scholarly journals ACSL3 is a novel GABARAPL2 interactor that links ufmylation and lipid droplet biogenesis

2020 ◽  
Author(s):  
Franziska Eck ◽  
Manuel Kaulich ◽  
Christian Behrends
Keyword(s):  
Functional Analysis ◽  
Lipid Droplet ◽  
Protein Complexes ◽  
Transmembrane Protein ◽  
Major Drawback ◽  
Interacting Protein ◽  
Binding Partner ◽  
Lipid Droplet Formation ◽  
Atg Genes ◽  
Interaction Proteomics

AbstractWhile studies of ATG genes in knockout models led to an explosion of knowledge about the functions of autophagy components, the exact roles of LC3/GABARAP proteins are still poorly understood. A major drawback for their understanding is that the available interactome data was largely acquired using overexpression systems. To overcome these limitations, we employed CRISPR/Cas9-based genome-editing to generate a panel of cells in which human ATG8 genes were tagged at their natural chromosomal locations with an N-terminal affinity epitope. This cellular resource was exemplarily employed to map endogenous GABARAPL2 protein complexes in response to autophagic modulation using interaction proteomics. This approach identified the ER transmembrane protein and lipid droplet biogenesis factor ACSL3 as a stabilizing GABARAPL2-binding partner. Through this interaction, the GABARAPL2-interacting protein and UFM1-activating enzyme UBA5 becomes anchored at the ER membrane. Functional analysis unveiled ACSL3 and lipid droplet formation as novel regulators of the enigmatic UFM1 conjugation pathway.

scholarly journals ACSL3 is a novel GABARAPL2 interactor that links ufmylation and lipid droplet biogenesis

2020 ◽  
Vol 133 (18) ◽  
pp. jcs243477 ◽  
Author(s):  
Franziska Eck ◽  
Santosh Phuyal ◽  
Matthew D. Smith ◽  
Manuel Kaulich ◽  
Simon Wilkinson ◽  
...  
Keyword(s):  
Binding Site ◽  
Genome Editing ◽  
Lipid Droplet ◽  
Protein Complexes ◽  
Major Drawback ◽  
Binding Partner ◽  
Atg Genes ◽  
Interaction Proteomics

ABSTRACTWhile studies of the autophagy-related (ATG) genes in knockout models have led to an explosion of knowledge about the functions of autophagy components, the exact roles of LC3 and GABARAP family proteins (human ATG8 equivalents) are still poorly understood. A major drawback in understanding their roles is that the available interactome data has largely been acquired using overexpression systems. To overcome these limitations, we employed CRISPR/Cas9-based genome-editing to generate a panel of cells in which human ATG8 genes were tagged at their natural chromosomal locations with an N-terminal affinity epitope. This cellular resource was employed to map endogenous GABARAPL2 protein complexes using interaction proteomics. This approach identified the ER-associated protein and lipid droplet (LD) biogenesis factor ACSL3 as a stabilizing GABARAPL2-binding partner. GABARAPL2 bound ACSL3 in a manner dependent on its LC3-interacting regions, whose binding site in GABARAPL2 was required to recruit the latter to the ER. Through this interaction, the UFM1-activating enzyme UBA5 became anchored at the ER. Furthermore, ACSL3 depletion and LD induction affected the abundance of several ufmylation components and ER-phagy. Together these data allow us to define ACSL3 as a novel regulator of the enigmatic UFM1 conjugation pathway.

ChemInform Abstract: Beauveriolides, Specific Inhibitors of Lipid Droplet Formation in Mouse Macrophages, Produced by Beauveria sp. FO-6979.

ChemInform ◽  
2010 ◽  
Vol 30 (27) ◽  
pp. no-no
Author(s):  
Ichiji Namatame ◽  
Hiroshi Tomoda ◽  
Shuyi Si ◽  
Yuichi Yamaguchi ◽  
Rokuro Masuma ◽  
...  
Keyword(s):  
Lipid Droplet ◽  
Droplet Formation ◽  
Lipid Droplet Formation ◽  
Mouse Macrophages ◽  
Specific Inhibitors

P0952 : Transient hepatic overexpression of the insuline-like growth factor 2 (IGF2) induces lipid droplet formation

2015 ◽  
Vol 62 ◽  
pp. S702-S703 ◽  
Author(s):  
S.M. Kessler ◽  
S. Laggai ◽  
E. Van Wonterghem ◽  
R.E. Vandenbroucke ◽  
M. Ogris ◽  
...  
Keyword(s):  
Growth Factor ◽  
Lipid Droplet ◽  
Droplet Formation ◽  
Lipid Droplet Formation

scholarly journals MicroRNA-122 Inhibits Lipid Droplet Formation and Hepatic Triglyceride Accumulation via Yin Yang 1

2017 ◽  
Vol 44 (4) ◽  
pp. 1651-1664 ◽  
Author(s):  
Guo-yi Wu ◽  
Chen Rui ◽  
Ji-qiao Chen ◽  
Eiketsu Sho ◽  
Shan-shan Zhan ◽  
...  
Keyword(s):  
Quantitative Pcr ◽  
Lipid Droplet ◽  
Droplet Formation ◽  
Luciferase Assay ◽  
Luciferase Reporter ◽  
Hepatic Triglyceride ◽  
Yin Yang 1 ◽  
Lipid Droplet Formation ◽  
Huh7 Cells ◽  
Yin Yang

Background/Aims: An increase in intracellular lipid droplet formation and hepatic triglyceride (TG) content usually results in nonalcoholic fatty liver disease. However, the mechanisms underlying the regulation of hepatic TG homeostasis remain unclear. Methods: Oil red O staining and TG measurement were performed to determine the lipid content. miRNA expression was evaluated by quantitative PCR. A luciferase assay was performed to validate the regulation of Yin Yang 1 (YY1) by microRNA (miR)-122. The effects of miR-122 expression on YY1 and its mechanisms involving the farnesoid X receptor and small heterodimer partner (FXR-SHP) pathway were evaluated by quantitative PCR and Western blot analyses. Results: miR-122 was downregulated in free fatty acid (FFA)-induced steatotic hepatocytes, and streptozotocin and high-fat diet (STZ-HFD) induced nonalcoholic steatohepatitis (NASH) in mice. Transfection of hepatocytes with miR-122 mimics before FFA induction inhibited lipid droplet formation and TG accumulation in vitro. These results were verified by overexpressing miR-122 in the livers of STZ-HFD-induced NASH mice. The 3’-untranslated region (3’UTR) of YY1 mRNA is predicted to contain an evolutionarily conserved miR-122 binding site. In silico searches, a luciferase reporter assay and quantitative PCR analysis confirmed that miR-122 directly bound to the YY1 3’UTR to negatively regulate YY1 mRNA in HepG2 and Huh7 cells. The (FXR-SHP) signaling axis, which is downstream of YY1, may play a key role in the mechanism of miR-122-regulated lipid homeostasis. YY1-FXR-SHP signaling, which is negatively regulated by FFA, was enhanced by miR-122 overexpression. This finding was also confirmed by overexpression of miR-122 in the livers of NASH mice. Conclusions: The present results indicate that miR-122 plays an important role in lipid (particularly TG) accumulation in the liver by reducing YY1 mRNA stability to upregulate FXR-SHP signaling.

scholarly journals Perilipin1 promotes unilocular lipid droplet formation through the activation of Fsp27 in adipocytes

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Zhiqi Sun ◽  
Jingyi Gong ◽  
Han Wu ◽  
Wenyi Xu ◽  
Lizhen Wu ◽  
...  
Keyword(s):  
Lipid Droplet ◽  
Droplet Formation ◽  
Lipid Droplet Formation

Characterisation of gene expression related to milk fat synthesis in the mammary tissue of lactating yaks

2017 ◽  
Vol 84 (3) ◽  
pp. 283-288 ◽  
Author(s):  
Jung Nam Lee ◽  
Yong Wang ◽  
Ya Ou Xu ◽  
Yu Can Li ◽  
Fang Tian ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dairy Cows ◽  
Lipid Droplet ◽  
Milk Fat ◽  
De Novo ◽  
Droplet Formation ◽  
Synthesis Process ◽  
Lipid Droplet Formation ◽  
Fat Synthesis ◽  
Milk Fat Synthesis

This research communication describes the profile of gene expression related to the synthesis of yak milk as determined via quantitative reverse transcription polymerase chain reaction (RT-qPCR). Significant up-regulation during lactation were observed in genes related to fatty acid (FA) uptake from blood (LPL, CD36), intracellular FA transport (FABP3), intracellular FA activation of long- and short-chain FAs (ACSS1, ACSS2, ACSL1), de novo synthesis (ACACA), desaturation (SCD), triacyglycerol (TAG) synthesis (AGPAT6, GPAM, LPIN1), lipid droplet formation (PLIN2, BTN1A1, XDH), ketone body utilisation (BDH1, OXCT1), and transcription regulation (THRSP, PPARGC1A). In particular, intracellular de novo FA synthesis (ACSS2, ACACA, and FABP3) and TAG synthesis (GPAM, AGPAT6, and LPIN1), whose regulation might be orchestrated as part of the gene network under the control of SERBF1 in the milk fat synthesis process, were more activated compared to levels in dairy cows. However, the genes involved in lipid droplet formation (PLIN2, XDH, and BTN1A1) were expressed at lower levels compared to those in dairy cows, where these genes are mainly controlled by the PPARG regulator.

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