Characterization and regulation of the expression of scyllatoxin (Leiurotoxin I) receptors in the human neuroblastoma cell line NB-OK 1.
125I-[Tyr2]scyllatoxin allowed to label a single class of high-affinity receptors in membranes from the human neuroblastoma cell line NB-OK 1. The Kd of these receptors was 60 pM for scyllatoxin (Leiurotoxin I) and 20 pM for apamin and the Bmax was low (3.8 fmol/mg membrane protein). K+ increased toxin binding at low concentrations but exerted opposite effects at high concentrations. Ca2+, guanidinium and Na+ exerted only inhibitory effects on binding. Scyllatoxin binding sites were overexpressed 2.5-fold after a 24-h cell pretreatment with 2 mM butyrate. This effect was suppressed by cycloheximide.
Gossen
D
D
Department of Biochemistry and Nutrition, Medical School, Université Libre de Bruxelles, Belgium.
Gesquière
J C
JC
Tastenoy
M
M
De Neef
P
P
Waelbroeck
M
M
Christophe
J
J
D000595:Amino Acid Sequence; D001030:Apamin / Q000037:antagonists & inhibitors / Q000378:metabolism; D002087:Butyrates / Q000494:pharmacology; D020148:Butyric Acid; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D003513:Cycloheximide / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects*; D019791:Guanidine; D006146:Guanidines / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D009447:Neuroblastoma; D011188:Potassium / Q000378:metabolism; D015221:Potassium Channels; D011869:Radioligand Assay; D011950:Receptors, Cholinergic / Q000187:drug effects / Q000378:metabolism*; D012604:Scorpion Venoms / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism; D014407:Tumor Cells, Cultured
D002087:Butyrates; D006146:Guanidines; D015221:Potassium Channels; D011950:Receptors, Cholinergic; D012604:Scorpion Venoms; C070000:scyllatoxin receptor; D020148:Butyric Acid; C056574:leiurotoxin I; D001030:Apamin; D003513:Cycloheximide; D012964:Sodium; D019791:Guanidine; D011188:Potassium; D002118:Calcium