Regulation of Plasma Membrane Sterol Homeostasis by Nonvesicular Lipid Transport

• Published in: Contact Vol. 4; p. 25152564211042451
• Main Authors: Zheng Koh, Dylan Hong, Saheki, Yasunori
• Format: Book Review Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 2021; Sage Publications Ltd; SAGE Publishing
• Subjects: Biosynthesis; Cell membranes; Cell signaling; Cellular structure; Endoplasmic reticulum; Eukaryotes; Homeostasis; Lipid transfer proteins; Lipids; Membrane fusion; Membranes; Organelles; Plasma; Proteins; Review; Sterols; Structural integrity; Yeasts; cholesterol; endosome; nonvesicular; plasma membrane; lipid transfer protein; endoplasmic reticulum
• ISSN: 2515-2564; 2515-2564
• DOI: 10.1177/25152564211042451

Sterol contributes to the structural integrity of cellular membranes and plays an important role in the regulation of cell signaling in eukaryotes. It is either produced in the endoplasmic reticulum or taken up from the extracellular environment. In most eukaryotic cells, however, the majority of sterol is enriched in the plasma membrane. Thus, the transport of sterol between the plasma membrane and other organelles, including the endoplasmic reticulum, is crucial for maintaining sterol homeostasis. While vesicular transport that relies on membrane budding and fusion reactions plays an important role in bulk sterol transport, this mode of transport is slow and non-selective. Growing evidence suggests a critical role of nonvesicular transport mediated by evolutionarily conserved families of lipid transfer proteins in more rapid and selective delivery of sterol. Some lipid transfer proteins act primarily at the sites of contacts formed between the endoplasmic reticulum and other organelles or the plasma membrane without membrane fusion. In this review, we describe the similarities and differences of sterol biosynthesis and uptake in mammals and yeast and discuss the role of their lipid transfer proteins in maintaining plasma membrane sterol homeostasis.