title: Proteomic characterization of biogenesis and functions of matrix vesicles released from mineralizing human osteoblast-like cells.
abstract: Matrix vesicles (MVs), released by budding from apical microvilli of osteoblasts during bone formation and development, are involved in the initiation of mineralization by promoting the formation of hydroxyapatite in their lumen. To gain additional insights into MV biogenesis and functions, MVs and apical microvilli were co-isolated from mineralizing osteoblast-like Saos-2 cells and their proteomes were characterized using LC-ESI-MS/MS and compared. In total, 282 MV and 451 microvillar proteins were identified. Of those, 262 were common in both preparations, confirming that MVs originate from apical microvilli. The occurrence of vesicular trafficking molecules (e.g. Rab proteins) and of the on-site protein synthetic machinery suggests that cell polarization and apical targeting are required for the incorporation of specific lipids and proteins at the site of MV formation. MV release from microvilli may be driven by actions of actin-severing proteins (gelsolin, cofilin 1) and contractile motor proteins (myosins). In addition to the already known proteins involved in MV-mediated mineralization, new MV residents were detected, such as inorganic pyrophosphatase 1, SLC4A7 sodium bicarbonate cotransporter or sphingomyelin phosphodiesterase 3, providing additional insights into MV functions.
authors.affiliation: Department of Biochemistry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland.
authors.forename: Cyril
authors.initials: C
authors.lastname: Thouverey
authors.forename: Agata
authors.initials: A
authors.lastname: Malinowska
authors.forename: Marcin
authors.initials: M
authors.lastname: Balcerzak
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Strzelecka-Kiliszek
authors.forename: René
authors.initials: R
authors.lastname: Buchet
authors.forename: Michal
authors.initials: M
authors.lastname: Dadlez
authors.forename: Slawomir
authors.initials: S
authors.lastname: Pikula
mesh_terms: D001857:Bone Matrix / Q000502:physiology; D002113:Calcification, Physiologic / Q000502:physiology; D002454:Cell Differentiation; D022162:Cytoplasmic Vesicles / Q000502:physiology*; D005109:Extracellular Matrix / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D006801:Humans; D008871:Microvilli / Q000502:physiology*; D010006:Osteoblasts / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology; D020543:Proteome / Q000032:analysis; D021241:Spectrometry, Mass, Electrospray Ionization; D014407:Tumor Cells, Cultured
chemical_list: D016326:Extracellular Matrix Proteins; D020543:Proteome