title: Developmental changes in the protein composition of sphingolipid- and cholesterol-enriched membrane domains of rat cerebellar granule cells.
abstract: The biological role of cell membrane domains has been investigated in a number of eukariotic cells, but less attention has been paid to the neuron. In the present investigation, we assessed the changes in lipid and protein composition of detergent-resistant membrane fractions prepared from cultured rat cerebellar granule cells, during differentiation and maturation in vitro. At any stage of the cell life, low-density, detergent-resistant fractions, characterised by the specific presence of prion protein, were enriched in glycolipids, cholesterol, and sphingomyelin. The enrichment in sphingomyelin was developmentally regulated, increasing continuously during cell differentiation and maturation. Concerning proteins, domains were enriched in Fyn and TAG-1, which present exclusively within this fraction at any stage of cell culture, and in GAP-43, mainly during the differentiation stage. On the other side, proteins affecting signal transduction and cytoskeleton-related proteins (heterotrimeric G-proteins, protein kinase C, MARCKS, tubulin), were not enriched within detergent-resistant fractions during cell differentiation, but were recovered within this fraction in mature neurons. These results indicate that during different cellular life stages, specific proteins are recruited within detergent-resistant membrane domains of the neuron and suggest their involvement in specific physiological phenomena (differentiation, maturation and/or aging).
authors.affiliation: Department of Experimental, Environmental Medicine and Biotechnologies (DIMESAB), University of Milano-Bicocca, Monza, Italy. paola.palestini@unimib.it
authors.forename: Paola
authors.initials: P
authors.lastname: Palestini
authors.forename: Laura
authors.initials: L
authors.lastname: Botto
authors.forename: Francesca
authors.initials: F
authors.lastname: Guzzi
authors.forename: Chiara
authors.initials: C
authors.lastname: Calvi
authors.forename: Daniela
authors.initials: D
authors.lastname: Ravasi
authors.forename: Massimo
authors.initials: M
authors.lastname: Masserini
authors.forename: Marina
authors.initials: M
authors.lastname: Pitto
mesh_terms: D000818:Animals; D015816:Cell Adhesion Molecules, Neuronal / Q000032:analysis; D002454:Cell Differentiation / Q000502:physiology; D002458:Cell Fractionation; D016922:Cellular Senescence / Q000502:physiology; D002531:Cerebellum / Q000166:cytology*; D058969:Contactin 2; D003902:Detergents; D015180:Electrophoresis, Gel, Two-Dimensional; D019922:GAP-43 Protein / Q000032:analysis; D021962:Membrane Microdomains / Q000737:chemistry / Q000378:metabolism*; D009474:Neurons / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D011493:Protein Kinase C / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D014404:Tubulin / Q000032:analysis
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; C548676:Cntn2 protein, rat; D058969:Contactin 2; D003902:Detergents; D019922:GAP-43 Protein; D014404:Tubulin; D011493:Protein Kinase C