays a critical role in lipid droplet (LD) biogenesis and in regulating LD morphology, pathogenic variants of which are associated with Berardinelli-Seip congenital generalized lipodystrophy type 2 (BSCL2). To model BSCL2 disease, we generated an orthologous BSCL2 variant, seip-1(A185P), in Caenorhabditis elegans. In this study, we conducted an unbiased chemical mutagenesis screen to identify genetic suppressors that restore embryonic viability in the seip-1(A185P) mutant background. A total of five suppressor lines were isolated and recovered from the screen. The defective phenotypes of seip-1(A185P), including embryonic lethality and impaired eggshell formation, were significantly suppressed in each suppressor line. Two of the five suppressor lines also alleviated the enlarged LDs in the oocytes. We then mapped a suppressor candidate gene, lmbr-1, which is an ortholog of human limb development membrane protein 1 (LMBR1). The CRISPR/Cas9 edited lmbr-1 suppressor alleles, lmbr-1(S647F) and lmbr-1(P314L), both significantly suppressed embryonic lethality and defective eggshell formation in the seip-1(A185P) background. The newly identified suppressor lines offer valuable insights into potential genetic interactors and pathways that may regulate seipin in the lipodystrophy model.
摘要：
Seipin(BSCL2),一种保守的内质网蛋白，在LD生物发生和调控LD形态中起着至关重要的作用，其致病变异与Berardinelli-Seip先天性全身性脂肪营养不良2型（BSCL2）相关。为BSCL2疾病建模，我们在秀丽隐杆线虫中产生了直系同源BSCL2变体seip-1（A185P）。在这项研究中,我们进行了无偏倚的化学诱变筛选,以鉴定在seip-1(A185P)突变体背景下恢复胚胎活力的遗传抑制因子.从筛子中分离并回收总共5条抑制器线。SEIP-1（A185P）的缺陷表型，包括胚胎致死性和蛋壳形成受损，在每个抑制器线中都被显著抑制。五个抑制系中的两个也减轻了卵母细胞中扩大的LD。然后我们绘制了一个抑制基因候选基因，lmbr-1,它是人LMBR1(肢体发育膜蛋白1)的直系同源物。CRISPR/Cas9编辑了lmbr-1抑制等位基因，lmbr-1(Ser647Phe)和lmbr-1(Pro314Leu)，两者均显着抑制了seip-1（A185P）背景下的胚胎致死性和蛋壳形成缺陷。新发现的抑制系提供了对可能调节脂肪营养不良模型中seipin的潜在遗传相互作用者和途径的有价值的见解。
