scholarly journals Acetyl-CoA mediated autoacetylation of fatty acid synthase in de novo lipogenesis

2022 ◽  
Author(s):  
Ting Miao ◽  
Jinoh Kim ◽  
Ping Kang ◽  
Hua Bai
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Regulatory System ◽  
De Novo Lipogenesis ◽  
Lysine Acetylation ◽  
Dependent Manner ◽  
Acetyl Coa ◽  
Lipogenic Genes

De novo lipogenesis (DNL) is a highly regulated metabolic process, which is known to be activated through transcriptional regulation of lipogenic genes, including fatty acid synthase (FASN). Unexpectedly, we find that the expression of FASN protein remains unchanged during Drosophila larval development when lipogenesis is hyperactive. Instead, acetylation modification of FASN is highly upregulated in fast-growing larvae. We further show that lysine K813 is highly acetylated in developing larvae, and its acetylation is required for upregulated FASN activity, body fat accumulation, and normal development. Intriguingly, K813 is rapidly autoacetylated by acetyl-CoA in a dosage-dependent manner, independent of known acetyltransferases. Furthermore, the autoacetylation of K813 is mediated by a conserved P-loop-like motif (N-xx-G-x-A). In summary, this work uncovers a novel role of acetyl-CoA-mediated autoacetylation of FASN in developmental lipogenesis and reveals a self-regulatory system that controls metabolic homeostasis by linking acetyl-CoA, lysine acetylation, and DNL.

scholarly journals Central Resistin Regulates Hypothalamic and Peripheral Lipid Metabolism in a Nutritional-Dependent Fashion

Endocrinology ◽  
2008 ◽  
Vol 149 (9) ◽  
pp. 4534-4543 ◽  
Author(s):  
María J. Vázquez ◽  
C. Ruth González ◽  
Luis Varela ◽  
Ricardo Lage ◽  
Sulay Tovar ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
Mrna Expression ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Acid Synthesis ◽  
Inhibitory Effect ◽  
De Novo Lipogenesis ◽  
Dependent Manner ◽  
Fed State

Evidence suggests that the adipocyte-derived hormone resistin (RSTN) directly regulates both feeding and peripheral metabolism through, so far, undefined hypothalamic-mediated mechanisms. Here, we demonstrate that the anorectic effect of RSTN is associated with inappropriately decreased mRNA expression of orexigenic (agouti-related protein and neuropeptide Y) and increased mRNA expression of anorexigenic (cocaine and amphetamine-regulated transcript) neuropeptides in the arcuate nucleus of the hypothalamus. Of interest, RSTN also exerts a profound nutrition-dependent inhibitory effect on hypothalamic fatty acid metabolism, as indicated by increased phosphorylation levels of both AMP-activated protein kinase and its downstream target acetyl-coenzyme A carboxylase, associated with decreased expression of fatty acid synthase in the ventromedial nucleus of the hypothalamus. In addition, we also demonstrate that chronic central RSTN infusion results in decreased body weight and major changes in peripheral expression of lipogenic enzymes, in a tissue-specific and nutrition-dependent manner. Thus, in the fed state central RSTN is associated with induced expression of fatty acid synthesis enzymes and proinflammatory cytokines in liver, whereas its administration in the fasted state does so in white adipose tissue. Overall, our results indicate that RSTN controls feeding and peripheral lipid metabolism and suggest that hepatic RSTN-induced insulin resistance may be mediated by central activation of de novo lipogenesis in liver.

scholarly journals Hepatic De Novo Lipogenesis Is Present in Liver-Specific ACC1-Deficient Mice

2007 ◽  
Vol 27 (5) ◽  
pp. 1881-1888 ◽  
Author(s):  
Naomoto Harada ◽  
Zenjun Oda ◽  
Yoshikazu Hara ◽  
Koji Fujinami ◽  
Mayumi Okawa ◽  
...  
Keyword(s):  
Fatty Acid Synthase ◽  
De Novo ◽  
Physiological Role ◽  
De Novo Lipogenesis ◽  
Null Mouse ◽  
Acetyl Coa ◽  
Dual Inhibitor ◽  
Malonyl Coa ◽  
Deficient Mice

ABSTRACT Acetyl coenzyme A (acetyl-CoA) carboxylase (ACC) catalyzes carboxylation of acetyl-CoA to form malonyl-CoA. In mammals, two isozymes exist with distinct physiological roles: cytosolic ACC1 participates in de novo lipogenesis (DNL), and mitochondrial ACC2 is involved in negative regulation of mitochondrial β-oxidation. Since systemic ACC1 null mice were embryonic lethal, to clarify the physiological role of ACC1 in hepatic DNL, we generated the liver-specific ACC1 null mouse by crossbreeding of an Acc1 lox(ex46) mouse, in which exon 46 of Acc1 was flanked by two loxP sequences and the liver-specific Cre transgenic mouse. In liver-specific ACC1 null mice, neither hepatic Acc1 mRNA nor protein was detected. However, to compensate for ACC1 function, hepatic ACC2 protein and activity were induced 1.4 and 2.2 times, respectively. Surprisingly, hepatic DNL and malonyl-CoA were maintained at the same physiological levels as in wild-type mice. Furthermore, hepatic DNL was completely inhibited by an ACC1/2 dual inhibitor, 5-tetradecyloxyl-2-furancarboxylic acid. These results strongly demonstrate that malonyl-CoA from ACC2 can access fatty acid synthase and become the substrate for the DNL pathway under the unphysiological circumstances that result with ACC1 disruption. Therefore, there does not appear to be strict compartmentalization of malonyl-CoA from either of the ACC isozymes in the liver.

scholarly journals The Glucose Sensor ChREBP Links De Novo Lipogenesis to PPARγ Activity and Adipocyte Differentiation

Endocrinology ◽  
2015 ◽  
Vol 156 (11) ◽  
pp. 4008-4019 ◽  
Author(s):  
Nicole Witte ◽  
Matthias Muenzner ◽  
Janita Rietscher ◽  
Miriam Knauer ◽  
Steffi Heidenreich ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Insulin Sensitivity ◽  
Fatty Acid Synthase ◽  
Adipocyte Differentiation ◽  
De Novo ◽  
Dominant Negative ◽  
De Novo Lipogenesis ◽  
Dependent Manner ◽  
Endogenous Fatty Acid

Reduced de novo lipogenesis in adipose tissue, often observed in obese individuals, is thought to contribute to insulin resistance. Besides trapping excess glucose and providing for triglycerides and energy storage, endogenously synthesized lipids can function as potent signaling molecules. Indeed, several specific lipids and their molecular targets that mediate insulin sensitivity have been recently identified. Here, we report that carbohydrate-response element-binding protein (ChREBP), a transcriptional inducer of glucose use and de novo lipogenesis, controls the activity of the adipogenic master regulator peroxisome proliferator-activated receptor (PPAR)γ. Expression of constitutive-active ChREBP in precursor cells activated endogenous PPARγ and promoted adipocyte differentiation. Intriguingly, ChREBP-constitutive-active ChREBP expression induced PPARγ activity in a fatty acid synthase-dependent manner and by trans-activating the PPARγ ligand-binding domain. Reducing endogenous ChREBP activity by either small interfering RNA-mediated depletion, exposure to low-glucose concentrations, or expressing a dominant-negative ChREBP impaired differentiation. In adipocytes, ChREBP regulated the expression of PPARγ target genes, in particular those involved in thermogenesis, similar to synthetic PPARγ ligands. In summary, our data suggest that ChREBP controls the generation of endogenous fatty acid species that activate PPARγ. Thus, increasing ChREBP activity in adipose tissue by therapeutic interventions may promote insulin sensitivity through PPARγ.

Regulation of the SREBP transcription factors by mTORC1

2011 ◽  
Vol 39 (2) ◽  
pp. 495-499 ◽  
Author(s):  
Caroline A. Lewis ◽  
Beatrice Griffiths ◽  
Claudio R. Santos ◽  
Mario Pende ◽  
Almut Schulze
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Target Genes ◽  
De Novo ◽  
Regulatory Element ◽  
Cholesterol Biosynthesis ◽  
Mammalian Target Of Rapamycin ◽  
Lipid Biosynthesis ◽  
De Novo Lipogenesis ◽  
Genes Encoding

In recent years several reports have linked mTORC1 (mammalian target of rapamycin complex 1) to lipogenesis via the SREBPs (sterol-regulatory-element-binding proteins). SREBPs regulate the expression of genes encoding enzymes required for fatty acid and cholesterol biosynthesis. Lipid metabolism is perturbed in some diseases and SREBP target genes, such as FASN (fatty acid synthase), have been shown to be up-regulated in some cancers. We have previously shown that mTORC1 plays a role in SREBP activation and Akt/PKB (protein kinase B)-dependent de novo lipogenesis. Our findings suggest that mTORC1 plays a crucial role in the activation of SREBP and that the activation of lipid biosynthesis through the induction of SREBP could be part of a regulatory pathway that co-ordinates protein and lipid biosynthesis during cell growth. In the present paper, we discuss the increasing amount of data supporting the potential mechanisms of mTORC1-dependent activation of SREBP as well as the implications of this signalling pathway in cancer.

scholarly journals Targeting de novo lipogenesis and the Lands cycle induces ferroptosis in KRAS-mutant lung cancer

2021 ◽  
Author(s):  
Caterina Bartolacci ◽  
Cristina Andreani ◽  
Goncalo Dias do Vale ◽  
Stefano Berto ◽  
Margherita Melegari ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Fatty Acid ◽  
Metabolic Networks ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Genetically Engineered ◽  
De Novo Lipogenesis ◽  
Main Process

Mutant KRAS (KM) is the most common oncogene in lung cancer (LC). KM regulates several metabolic networks, but their role in tumorigenesis is still not sufficiently characterized to be exploited in cancer therapy. To identify metabolic networks specifically deregulated in KMLC, we characterized the lipidome of genetically engineered LC mice, cell lines, patient derived xenografts and primary human samples. We also determined that KMLC, but not EGFR-mutant (EGFR-MUT) LC, is enriched in triacylglycerides (TAG) and phosphatidylcholines (PC). We also found that KM upregulates fatty acid synthase (FASN), a rate-limiting enzyme in fatty acid (FA) synthesis promoting the synthesis of palmitate and PC. We determined that FASN is specifically required for the viability of KMLC, but not of LC harboring EGFR-MUT or wild type KRAS. Functional experiments revealed that FASN inhibition leads to ferroptosis, a reactive oxygen species (ROS)-and iron-dependent cell death. Consistently, lipidomic analysis demonstrated that FASN inhibition in KMLC leads to accumulation of PC with polyunsaturated FA (PUFA) chains, which are the substrate of ferroptosis. Integrating lipidomic, transcriptome and functional analyses, we demonstrated that FASN provides saturated (SFA) and monounsaturated FA (MUFA) that feed the Lands cycle, the main process remodeling oxidized phospholipids (PL), such as PC. Accordingly, either inhibition of FASN or suppression of the Lands cycle enzymes PLA2 and LPCAT3, promotes the intracellular accumulation of lipid peroxides and ferroptosis in KMLC both in vitro and in vivo. Our work supports a model whereby the high oxidative stress caused by KM dictates a dependency on newly synthesized FA to repair oxidated phospholipids, establishing a targetable vulnerability. These results connect KM oncogenic signaling, FASN induction and ferroptosis, indicating that FASN inhibitors already in clinical trial in KMLC patients (NCT03808558) may be rapidly deployed as therapy for KMLC.

Abstract 325: Response Gene to Complement 32 Deficiency Protects Against Hepatic Steatosis by Inhibiting Lipogenesis in Mice

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Xiaobing Cui ◽  
Junna Luan ◽  
Shiyou Chen
Keyword(s):  
Hepatic Steatosis ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Regulatory Element ◽  
In Vitro Study ◽  
De Novo Lipogenesis ◽  
Dependent Manner ◽  
Response Gene ◽  
Normal Chow

Hepatic steatosis is associated with obesity due to the increased lipogenesis. Previously, we have found that RGC-32 (response gene to complement 32) deficiency prevents the mice from high-fat diet (HFD)-induced obesity and insulin resistance. The present study was conducted to determine the role of RGC-32 in the control of hepatic steatosis. We observed that hepatic RGC-32 expression was dramatically induced by HFD challenge. RGC-32 knockout (RGC32-/-) mice were resistant to HFD-induced hepatic steatosis. More importantly, hepatic triglyceride contents of RGC32-/- mice were significantly decreased compared with wild-type (WT) controls on both normal chow and HFD. Mechanistically, RGC-32 deficiency decreased expression of lipogenesis-related genes, sterol regulatory element (SRE) binding protein (SREBP)-1c, fatty acid synthase (FAS) and stearoyl-CoA desaturase-1 (SCD1). Our in vitro study showed that RGC-32 knockdown decreased while RGC-32 overexpression increased SCD1 expression in hepatocytes. Deletion or mutation of SRE in the SCD1 promoter abolished the function of RGC-32. These data demonstrate that RGC-32 contributes to HFD-induced hepatic steatosis by facilitating de novo lipogenesis in a SREBP-1c dependent manner. Therefore, RGC-32 may be a novel drug target in the treatment of hepatic steatosis and its related diseases.

scholarly journals A bioorthogonal chemical reporter for fatty acid synthase-dependent protein acylation

2021 ◽  
Author(s):  
Krithika P. Karthigeyan ◽  
Lizhi Zhang ◽  
David R. Loiselle ◽  
Timothy A.J. Haystead ◽  
Menakshi Bhat ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Matrix Protein ◽  
De Novo ◽  
Transmembrane Protein ◽  
Cellular Protein ◽  
Metabolic Labeling ◽  
Dependent Manner ◽  
Dependent Protein ◽  
Protein Acylation

Cells acquire fatty acids from dietary sources or via de novo palmitate production by fatty acid synthase (FASN). Although most cells express FASN at low levels, it is upregulated in cancers and during replication of many viruses. The precise role of FASN in disease pathogenesis is poorly understood, and whether de novo fatty acid synthesis contributes to host or viral protein acylation has been traditionally difficult to study. We describe a cell permeable, click-chemistry compatible alkynyl-acetate analog (Alk-4) that functions as a reporter of FASN-dependent protein acylation. In a FASN-dependent manner, Alk-4 selectively labeled the cellular protein interferon-induced transmembrane protein 3 (IFITM3) at its palmitoylation sites, and the HIV-1 matrix protein at its myristoylation site. Alk-4 metabolic labeling also enabled biotin-based purification and identification of more than 200 FASN-dependent acylated cellular proteins. Thus, Alk-4 is a useful bioorthogonal tool to selectively probe FASN-mediated protein acylation in normal and diseased states.

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