title: Neurospora crassa mitochondria contain two forms of a 4'-phosphopantetheine-modified protein.
abstract: When Neurospora crassa was labeled with [14C]pantothenic acid during growth, the mitochondrial fraction contained two bands of radioactivity of Mr 19,000 and 22,000 by sodium dodecyl sulfate gel electrophoresis. The 19-kDa band was converted to the 22-kDa band by four treatments which are characteristic of the cleavage of a thioester bond: dithiothreitol and 2-mercaptoethanol at basic but not neutral pH, alkaline methanolysis, sodium borohydride in tetrahydrofuran, and hydroxylamine at neutral pH. Mitochondrial subfractionation indicated that the 22-kDa form was preferentially associated with the soluble fraction while the 19-kDa form was found in all fractions. Several properties of the mitochondrial protein were similar to the Escherichia coli acyl carrier protein: Mr on sodium dodecyl sulfate gels, decreased electrophoretic mobility under deacylating conditions, isoelectric point, and covalent attachment of 4'-phosphopantetheine. The 19- and 22-kDa bands may therefore represent acylated and deacylated forms of a mitochondrial acyl carrier protein.
mesh_terms: D000213:Acyl Carrier Protein / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004229:Dithiothreitol / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000032:analysis; D005656:Fungal Proteins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D019811:Hydroxylamine; D006898:Hydroxylamines / Q000494:pharmacology; D007526:Isoelectric Point; D008623:Mercaptoethanol / Q000494:pharmacology; D008928:Mitochondria / Q000378:metabolism*; D008970:Molecular Weight; D009491:Neurospora / Q000648:ultrastructure*; D009492:Neurospora crassa / Q000648:ultrastructure*; D010204:Pantetheine / Q000031:analogs & derivatives / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000378:metabolism*
chemical_list: D000213:Acyl Carrier Protein; D005656:Fungal Proteins; D006898:Hydroxylamines; D013438:Sulfhydryl Compounds; D019811:Hydroxylamine; D010204:Pantetheine; D008623:Mercaptoethanol; C003129:4'-phosphopantetheine; D004229:Dithiothreitol