title: Small GTP-binding proteins in human neuroblastoma cell lines.
abstract: The presence of small G proteins was investigated by [gamma-35S]GTP-binding in 3 human neuroblastoma cell lines. IMR-32, SK-N-BE and SH-SY5Y, before and after treatment with differentiating agents (dibutyryl-cAMP, 5-bromodeoxyuridine or retinoic acid) which induce the appearance of secretory organelles. One major component of about 24 kDa and 3 minor components of smaller Mr were found to bind specifically [gamma-35S]GTP in all 3 cell lines already before differentiation. Differentiation did not affect the expression of small G proteins in IMR-32 cells and only modestly affected it in the other two cell lines. The possibility that the expression of small G proteins in neuroblastoma cells is not coupled with the assembly of secretory organelles is discussed.
authors.affiliation: Department of Medical Pharmacology, University of Milan, Italy.
authors.forename: A M
authors.initials: AM
authors.lastname: Giudici
authors.forename: C
authors.initials: C
authors.lastname: Bisiani
authors.forename: A
authors.initials: A
authors.lastname: Zanini
authors.forename: F
authors.initials: F
authors.lastname: Clementi
mesh_terms: D002454:Cell Differentiation; D002460:Cell Line; D003594:Cytoplasmic Granules / Q000378:metabolism / Q000648:ultrastructure; D019204:GTP-Binding Proteins / Q000032:analysis*; D006801:Humans; D009447:Neuroblastoma / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D019204:GTP-Binding Proteins