PML isoform II plays a critical role in nuclear lipid droplet formation.
PML isoform II plays a critical role in nuclear lipid droplet formation.
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DOI：
10.1083/jcb.201507122
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发表时间：
2016-01-04
期刊：
影响因子：
--
通讯作者：
Fujimoto T
中科院分区：
文献类型：
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作者：
Ohsaki Y;Kawai T;Yoshikawa Y;Cheng J;Jokitalo E;Fujimoto T
PML-II 在核脂滴的产生中起着关键作用，核脂滴与早幼粒细胞白血病核体以及内核膜的延伸有关。肝细胞来源的细胞系细胞核中的脂滴 (LD) 被发现与早幼粒细胞白血病 (PML) 核体 (NB) 和 I 型核质网 (NR) 或内核膜的延伸有关。 PML 同工型 II (PML-II) 的敲低导致核 LD 和 I 型 NR 显着降低，而 PML-II 的过表达则两者均增加。值得注意的是，这些效应仅在有限类型的细胞中明显，其中本质上存在中等数量的核 LD，并且 PML-II 不仅针对 PML NB，而且针对核膜，不包括核纤层蛋白和 SUN 蛋白。敲低 SUN 蛋白会导致 I 型 NR 和核 LD 显着增加，但这些影响会被同时敲低 PML-II 所抵消。核 LD 含有二酰甘油 O-酰基转移酶 2 和 CTP：磷酸胆碱胞苷酰转移酶 α，并掺入新合成的脂质酯。这些结果证实 PML-II 在特定细胞类型中产生核 LD 中发挥着关键作用。
PML-II plays a critical role in generating nuclear lipid droplets, which are associated with promyelocytic leukemia nuclear bodies as well as with the extension of the inner nuclear membrane. Lipid droplets (LDs) in the nucleus of hepatocyte-derived cell lines were found to be associated with premyelocytic leukemia (PML) nuclear bodies (NBs) and type I nucleoplasmic reticulum (NR) or the extension of the inner nuclear membrane. Knockdown of PML isoform II (PML-II) caused a significant decrease in both nuclear LDs and type I NR, whereas overexpression of PML-II increased both. Notably, these effects were evident only in limited types of cells, in which a moderate number of nuclear LDs exist intrinsically, and PML-II was targeted not only at PML NBs, but also at the nuclear envelope, excluding lamins and SUN proteins. Knockdown of SUN proteins induced a significant increase in the type I NR and nuclear LDs, but these effects were cancelled by simultaneous knockdown of PML-II. Nuclear LDs harbored diacylglycerol O-acyltransferase 2 and CTP:phosphocholine cytidylyltransferase α and incorporated newly synthesized lipid esters. These results corroborated that PML-II plays a critical role in generating nuclear LDs in specific cell types.