Characterization of translational-control ribonucleic acid isolated from embryonic chick muscle

Abstract

Myosin H chain (MHC) mRNP [messenger ribonucleoprotein] particles were purified from 13-day chick embryonic skeletal muscle by a combination of sucrose density gradient centrifugation and metrizamide buoyant density centrifugation. Associated with the mRNP are at least 3 distinct low MW RNA molecules including translational-control RNA (tcRNA). This particular RNA contains 102 nucleotides and is uridine and guanine rich, and its nucleotide sequence was determined. tcRNA102 is capable of inhibiting the translation of the mRNA with which it is associated upon preincubation in stoichiometric amounts. Under these conditions, endogenous reticulocyte mRNA is not inhibited. Under appropriate salt and temperature conditions, tcRNA102 is capable of reassociating with MHC mRNA, thus altering the sedimentation characteristics of the mRNA. The mRNA-tcRNA102 interactions apparently alter the secondary structure of the mRNA. tcRNA102 does not associate with rRNA or globin mRNA, suggesting that some degree of specificity is involved with the RNA-RNA interactions.