Effect of heparin contained in preparations of small cytoplasmic RNAs on cell-free translation.
It has been reported that small cytoplasmic RNA (scRNA) from human placenta inhibits translation of most mRNAs in both wheat germ extracts and reticulocyte lysates (Lorberboum, H., Digweed, M., Erdmann, V. A., Servadio, Y., Weinstein, D., De Groot, N., and Hochberg, A. A. (1986) Eur. J. Biochem. 155, 279-287). We have investigated the mechanism by which scRNA preparations inhibit mRNA translation in vitro. We demonstrate that the inhibitory agent(s) is not sensitive to treatment with various ribonucleases but that translational inhibition is sensitive to incubation with 1 N NaOH at 95 degrees C or to treatment with heparinase. Based on these findings and on the ability of heparin to inhibit cell-free translation by itself, we conclude that the presence of heparin in preparations of scRNA from human placenta is responsible for effects which have previously been attributed to inhibitory RNA molecules. Since heparin is also frequently used in the isolation of translationally inhibitory scRNAs from other sources, we suggest that the sensitivity of these preparations to ribonucleases and heparinase should be examined.
Johansson
H E
HE
European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany.
De Groot
N
N
Hochberg
A A
AA
Hentze
M W
MW
D000818:Animals; D002474:Cell-Free System; D003851:Deoxyribonucleases / Q000494:pharmacology; D019286:Endopeptidase K; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D014176:Protein Biosynthesis / Q000187:drug effects*; D012313:RNA / Q000737:chemistry / Q000378:metabolism*; D020733:RNA, Small Cytoplasmic; D011817:Rabbits; D012260:Ribonucleases / Q000494:pharmacology; D012697:Serine Endopeptidases / Q000494:pharmacology; D012972:Sodium Hydroxide / Q000737:chemistry
D020733:RNA, Small Cytoplasmic; D012972:Sodium Hydroxide; D012313:RNA; D006493:Heparin; D003851:Deoxyribonucleases; D012260:Ribonucleases; D012697:Serine Endopeptidases; D019286:Endopeptidase K