Regulation of cellular cholesterol distribution via non-vesicular lipid transport at ER-Golgi contact sites
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ABSTRACT:
PROVIDER: PRJNA1005938 | ENA |
REPOSITORIES: ENA
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Project description:Abnormal distribution of cellular cholesterol is associated with numerous diseases, including cardiovascular and neurodegenerative diseases. Regulated transport of cholesterol is critical for maintaining its proper distribution in the cell, yet the underlying mechanisms remain unclear. Here, we show that lipid transfer proteins, namely ORP9, OSBP, and GRAMD1s/Asters (GRAMD1a/GRAMD1b/GRAMD1c), control non-vesicular cholesterol transport at points of contact between the ER and the trans-Golgi network (TGN), thereby maintaining cellular cholesterol distribution. ORP9 localizes to the TGN via interaction between its tandem α-helices and ORP10/ORP11. ORP9 extracts PI4P from the TGN to prevent its overaccumulation and suppresses OSBP-mediated PI4P-driven cholesterol transport to the Golgi. By contrast, GRAMD1s transport excess cholesterol from the Golgi to the ER, thereby preventing its build-up. Cells lacking ORP9 exhibit accumulation of cholesterol at the Golgi, which is further enhanced by additional depletion of GRAMD1s with major accumulation in the plasma membrane. This is accompanied by chronic activation of the SREBP-2 signalling pathway. Our findings reveal the importance of regulated lipid transport at ER-Golgi contacts for maintaining cellular cholesterol distribution and homeostasis.
2023-09-24 | GSE240960 | GEO
Project description:Schizophrenia (SCZ) is a common, disabling mental illness with high heritability but complex, poorly understood genetic etiology. As the first phase of a genomic convergence analysis of SCZ, we generated 16.7 billion nucleotides of short read, shotgun sequences of cDNA from post-mortem cerebellar cortices of 14 patients and six matched controls. A rigorous analysis pipeline was developed for analysis of digital gene expression studies. Sequences aligned to approximately 33,200 transcripts in each sample, with average coverage of 450 reads per gene. Following adjustments for confounding clinical, sample and experimental sources of variation, 215 genes differed significantly in expression between cases and controls. Golgi apparatus, vesicular transport, membrane association, Zinc binding and regulation of transcription were over-represented among differentially expressed genes. Twenty three genes with altered expression and involvement in presynaptic vesicular transport, Golgi function and GABAergic neurotransmission define a unifying molecular hypothesis for dysfunction in cerebellar cortex in SCZ.
2008-11-12 | GSE12297 | GEO
Project description:Vesicular traffic and membrane contact sites between organelles enable the exchange of proteins, lipids, and metabolites. Recruitment of membrane tethers to contact sites between the endoplasmic reticulum (ER) and the plasma membrane is often triggered by calcium. In contrast, we reveal here a function for calcium in the repression of cholesterol export at membrane contact sites between the ER and the Golgi complex. We show that calcium efflux from ER stores induced by inositol-triphosphate [IP3] accumulation upon loss of the inositol 5-phosphatase INPP5A or sustained receptor signaling triggers the depletion of cholesterol and associated complex glycosphingolipids from the cell surface, resulting in a blockade of clathrin-independent endocytosis (CIE) of bacterial Shiga toxin. This phenotype is caused by the calcium-induced dissociation of oxysterol binding protein (OSBP) from the Golgi complex and from VAP-containing membrane contact sites. Our findings reveal a crucial function for INPP5A-mediated IP3 hydrolysis in the control of lipid exchange at membrane contact sites.
2021-05-06 | MTBLS2444 | MetaboLights
Project description:Schizophrenia (SCZ) is a common, disabling mental illness with high heritability but complex, poorly understood genetic etiology. As the first phase of a genomic convergence analysis of SCZ, we generated 16.7 billion nucleotides of short read, shotgun sequences of cDNA from post-mortem cerebellar cortices of 14 patients and six matched controls. A rigorous analysis pipeline was developed for analysis of digital gene expression studies. Sequences aligned to approximately 33,200 transcripts in each sample, with average coverage of 450 reads per gene. Following adjustments for confounding clinical, sample and experimental sources of variation, 215 genes differed significantly in expression between cases and controls. Golgi apparatus, vesicular transport, membrane association, Zinc binding and regulation of transcription were over-represented among differentially expressed genes. Twenty three genes with altered expression and involvement in presynaptic vesicular transport, Golgi function and GABAergic neurotransmission define a unifying molecular hypothesis for dysfunction in cerebellar cortex in SCZ. Experiment Overall Design: 16.7 billion nucleotides of shotgun, full length cDNA sequence data were generated using Illumina Genome Analyzer platforms with sequencing-by-synthesis (SBS) chemistry from 20 mRNA samples (Lister et al., 2008; Morin et al., 2008)(Mortazvi et al., 2008). mRNA samples were isolated post-mortem from the lateral hemispheres of the cerebellar cortices of 14 patients with SCZ and 6 control individuals (Paz et al., 2006; Bullock et al., In Press)(Table 1). Unrelated subjects were chosen to facilitate sampling of genetic heterogeneity (Freimer and Sabatti, 2004; McClellan et al., 2007). Cases and controls were approximately matched for age (cases, 45.2 + 11.8 years; controls 41.3 + 9.2 years), sex (all male), race, post-mortem interval (cases, 12.2 + 5.0 hours; controls 17.7 + 3.3 hours), cause of death, autopsy brain pH (cases, 6.54 + 0.19; controls 6.46 + 0.10) and RNA integrity number (cases, 8.06 + 0.53; controls, 7.87 + 0.41) (Table 1). 12.5 – 38.7 million, high quality sequences of length 32 – 36 bp were generated per sample (Table 2). Sequences were aligned to the human genome and RefSeq transcript databases using the algorithm GMAP, which allowed < 2 (< 6%) mismatches (Wu and Watanabe, 2005). There was little intra-sample variability in the number of sequences aligned to each locus from run-to-run or instrument-to-instrument (Fig. 1A; all source coefficient of variation 3.4%). 43.5 + 6.7% of sequences aligned to a transcript and 69.4 + 9.6% to the genome, evidence that annotation of mRNA isoforms in Homo sapiens is incomplete (Birney et al., 2007) (Table 2). 91% of alignments were unique (Table 2). Reads aligning to more than one location contained repetitive, paralogous, polymorphic or low complexity sequences and primarily mapped to untranslated regions or highly polymorphic gene families, such as major histocompatibility genes (Sugarbaker et al., 2008). Unmapped sequences did not align to mitochondrial or 1879 viral genomes, offering negative evidence of chronic viral etiology for SCZ in these patients.
2009-08-29 | E-GEOD-12297 | biostudies-arrayexpress
Project description:Amniotic fluid (AF) volume (AFV) is determined primarily by the rate of intramembranous (IM) transport of AF across the amnion. Intramembranous transport is characterized as vesicular endocytotic and transcytotic processes regulated by fetal urine-derived stimulators and AF inhibitors. Our objectives were to utilize a large-scale multiomics approach to decipher the vesicular transport pathways in the amnion and to identify potential transport regulators in AF and fetal urine. We utilized fetal sheep to experimentally induce alterations in IM transport rate and analyze the expression profiles of transcripts and proteins in amnion, AF and fetal urine. Four experimental groups were studied: control (C), urine drainage with reduced IM transport rate and AFV (UD), urine drainage and fluid replacement with decreased IM transport rate but increased AFV (UDR), and intra-amniotic fluid infusion with augmented IM transport rate and AFV (IA). Amnion and fluid samples were subjected to transcriptomics (RNA-Seq) and proteomics studies followed by bioinformatics analyses using Ingenuity Pathway Analysis software. The analyses revealed 9 functional transport pathways and a panel of differentially expressed transcripts and proteins that are known mediators of vesicular transport and energy metabolism. During UD, expressions of endocytosis and trafficking mediators were reduced as compared to controls. Under UDR, expressions of energy metabolism activators increased while trafficking mediators decreased. During IA, expressions of vesicular uptake and transcellular trafficking regulators were enhanced. Co-expression of the motor protein, cytoplasmic dynein light chain-1, in both AF and fetal urine suggest that this molecule may function as a urine-derived stimulator of IM transport.
2019-03-30 | GSE129077 | GEO
Project description:RBFOX2/GOLIM4 Splicing Axis Activates Vesicular Transport Pathway to Promote Nasopharyngeal Carcinogenesis
| PRJNA737638 | ENA
Project description:Compelling evidence indicates that defects in nucleocytoplasmic transport contribute to the pathogenesis of amyotrophic lateral sclerosis (ALS). In particular, hexanucleotide (G4C2) repeat expansions in C9orf72, the most common cause of genetic ALS, have a widespread impact on the transport machinery that regulates the nucleocytoplasmic distribution of proteins and RNAs, thereby affecting their functions. We have previously reported that the expression of G4C2 hexanucleotide repeats in cultured human and mouse cells caused a marked accumulation of poly(A) mRNAs in cell nuclei, suggesting that mRNA trafficking is impaired by expanded C9orf72-ALS repeats. To further characterize the process, in this work we set out to systematically identify the specific mRNAs that are altered in their nucleocytoplasmic distribution in the presence of C9orf72-ALS repeats. Results from RNAseq profiling of nuclear and cytoplasmic RNA fractions obtained from cells expressing G4C231 repeats show a significant accumulation of mRNAs in the nuclei of G4C231 cells, further suggesting that nuclear retention of mRNAs is a major effect of C9orf72 expanded repeats expression. Interestingly, pathway analysis shows that mRNAs involved in ER-to-Golgi trafficking are particularly enriched among the identified mRNAs. Most importantly, functional studies in cultured cells and Drosophila indicate that the membrane trafficking route regulated by ARFGAP1, a GTPase-activating protein that associates with Golgi, is specifically affected by expanded C9orf72 repeats, as well as by C9orf72-related dipeptide repeat proteins (C9-DPRs), pointing to ER-to-Golgi vesicle-mediated transport as a target of C9orf72 toxicity.
2023-08-21 | GSE235448 | GEO
Project description:Studies on vesicle formation by the Coat Protein I (COPI) complex have contributed to a basic understanding of how vesicular transport is initiated. We have identified that short chain lipids promote membrane properties that are conducive for fission. Here we investigated short chain PCs on Golgi membrane. These findings will advance the understanding of how lipid geometry contributes to membrane deformation needed for vesicle fission.
2019-04-25 | ST001177 | MetabolomicsWorkbench
Project description:Multiomics Analyses of Vesicular Transport Pathway-Specific Transcripts and Proteins in Ovine Amnion: Responses to Altered Intramembranous Transport
| PRJNA529913 | ENA
Project description:Amniotic fluid volume (AFV) is determined primarily by the rate of intramembranous (IM) transport of AF cross the amnion. Intramembranous transport is characterized as vesicular endocytotic and transcytotic processes regulated by fetal urine-derived stimulators and AF inhibitors. Our objectives were to utilize a large-scale multiomics approach to decipher the vesicular transport pathways in the amnion and to identify potential transport regulators in AF and fetal urine. We utilized fetal sheep to experimentally induce alterations in IM transport rate and analyze the expression profiles of transcripts and proteins in amnion, AF and fetal urine. Four experimental groups were studied: control (C), urine drainage with reduced IM transport rate and AFV (UD), urine drainage and fluid replacement with decreased IM transport rate but increased AFV (UDR), and intra-amniotic fluid infusion with increased IM transport rate and AFV (IA). Amnion and fluid samples were subjected to transcriptomics (RNA-Seq) and isobaric labeling proteomics studies followed by bioinformatics analyses using Ingenuity Pathway Analysis software. The analyses revealed 9 functional transport pathways and a panel of differentially expressed transcripts and proteins that are known mediators of vesicular transport and cellular trafficking. During UD, expression of transport and trafficking mediators were reduced as compared to controls. With UDR, expression of energy metabolism activators increased while trafficking mediators decreased. During IA, expression of vesicular uptake molecules increased while trafficking mediators decreased. Co-expression of the motor protein, cytoplasmic dynein light chain-1, in both AF and fetal urine suggest that this molecule may function as a urine-derived stimulator of IM transport.
2021-07-21 | PXD013135 | Pride