Aster-B coordinates with Arf1 to regulate mitochondrial cholesterol transport
| Autor: | Yuguang Shi, John Paul Andersen, Jun Zhang, Jia Nie, Jiankang Liu, Haoran Sun, Xuyun Liu |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Regulator CPT-1 Carnitine Palmitoyltransferase I KRPH Kreb's Ringer Phosphate Buffer with HEPES GTPase Mitochondrion Endoplasmic Reticulum GRAMD1B GRAM Domain-Containing Protein 1B PBS Phosphate-Buffered saline Mice chemistry.chemical_compound 0302 clinical medicine Arf1 Pancreatic Elastase MAM Mitochondria-Associated Membrane GRAMD1b ER Endoplasmic Reticulum Mitochondria Cell biology Cholesterol COPA Coatomer Subunit Alpha GAPDH Glyceraldehyde 3-Phosphate Dehydrogenase Mitochondrial Membranes Original Article lipids (amino acids peptides and proteins) lcsh:Internal medicine VASt domain VAD1 analog of StAR-Related Lipid Transfer Domain 030209 endocrinology & metabolism MTS Mitochondrial Targeting Sequence Cell Line DMEM Dulbecco's Modified Eagle's Medium 03 medical and health sciences Cholesterol transport Animals Humans COPI Coat Protein Complex I Fatty acids lcsh:RC31-1245 Molecular Biology Gene Mitochondrial transport CRISPR/Cas 9 Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-Associated Protein 9 Endoplasmic reticulum STARD1 Steroidogenic Acute Regulatory Protein Membrane Proteins Membrane Transport Proteins Biological Transport Cell Biology 030104 developmental biology Arf1 ADP Ribosylation Factor 1 chemistry OCR Oxygen Consumption Rate Cell culture ADP-Ribosylation Factor 1 MCD Methyl-Beta Cyclodextrin Carrier Proteins HeLa Cells |
| Zdroj: | Molecular Metabolism Molecular Metabolism, Vol 42, Iss, Pp 101055-(2020) |
| ISSN: | 2212-8778 |
| DOI: | 10.1016/j.molmet.2020.101055 |
| Popis: | Objective Cholesterol plays a pivotal role in mitochondrial steroidogenesis, membrane structure, and respiration. Mitochondrial membranes are intrinsically low in cholesterol content and therefore must be replenished with cholesterol from other subcellular membranes. However, the molecular mechanisms underlying mitochondrial cholesterol transport remains poorly understood. The Aster-B gene encodes a cholesterol binding protein recently implicated in cholesterol trafficking from the plasma membrane to the endoplasmic reticulum (ER). In this study, we investigated the function and underlying mechanism of Aster-B in mediating mitochondrial cholesterol transport. Methods CRISPR/Cas9 gene editing was carried out to generate cell lines deficient in Aster-B expression. The effect of Aster-B deficiency on mitochondrial cholesterol transport was examined by both confocal imaging analysis and biochemical assays. Deletion mutational analysis was also carried out to identify the function of a putative mitochondrial targeting sequence (MTS) at the N-terminus of Aster-B for its role in targeting Aster-B to mitochondria and in mediating mitochondrial cholesterol trafficking. Results Ablation of Aster-B impaired cholesterol transport from the ER to mitochondria, leading to a significant decrease in mitochondrial cholesterol content. Aster-B is also required for mitochondrial transport of fatty acids derived from hydrolysis of cholesterol esters. A putative MTS at the N-terminus of Aster-B mediates the mitochondrial cholesterol uptake. Deletion of the MTS or ablation of Arf1 GTPase which is required for mitochondrial translocation of ER proteins prevented mitochondrial cholesterol transport, leading to mitochondrial dysfunction. Conclusions We identified Aster-B as a key regulator of cholesterol transport from the ER to mitochondria. Aster-B also coordinates mitochondrial cholesterol trafficking with uptake of fatty acids derived from cholesterol esters, implicating the Aster-B protein as a novel regulator of steroidogenesis. Highlights • Ablation of Aster-B impairs cholesterol transport from the ER to mitochondria. • Aster-B couples mitochondrial cholesterol transport with uptake of fatty acids derived from hydrolysis of cholesterol ester. • An MTS at the N-terminus of Aster-B is required for the mitochondrial targeting and cholesterol transport. • Ablation or inhibition of Arf1 disrupts the mitochondrial cholesterol transport and causes mitochondrial dysfunction. |
| Databáze: | OpenAIRE |
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