| Autor: |
Sepalika Bandara, Jean Moon, Srinivasagan Ramkumar, Johannes von Lintig |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
|
| Zdroj: |
Journal of Lipid Research, Vol 64, Iss 5, Pp 100369- (2023) |
| Druh dokumentu: |
article |
| ISSN: |
0022-2275 |
| DOI: |
10.1016/j.jlr.2023.100369 |
| Popis: |
The scavenger receptor class B type 1 (SR-B1) facilitates uptake of cholesterol and carotenoids into the plasma membrane (PM) of mammalian cells. Downstream of SR-B1, ASTER-B protein mediates the nonvesicular transport of cholesterol to mitochondria for steroidogenesis. Mitochondria also are the place for the processing of carotenoids into diapocarotenoids by β-carotene oxygenase-2. However, the role of these lipid transport proteins in carotenoid metabolism has not yet been established. Herein, we showed that the recombinant StART-like lipid-binding domain of ASTER-A and B preferentially binds oxygenated carotenoids such as zeaxanthin. We established a novel carotenoid uptake assay and demonstrated that ASTER-B expressing A549 cells transport zeaxanthin to mitochondria. In contrast, the pure hydrocarbon β-carotene is not transported to the organelles, consistent with its metabolic processing to vitamin A in the cytosol by β-carotene oxygenase-1. Depletion of the PM from cholesterol by methyl-β-cyclodextrin treatment enhanced zeaxanthin but not β-carotene transport to mitochondria. Loss-of-function assays by siRNA in A549 cells and the absence of zeaxanthin accumulation in mitochondria of ARPE19 cells confirmed the pivotal role of ASTER-B in this process. Together, our study in human cell lines established ASTER-B protein as key player in nonvesicular transport of zeaxanthin to mitochondria and elucidated the molecular basis of compartmentalization of the metabolism of nonprovitamin A and provitamin A carotenoids in mammalian cells. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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