Unlike most other organelles found in multiple copies, the endoplasmic reticulum (ER) is a unique singular organelle within eukaryotic cells. Despite its continuous membrane structure, encompassing more than half of the cellular endomembrane system, the ER is subdivided into specialized sub-compartments, including morphological, membrane contact site (MCS), and de novo organelle biogenesis domains. In this review, we discuss recent emerging evidence indicating that, in response to nutrient stress, cells undergo a reorganization of these sub-compartmental ER domains through two main mechanisms: non-destructive remodeling of morphological ER domains via regulation of MCS and organelle hitchhiking, and destructive remodeling of specialized domains by ER-phagy. We further highlight and propose a critical role of membrane lipid metabolism in this ER remodeling during starvation.

与大多数其他多拷贝细胞器不同，内质网（ER）是真核细胞内独特的单一细胞器。尽管其具有连续的膜结构，涵盖了一半以上的细胞内膜系统，但内质网被细分为专门的子区室，包括形态、膜接触位点 (MCS) 和从头细胞器生物发生域。在这篇综述中，我们讨论了最近出现的证据，这些证据表明，为了应对营养应激，细胞通过两种主要机制对这些亚区室 ER 结构域进行重组：通过调节 MCS 和细胞器搭便车对形态 ER 结构域进行非破坏性重塑，以及内质网自噬对特殊结构域的破坏性重塑。我们进一步强调并提出膜脂代谢在饥饿期间内质网重塑中的关键作用。