Effect of 7-methylguanosine-5'-phosphate on the translation of rat milk-protein mRNAs in the wheat-germ cell-free system.
The translation of polyadenylated and of non-polyadenylated RNA obtained from lactating rat mammary gland was almost totally inhibited by 0.5 mM 7-methylguanosine-5'-phosphate in the wheat-germ cell-free system. This inhibition was maintained during the preparation of the 9S whey-protein mRNA and of the 12S and 15S casein mRNAs. Chemical decapping of these mRNAs caused a similar reduction of their activity. Although a large fraction of milk-protein mRNAs have been reported to lack 3'-polyadenylation, these results show that the mRNAs in the mammary gland do contain a 5'-terminal 7-methylguanosine cap.
D000818:Animals; D002474:Cell-Free System; D005260:Female; D066298:In Vitro Techniques; D007774:Lactation; D008321:Mammary Glands, Animal / Q000378:metabolism; D008894:Milk Proteins / Q000096:biosynthesis* / Q000235:genetics; D011247:Pregnancy; D014176:Protein Biosynthesis / Q000187:drug effects*; D012314:RNA Cap Analogs / Q000494:pharmacology*; D012315:RNA Caps / Q000378:metabolism / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D008894:Milk Proteins; D012314:RNA Cap Analogs; D012315:RNA Caps; D012333:RNA, Messenger; C011925:7-methylguanosine-5'-monophosphate