Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Department of Medicine and the Canadian Centre for Health and Safety in Agriculture, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
PLoS One. 2019 Jan 7;14(1):e0210396. doi: 10.1371/journal.pone.0210396. eCollection 2019.
Triacylglycerol synthesis is catalyzed by acyl CoA:diacylglycerol acyltransferase-2 (DGAT2). DGAT2 is an integral membrane protein that is localized to the endoplasmic reticulum and interacts with lipid droplets. Using BioId, a method to detect proximal and interacting proteins, we identified calnexin as a DGAT2-interacting protein. Co-immunoprecipitation and proximity ligation assays confirmed this finding. We found that calnexin-deficient mouse embryonic fibroblasts had reduced intracellular triacylglycerol levels and fewer large lipid droplets (>1.0 μm2 area). Despite the alterations in triacylglycerol metabolism, in vitro DGAT2 activity, localization and protein stability were not affected by the absence of calnexin.
三酰基甘油的合成是由酰基辅酶 A：二酰基甘油酰基转移酶-2（DGAT2）催化的。DGAT2 是一种位于内质网上的完整膜蛋白，与脂滴相互作用。使用 BioId，一种检测邻近和相互作用蛋白的方法，我们鉴定出钙连蛋白是 DGAT2 的相互作用蛋白。共免疫沉淀和邻近连接测定证实了这一发现。我们发现钙连蛋白缺陷型小鼠胚胎成纤维细胞的细胞内三酰基甘油水平降低，大脂滴（>1.0μm2 面积）减少。尽管三酰基甘油代谢发生了改变，但钙连蛋白缺失并不影响 DGAT2 的体外活性、定位和蛋白稳定性。
