Polypeptides related to mammalian procholecystokinin in the brain of an invertebrate, a marine worm, Nereis diversicolor: evidence from in ovo translation of mRNA.
Total mRNA extracted from brain of a sea worm Nereis diversicolor (Annelida, Polychaeta) were injected into Xenopus oocytes. The in ovo-translated polypeptides were analyzed through electrophoresis of immunoprecipitated products or Western blotting techniques. Some of these polypeptides cross-reacted antibodies elaborated against three mammalian (human and rat) procholecystokinin (pro-CCK) sequences. Polypeptides of 15, 64, and 70 kDa were determined, but two families of less obvious products, whose molecular masses were between 27-34 kDa and 46-60 kDa, appeared. Furthermore, the Western blotting technique also showed a cross-reaction between some of the polypeptides (64 and 70 kDa) extracted from brains and the antibodies used. From this work, evidence is given of the presence of epitopes shared by cellular polypeptides extracted from the brain, in ovo-translated products and mammalian pro-CCK. Furthermore, these data suggest the existence of a CCK precursor in the brain of N. diversicolor.
Guissi-Kadri
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Laboratoire d'Endocrinologie des Invertébrés, C.N.R.S., UA 148, Université de Lille Flandres Artois, Villeneuve d'Ascq, France.
Bulet
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Curgy
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JJ
D000818:Animals; D015153:Blotting, Western; D001923:Brain Chemistry; D002766:Cholecystokinin / Q000096:biosynthesis / Q000276:immunology / Q000302:isolation & purification*; D003429:Cross Reactions / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D009479:Neuropeptides / Q000096:biosynthesis / Q000276:immunology / Q000302:isolation & purification*; D009865:Oocytes / Q000378:metabolism; D011077:Polychaeta / Q000032:analysis* / Q000235:genetics; D011233:Precipitin Tests; D014176:Protein Biosynthesis; D011498:Protein Precursors / Q000096:biosynthesis / Q000276:immunology / Q000302:isolation & purification*; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D051381:Rats; D014981:Xenopus
D009479:Neuropeptides; D011498:Protein Precursors; D012333:RNA, Messenger; C060249:procholecystokinin; D002766:Cholecystokinin