The endoplasmic reticulum (ER) is a highly organized organelle that performs vital functions including de novo membrane lipid synthesis and transport. Accordingly, numerous lipid biosynthesis enzymes are localized in the ER membrane. However, it is now evident that lipid metabolism is sub-compartmentalized within the ER and that lipid biosynthetic enzymes engage with lipid transfer proteins (LTPs) to rapidly shuttle newly synthesized lipids from the ER to other organelles. As such, intimate relationships between lipid metabolism and lipid transfer pathways exist within the ER network. Notably, certain LTPs enhance the activities of lipid metabolizing enzymes; likewise, lipid metabolism can ensure the specificity of LTP transfer/exchange reactions. Yet, our understanding of these mutual relationships is still emerging. Here, we highlight past and recent key findings on specialized ER membrane domains involved in efficient lipid metabolism and transport and consider unresolved issues in the field.

内质网（ER）是一种高度组织化的细胞器，执行重要功能，包括从头开始膜脂质的合成与运输。因此，许多脂质生物合成酶位于ER膜中。但是，现在很明显，脂质代谢在ER内是小室的，并且脂质生物合成酶与脂质转移蛋白（LTP）结合，将新合成的脂质从ER快速穿梭到其他细胞器中。这样，ER网络内存在脂质代谢和脂质转移途径之间的密切关系。值得注意的是，某些LTP增强了脂质代谢酶的活性。同样，脂质代谢可以确保LTP转移/交换反应的特异性。但是，我们对这些相互关系的理解仍在不断涌现。这里，