Microinjected Xenopus oocytes synthesize active human plasminogen activator.
Induction of synthesis of the protease plasminogen activator (PA) by hormones, oncogenic viruses and tumor promoters occurs at the transcription level. A novel bioassay for PA messenger RNA was developed to study the regulation of PA synthesis and the genetic elements involved in it. Poly(A)-containing RNA from HEp-3, a PA-rich tumor of human origin, was found to direct the synthesis of a new proteolytic activity when microinjected into Xenopus oocytes. Newly synthesized protease can be detected within a few hours after microinjection of minute quantities of unfractionated mRNA. The new enzymatic activity is indistinguishable from human PA: it is absolutely dependent on human plasminogen; it is neutralized by serum raised against urokinase, the human urinary PA; and it comigrates with urokinase and HEp-3 PA in gel electrophoresis, exhibiting a molecular weight of 60,000.
D000818:Animals; D005260:Female; D006801:Humans; D007700:Kinetics; D008845:Microinjections; D009865:Oocytes / Q000378:metabolism*; D010063:Ovum / Q000378:metabolism*; D010960:Plasminogen Activators / Q000096:biosynthesis / Q000235:genetics*; D011061:Poly A / Q000235:genetics; D012313:RNA / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D013045:Species Specificity; D014158:Transcription, Genetic; D014981:Xenopus
D012333:RNA, Messenger; D011061:Poly A; D012313:RNA; D010960:Plasminogen Activators