title: NPA binding activity is peripheral to the plasma membrane and is associated with the cytoskeleton.
abstract: N-1-Naphthylphthalamic acid (NPA) binding activity is released into the supernatant when plasma membranes are subjected to high-salt treatment, indicating that this activity is peripherally associated with the membrane. Extraction of plasma membrane vesicles with Triton X-100 resulted in retention of NPA binding activity in the detergent-insoluble cytoskeletal pellet. Treatment of this pellet with KI released NPA binding activity, actin, and alpha-tubulin. Dialysis to remove KI led to the repolymerization of cytoskeletal elements and movement of NPA binding activity into an insoluble cytoskeletal pellet. NPA binding activity partitioned into the detergent-insoluble cytoskeletal pellet obtained from both zucchini and maize membranes and was released from these pellets by KI treatment. Treatment of a cytoskeletal pellet with cytochalasin B doubled NPA binding activity in the resulting supernatant. Together, these experiments indicate that NPA binding activity is peripherally associated with the plasma membrane and interacts with the cytoskeleton in vitro.
authors.affiliation: Wake Forest University, Department of Biology, Winston-Salem, North Carolina 27109, USA.
authors.forename: D N
authors.initials: DN
authors.lastname: Cox
authors.forename: G K
authors.initials: GK
authors.lastname: Muday
mesh_terms: D000199:Actins / Q000378:metabolism; D001665:Binding Sites; D001692:Biological Transport; D002254:Carbonates / Q000494:pharmacology; D002352:Carrier Proteins / Q000302:isolation & purification* / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D019662:Cucurbitaceae / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D003571:Cytochalasin B / Q000494:pharmacology; D003599:Cytoskeleton / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D007210:Indoleacetic Acids / Q000037:antagonists & inhibitors / Q000378:metabolism; D017830:Octoxynol / Q000494:pharmacology; D010797:Phthalimides / Q000378:metabolism*; D010940:Plant Proteins / Q000302:isolation & purification* / Q000378:metabolism; D011193:Potassium Iodide / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D003313:Zea mays / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism
chemical_list: D000199:Actins; D002254:Carbonates; D002352:Carrier Proteins; D003902:Detergents; D007210:Indoleacetic Acids; D010797:Phthalimides; D010940:Plant Proteins; D011193:Potassium Iodide; C002687:alpha-naphthylphthalamic acid; D003571:Cytochalasin B; C005686:sodium carbonate; D017830:Octoxynol