Non-vesicular lipid transport by lipid-transfer proteins and beyond

• Published in: Nature reviews. Molecular cell biology Vol. 11; no. 10; pp. 739 - 750
• Main Author: Lev, Sima
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.10.2010; Nature Publishing Group
• Subjects: 631/443/319/1557; 631/45/287; 631/80/313/2380; Animals; Biochemistry; Biological Transport; Biology; Biomedical and Life Sciences; Cancer Research; Carrier Proteins - metabolism; Cell Biology; Cellular proteins; Cholesterol - metabolism; Developmental Biology; Diffusion; Diglycerides - metabolism; Golgi Apparatus - metabolism; Health aspects; Homeostasis; Intracellular Membranes - metabolism; Life Sciences; Lipid Bilayers - metabolism; Lipids; Lipids - physiology; Membranes; Metabolism; Metabolites; Physiological aspects; Proteins; review-article; Signal transduction; Stem Cells; United States
• ISSN: 1471-0072; 1471-0080; 1471-0080
• DOI: 10.1038/nrm2971

Key Points Non-vesicular lipid transport plays a crucial part in intracellular lipid trafficking and can be mediated by spontaneous lipid transport or by lipid-transfer proteins (LTPs). LTPs markedly facilitate (by several orders of magnitude) the transport of lipids between membranes in vitro . Non-vesicular lipid transport is thought to be greatly enhanced at membrane contact sites; small cytosolic gaps between the endoplasmic reticulum membrane and virtually all other cellular organelles. LTPs do not mediate a simple vectorial lipid transport from one membrane to another. Rather, they facilitate lipid transport between membranes according to their membrane environment. LTPs use their lipid-transfer activity to regulate various cellular processes, including vesicular trafficking, signal transduction and lipid metabolism. Non-vesicular lipid transport between intracellular membranes can be mediated by spontaneous lipid transfer or lipid-transfer proteins (LTPs) and is crucial for maintaining the identities of different cellular membranes. Current studies focus on further understanding the mechanisms of non-vesicular lipid transport and elucidating the role of LTPs in intact cells. The movement of lipids within and between intracellular membranes is mediated by different lipid transport mechanisms and is crucial for maintaining the identities of different cellular organelles. Non-vesicular lipid transport has a crucial role in intracellular lipid trafficking and distribution, but its underlying mechanisms remain unclear. Lipid-transfer proteins (LTPs), which regulate diverse lipid-mediated cellular processes and accelerate vectorial transport of lipid monomers between membranes in vitro , could potentially mediate non-vesicular intracellular lipid trafficking. Understanding the mechanisms by which lipids are transported and distributed between cellular membranes, and elucidating the role of LTPs in intracellular lipid transport and homeostasis, are currently subjects of intensive study.