Dataset Information

The human cholesterogenic enzymes DHCR14 and LBR are differentially regulated transcriptionally and post-translationally

ABSTRACT: Cholesterol synthesis is a tightly regulated process, both transcriptionally and post-translationally. Transcriptional control of cholesterol synthesis is relatively well understood. However, of the ~20 enzymes in cholesterol biosynthesis, post-translational regulation has only been examined for a small number. Three of the four sterol reductases, DHCR7, DHCR14 and LBR, share evolutionary ties with a high level of sequence homology and predicted structural homology. Despite their homology and that they uniquely share the same 14 reductase activity in cholesterol biosynthesis, little is known about the post-translational regulation of DHCR14 and LBR. Using CHO-7 cells stably expressing epitope tagged DHCR14 or LBR we investigated the post-translational regulation of these enzymes. We found that DHCR14 and LBR undergo differential post translational regulation, with DHCR14 being rapidly turned over, triggered by cholesterol and other sterol intermediates while LBR remained stable. DHCR14 is degraded via the ubiquitin-proteasome system and we identified several DHCR14 and DHCR7 putative interaction partners including the E3 ligase WWP2, which plays a role in the basal and cholesterol-mediated regulation of DHCR14. Interestingly, we found that gene expression across an array of human tissues showed that the C14-SRs gene expression is negatively related; one enzyme or the other tends to be predominately expressed in each tissue. Overall, our findings indicate that while LBR tends to be the constitutively active C14-SR, DHCR14 levels are tuneable, responding to the local cellular demands for cholesterol.

INSTRUMENT(S): Orbitrap Fusion Lumos, LTQ Orbitrap Velos

ORGANISM(S): Homo Sapiens (human) Cricetulus Griseus (chinese Hamster) (cricetulus Barabensis Griseus)

TISSUE(S): Cell Culture

SUBMITTER: Gene Hart-Smith

LAB HEAD: Andrew J Brown

PROVIDER: PXD016417 | Pride | 2020-01-15

REPOSITORIES: Pride

ACCESS DATA

Publications

Twin enzymes, divergent control: The cholesterogenic enzymes DHCR14 and LBR are differentially regulated transcriptionally and post-translationally.

Capell-Hattam Isabelle M IM Sharpe Laura J LJ Qian Lydia L Hart-Smith Gene G Prabhu Anika V AV Brown Andrew J AJ

The Journal of biological chemistry 20200107 9

Cholesterol synthesis is a tightly regulated process, both transcriptionally and post-translationally. Transcriptional control of cholesterol synthesis is relatively well-understood. However, of the ∼20 enzymes in cholesterol biosynthesis, post-translational regulation has only been examined for a small number. Three of the four sterol reductases in cholesterol production, 7-dehydrocholesterol reductase (DHCR7), 14-dehydrocholesterol reductase (DHCR14), and lamin-B receptor (LBR), share evolutio ...[more]

PMID: 31911440

Similar Datasets

Project description:Background: It is recognized that atherosclerosis can regresses at least in animal models. However, little is known about the mechanisms. We induced regression of advanced atherosclerosis in apolipoprotein E deficient (APOE/) mice and studied underlying mechanisms. Unexpectedly, our study led to the role of interleukin-7 (IL-7) in atherogenesis. Methods and Results: We treated APOE/ mice fed a high cholesterol diet for 30 weeks to induce advanced lesions with a helper-dependent adenoviral vector expressing human apoE3 (HDAd-gE3), and analyzed the regression of atherosclerosis after 41 weeks. Using microarray analysis, we identified IL-7 as one of most significantly affected genes by lowering cholesterol. To answer why IL-7 is downregulated by reduced cholesterol, we studied effects of IL-7 on endothelial cells (ECs). Our major findings were (1) long-term lowering cholesterol induced regression of advanced atherosclerosis. (2) Microarray analysis identified multiple signaling pathways affected by lowering cholesterol. (3) Correction for multiple testing revealed that IL-7 expression was downregulated, whereas gamma-sarcoglycan and Î±-actin were upregulated. (4) Oxidized LDL upregulated IL-7 expression in macrophages but not in aorta ECs or smooth muscle cells. (5) IL-7 increased the expression of cell adhesion molecules and chemokine in ECs and promoted monocyte adhesion to ECs. (6) Systemic elevation of IL-7 induced inflammatory response and recruited monocyte/macrophage to the lesions without increasing plasma cholesterol. Conclusion: Our finding suggest that IL-7 inflames endothelium and triggers the adhesion/recruitment of monocyte/macrophages to the atherosclerotic lesions and thus plays a direct role in development of atherosclerosis. Key Words: arteriosclerosis, gene therapy, hypercholesterolemia, interleukins, cell adhesion molecules Female APOE-/- mice (8 weeks of age) on a C57BL/6 background were purchased from Jackson Laboratory and were fed a diet containing 0.2% (w/w) cholesterol and 10% (v/w) coconut oil to induce atherosclerosis for 30 weeks. Mice were then divided into 3 groups, (n=15/group), treated with a tail vein injection of helper-dependent adenovirus expressing human apolipoprotein E3 (HDAd-gE3, 5 x 1012 viral particles/kg, n=11, vector), empty vector (HDAd-0, 5 x 1012 VP/kg, n=11, vector control) or phosphate buffered saline (PBS, vehicle) and sacrificed 10 days after. Three aortas extending sinus to arch were pooled for RNA extraction with an RNeasy kit (Qiagen). Sample ID 12031: E4: vector control (HDAd-0) 12043: E5: vector control 12046: V2: vector 12047: V3: vector 12048: V4: vector 12051: B1: vehicle (PBS) 12053: B3: vehicle 12054: B4: vehicle 12039: E3: vector control

Dataset Information

The human cholesterogenic enzymes DHCR14 and LBR are differentially regulated transcriptionally and post-translationally

Publications

Twin enzymes, divergent control: The cholesterogenic enzymes DHCR14 and LBR are differentially regulated transcriptionally and post-translationally.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure