Proteomic profiling of detergent resistant membranes (lipid rafts) of prostasomes
2015 (English)In: Molecular & Cellular Proteomics, ISSN 1535-9476, E-ISSN 1535-9484, Vol. 14, no 11, 3015-3022 p.Article in journal (Refereed) Published
Prostasomes are exosomes derived from prostate epithelial cells through exocytosis by multivesicular bodies. Prostasomes have a bilayered membrane and readily interact with sperm. The membrane lipid composition is unusual with a high contribution of sphingomyelin at the expense of phosphatidylcholine and saturated and monounsaturated fatty acids are dominant. Lipid rafts are liquid-ordered domains that are more tightly packed than the surrounding non-raft phase of the bilayer. Lipid rafts are proposed to be highly dynamic, submicroscopic assemblies that float freely within the liquid disordered membrane bilayer and some proteins preferentially partition into the ordered raft domains. We asked the question whether lipid rafts do exist in prostasomes and, if so, which proteins might be associated with them. Prostasomes of density range 1.13-1.19g/mL were subjected to density gradient ultracentrifugation in sucrose fabricated by phosphate buffered saline (PBS) containing 1% Triton X-100 with capacity for banding at 1.10g/mL, i.e. the classical density of lipid rafts. Prepared prostasomal lipid rafts (by gradient ultracentrifugation) were analyzed by mass spectrometry and electron microscopy. The clearly visible band on top of 1.10g/mL sucrose in the Triton X-100 containing gradient was subjected to LC-MS/MS and more than 370 lipid raft associated proteins were identified. Several of them were involved in intraluminal vesicle formation, e.g. tetraspanins, ESCRTs and Ras-related proteins. This is the first comprehensive LC-MS/MS profiling of proteins in lipid rafts derived from exosomes. Data are available via ProteomeXchange with identifier PXD002163.
Place, publisher, year, edition, pages
2015. Vol. 14, no 11, 3015-3022 p.
Urology and Nephrology
IdentifiersURN: urn:nbn:se:uu:diva-261543DOI: 10.1074/mcp.M114.047530ISI: 000365636800014PubMedID: 26272980OAI: oai:DiVA.org:uu-261543DiVA: diva2:850604