title: Effect of calmodulin inhibitor, Stelazine, on the endocytosis of vitellogenin and transglutaminase activity in Xenopus laevis oöcytes.
abstract: The specific endocytosis of vitellogenin was measured in the presence of various concentrations of Stelazine, a specific inhibitor of the calcium regulating protein, calmodulin. Stelazine (200 microM) was found to inhibit the endocytosis of vitellogenin by 63% as determined by decreased uptake of vitellogenin into transitional yolk bodies and yolk platelets. The enzymatic activity of transglutaminase, a calcium-requiring enzyme implicated in receptor-mediated endocytosis, was not affected by these concentrations of Stelazine.
mesh_terms: D000217:Acyltransferases / Q000037:antagonists & inhibitors*; D000818:Animals; D002135:Calcium-Binding Proteins / Q000037:antagonists & inhibitors*; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D004705:Endocytosis / Q000187:drug effects; D005260:Female; D008074:Lipoproteins / Q000378:metabolism*; D009865:Oocytes / Q000187:drug effects / Q000201:enzymology*; D010063:Ovum / Q000201:enzymology*; D011700:Putrescine / Q000378:metabolism; D011503:Transglutaminases; D014819:Vitellogenins / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D002135:Calcium-Binding Proteins; D002147:Calmodulin; D008074:Lipoproteins; D014819:Vitellogenins; D000217:Acyltransferases; D011503:Transglutaminases; D011700:Putrescine