title: Pertussis toxin-sensitive GTP-binding proteins characterized in synaptosomal fractions of embryonic avian cerebral cortex.
abstract: Pertussis toxin (PTX)-sensitive GTP-binding proteins (G proteins) are essential intermediaries subserving neuronal signal transduction pathways that regulate excitation-secretion coupling. Despite this established role, relatively little is known regarding the identity, subcellular distribution, and relative abundance of this class of G proteins in synaptic nerve endings. Here, sucrose density gradient centrifugation was combined with 1- and 2-dimensional gel electrophoresis to characterize PTX-sensitive G protein alpha subunits in synaptosomal fractions of embryonic (day 12) chick cerebral cortical homogenates. These findings demonstrate multiple isoforms of M(r) 40-41 kDa Gi alpha and G(o) alpha subunits that can be identified on the basis of PTX-catalyzed ADP-ribosylation and immunoblot analysis.
authors.affiliation: Diabetes Unit, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA. holz@helix.mgh.harvard.edu
authors.forename: G G
authors.initials: GG
authors.lastname: Holz
authors.forename: T J
authors.initials: TJ
authors.lastname: Turner
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002540:Cerebral Cortex / Q000378:metabolism*; D002642:Chick Embryo; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006150:Guanine Nucleotides / Q000378:metabolism; D008970:Molecular Weight; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism; D037342:Pertussis Toxin; D011487:Protein Conformation; D013347:Subcellular Fractions / Q000378:metabolism; D013574:Synaptosomes / Q000378:metabolism; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
chemical_list: D006150:Guanine Nucleotides; D009842:Oligopeptides; D010566:Virulence Factors, Bordetella; D000246:Adenosine Diphosphate Ribose; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins