Maintaining the proper lipid composition of cellular membranes is critical for numerous cellular processes but mechanisms of membrane lipid homeostasis are not well understood. There is growing evidence that membrane contact sites (MCSs), regions where two organelles come in close proximity to one another, play major roles in the regulation of intracellular lipid composition and distribution. MCSs are thought to mediate the exchange of lipids and signals between organelles. In this review, we discuss how lipid exchange occurs at MCSs and evidence for roles of MCSs in regulating lipid synthesis and degradation. We also discuss how networks of organelles connected by MCSs may modulate cellular lipid homeostasis and help determine organelle lipid composition.

中文翻译：

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膜接触部位，脂质稳态的通道。

维持适当的细胞膜脂质组成对于许多细胞过程至关重要，但是膜脂质稳态的机制尚不十分清楚。越来越多的证据表明，膜接触位点（MCS）（两个细胞器彼此非常靠近的区域）在调节细胞内脂质的组成和分布中起着重要作用。MCS被认为介导细胞器之间脂质和信号的交换。在这篇综述中，我们讨论了脂质交换在MCS处如何发生，以及MCS在调节脂质合成和降解中作用的证据。我们还讨论了通过MCS连接的细胞器网络如何调节细胞脂质稳态，并帮助确定细胞器脂质组成。