Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Lipid exchange at ER-trans Golgi contact sites governs polarized cargo sorting

ABSTRACT: Oxysterol Binding Protein (OSBP) extracts cholesterol from the ER to deliver it to the TGN via the counter exchange and subsequent hydrolysis of the phosphoinositide PI(4)P. Here, we show that this pathway is essential in polarized epithelial cells where it contributes not only to the proper subcellular distribution of cholesterol, but also to the trans-Golgi sorting and trafficking of numerous plasma membrane cargo proteins with apical or basolateral localization. Reducing the expression of OSBP, blocking its activity or inhibiting a PI4Kinase that fuels OSBP with PI(4)P abolishes the epithelial phenotype. Waves of cargo enrichment in the TGN in phase with OSBP and PI(4)P dynamics suggest that OSBP promotes the formation of lipid gradients along the TGN, which help cargo sorting. During their transient passage through the trans-Golgi, polarized plasma membrane proteins get close to OSBP, but fail to be sorted when OSBP is silenced. Thus, OSBP lipid exchange activity is decisive for polarized cargo sorting and distribution in epithelial cells.

INSTRUMENT(S): Orbitrap Exploris 480

ORGANISM(S): Canis Familiaris (dog) (canis Lupus Familiaris)

TISSUE(S): Epithelial Cell

SUBMITTER: David Kovacs

LAB HEAD: Anne-Sophie Gay

PROVIDER: PXD046322 | Pride | 2023-11-20

REPOSITORIES: Pride

ACCESS DATA

Json Xml

Similar Datasets

Regulation of cellular cholesterol distribution via non-vesicular lipid transport at ER-Golgi contact sites

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

Label-free proteomics of immuno-purified SYP61-trans-Golgi Network compartment in control condition and upon sphingolipid acyl-chain length reduction by metazachlor.

Project description:The trans-Golgi Network (TGN) in plants is a main sorting hub for proteins and lipids. The lipid composition at the TGN is instrumental to the polar sorting of the auxin efflux carrier PIN2 from TGN to the apical membrane. Here, we immuno-purified the full and intact TGN using the TGN-resident syntaxin SYP61 to identify and quantify TGN-proteins which abundance at TGN is dependent on the acyl-chain length of very-long chain fatty acids-containing lipids such as sphingolipids.

2021-12-01 | PXD026252 | Pride

Inceptor facilitates acrosomal vesicle formation in spermatids and is required for male fertility

Project description:Spermatogenesis is a crucial biological process that enables the production of functional sperm, allowing for successful reproduction. Proper germ cell differentiation and maturation require tight regulation of hormonal signals, cellular signaling pathways, and cell biological processes. The acrosome is a lysosome-related organelle at the anterior of the sperm head that contains enzymes and receptors essential for egg-sperm recognition and fusion. Even though several factors crucial for acrosome biogenesis have been discovered, the precise molecular mechanism of pro-acrosomal vesicle formation and fusion is not known. In this study, we investigated the role of the insulin inhibitory receptor (inceptor) in acrosome formation. Inceptor is a single-pass transmembrane protein with similarities to mannose-6-phosphate receptors (M6PR). Inceptor knockout mice are infertile due to malformations in the acrosome and defects in the nuclear shape of spermatozoa. We show that inceptor is expressed in early spermatids and mainly localizes to vesicles between the Golgi apparatus and acrosome. We propose that inceptor is an important factor in the intracellular transport of trans-Golgi network (TGN)-derived clathrin-coated vesicles delivering acrosomal cargo in maturing spermatids, and its absence results in vesicle-fusion defects, acrosomal malformation, and male infertility. These findings support our hypothesis of inceptor as a universal lysosomal or lysosome-related organelle sorting receptor expressed in several secretory tissues.

2023-08-28 | PXD043946 | Pride

Proteomic analysis of separated Golgi cisternae gives insights into secretory pathway organization Proteomic analysis of separated Golgi cisternae gives insights into secretory pathway organization

Project description:The Golgi apparatus is the hub of the secretory pathway, trafficking proteins and lipids and synthesizing complex glycans. The spatial distribution of resident proteins across individual Golgi cisternae is functionally essential for complex molecule biosynthesis. However, the inability to-date to separate Golgi cisternae means both the distribution of most residents, and the mechanisms determining their distribution, are unknown. Here, we exploit differences in surface charge between membranes to perform the first separation of Golgi cisternae. We localize over 400 proteins to the Golgi and describe the cisternal distribution of over 250 Golgi residents, as well as complex glycans. Both protein and glycan distributions are validated in-vivo using super-resolution microscopy. Results reveal distinct functional compartmentalization amongst resident Golgi proteins, which relates to the distribution of carbohydrate reaction products. Analysis of cisternal proteomes shows that exoplasmic protein pI, exoplasmic hydrophobicity, Ser content and asymmetric Phe distribution increase across the Golgi.

2019-09-11 | PXD009978 | Pride

NPC1 regulates the distribution of phosphatidylinositol 4 kinases at Golgi and Lysosome membranes

Project description:Cholesterol and phosphoinositides (PI) are two critically important lipids that are found in cellular membranes and dysregulated in many disorders. Therefore, uncovering molecular pathways connecting these essential lipids may offer new therapeutic insights. We report that loss of function of lysosomal Niemann-Pick Type C1 (NPC1) cholesterol transporter, which leads to neurodegenerative NPC disease, initiates a signaling cascade that alters the cholesterol/phosphatidylinositol 4-phosphate (PtdIns4P) countertransport cycle between Golgi-endoplasmic reticulum (ER), as well as lysosome-ER membrane contact sites (MCS). Central to these disruptions is increased recruitment of phosphatidylinositol 4-kinases-PI4KIIα and PI4KIIIβ-which boosts PtdIns4P metabolism at Golgi and lysosomal membranes. Aberrantly increased PtdIns4P levels elevate constitutive anterograde secretion from the Golgi complex, and mTORC1 recruitment to lysosomes. NPC1 disease mutations phenocopy the transporter loss of function and can be rescued by inhibition or knockdown of either key phosphoinositide enzymes or their recruiting partners. In summary, we show that the lysosomal NPC1 cholesterol transporter tunes the molecular content of Golgi and lysosome MCS to regulate intracellular trafficking and growth signaling in health and disease.

2021-09-15 | MTBLS2612 | MetaboLights

Arabidopsis endomembrane enrichments: Affinity enrichment of YFP-VAMP711

Project description:Our aim was to dissect subcellular trafficking routes by enriching for partially overlapping subpopulations of endosomal proteomes associated with endomembrane markers. We selected RABD2a/ARA5, RABF2b/ARA7, RABF1/ARA6, and RABG3f as markers for combinations of the Golgi, trans-Golgi Network (TGN), Early Endosomes (EE), secretory vesicles, Late Endosomes (LE), Multivesicular Bodies (MVB) compartments and tonoplast. As comparisons we used Golgi transport 1 (GOT1), which localises to the Golgi, Clathrin Light Chain 2 (CLC2) labelling Clathrin-coated vesicles and pits and the Vesicle Associated Membrane Protein 711 (VAMP711) present at the tonoplast. We developed an easy-to-use method by refining published protocols based on affinity purification of fluorescent fusion constructs to these seven subcellular marker proteins in Arabidopsis thaliana seedlings.

2015-04-22 | PXD001878 | Pride

Arabidopsis endomembrane enrichments: Affinity enrichment of RABF1/ARA6-RFP

2015-04-22 | PXD001879 | Pride

Arabidopsis endomembrane enrichments: Affinity enrichment of GFP bait

2015-04-22 | PXD001885 | Pride

Arabidopsis endomembrane enrichments: Affinity enrichment ofYFP-RABD2a/ARA5

2015-04-22 | PXD001882 | Pride

Arabidopsis endomembrane enrichments: Affinity enrichment of YFP-RABG3f

2015-04-22 | PXD001881 | Pride