Calmodulin in starfish oocytes: I. Calmodulin antagonists inhibit meiosis reinitiation

[摘要] Aheat-stablefactorhasbeenfoundinstarfish(PatiriaminiataandMarthasteriasglacialis)oocytesthatactivatestwocalmodulin-dependentenzymes:bovinebrainphosphodiesterase(10-foldincrease)andseaurchineggNAD-kinase(10-to50-foldincrease).Thedose-responsecurvesforactivationoftheseenzymeswerefoundtobeparallelforthestarfisheggextractandpuremammalianbraincalmodulin.TheactivefactorwaspurifiedbychromatographyonDE52cellulosetowhichitremainedboundandwaselutedby0.225Mammoniumsulfate.Activefractionswerepooled,dialyzed,andrunonapolyacrylamidegel.Thestarfishactivefactorcomigratedwithpurebovinebraincalmodulin.Aradioimmunoassaywasperformedonthepurifiedfactor;itcross-reactedwithantibodiesagainstpurecalmodulin.Thatcalmodulinmayplayaroleinhormonallyinducedmaturationofstarfishoocytesissuggestedbythefactthattwocalmodulinantagonists(trifluoperazineandvinblastine),whicharealsoinhibitorsofNAD-kinase,werefoundtoblock1-methyladenine-inducedoocytematuration.Theinhibitioncouldbereversedbyincreasingthehormoneconcentration.Oocytesweresensitivetotrifluoperazineonlyduringthehormone-dependentperiod.

[学科分类] 生物科学（综合）